| 1. |
Morikawa K,
Inose Y,
Okamura H,
Maruyama A,
Hayashi H,
Takeyasu K,
Ohta T,
( 2003 ) A new staphylococcal sigma factor in the conserved gene cassette: functional significance and implication for the evolutionary processes. PMID : 12875655 : Abstract >>
Staphylococcus aureus is a major human pathogen and causes a serious hospital infection due to the acquired multidrug resistance. Unlike the well-studied bacteria such as Escherichia coli and Bacillus subtilis, which have seven and 18 sigma factors, respectively, only two sigma factors have been known for S. aureus. We searched for possible sigma factor genes by examining the S. aureus genome with a special attention to the gene arrangement around the sigma factor genes of a close relative, B. subtilis. A new sigma factor gene was identified in Staphylococcus. The gene constituted a conserved gene cluster with other genes including translation- and transcription-related genes. Phylogenetic analysis and comparison of the gene sequences among species indicated that the staphylococcal sigma factor originated from a common ancestor of B. subtilis SigH. An over-expression of this sigma factor in S. aureus resulted in a drastic induction of the expression of the com operons that encode proteins required for the natural genetic competence. We demonstrated that the newly identified staphylococcal sigma factor participated in a regulatory network of transcription that controlled the genetic competence genes. In our phylogenetic tree, the factor was classified as a single group with a common function.
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2. |
Anthonisen IL,
Sunde M,
Steinum TM,
Sidhu MS,
Sørum H,
( 2002 ) Organization of the antiseptic resistance gene qacA and Tn552-related beta-lactamase genes in multidrug- resistant Staphylococcus haemolyticus strains of animal and human origins. PMID : 12384372 : DOI : 10.1128/aac.46.11.3606-3612.2002 PMC : PMC128698 Abstract >>
A part (12 kb) of a plasmid containing the beta-lactamase genes of Tn552, the disinfectant resistance gene qacA, and flanking DNA has been cloned from a Staphylococcus haemolyticus isolate and sequenced. This region was used to map the corresponding regions in six other multiresistant S. haemolyticus isolates of human and animal origin. The organizations of the genetic structures were almost identical in all isolates studied. The beta-lactamase and qacA genes from S. haemolyticus have >99.9% identities at the nucleotide level with the same genes from S. aureus, demonstrating that various staphylococcal species able to colonize animal and human hosts can exchange the genetic elements involved in resistance to antibiotics and disinfectants. The use of antibiotics and disinfectants in veterinary practice and animal husbandry may also contribute to the selection and maintenance of resistance factors among the staphylococcal species. Different parts of the 12-kb section analyzed had high degrees of nucleotide identity with regions from several other different Staphylococcus aureus plasmids. This suggests the contribution of interplasmid recombination in the evolutionary makeup of this 12-kb section involving plasmids that can intermingle between various staphylococcal species. The lateral spread of resistance genes between various staphylococcal species is probably facilitated by the generation of large multiresistance plasmids and the subsequent interspecies exchange of them.
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3. |
Poyart C,
Quesne G,
Boumaila C,
Trieu-Cuot P,
( 2001 ) Rapid and accurate species-level identification of coagulase-negative staphylococci by using the sodA gene as a target. PMID : 11724835 : PMC : PMC88539 DOI : 10.1128/JCM.39.12.4296-4301.2001 Abstract >>
Simple PCR and sequencing assays that utilize a single pair of degenerate primers were used to characterize a 429-bp-long DNA fragment internal (sodA(int)) to the sodA gene encoding the manganese-dependent superoxide dismutase in 40 coagulase-negative staphylococcal (CNS) type strains. The topology of the phylogenetic tree obtained was in general agreement with that which was inferred from an analysis of their 16S rRNA or hsp60 gene sequences. Sequence analysis revealed that the staphylococcal sodA genes exhibit a higher divergence than does the corresponding 16S ribosomal DNA. These results confirm that the sodA gene constitutes a highly discriminative target sequence for differentiating closely related bacterial species. Clinical isolates that could not be identified at the species level by phenotypical tests were identified by use of this database. These results demonstrate the usefulness of this method for rapid and accurate species identification of CNS isolates, although it does not allow discrimination of subspecies. The sodA sequence polymorphisms observed with staphylococcal species offer good opportunities for the development of assays based on DNA chip technologies.
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4. |
Drancourt M,
Raoult D,
( 2002 ) rpoB gene sequence-based identification of Staphylococcus species. PMID : 11923353 : DOI : 10.1128/jcm.40.4.1333-1338.2002 PMC : PMC140360 Abstract >>
The complete sequence of rpoB, the gene encoding the beta subunit of RNA polymerase was determined for Staphylococcus saccharolyticus, Staphylococcus lugdunensis, S taphylococcus caprae, and Staphylococcus intermedius and partial sequences were obtained for an additional 27 Staphylococcus species. The complete rpoB sequences varied in length from 3,452 to 3,845 bp and had a 36.8 to 39.2% GC content. The partial sequences had 71.6 to 93.6% interspecies homology and exhibited a 0.08 to 0.8% intraspecific divergence. With a few exceptions, the phylogenetic relationships inferred from the partial rpoB sequences were in agreement with those previously derived from DNA-DNA hybridization studies and analyses of 16S ribosomal DNA gene sequences and partial HSP60 gene sequences. The staphylococcal rpoB sequence database we established enabled us to develop a molecular method for identifying Staphylococcus isolates by PCR followed by direct sequencing of the 751-bp amplicon. In blind tests, this method correctly identified 10 Staphylococcus isolates, and no positive results were obtained with 10 non-Staphylococcus gram-positive and gram-negative bacterial isolates. We propose partial sequencing of the rpoB gene as a new tool for the accurate identification of Staphylococcus isolates.
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5. |
Martineau F,
Picard FJ,
Ke D,
Paradis S,
Roy PH,
Ouellette M,
Bergeron MG,
( 2001 ) Development of a PCR assay for identification of staphylococci at genus and species levels. PMID : 11427566 : DOI : 10.1128/JCM.39.7.2541-2547.2001 PMC : PMC88182 Abstract >>
We have developed a PCR-based assay which allows the detection of staphylococci at the genus level by targeting the tuf gene, which encodes the elongation factor Tu. Degenerate PCR primers derived from consensus regions of several tuf genes were used to amplify a target region of 884 bp from 11 representative staphylococcal species. Subsequently, the entire nucleotide sequence of these amplicons was determined. The analysis of a multiple alignment of these sequences revealed regions conserved among staphylococci but distinct from those of other gram-positive bacteria genetically related to staphylococci. PCR primers complementary to these regions could amplify specifically and efficiently a DNA fragment of 370 bp for all of 27 different staphylococcal species tested. There was no amplification with genomic DNA prepared from 53 nonstaphylococcal species tested to verify the specificity of the assay (20 gram positive and 33 gram negative). Furthermore, this assay amplified efficiently all 27 American Type Culture Collection (ATCC) staphylococcal reference strains as well as 307 clinical isolates of staphylococci from the Qu?bec City region. Analysis of the multiple sequence alignment for the 884-bp fragment for the 11 staphylococcal species as well as comparison of the sequences for the 370-bp amplicon from five unrelated ATCC and clinical strains for each of the species S. aureus, S. epidermidis, S. haemolyticus, S. hominis, and S. saprophyticus demonstrated sufficient interspecies polymorphism to generate genus- and species-specific capture probes. This sequence information allowed the development of Staphylococcus-specific and species-specific (targeting S. aureus, S. epidermidis, S. haemolyticus, S. hominis, or S. saprophyticus) capture probes hybridizing to the 370-bp amplicon. In conclusion, this PCR assay is suitable for detection of staphylococci at both genus and species levels.
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6. |
Fallgren C,
Utt M,
Ljungh A,
( 2001 ) Isolation and characterisation of a 17-kDa staphylococcal heparin-binding protein with broad specificity. PMID : 11393292 : DOI : 10.1099/0022-1317-50-6-547 Abstract >>
A previous study reported the ability of staphylococci to bind heparin and heparin-dependent host growth factors. The present study isolated and identified heparin- and basic fibroblast growth factor (bFGF)-binding surface components of S. epidermidis strain RP12 and S. haemolyticus strain SM 131. The staphylococcal heparin-binding component(s) were purified by affinity chromatography on heparin-Sepharose and a major heparin-binding protein, here designated HBP, was identified by immunoblot in these two coagulase-negative staphylococcal (CNS) species. The HBP was shown to be acidic with an approximate pI of 4.6 and a molecular mass around 17 kDa. The binding of heparin to HBP was inhibited by heparin, fucoidan, pentosan polysulphate and various other sulphated polysaccharides, but not by non-sulphated compounds. However, the purified HBP from both S. epidermidis and S. haemolyticus revealed broad specificity, and also bound bFGF, thrombospondin, von Willebrand factor and, weakly, fibrinogen. The N-terminal sequences of the 17-kDa HBP from S. epidermidis and S. haemolyticus showed only limited identity. Comparison of the first 15 amino acid residues derived from either strain with known sequences in the protein databases revealed no close similarities. Taken together, these results suggest that the adhesion of at least some CNS to host sulphated glycosaminoglycans may be mediated by a previously uncharacterised group of surface proteins.
