Molecular characterization of methicillin-resistant Staphylococcus epidermidis strains from bacteraemic patients

Abstract

In order to study the clonality of clinical methicillin-resistant Staphylococcus epidermidis (MRSE) strains and their staphylococcal cassette chromosome mec (SCCmec) elements, 60 isolates of MRSE from bacteraemic patients in three units of the Helsinki University Hospital, Finland were selected, covering the periods 1990-1993 and 1997-1998. The MRSE strains were analysed by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing and SCCmec typing. Eleven PFGE types (FIN-SE-1-11) with sequence type ST2 (clonal complex 2; CC2) were identified. The previously established methicillin-resistant Staphylococcus aureus SCCmec criteria were applied to name the MRSE SCCmec complexes, and it was found that 7% of the isolates carried SCCmec type IA (ccrA1, class B), whereas the majority (93%) yielded six non-typeable SCCmec PCR patterns (P1-P6). Within each SCCmec PCR pattern, two ccr recombinase genes (ccrA2 and ccrA3) and two mec gene complexes (class A and class B) were detected. In addition, the ccrC gene was associated with three of the six patterns. In conclusion, the MRSE strains were genetically related to each other (ST2) but their SCCmec complexes were unique combinations of elements previously recognized among SCCmec types III and IV.

A Multidrug-Resistant Staphylococcus epidermidis Clone (ST2) Is an Ongoing Cause of Hospital-Acquired Infection in a Western Australian Hospital

“…Several investigations have demonstrated that certain multidrug-resistant S. epidermidis (MDRSE) genotypes become established as opportunistic pathogens in the health care setting as a novel ecological niche (8,10,12). In addition, recent studies identified several worldwide epidemic clonal lineages (9,12,13,18,21).…”

Carriage of Methicillin-Resistant Staphylococci and Their SCC mec Types in a Long-Term-Care Facility

“…Up to now, six different SCCmec types (I to VI) have been recognized, each of which is different in size (21 to 67 kb) and characterized by a different set of ccr recombinase genes and mec gene complex (3,12,13,22,24,32). In addition to the major types, a number of new SCCmec elements, including non-mecA-encoding cassettes, have been discovered (2,3,11,16,19,20,28). New types may be generated continuously (5,9).…”

Genetic Analysis of Glycopeptide-Resistant Staphylococcus epidermidis Strains from Bone and Joint Infections

“…Resistance to fluoroquinolones, erythromycin, clindamycin, gentamicin, rifampin, tetracycline, and chloramphenicol is also frequent (1,(6)(7)(8). Multilocus sequence typing (MLST) analysis suggests that multidrug resistance in S. epidermidis is associated with a small number of related clones, mostly belonging to ST2 and related sequence types (STs) (9)(10)(11).…”