title: Diversity of staphylococcal cassette chromosome mec elements in nosocomial multiresistant Staphylococcus haemolyticus isolates.
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-ccrABship, was found in S. haemolitycus. The ccrABshipwas 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.
authors.affiliation: Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, Poznań, 61-614, Poland. ewasz@amu.edu.pl.
authors.forename: Ewa
authors.initials: E
authors.lastname: Szczuka
authors.affiliation: Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, Poznań, 61-614, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Krajewska
authors.affiliation: Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, Poznań, 61-614, Poland.
authors.forename: Dagmara
authors.initials: D
authors.lastname: Lijewska
authors.affiliation: Department of Microbiological and Laboratory Diagnostics, Bacteriological Laboratory, Regional Hospital in Poznań, Juraszów 7/19, Poznań, 60-479, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Bosacka
authors.affiliation: Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, ul. Umultowska 89, Poznań, 61-614, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Kaznowski
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D006801:Humans; D016106:Methicillin Resistance; D017422:Sequence Analysis, DNA; D041162:Staphylococcus haemolyticus / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial
keywords: Antibiotic resistance; SCCmec; Staphylococcus haemolyticus