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7. |
Linde HJ,
Schmidt M,
Fuchs E,
Reischl U,
Niller HH,
Lehn N,
( 2001 ) In vitro activities of six quinolones and mechanisms of resistance in Staphylococcus aureus and coagulase-negative staphylococci. PMID : 11302827 : DOI : 10.1128/AAC.45.5.1553-1557.2001 PMC : PMC90505 Abstract >>
Of 94 clinical isolates of Staphylococcus aureus (n = 51) and coagulase-negative staphylococci (CNS) (n = 43), mutations in the quinolone resistance-determining region of topoisomerases GrlA, GrlB, GyrA, and GyrB together with MICs of six quinolones were analyzed. Amino acid substitutions at identical residues (GrlA residues 80 and 84; GyrA residues 84 and 88) were found in S. aureus and CNS. Active efflux, as suggested by blocking by reserpine, contributed substantially to the resistance phenotype in some strains. Among ciprofloxacin, clinafloxacin, levofloxacin, nalidixic acid, trovafloxacin, and sparfloxacin, a 0.5-microg/ml concentration of sparfloxacin discriminated best between strains with two or three mutations and those with no mutations.
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8. |
Ingraham KA,
Iordanescu S,
So CY,
Holmes DJ,
Chalker AF,
Bryant AP,
Brown JR,
Wilding EI,
( 2000 ) Identification, evolution, and essentiality of the mevalonate pathway for isopentenyl diphosphate biosynthesis in gram-positive cocci. PMID : 10894743 : DOI : 10.1128/jb.182.15.4319-4327.2000 PMC : PMC101949 Abstract >>
The mevalonate pathway and the glyceraldehyde 3-phosphate (GAP)-pyruvate pathway are alternative routes for the biosynthesis of the central isoprenoid precursor, isopentenyl diphosphate. Genomic analysis revealed that the staphylococci, streptococci, and enterococci possess genes predicted to encode all of the enzymes of the mevalonate pathway and not the GAP-pyruvate pathway, unlike Bacillus subtilis and most gram-negative bacteria studied, which possess only components of the latter pathway. Phylogenetic and comparative genome analyses suggest that the genes for mevalonate biosynthesis in gram-positive cocci, which are highly divergent from those of mammals, were horizontally transferred from a primitive eukaryotic cell. Enterococci uniquely encode a bifunctional protein predicted to possess both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and acetyl-CoA acetyltransferase activities. Genetic disruption experiments have shown that five genes encoding proteins involved in this pathway (HMG-CoA synthase, HMG-CoA reductase, mevalonate kinase, phosphomevalonate kinase, and mevalonate diphosphate decarboxylase) are essential for the in vitro growth of Streptococcus pneumoniae under standard conditions. Allelic replacement of the HMG-CoA synthase gene rendered the organism auxotrophic for mevalonate and severely attenuated in a murine respiratory tract infection model. The mevalonate pathway thus represents a potential antibacterial target in the low-G+C gram-positive cocci.
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9. |
Av-Gay Y,
Dovichi NJ,
Chow AW,
Bay SJ,
Su SC,
Reynolds RP,
( 1999 ) Species identification and phylogenetic relationships based on partial HSP60 gene sequences within the genus Staphylococcus. PMID : 10425778 : DOI : 10.1099/00207713-49-3-1181 Abstract >>
The phylogenetic relationships among 36 validly described species or subspecies within the genus Staphylococcus were investigated by cloning and sequencing their 60 kDa heat-shock protein (HSP60) genes using a set of universal degenerate HSP60 PCR primers. The cloned partial HSP60 DNA sequences from nine Staphylococcus aureus strains were highly conserved (97-100% DNA sequence similarity; mean 98%), indicating that the HSP60 gene of multiple isolates within the same species have little microheterogeneity. At the subspecies level, DNA sequence similarity among members of S. aureus, Staphylococcus schleiferi, Staphylococcus cohnii and Staphylococcus capitis ranged from 91 to 98%. At the interspecies level, sequence similarity among 23 distinct species of staphylococci ranged from 74 to 93% (mean 82%). By comparison, the highest sequence similarity of Bacillus subtilis and Escherichia coli with members within the genus Staphylococcus was only 70 and 59%, respectively. Importantly, phylogenetic analysis based on the neighbour-joining distance method revealed remarkable concordance between the tree derived from partial HSP60 gene sequences and that based on genomic DNA-DNA hybridization, while 16S rRNA gene sequences correlated less well. The results demonstrate that DNA sequences from the highly conserved and ubiquitous HSP60 gene offer a convenient and accurate tool for species-specific identification and phylogenetic analysis of staphylococci.
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10. |
Fitzgibbon JE,
Nahvi MD,
John JF,
( 1999 ) Topoisomerase sequences of coagulase-negative staphylococcal isolates resistant to ciprofloxacin or trovafloxacin. PMID : 10390214 : PMC : PMC89335 Abstract >>
Coagulase-negative staphylococcal isolates (n = 188) were screened for susceptibility to oxacillin, ciprofloxacin, and trovafloxacin, a new fluoroquinolone. At an oxacillin concentration of >/=4 microg/ml, 43% were methicillin resistant; of these, 70% were ciprofloxacin resistant (MIC, >/=4 microg/ml). Of the methicillin-resistant, ciprofloxacin-resistant isolates, 46% were susceptible to /=8 microg/ml) and increased trovafloxacin MICs (0.25 to 2 microg/ml) could be conferred by the combined presence of single mutations in each gyrA and grlA gene. Trovafloxacin MICs of >/=8 microg/ml also occurred, but these required an additional mutation in grlA.
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11. |
Layer F,
Ghebremedhin B,
König W,
König B,
( 2007 ) Differentiation of Staphylococcus spp. by terminal-restriction fragment length polymorphism analysis of glyceraldehyde-3-phosphate dehydrogenase-encoding gene. PMID : 17681623 : DOI : 10.1016/j.mimet.2007.06.015 Abstract >>
Classical phenotypic and biochemical testing do not lead to correct identification of the distinct Staphylococcus species. Therefore, the aim of our study was to develop a method for the reliable and accurate determination of distinct Staphylococcus species. In the present study, the 931-934-bp partial sequences of the glyceraldehyde-3-phosphate dehydrogenase-encoding (gap) gene of 28 validly described Staphylococcus species were amplified and sequenced. By using the respective sequence information we performed a terminal-restriction fragment length polymorphism (T-RFLP) analysis. For T-RFLP the partial gap gene was amplified with double-fluorescently labelled primers and digested with the restriction enzymes DdeI, BspHI and TaqI. Distinctive T-RFLP patterns were rendered by the use of capillary electrophoresis with laser-induced fluorescence detection. This molecular method allowed us to identify all 28 Staphylococcus species with high specificity. This was validated by analysis of 34 Staphylococcus epidermidis and 28 Staphylococcus haemolyticus isolates. These results demonstrate the feasibility and applicability of the T-RFLP method based on the partial gap gene sequences for rapid and accurate species identification.
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12. |
Lüthje P,
von Köckritz-Blickwede M,
Schwarz S,
( 2007 ) Identification and characterization of nine novel types of small staphylococcal plasmids carrying the lincosamide nucleotidyltransferase gene lnu(A). PMID : 17329268 : DOI : 10.1093/jac/dkm008 Abstract >>
To date, very little is known about lincosamide resistance plasmids in staphylococci with only a single lnu(A)-carrying staphylococcal plasmid having been sequenced completely. The aim of this study was to characterize small lnu(A)-carrying plasmids isolated from bovine coagulase-negative staphylococci (CoNS). Nine CoNS isolates with MICs of the lincosamide pirlimycin of 1-4 mg/L were tested for the presence of the lnu(A) gene. Its location was determined by Southern-blot hybridization. The lnu(A)-carrying plasmids were transformed into Staphylococcus aureus RN4220 and compared by restriction mapping and subsequent sequencing. Selected plasmids were investigated for their copy number and their lnu(A) gene expression via RT real-time PCR. The lnu(A) gene was detected on plasmids in all isolates. Sequence analysis revealed that these plasmids carried a rep gene, coding for the replication initiator protein, and the resistance gene lnu(A), coding for a lincosamide nucleotidyltransferase. While the Lnu(A) proteins were closely related (91.3-100% amino acid identity), the Rep proteins differed distinctly (27.4-100% amino acid identity), but showed similarity (81.4-98.5%) to Rep proteins of other small staphylococcal resistance plasmids. Sequence features of rolling-circle plasmids, such as the single-strand (ssoA) and double-strand (dso) origins of replication, were identified. For two plasmid types detected, the lincosamide resistance level varied with regard to the amounts of lnu(A) transcripts detected. Structurally different lnu(A)-carrying plasmids were detected in various CoNS species. The detection of the same lnu(A) gene in different plasmid backbones suggested the exchange of the gene via interplasmid recombinational events.
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13. |
Hanssen AM,
Sollid JU,
( 2007 ) Multiple staphylococcal cassette chromosomes and allelic variants of cassette chromosome recombinases in Staphylococcus aureus and coagulase-negative staphylococci from Norway. PMID : 17307983 : DOI : 10.1128/AAC.00978-06 PMC : PMC1855542 Abstract >>
We investigated the nature of the staphylococcal cassette chromosome mec (SCCmec) elements and cognate insertion sites in a collection of 42 clinical staphylococcal isolates of various species from Norway. The ccr and mec genes and the attachment sites (attL/attR) were identified by PCR, Southern blot hybridization, and DNA sequencing. We found 10 possibly new SCCmec types and one previously unreported variant of SCCmec type III (mec complex A, ccrAB3, and ccrC7) in Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis. Eleven of 42 strains contained multiple copies of ccr, suggesting the presence of mosaic structures composed of multiple SCC elements. S. haemolyticus contained ccrAB2 genes identical to those in S. aureus SCCmec type IV but lacked IS1272 and mec regulators. Two new allelic ccr variants, ccrC6 and ccrC7, were identified. Also, the presumed functional version of ccrB1 was found in a mecA-positive S. hominis strain and in mecA-negative S. epidermidis and S. hominis strains. Only minor differences in direct repeats in the left and right boundaries (attR/attL) were observed, while there was more variation in the inverted repeats. Coagulase-negative staphylococci (CoNS) contained several representatives of different ccr complexes and thus seemed to harbor multiple or composite new types of SCCmec. The enormous diversity observed in the SCCmec elements implies a large SCCmec reservoir in CoNS.
