부산대학교 도서관

Staphylococcus haemolyticusis 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. haemolyticusstrains recovered from hospitalized patients. All these strains expressed methicillin resistance and carried a mecAgene. Moreover, all strains possessed a multiresistant phenotype, i.e., exhibited resistance to more than three classes of antibiotics. Eleven strains (18 %) harbored the SCCmectype V, containing ccrCand meccomplex C. Three isolates harboring the ccrCgene did not contain a known meccomplex. One strain positive for meccomplex C was not typeable for ccr. This suggests that ccrCand meccomplex Cmay exist autonomously. Only four strains carried meccomplex B, whereas none of the S. haemolyticusharboured meccomplex A. A new combination, which is meccomplex B-ccrABship, was found in S. haemolitycus. The ccrABshipwas also identified in two strains of S. haemolitycusin which the mecgene complex was not identified. The results of the present study indicate that in S. haemolyticusthe mecgene complex and the ccrgenes are highly divergent. However, ccrsequence analysis does not allow the identification of a new allotype, based on a cut-off value of 85 % identity. The ccrgenes in the S. haemolitycusstrain showed ≥96 % sequence identity to the ccrAB2genes.