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14. |
Yazdankhah SP,
Asli AW,
Sørum H,
Oppegaard H,
Sunde M,
( 2006 ) Fusidic acid resistance, mediated by fusB, in bovine coagulase-negative staphylococci. PMID : 17060340 : DOI : 10.1093/jac/dkl418 Abstract >>
The aim of this study was to determine the occurrence of fusidic acid resistance, mediated by the fusB gene, among coagulase-negative staphylococci (CoNS) isolated from bovine mastitis. A total of 113 CoNS isolates were screened for susceptibility to fusidic acid by using a disc diffusion method. The fusB gene was detected by using PCR and subsequent DNA sequencing. The localization of fusB was determined by hybridization. The fusB gene was detected in 3 of 11 fusidic acid-resistant bovine CoNS isolates. The organization of the fusB downstream region on a 40 kb plasmid in a Staphylococcus haemolyticus isolate (288/96) was highly similar to the previously reported organization of fusB on plasmid pUB101 from a Staphylococcus aureus isolate of human origin. The fusB gene was chromosomally located in the remaining two isolates. Fusidic acid resistance mediated by fusB is not the dominant resistance mechanism in fusidic acid-resistant CoNS studied in this work. The similarity between the organization of the fusB downstream region in S. haemolyticus (isolate 288/96) and on plasmid pUB101 from an S. aureus isolate of human origin indicates a common ancestral origin of these genes.
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15. |
Novotna G,
Janata J,
( 2006 ) A new evolutionary variant of the streptogramin A resistance protein, Vga(A)LC, from Staphylococcus haemolyticus with shifted substrate specificity towards lincosamides. PMID : 17015629 : DOI : 10.1128/AAC.00799-06 PMC : PMC1693986 Abstract >>
We found a new variant of the streptogramin A resistance gene, vga(A)LC, in clinical isolates of Staphylococcus haemolyticus resistant to lincomycin and clindamycin but susceptible to erythromycin and in which no relevant lincosamide resistance gene was detected. The gene vga(A)LC, differing from the gene vga(A) at the protein level by seven amino acid substitutions, was present exclusively in S. haemolyticus strains resistant to both lincosamides and streptogramin A (LS(A) phenotype). Antibiotic resistance profiles of the ATP-binding cassette (ABC) proteins Vga(A)(LC) and Vga(A) in the antibiotic-susceptible host S. aureus RN4220 were compared. It was shown that Vga(A)LC conferred resistance to both lincosamides and streptogramin A, while Vga(A) conferred significant resistance to streptogramin A only. Detailed analysis of the seven amino acid substitutions, distinguishing the two related ABC proteins with different substrate specificities, identified the substrate-recognizing site: four clustered substitutions (L212S, G219V, A220T, and G226S) in the spacer between the two ATP-binding cassettes altered the substrate specificity and constituted the lincosamide-streptogramin A resistance phenotype. A transport experiment with radiolabeled lincomycin demonstrated that the mechanism of lincosamide resistance in S. haemolyticus was identical to that of the reported macrolide-streptogramin B resistance conferred by Msr(A).
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16. |
Layer F,
Ghebremedhin B,
Moder KA,
König W,
König B,
( 2006 ) Comparative study using various methods for identification of Staphylococcus species in clinical specimens. PMID : 16891498 : DOI : 10.1128/JCM.00226-06 PMC : PMC1594629 Abstract >>
Coagulase-negative staphylococci (CNS) play a predominant role in nosocomial infections. Rapid, reliable identification of these organisms is essential for accurate diagnosis and prompt effective treatment of these infections. Quite recently, the VITEK 2 g-positive (gram-positive [GP]) identification card (bioM?rieux) has been redesigned for greater accuracy in the identification of gram-positive cocci. We compared the BD Phoenix (Becton Dickinson) and VITEK 2 (bioM?rieux) automated microbiology systems, using their respective update version cards, and the API ID32 STAPH test. The glyceraldehyde-3-phosphate dehydrogenase (gap) gene-based T-RFLP (terminal restriction fragment length polymorphism) method was used for verifying the results. In total, 86 clinical isolates of CNS and 27 reference strains were analyzed. The results show that for identification of CNS, the automated identification methods using the newest VITEK 2 and BD Phoenix identification cards are comparable. However, API ID32 STAPH revealed more correct results compared to both automated microbiology systems. Despite the increased performance of the phenotypic automated identification systems compared to the former versions, molecular methods, e.g., the gap-based T-RFLP method, still show superior accuracy in identifying Staphylococcus species other than Staphylococcus aureus.
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17. |
Olsen JE,
Christensen H,
Aarestrup FM,
( 2006 ) Diversity and evolution of blaZ from Staphylococcus aureus and coagulase-negative staphylococci. PMID : 16449305 : DOI : 10.1093/jac/dki492 Abstract >>
To elucidate the diversity and evolutionary history of plasmid- and chromosomally-located blaZ, to detect indications of frequent exchange of blaZ between human and bovine staphylococci and to estimate the frequency of transfer of blaZ between coagulase-negative staphylococci (CoNS) and Staphylococcus aureus of bovine origin. blaZ was detected in 143 strains of penicillin-resistant S. aureus and CoNS from five Danish cattle herds (n = 25/23), random CoNS isolates from Denmark (n = 37), a collection of S. aureus from six different countries (n = 52), humans in Denmark (n = 3) and beta-lactamase control strains (n = 3). The sequence was determined in 105 strains and compared to published sequences by pairwise and multiple alignments. Maximum likelihood analysis was performed including bootstrap analysis. Parsimony, neighbour joining and consensus comparisons were performed for recombination. The localization of blaZ was determined by Southern blotting in 108 isolates. All penicillin-resistant strains carried blaZ and showed a similar organization of blaR1 and blaZ. The blaZ gene was localized to a plasmid in only 16 of the resistant strains. Sixty-nine sequences representing 105 isolates and sequences retrieved from public databases were compared. A phylogenetic tree showed that blaZ exists in three evolutionary lines: one group was of plasmid origin, one group was of chromosomal origin and one intermediate group. Sixty-nine sequence types were demonstrated. They translated into 11 BlaZ protein types. The major types all contained strains of both human and bovine origin, and more than one Staphylococcus species, demonstrating a shared gene pool. In a comparison of S. aureus and CoNS obtained from five Danish cattle herds, the same type of blaZ was only detected in one case. Results indicated a separate evolution for plasmid- and chromosomally-encoded blaZ. Although a common gene pool seems to exist among staphylococci, exchange of blaZ between strains and species is judged to be an extremely rare event.
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18. |
Bronstein JC,
Olson SL,
LeVier K,
Tomilo M,
Weber PC,
( 2004 ) Purification and characterization of recombinant Staphylococcus haemolyticus DNA gyrase and topoisomerase IV expressed in Escherichia coli. PMID : 15215131 : DOI : 10.1128/AAC.48.7.2708-2711.2004 PMC : PMC434177 Abstract >>
The subunits of DNA gyrase and topoisomerase IV from Staphylococcus haemolyticus were expressed in Escherichia coli, purified to homogeneity, and used to reconstitute active enzymes that were sensitive to known topoisomerase inhibitors. This represents the first description of a method for isolating type II topoisomerases of a coagulase-negative staphylococcal species.
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19. |
Urushibara N,
Paul SK,
Hossain MA,
Kawaguchiya M,
Kobayashi N,
( 2011 ) Analysis of Staphylococcal cassette chromosome mec in Staphylococcus haemolyticus and Staphylococcus sciuri: identification of a novel ccr gene complex with a newly identified ccrA allotype (ccrA7). PMID : 21388304 : DOI : 10.1089/mdr.2010.0144 Abstract >>
Methicillin resistance in staphylococci is conferred by the acquisition in its chromosome of the mecA gene, which is located on a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec). Genetic type of SCCmec is defined by combination of mec gene complex class and cassette chromosome recombinase gene (ccr) allotype. In this study, we analyzed genetic diversity of the SCCmec in 11 Staphylococcus haemolyticus strains and a Staphylococcus sciuri strain, which were recently isolated from clinical specimens in Bangladesh. Among these strains, only two S. haemolyticus strains were proved to have the known types of SCCmec, that is, SCCmec V (class C2 mec-ccrC) and VII (class C1 mec-ccrC). Five S. haemolyticus strains were assigned two unique mec-ccr gene complexes combination; that is, class C1 mec-ccrA4B4 (four isolates) and class A mec-ccrC (one isolate). In the remaining four S. haemolyticus strains with class C1 mec, no known ccr allotypes could be detected. A single S. sciuri strain with class A mec complex carried a ccrA gene belonging to a novel allotype designated ccrA7, together with ccrB3. The ccrA7 gene in the S. sciuri strain showed 61.7%-82.7% sequence identity to the ccrA gene sequences published so far, and 75.3% identity to ccrA3, which is a component of the type 3 ccr complex (ccrA3-ccrB3) in methicillin-resistant Staphylococcus aureus. The results of the present study indicated that mec gene complex and ccr genes in coagulase-negative staphylococci are highly divergent, and distinct from those of common methicillin-resistant S. aureus. Identification of the novel ccrA7 allotype combined with ccrB3 suggested an occurrence of recombination between different ccr complexes in nature.
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20. |
Bergeron M,
Dauwalder O,
Gouy M,
Freydiere AM,
Bes M,
Meugnier H,
Benito Y,
Etienne J,
Lina G,
Vandenesch F,
Boisset S,
( 2011 ) Species identification of staphylococci by amplification and sequencing of the tuf gene compared to the gap gene and by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. PMID : 20967479 : DOI : 10.1007/s10096-010-1091-z Abstract >>
Staphylococcal species, notably, coagulase-negative staphylococci (CoNS), are frequently misidentified using phenotypic methods. The partial nucleotide sequences of the tuf and gap genes were determined in 47 reference strains to assess their suitability, practicability, and discriminatory power as target molecules for staphylococcal identification. The partial tuf gene sequence was selected and further assessed with a collection of 186 strains, including 35 species and subspecies. Then, to evaluate the efficacy of this genotyping method versus the technology of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), the 186 strains were identified using MALDI-TOF-MS (Axima? Shimadzu) coupled to the SARAMIS? database (AnagnosTec). The French National Reference Center for Staphylococci identification method was used as a reference. One hundred and eighty-four strains (98.9%) were correctly identified by tuf gene sequencing. Only one strain was misidentified and one was unidentified. MALDI-TOF-MS identified correctly 138 isolates (74.2%). Four strains were misidentified, 39 were unidentified, five were identified at the group (hominis/warneri) level, and one strain was identified at the genus level. These results confirm the value of MALDI-TOF-MS identification for common species in clinical laboratory practice and the value of the partial tuf gene sequence for the identification of all staphylococcal species as required in a reference laboratory.
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21. |
Bal EB,
Bayar S,
Bal MA,
( 2010 ) Antimicrobial susceptibilities of coagulase-negative staphylococci (CNS) and streptococci from bovine subclinical mastitis cases. PMID : 20571942 : DOI : 10.1007/s12275-010-9373-9 Abstract >>
The prevalence and antimicrobial susceptibilities of Staphylococci and Streptococci were assessed from subclinical mastitis cases. One hundred Coagulase-Negative Staphylococci (CNS) and 34 Streptococci were identified. The most frequently isolated species were Staphylococcus haemolyticus (27%) and Staphylococcus simulans (24%). Susceptible CNS species revealed the highest resistance to penicillin G (58%), ampicillin (48%), neomycin (20%), and oleandomycin (14%). CNS methicillin resistance rates within 82 isolates were 21.95% and 1.22% by disk diffusion and PCR methods, respectively. These results suggested the disk diffusion method was more prone to yield false positives. Partial sequencing of the 16S rRNA region from the mecA carrying isolate (S. haemolyticus) was homologous with S. haemolyticus sequences/accessions obtained from GenBank. However, the mecA gene sequence from this isolate was more closely allied with the S. aureus mecA gene of human origins. Identical sequence data was acquired from the National Center for Biotechnology Information (NCBI) database, suggesting horizontal gene transfer between the two species. CNS beta-lactamase activity within 81 isolates was 29.63%. The most frequently isolated Streptococcus species were S. uberis (52%) and S. agalactiae (15%). Oleandomycin was the least effective antimicrobial agent on these isolates with 59% susceptibility. Results indicated that CNS and Streptococci exhibited various antimicrobial resistance responses. Consequently, isolation and identification of udder pathogens in herds suffering from subclinical agents is essential to select the most effective antimicrobial agent. Moreover, multiple resistance features of methicillin resistant (MR) isolates should be considered during antimicrobial susceptibility tests.
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22. |
Yoo JI,
Shin ES,
Chung GT,
Lee KM,
Yoo JS,
Lee YS,
( 2010 ) Restriction fragment length polymorphism (RFLP) patterns and sequence analysis of high-level mupirocin-resistant meticillin-resistant staphylococci. PMID : 19900793 : DOI : 10.1016/j.ijantimicag.2009.08.017 Abstract >>
High-level mupirocin resistance results from the acquisition of a mupirocin resistance (Mupr) plasmid carrying the mupA gene. In this study, we investigated the heterogeneous location of the mupA gene as well as sequence variations in mupA restriction fragment length polymorphism (RFLP) types of high-level mupirocin-resistant (MuH) staphylococci isolated from tertiary hospitals and long-term care facilities in South Korea. RFLP patterns of the mupA gene were investigated in 14 MuH staphylococci isolates, and sequence variations of the cassette-like construction composed of the transfer gene complex (trs), an insertion sequence (IS257-like) and the mupA gene of the Mupr plasmid were also studied. Among the 14 isolates, four different EcoRI/HindIII banding patterns were observed, which were determined to be caused by sequence deletion between the mupA gene and trsLM of the trs gene complex. Four different sequence types were also identified for the trsLM-IS257-like-mupA cassette. The IS257-like sequence of all MuH staphylococci showed two base pair substitutions and one base deletion compared with the sequence of IS257. The heterogeneous location of the mupA gene was caused by sequence deletion adjacent to the IS257-like sequence of the trsLM-IS257-like-mupA cassette construction, and the IS257-like sequence was found in all MuH staphylococci.
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23. |
Potter A,
Ceotto H,
Giambiagi-Demarval M,
dos Santos KR,
Nes IF,
Bastos Mdo C,
( 2009 ) The gene bap, involved in biofilm production, is present in Staphylococcus spp. strains from nosocomial infections. PMID : 19557349 : DOI : 10.1007/s12275-009-0008-y Abstract >>
This study analyzed ten strains of coagulase-negative staphylococci (CNS) involved in nosocomial infections in three Brazilian hospitals. Their antibiotic susceptibility profile showed that most strains exhibited multiple antibiotic resistance and possessed the mecA gene. The ability of these strains to adhere to polystyrene microtiter plates was also tested and nine of them proved to be biofilm producers at least in one of the three conditions tested: growth in TSB, in TSB supplemented with NaCl, or in TSB supplemented with glucose. The presence of the bap gene, which codes for the biofilm-associated protein (Bap), was investigated in all ten strains by PCR. AU strains were bop-positive and DNA sequencing experiments confirmed that the fragments amplified were indeed part of a bap gene. The presence of the icaA gene, one of the genes involved in polysaccharide intercellular adhesin (PIA) formation, was also detected by PCR in eight of the ten strains tested. The two icaA-negative strains were either weak biofilm producer or no biofilm producer, although they were bop-positive. To our knowledge, this is the first report demonstrating the presence of the bap gene in nosocomial isolates of CNS, being also the first report on the presence of this gene in Staphylococcus haemolyticus and S. cohnii.
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24. |
Fredheim EG,
Klingenberg C,
Rohde H,
Frankenberger S,
Gaustad P,
Flaegstad T,
Sollid JE,
( 2009 ) Biofilm formation by Staphylococcus haemolyticus. PMID : 19144798 : DOI : 10.1128/JCM.01891-08 PMC : PMC2668337 Abstract >>
Infections due to coagulase-negative staphylococci (CoNS) most frequently occur after the implantation of medical devices and are attributed to the biofilm-forming potential of CoNS. Staphylococcus haemolyticus is the second most frequently isolated CoNS from patients with hospital-acquired infections. There is only limited knowledge of the nature of S. haemolyticus biofilms. The aim of this study was to characterize S. haemolyticus biofilm formation. We analyzed the biofilm-forming capacities of 72 clinical S. haemolyticus isolates. A detachment assay with NaIO(4), proteinase K, or DNase was used to determine the main biofilm components. Biofilm-associated genes, including the ica operon, were analyzed by PCR, and the gene products were sequenced. Confocal laser scanning microscopy (CLSM) was used to elucidate the biofilm structure. Fifty-three isolates (74%) produced biofilms after growth in Trypticase soy broth (TSB) with glucose, but only 22 (31%) produced biofilms after growth in TSB with NaCl. It was necessary to dissolve the biofilm in ethanol-acetone to measure the optical density of the full biofilm mass. DNase, proteinase K, and NaIO(4) caused biofilm detachment for 100%, 98%, and 38% of the isolates, respectively. icaRADBC and polysaccharide intercellular adhesin (PIA) production were found in only two isolates. CLSM indicated that the biofilm structure of S. haemolyticus clearly differs from that of S. epidermidis. We conclude that biofilm formation is a common phenotype in clinical S. haemolyticus isolates. In contrast to S. epidermidis, proteins and extracellular DNA are of functional relevance for biofilm accumulation, whereas PIA plays only a minor role. The induction of biofilm formation and determination of the biofilm mass also needed to be optimized for S. haemolyticus.
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25. |
Berglund C,
Söderquist B,
( 2008 ) The origin of a methicillin-resistant Staphylococcus aureus isolate at a neonatal ward in Sweden-possible horizontal transfer of a staphylococcal cassette chromosome mec between methicillin-resistant Staphylococcus haemolyticus and Staphylococcus aureus. PMID : 19040477 : DOI : 10.1111/j.1469-0691.2008.02090.x Abstract >>
The first methicillin-resistant Staphylococcus aureus (MRSA) strain originated when a staphylococcal cassette chromosome mec (SCCmec) with the gene mecA was integrated into the chromosome of a susceptible S. aureus cell. The SCCmec elements are common among the coagulase-negative staphylococci, e.g. Staphylococcus haemolyticus, and these are considered to be potential SCCmec donors when new clones of MRSA arise. An outbreak of MRSA occurred at a neonatal intensive-care unit, and the isolates were all of sequence type (ST) 45, as characterized by multilocus sequence typing, but were not typeable with respect to SCCmec types I, II, III or IV. During the same time period, methicillin-resistant S. haemolyticus (MRSH) isolates identified in blood cultures at the same ward were found to be genotypically homogenous by pulsed-field gel electrophoresis, and did not carry a type I, II, III or IV SCCmec either. Thus, the hypothesis was raised that an SCCmec of MRSH had been transferred to a methicillin-susceptible S. aureus strain and thereby created a new clone of MRSA that caused the outbreak. This study showed that MRSA from the outbreak carried a ccrC and a class C mec complex that was also found among MRSH isolates. Partial sequencing of the mec complexes showed more than 99% homology, indicative of a common type V SCCmec. This finding may provide evidence for a recent horizontal transfer of an SCCmec from MRSH to an identified potential recipient, an ST45 methicillin-susceptible S. aureus strain, thereby creating a new clone of MRSA that caused the outbreak.
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26. |
Capurro A,
Artursson K,
Waller KP,
Bengtsson B,
Ericsson-Unnerstad H,
Aspán A,
( 2009 ) Comparison of a commercialized phenotyping system, antimicrobial susceptibility testing, and tuf gene sequence-based genotyping for species-level identification of coagulase-negative staphylococci isolated from cases of bovine mastitis. PMID : 18930604 : DOI : 10.1016/j.vetmic.2008.08.028 Abstract >>
In order to evaluate the usefulness of some phenotypic and genotypic methods for species identification of coagulase-negative staphylococci (CNS), isolates were obtained from bovine cases of clinical and sub-clinical mastitis from different geographical areas in Sweden. By using the Staph-Zym test, antimicrobial susceptibility testing, and sequencing of part of the CNS tuf gene and, when needed, part of the 16S rRNA gene we characterized 82 clinical isolates and 24 reference strains of 18 different species of staphylococci. The genotypic methods identified nine different species of CNS among the 82 milk isolates. A comparison with results obtained by tuf gene sequencing showed that Staph-Zym correctly identified CNS reference strains to species level more often than bovine milk CNS isolates (83% and 61%, respectively). In addition, tests supplementary to the Staph-Zym were frequently needed in both groups of isolates (50% of reference strains and 33% of milk isolates) to obtain an identification of the strain. It is notable that Staph-Zym judged two isolates as CNS, although they belonged to other species, could not give a species name in 11% of the bovine CNS isolates, and gave 28% of the isolates an incorrect species name. The present study indicates that the studied phenotypic methods are unreliable for identification of CNS from bovine intra-mammary infections.
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27. |
Correa JE,
De Paulis A,
Predari S,
Sordelli DO,
Jeric PE,
( 2008 ) First report of qacG, qacH and qacJ genes in Staphylococcus haemolyticus human clinical isolates. PMID : 18708646 : DOI : 10.1093/jac/dkn327 Abstract >>
To investigate phenotypically and genotypically the presence of MDR efflux pumps in 21 clinical isolates of Staphylococcus haemolyticus collected over a period of 10 years. MICs of different antibiotics and biocides were determined by the broth dilution method in the presence/absence of carbonyl cyanide-m-chlorophenylhydrazone (CCCP), an efflux pump inhibitor. PCR followed by sequencing was performed to detect the qac genes that encode for antiseptic resistance. Clonal relationships were determined by PFGE SmaI patterns using a standard protocol. All the isolates were resistant to gentamicin, 15 to erythromycin, 18 to ciprofloxacin, 7 to chloramphenicol and 1 to tetracycline. They showed higher susceptibility to antibiotics when they were exposed to CCCP. The MICs of ethidium bromide, SDS and benzalkonium chloride were also decreased, whereas the MIC of triclosan was decreased in only four isolates in the presence CCCP. Of the 21 isolates, qacA/B was detected in 5 isolates, smr in all of the isolates, qacG in 11 isolates, qacH in 10 isolates and qacJ in 4 isolates. PFGE analysis of the 21 isolates clustered them into 14 clones at 90% similarity corresponding to differences of between 7 and 16 bands among the clones. The efflux mechanism seems to be an important mechanism to confer resistance to antibiotics and biocides through MDR pumps. It was observed that several qac genes coexist in some of the isolates and seem to act simultaneously in the removal of different compounds out of the bacterial cell. The qac genes are horizontally spread among different clones.
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28. |
Deng F,
Wang H,
Liao Y,
Li J,
Fe?ler AT,
Michael GB,
Schwarz S,
Wang Y,
( 2017 ) Detection and Genetic Environment of Pleuromutilin-Lincosamide-Streptogramin A Resistance Genes in Staphylococci Isolated from Pets. PMID : 28261187 : DOI : 10.3389/fmicb.2017.00234 PMC : PMC5306371 Abstract >>
Increasing emergence of staphylococci resistant to pleuromutilins, lincosamides, and streptogramin A (PLSA) and isolated from humans and pets is a growing public health concern worldwide. Currently, there was only one published study regarding one of the PLSA genes, vga(A) detected in staphylococci isolated from cat. In this study, eleven pleuromutilin-resistant staphylococci from pets and two from their owners were isolated and further characterized for their antimicrobial susceptibilities, plasmid profiles, genotypes, and genetic context of the PLSA resistance genes. The gene sal(A) identified in 11 staphylococcal isolates was found for the first time in Staphylococcus haemolyticus, Staphylococcus epidermidis, and Staphylococcus xylosus. Moreover, these 11 isolates shared the identical regions flanking the sal(A) gene located in the chromosomal DNA. Two S. haemolyticus isolates from a cat and its owner carried similar vga(A)LC plasmids and displayed indistinguishable PFGE patterns. A novel chromosomal multidrug resistance genomic island (MDRGI) containing 13 resistance genes, including lsa(E), was firstly identified in S. epidermidis. In addition, vga(A)LC, sal(A), and lsa(E) were for the first time identified in staphylococcal isolates originating from pet animals. The plasmids, chromosomal DNA region, and MDRGI associated with the PLSA resistance genes vga(A), vga(A)LC, sal(A), and lsa(E) are present in staphylococci isolated from pets and humans and present significant challenges for the clinical management of infections by limiting therapeutic options.
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29. |
Naushad S,
Barkema HW,
Luby C,
Condas LA,
Nobrega DB,
Carson DA,
De Buck J,
( 2016 ) Comprehensive Phylogenetic Analysis of Bovine Non-aureus Staphylococci Species Based on Whole-Genome Sequencing. PMID : 28066335 : DOI : 10.3389/fmicb.2016.01990 PMC : PMC5168469 Abstract >>
Non-aureus staphylococci (NAS), a heterogeneous group of a large number of species and subspecies, are the most frequently isolated pathogens from intramammary infections in dairy cattle. Phylogenetic relationships among bovine NAS species are controversial and have mostly been determined based on single-gene trees. Herein, we analyzed phylogeny of bovine NAS species using whole-genome sequencing (WGS) of 441 distinct isolates. In addition, evolutionary relationships among bovine NAS were estimated from multilocus data of 16S rRNA, hsp60, rpoB, sodA, and tuf genes and sequences from these and numerous other single genes/proteins. All phylogenies were created with FastTree, Maximum-Likelihood, Maximum-Parsimony, and Neighbor-Joining methods. Regardless of methodology, WGS-trees clearly separated bovine NAS species into five monophyletic coherent clades. Furthermore, there were consistent interspecies relationships within clades in all WGS phylogenetic reconstructions. Except for the Maximum-Parsimony tree, multilocus data analysis similarly produced five clades. There were large variations in determining clades and interspecies relationships in single gene/protein trees, under different methods of tree constructions, highlighting limitations of using single genes for determining bovine NAS phylogeny. However, based on WGS data, we established a robust phylogeny of bovine NAS species, unaffected by method or model of evolutionary reconstructions. Therefore, it is now possible to determine associations between phylogeny and many biological traits, such as virulence, antimicrobial resistance, environmental niche, geographical distribution, and host specificity.
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30. |
Szczuka E,
Krajewska M,
Lijewska D,
Bosacka K,
Kaznowski A,
( 2016 ) Diversity of staphylococcal cassette chromosome mec elements in nosocomial multiresistant Staphylococcus haemolyticus isolates. PMID : 27056386 : DOI : 10.1007/s13353-016-0346-5 PMC : PMC5061825 Abstract >>
Staphylococcus haemolyticus is the second, most frequently isolated coagulase-negative staphyloccus (CoNS) from patients with hospital-acquired infections, and it is usually resistant to methicillin and other semisynthetic penicillins. The purpose of this study was to characterize staphylococcal cassette chromosome mec (SCCmec) elements and assess the in-vitro activity of antibiotics against 60 S. haemolyticus strains recovered from hospitalized patients. All these strains expressed methicillin resistance and carried a mecA gene. Moreover, all strains possessed a multiresistant phenotype, i.e., exhibited resistance to more than three classes of antibiotics. Eleven strains (18 %) harbored the SCCmec type V, containing ccrC and mec complex C. Three isolates harboring the ccrC gene did not contain a known mec complex. One strain positive for mec complex C was not typeable for ccr. This suggests that ccrC and mec complex C may exist autonomously. Only four strains carried mec complex B, whereas none of the S. haemolyticus harboured mec complex A. A new combination, which is mec complex B-ccrAB ship, was found in S. haemolitycus. The ccrAB ship was also identified in two strains of S. haemolitycus in which the mec gene complex was not identified. The results of the present study indicate that in S. haemolyticus the mec gene complex and the ccr genes are highly divergent. However, ccr sequence analysis does not allow the identification of a new allotype, based on a cut-off value of 85 % identity. The ccr genes in the S. haemolitycus strain showed ?96 % sequence identity to the ccrAB2 genes.
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31. |
Bouchami O,
de Lencastre H,
Miragaia M,
( 2016 ) Impact of Insertion Sequences and Recombination on the Population Structure of Staphylococcus haemolyticus. PMID : 27249649 : DOI : 10.1371/journal.pone.0156653 PMC : PMC4889114 Abstract >>
Staphylococcus haemolyticus is one of the most common pathogens associated with medical-device related infections, but its molecular epidemiology is poorly explored. In the current study, we aimed to better understand the genetic mechanisms contributing to S. haemolyticus diversity in the hospital environment and their impact on the population structure and clinical relevant phenotypic traits. The analysis of a representative S. haemolyticus collection by multilocus sequence typing (MLST) has identified a single highly prevalent and diverse genetic lineage of nosocomial S. haemolyticus clonal complex (CC) 29 accounting for 91% of the collection of isolates disseminated worldwide. The examination of the sequence changes at MLST loci during clonal diversification showed that recombination had a higher impact than mutation in shaping the S. haemolyticus population. Also, we ascertained that another mechanism contributing significantly to clonal diversification and adaptation was mediated by insertion sequence (IS) elements. We found that all nosocomial S. haemolyticus, belonging to different STs, were rich in IS1272 copies, as determined by Southern hybridization of macrorestriction patterns. In particular, we observed that the chromosome of a S. haemolyticus strain within CC29 was highly unstable during serial growth in vitro which paralleled with IS1272 transposition events and changes in clinically relevant phenotypic traits namely, mannitol fermentation, susceptibility to beta-lactams, biofilm formation and hemolysis. Our results suggest that recombination and IS transposition might be a strategy of adaptation, evolution and pathogenicity of the major S. haemolyticus prevalent lineage in the hospital environment.
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32. |
Yu D,
Pi B,
Chen Y,
Wang Y,
Ruan Z,
Otto M,
Yu Y,
( 2014 ) Characterization of the staphylococcal cassette chromosome composite island of Staphylococcus haemolyticus SH32, a methicillin-resistant clinical isolate from China. PMID : 24466348 : DOI : 10.1371/journal.pone.0087346 PMC : PMC3900703 Abstract >>
Staphylococcal cassette chromosome (SCC) elements contribute considerably to virulence and resistance to antibiotic agents in staphylococci. SCC elements in coagulase-negative staphylococci (CoNS) are highly diverse and there is evidence suggesting that they serve as a reservoir for antibiotic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA). However, only a small number of SCC elements have been characterized in CoNS and their exact roles in the emergence and evolution of MRSA remain to be demonstrated. Here, we determined the structure of an SCC composite island (CISH32) found in the clinical Staphylococcus haemolyticus isolate SH32 by whole-genome DNA sequencing. CISH32 was 48 kb in length and mainly composed of two imperfect SCC elements, namely (i) a �ZSCCmec(SH32) part containing a class C1 mec gene complex but lacking ccr genes and (ii) a SCCSH32 part with a ccrA5B3 gene complex but lacking mec genes. In addition, CISH32 contained a type III restriction-modification system and several resistance loci, for example genes conferring resistance to cadmium and arsenic. �ZSCCmec(SH32) is almost entirely identical to a pseudo SCCmec element found in S. haemolyticus WCH1 and shares pronounced sequence similarity to a �ZSCCmec element of S. haemolyticus JCSC1435. However, staphylococci other than S. haemolyticus, including S. aureus and S. epidermidis, contain homologs of SCCSH32 that are more similar to SCCSH32 than those elements found in S. haemolyticus, suggesting that CISH32 of S. haemolyticus SH32 was assembled in recent evolutionary events. Moreover, the composite structure of CISH32 indicates that the detection of class C1 mec and ccrA5B3 gene complexes in S. haemolyticus does not always indicate the existence of a UT9-type SCCmec element, which has remained questionable.
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33. |
( 1997 ) Molecular analysis of naturally occuring ermC-encoding plasmids in staphylococci isolated from animals with and without previous contact with macrolide/lincosamide antibiotics. PMID : 9215582 : DOI : 10.1111/j.1574-695X.1997.tb01022.x Abstract >>
A total of 16 epidemiologically unrelated macrolide-resistant staphylococcal isolates of various animal origins were investigated for the molecular basis of macrolide resistance with respect to previous contact of their host animals with macrolides and lincosamides. All isolates carried ermC-encoding plasmids of 2.3-4.0 kbp. The eight plasmids of staphylococci from animals which had not received macrolides or lincosamides showed inducible ermC gene expression and did not exhibit alterations in the ermC regulatory region. The remaining eight plasmids expressed the ermC gene constitutively. Six of these plasmids were from staphylococci from animals which had received tylosin or spiramycin as feed additives or lincomycin for therapeutic purposes. All constitutively expressed ermC genes revealed either sequence deletions or sequence duplications in their ermC regulatory region, as detected by a PCR assay and by sequence analysis. These sequence deletions and duplications found in naturally occurring plasmids corresponded closely to the mutations seen in the ermC-encoding plasmids after growth of an inducibly resistant strain in the presence of non-inducing macrolides or lincosamides under in vitro conditions.
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34. |
( 1997 ) Plasmid-encoded fosfomycin resistance in bacteria isolated from the urinary tract in a multicentre survey. PMID : 9338493 : DOI : 10.1093/jac/40.3.393 Abstract >>
Sixty out of 219 fosfomycin-resistant bacteria selected from more than 7400 urinary pathogens in an epidemiological multicentre survey performed in Italy were screened for plasmid genes fosA and fosB conferring fosfomycin resistance. Only five strains, three enterobacteria and two staphylococci, carried plasmids harbouring, respectively, fosA and fosB genes. Fosfomycin resistance in the other isolates was caused by an alteration of the chromosomally encoded GlpT transport system. One strain, Morganella morganii 279, incorporated alpha-glycerolphosphate and its mechanism of fosfomycin resistance needs to be further investigated. Our study showed that PCR amplification is the most accurate, simple and rapid method for epidemiological studies of plasmid-encoded fosfomycin resistance, and that fosfomycin resistance conferred by plasmid genes (both fosA and fosB) accounts for only a low percentage of the fosfomycin-resistant strains.
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35. |
Zong Z,
Peng C,
Lü X,
( 2011 ) Diversity of SCCmec elements in methicillin-resistant coagulase-negative staphylococci clinical isolates. PMID : 21637845 : DOI : 10.1371/journal.pone.0020191 PMC : PMC3102682 Abstract >>
Methicillin-resistant coagulase-negative staphylococci (MR-CoNS) are opportunistic pathogens and serve as a large reservoir of staphylococcal cassette chromosome mec (SCCmec). Characterization of SCCmec in MR-CoNS can generate useful information on the mobilization and evolution of this element. Non-repetitive MR-CoNS clinical isolates (n = 84; 39 S. epidermidis, 19 S. haemolyticus, 9 S. hominis, 6 S. capitis, 4 S. warneri, 2 S. cohnii, 2 S. saprophyticus, 1 S. kloosii, 1 S. simulans and 1 S. massiliensis) were collected. All isolates could grow on plates with 4 mg/L cefoxitin and all had mecA as detected by PCR. Strain typing using RAPD and ERIC-PCR revealed that almost all isolates were of different strains. SCCmec typing was performed using multiplex PCR published previously. For isolates in which SCCmec could not be typed, the mec complex classes were determined by additional PCR and the ccr genes were amplified with published or newly-designed primers and then sequenced. SCCmec types were assigned for 63 isolates by multiplex PCR and were assigned for 14 other isolates by PCR targeting mec and ccr. Among 77 isolates with determined SCCmec types, 54 had a single type, including type III (n = 19), IV (n = 14), V (n = 10), II (n = 2), I (n = 1), VIII (n = 1) and five unnamed types (n = 7), while 23 isolates had two types, III+V (n = 12), II+V (n = 8), II+IV (n = 2) or IV+V (n = 1). The five unnamed types were assigned UT1 (class A mec, ccrA1/ccrB4), UT2 (class C1 mec, ccrA4/ccrB4), UT3 (class A mec, ccrA5/ccrB3), UT4 (class C2 mec, ccrA2/ccrB2 plus ccrC1) and UT5 (class A mec, ccrA1/ccrB1 plus ccrC1). SCCmec types III, IV and V were prevalent in MR-CoNS and many isolates could harbor more than one type. Several new types of SCCmec were identified, highlighting the great genetic diversity and the need of developing classification schemes for SCCmec in MR-CoNS.
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36. |
( 1996 ) Tandem duplication in ermC translational attenuator of the macrolide-lincosamide-streptogramin B resistance plasmid pSES6 from Staphylococcus equorum. PMID : 8787908 : PMC : PMC163085 Abstract >>
A tandem duplication of 23 bp in the ermC gene translational attenuator of plasmid pSES6 from Staphylococcus equorum which mediated constitutive resistance to macrolide-lincosamide-streptogramin B antibiotics was identified. This duplication included the ribosome binding site for the ermC gene as well as the first 5 bp of the ermC coding sequence. It was postulated that this sequence duplication affects the possible RNA conformations so that the ribosome binding site for ErmC synthesis is readily accessible to the ribosomes and thus constitutive expression of the ermC gene occurs.
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37. |
( 1996 ) HSP60 gene sequences as universal targets for microbial species identification: studies with coagulase-negative staphylococci. PMID : 8815090 : PMC : PMC228899 Abstract >>
A set of universal degenerate primers which amplified, by PCR, a 600-bp oligomer encoding a portion of the 60-kDa heat shock protein (HSP60) of both Staphylococcus aureus and Staphylococcus epidermidis were developed. However, when used as a DNA probe, the 600-bp PCR product generated from S. epidermidis failed to cross-hybridize under high-stringency conditions with the genomic DNA of S. aureus and vice versa. To investigate whether species-specific sequences might exist within the highly conserved HSP60 genes among different staphylococci, digoxigenin-labelled HSP60 probes generated by the degenerate HSP60 primers were prepared from the six most commonly isolated Staphylococcus species (S. aureus 8325-4, S. epidermidis 9759, S. haemolyticus ATCC 29970, S. schleiferi ATCC 43808, S. saprophyticus KL122, and S. lugdunensis CRSN 850412). These probes were used for dot blot hybridization with genomic DNA of 58 reference and clinical isolates of Staphylococcus and non-Staphylococcus species. These six Staphylococcus species HSP60 probes correctly identified the entire set of staphylococcal isolates. The species specificity of these HSP60 probes was further demonstrated by dot blot hybridization with PCR-amplified DNA from mixed cultures of different Staphylococcus species and by the partial DNA sequences of these probes. In addition, sequence homology searches of the NCBI BLAST databases with these partial HSP60 DNA sequences yielded the highest matching scores for both S. epidermidis and S. aureus with the corresponding species-specified probes. Finally, the HSP60 degenerate primers were shown to amplify an anticipated 600-bp PCR product from all 29 Staphylococcus species and from all but 2 of 30 other microbial species, including various gram-positive and gram-negative bacteria, mycobacteria, and fungi. These preliminary data suggest the presence of species-specific sequence variation within the highly conserved HSP60 genes of staphylococci. Further work is required to determine whether these degenerate HSP60 primers may be exploited for species-specific microbic identification and phylogenetic investigation of staphylococci and perhaps other microorganisms in general.
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38. |
( 1996 ) DNA gyrase gyrA mutations in quinolone-resistant clinical isolates of Staphylococcus haemolyticus. PMID : 8849234 : PMC : PMC163266 Abstract >>
N/A
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39. |
( 1995 ) Functional cloning of the dihydropteroate synthase gene of Staphylococcus haemolyticus. PMID : 8586264 : DOI : 10.1111/j.1574-6968.1995.tb07932.x Abstract >>
A 1,7-kilobase fragment of the Staphylococcus haemolyticus chromosome containing the dihydropteroate synthase gene has been cloned by complementation in a temperature-sensitive mutant of Escherichia coli. The gene, designated folP, predicts a gene product of 29613 Da which shares significant amino acid sequence identity with other known bacterial dihydropteroate synthases. Analysis of the DNA sequence upstream and downstream of folP identified two further, incomplete open reading frames, one of which shows predicted amino acid sequence similarity to a second bacterial folic acid synthesis enzyme, dihydroneopterin aldolase.
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40. |
( 1995 ) Cloning and characterization of a novel, plasmid-encoded trimethoprim-resistant dihydrofolate reductase from Staphylococcus haemolyticus MUR313. PMID : 8540692 : DOI : 10.1128/aac.39.9.1920 PMC : PMC162857 Abstract >>
In recent years resistance to the antibacterial agent trimethoprim (Tmp) has become more widespread, and several trimethoprim-resistant (Tmpr) dihydrofolate reductases (DHFRs) have been described from gram-negative bacteria. In staphylococci, only one Tmpr DHFR has been described, the type S1 DHFR, which is encoded by the dfrA gene found on transposon Tn4003. In order to investigate the coincidence of high-level Tmp resistance and the presence of dfrA, we analyzed the DNAs from various Tmpr staphylococci for the presence of dfrA sequences by PCR with primers specific for the thyE-dfrA genes from Tn4003. We found that 30 or 33 isolates highly resistant to Tmp (MICs, > or = 512 micrograms/ml) contained dfrA sequences, whereas among the Tmpr (MICs, < or = 256 micrograms/ml) and Tmps isolates only the Staphylococcus epidermidis isolates (both Tmpr and Tmps) seemed to contain the dfrA gene. Furthermore, we have cloned and characterized a novel, plasmid-encoded Tmpr DHFR from Staphylococcus haemolyticus MUR313. The dfrD gene of plasmid pABU17 is preceded by two putative Shine-Dalgarno sequences potentially allowing for the start of translation at two triplets separated by nine nucleotides. The predicted protein of 166 amino acids, designated S2DHFR, encoded by the longer open reading frame was overproduced in Escherichia coli, purified, and characterized. The molecular size of the recombinant S2DHFR was determined by ion spray mass spectrometry to be 19,821.2 +/- 2 Da, which is in agreement with the theoretical value of 19,822 Da. In addition, the recombinant S2DHFR was shown to exhibit DHFR activity and to be highly resistant to Tmp.
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41. |
Pucci MJ,
Thanassi JA,
Ho HT,
Falk PJ,
Dougherty TJ,
( 1995 ) Staphylococcus haemolyticus contains two D-glutamic acid biosynthetic activities, a glutamate racemase and a D-amino acid transaminase. PMID : 7814322 : DOI : 10.1128/jb.177.2.336-342.1995 PMC : PMC176596 Abstract >>
Two D-glutamic acid biosynthetic activities, glutamate racemase and D-amino acid transaminase, have been described previously for bacteria. To date, no bacterial species has been reported to possess both activities. Genetic complementation studies using Escherichia coli WM335, a D-glutamic acid auxotroph, and cloned chromosomal DNA fragments from Staphylococcus haemolyticus revealed two distinct DNA fragments containing open reading frames which, when present, allowed growth on medium without exogenous D-glutamic acid. Amino acid sequences of the two open reading frames derived from the DNA nucleotide sequences indicated extensive identity with the amino acid sequence of Pediococcus pentosaceous glutamate racemase in one case and with that of the D-amino acid transaminase of Bacillus spp. in the second case. Enzymatic assays of lysates of E. coli WM335 strains containing either the cloned staphylococcal racemase or transminase verified the identities of these activities. Subsequent DNA hybridization experiments indicated that Staphylococcus aureus, in addition to S. haemolyticus, contained homologous chromosomal DNA for each of these genes. These data suggest that S. haemolyticus, and probably S. aureus, contains genes for two D-glutamic acid biosynthetic activities, a glutamate racemase (dga gene) and a D-amino acid transaminase (dat gene).
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42. |
( 1994 ) Dissemination among staphylococci of DNA sequences associated with methicillin resistance. PMID : 7911288 : DOI : 10.1128/aac.38.3.447 PMC : PMC284478 Abstract >>
DNA probes consisting of pUC19 containing cloned Staphylococcus aureus chromosomal fragments were constructed from two methicillin-resistant S. aureus strains with different DNA sequences 5' to mecA, the gene that mediates methicillin resistance. The probe from one strain, BMS1, contained a portion of the regulatory sequences (the terminal 641 bp of mecR1 and all of mecI) associated with the induction and repression of mecA transcription (pGO195). The second probe, from strain COL (pGO198), contained DNA not found in strain BMS1. This DNA was within the sequences added at the site of a mecR1 deletion. Genomic digests of 14 S. aureus isolates recovered between 1961 and 1969 all hybridized with pGO198. In contrast, 78% (36 of 46) of the S. aureus organisms isolated since 1988 hybridized with pGO195 but not with pGO198; the remainder hybridized with pGO198. No S. aureus isolates hybridized with both probes. Staphylococcus epidermidis digests hybridized with pGO198 (46%), pGO195 (14%), or both probes (35%); all 20 Staphylococcus haemolyticus isolates hybridized with pGO198. The restriction fragment length polymorphism patterns of all pGO198-hybridizing regions in S. aureus were identical to those in strain COL. In addition, the mecR1 deletion junction nucleotide sequences of eight S. aureus and six S. epidermidis isolates were identical. However, 21 of 23 S. epidermidis and all 20 S. haemolyticus isolates had from 5 to more than 20 additional chromosomal bands that hybridized with pGO198; none of 21 S. aureus isolates had additional hybridizing bands. These data suggest that the additional DNA responsible for the mecR1 deletion was part of a repetitive, and possibly mobile, element resident in coagulase-negative staphylococci but not in S. aureus. These data also support a hypothesis that the deletion event occurred in a coagulase-negative staphylococcus with subsequent acquisition of the interrupted sequences by S. aureus.
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43. |
Gabri EE,
Lázár CH,
Török E,
Kremmer B,
Mészáros TJ,
Katona ?,
Fazakas E,
Coldea L,
Popescu O,
Jakab E,
Colcieru M,
Jakab RI,
( 2019 ) Screening of mecI Gene in Staphylococcus Strains Isolated in Transylvania Region of Romania. PMID : 30614756 : DOI : 10.1089/mdr.2018.0205 Abstract >>
In the last few decades, methicillin-resistant Staphylococcus aureus (MRSA) strains have become a serious health care problem. However, in the European Union/European Economic Area countries the prevalence of the invasive MRSA isolates has decreased in recent years; in Romania, the considerably high prevalence of these strains is still unchanged. In this study, 396 staphylococcal strains were screened using molecular biology techniques for the presence of the nucA, mecA, and mecI genes and for the detection of the possible mutations accumulated in the mecI gene. More than half of the collected Staphylococcus strains (59.34%) were determined as S. aureus, and 63 strains were considered as MRSA. Small number of MRSA strains (n = 6; 54.54% of invasive S. aureus) originated from hemoculture. The mecI gene was present in 22 MRSA strains and in 4 methicillin-resistant coagulase-negative staphylococci strains. The majority of the mecI-positive MRSA strains contained the C to T substitution at position 202; furthermore, one previously undescribed mutation (C to G transversion at nucleotide position 285) was detected in one MRSA strain.
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44. |
Watson DC,
Yaguchi M,
Bisaillon JG,
Beaudet R,
Morosoli R,
( 1988 ) The amino acid sequence of a gonococcal growth inhibitor from Staphylococcus haemolyticus. PMID : 3138972 : DOI : 10.1042/bj2520087 PMC : PMC1149110 Abstract >>
A gonococcal inhibitor produced by Staphylococcus haemolyticus was separated into three components by reverse-phase h.p.l.c. The amino acid composition analysis of each of the three components indicated extensive similarities. N-Terminal sequence analysis of all three components allowed the identification of the first 27-30 residues of each. The complete primary structure of each component was determined from the sequence analysis of trypic peptides and peptides generated by mild acid hydrolysis. Each component is composed of 44 amino acid residues, with evidence suggesting the presence of an N-terminal formylmethionine residue in each. The components I, II and III have respectively 33, 29 and 33 identical amino acid residues in their sequences, which represents 75%, 65.9% and 75% homology. These components contain a high proportion of hydrophobic amino acids, and their hydrophobicity profiles are closely related. Also, each of the three components contains a positively charged residue (lysine) as the third residue, followed by a core of hydrophobic residues. These results suggest that the three components are possible signal sequences of one or more secreted or membrane-associated proteins.
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45. |
Brisson-Noël A,
Courvalin P,
( 1986 ) Nucleotide sequence of gene linA encoding resistance to lincosamides in Staphylococcus haemolyticus. PMID : 3091456 : DOI : 10.1016/0378-1119(86)90213-1 Abstract >>
We have determined the nucleotide sequence of gene linA in plasmid pIP855, which confers resistance to lincomycin by inactivating it in Staphylococcus haemolyticus. The gene was defined by start and stop codons and an open reading frame of 483 bp corresponding to a product with an Mr of 19020. The apparent size of the resistance-conferring protein was 21 kDa, when a minicell extract was electrophoresed in the sodium dodecyl sulfate-polyacrylamide gels. Full expression of linA was obtained both in Escherichia coli and Bacillus subtilis.
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46. |
( 2013 ) Cfr-mediated linezolid-resistance among methicillin-resistant coagulase-negative staphylococci from infections of humans. PMID : 23437319 : DOI : 10.1371/journal.pone.0057096 PMC : PMC3577776 Abstract >>
Four methicillin-resistant coagulase-negative staphylococci (MRCoNS), one Staphylococcus haemolyticus and three Staphylococcus cohnii, from infections of humans collected via the Ministry of Health National Antimicrobial Resistance Surveillance Net (Mohnarin) program in China were identified as linezolid-resistant. These four isolates were negative for the 23S rRNA mutations, but positive for the gene cfr. Mutations in the gene for the ribosomal protein L3, which resulted in the amino acid exchanges Gly152Asp and Tyr158Phe, were identified in S. haemolyticus 09D279 and S. cohnii NDM113, respectively. In each isolate, the cfr gene was located on a plasmid of ca. 35.4 kb, as shown by S1 nuclease pulsed-field gel electrophoresis and Southern blotting experiments. This plasmid was indistinguishable from the previously described plasmid pSS-02 by its size, restriction pattern, and a sequenced 14-kb cfr-carrying segment. Plasmid pSS-02 was originally identified in staphylococci isolated from pigs. This is the first time that a cfr-carrying plasmid has been detected in MRCoNS obtained from intensive care patients in China. Based on the similarities to the cfr-carrying plasmid pSS-02 from porcine coagulase-negative staphylococci, a transmission of this cfr-carrying plasmid between staphylococci from pigs and humans appears to be likely.
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47. |
Wanecka A,
Król J,
Twardo? J,
Mrowiec J,
Bania J,
Korzeniowska-Kowal A,
Tobiasz A,
( 2018 ) Characterization of a genetically distinct subpopulation of Staphylococcus haemolyticus isolated from milk of cows with intramammary infections. PMID : 29408029 : DOI : 10.1016/j.vetmic.2017.12.004 Abstract >>
The aim of this paper is to describe a novel subpopulation of Staphylococcus haemolyticus isolated from intramammary gland infections (IMI) in cattle. In total, eight isolates originating from milk samples from two unrelated dairy farms were examined phenotypically (using the ID 32 STAPH system) and genotypically. These isolates had almost identical sequences of each of the housekeeping genes examined (dnaJ, rpoB and sodA) but these sequences displayed similarity of only ?92.5%, 95.0% and 96.8%, respectively, with known S. haemolyticus sequences. The atypical isolates could also be distinguished biochemically by the positive �]-galactosidase test (with 2-naphthyl-�]-d-galactopyranoside as the substrate). All the isolates were identified as S. haemolyticus upon MALDI-TOF analysis but half of them, that achieved scores 1.7-1.999 (not reliable species identification), required expanding the commercial database for secure identification. Our study has shown that IMI in cattle may be caused by two distinct subpopulations of S. haemolyticus, differing clearly by some genotypic and phenotypic properties. The first of these subpopulations seems to be common to many hosts (including humans), whereas the second (possibly at the subspecies rank) is, so far, found only in cattle.
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48. |
( 2013 ) Characterization of a complex context containing mecA but lacking genes encoding cassette chromosome recombinases in Staphylococcus haemolyticus. PMID : 23521926 : DOI : 10.1186/1471-2180-13-64 PMC : PMC3637587 Abstract >>
Methicillin resistance determinant mecA is generally transferred by SCCmec elements. However, the mecA gene might not be carried by a SCCmec in a Staphylococcus haemolyticus clinical isolate, WCH1, as no cassette chromosome recombinase genes were detected. Therefore, the genetic context of mecA in WCH1 was investigated. A 40-kb region containing mecA was obtained from WCH1, bounded by orfX at one end and several orfs of S. haemolyticus core chromosome at the other. This 40-kb region was very complex in structure with multiple genetic components that appeared to have different origins. For instance, the 3.7-kb structure adjacent to orfX was almost identical to that on the chromosome of Staphylococcus epidermidis RP62a but was absent from S. haemolyticus JCSC1435. Terminal inverted repeats of SCC were found but no ccr genes could be detected. mecA was bracketed by two copies of IS431, which was flanked by 8-bp direct target repeat sequence (DR). The presence of 8-bp DR suggests that the two copies of IS431 might have formed a composite transposon for mobilizing mecA. This finding is of significance as multiple copies of IS431 are commonly present in the contexts of mecA, which might have the potential to form various composite transposons that could mediate the mobilization of mecA. This study also provides an explanation for the absence of ccr in some staphylococci isolates carrying mecA.
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49. |
( 2013 ) Genetic characterization of antimicrobial resistance in coagulase-negative staphylococci from bovine mastitis milk. PMID : 23415536 : DOI : 10.3168/jds.2012-6091 Abstract >>
Coagulase-negative staphylococci (CNS; n=417) were isolated from bovine milk and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Nineteen different species were identified, and Staphylococcus xylosus, Staphylococcus chromogenes, Staphylococcus haemolyticus, and Staphylococcus sciuri were the most prevalent species. Resistance to oxacillin (47.0% of the isolates), fusidic acid (33.8%), tiamulin (31.9%), penicillin (23.3%), tetracycline (15.8%), streptomycin (9.6%), erythromycin (7.0%), sulfonamides (5%), trimethoprim (4.3%), clindamycin (3.4%), kanamycin (2.4%), and gentamicin (2.4%) was detected. Resistance to oxacillin was attributed to the mecA gene in 9.7% of the oxacillin-resistant isolates. The remaining oxacillin-resistant CNS did not contain the mecC gene or mecA1 promoter mutations. The mecA gene was detected in Staphylococcus fleurettii, Staphylococcus epidermidis, Staph. haemolyticus, and Staph. xylosus. Resistance to tetracycline was attributed to the presence of tet(K) and tet(L), penicillin resistance to blaZ, streptomycin resistance to str and ant(6)-Ia, and erythromycin resistance to erm(C), erm(B), and msr. Resistance to tiamulin and fusidic acid could not be attributed to an acquired resistance gene. In total, 15.1% of the CNS isolates were multidrug resistant (i.e., resistant to 2 or more antimicrobials). The remaining CNS isolates were susceptible to antimicrobials commonly used in mastitis treatment. Methicillin-resistant CNS isolates were diverse, as determined by mecA gene sequence analysis, staphylococcal cassette chromosome mec typing, and pulsed-field gel electrophoresis. Arginine catabolic mobile element types 1 and 3 were detected in both methicillin-resistant and methicillin-susceptible Staph. epidermidis and were associated with sequence types ST59 and ST111. Because this study revealed the presence of multidrug-resistant CNS in a heterogeneous CNS population, we recommend antibiogram analysis of CNS in persistent infections before treatment with antimicrobials.
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50. |
( 2013 ) Staphylococcus jettensis sp. nov., a coagulase-negative staphylococcal species isolated from human clinical specimens. PMID : 23456811 : DOI : 10.1099/ijs.0.044438-0 Abstract >>
Eight coagulase-negative, novobiocin-susceptible staphylococcal strains were isolated from human clinical specimens at two different Belgian medical facilities. All strains were non-motile, Gram-stain-positive, catalase-positive cocci. DNA G+C content, peptidoglycan type, menaquinone pattern, the presence of teichoic acid and cellular fatty acid composition were in agreement with the characteristics of species of the genus Staphylococcus. Sequencing of the 16S rRNA gene and four housekeeping genes (dnaJ, tuf, gap and rpoB) demonstrated that these strains constitute a separate taxon within the genus Staphylococcus. Less than 41% DNA-DNA hybridization with the most closely related species of the genus Staphylococcus (Staphylococcus haemolyticus, Staphylococcus hominis and Staphlococcus lugdunensis) was observed. Key biochemical characteristics that allowed these bacteria to be distinguished from their nearest phylogenetic neighbours are arginine dihydrolase positivity, ornithine decarboxylase negativity and inability to produce acid aerobically from D-mannose, �\-lactose and turanose. Acid is produced aerobically from trehalose. Based on these results, a novel species of the genus Staphylococcus is described and named Staphylococcus jettensis sp. nov. The type strain is SEQ110(T) (=LMG 26879(T) =CCUG 62657(T) =DSM 26618(T)).
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