Related Clones Containing SCC mec Type IV Predominate among Clinically Significant Staphylococcus epidermidis Isolates

Abstract

SCCmec is a mobile genetic element that carries the gene (mecA) mediating methicillin resistance in staphylococci. For Staphylococcus aureus, four SCCmec types have been described, one (type IV) of which has been associated with newly identified community-acquired methicillin-resistant S. aureus. However, the distribution of SCCmec types among S. epidermidis is not known. SCCmec typing of a collection of 44 methicillinresistant Staphylococcus epidermidis (MRSE) isolates recovered between 1973 and 1983 from the blood of patients with prosthetic valve endocarditis (PVE) was performed by PCR amplification of key genetic elements (mecA, mecI, IS1272, and ccrAB). Of the 44 isolates, 1 (2%) harbored SCCmec type I, 15 (34%) harbored type II, 12 (28%) harbored type III, and 16 (36%) harbored type IV. The complete nucleotide sequence of SCCmec type IV was determined for 16 isolates and found to be identical in size (24 kb) and 98% homologous to DNA sequences published for S. aureus. Type IV SCCmec was also common (5 of 10 isolates) among a geographically dispersed collection of 10 recent (1998 to 2001) S. epidermidis bloodstream isolates. Multilocus sequence typing (MLST) (using the same seven genes presently employed for S. aureus MLST) of these MRSE isolates and of 10 additional recent geographically dispersed methicillin-susceptible isolates demonstrated that all 16 PVE isolates and 2 of 5 recent isolates harboring type IV SCCmec were in three related clonal groups. All three MSSE PVE isolates recovered from patients between 1976 and 1979 were in the same clonal groups as type IV SCCmec MRSE isolates. These data support the hypothesis of intra-and interspecies transfer of type IV SCCmec and suggest that there are clonal associations in S. epidermidis that correlate with SCCmec type.

Phylogenetic diversity and vertical distribution of a halobacterial community in the atmosphere of an Asian dust (KOSA) source region, Dunhuang City

“…These phylotypes were not detected from the DNA directly extracted from bioaerosol samples, indicating that Staphylococcus is a less dominant member of the bacterial community in the atmosphere over Dunhuang City and/or in the KOSA source regions. Several members of the genus Staphylococcus, which often colonize on the skin or in the oral cavities of humans, are capable of causing human disease (Spellerberg et al 1998;Zhang et al 2003) and are known to survive aerosol transport (Wisplinghoff et al 2003). Related bacterial species, such as S. xylosus and S. epidermidis, in addition to B. pumilus, have been identified in aerosols collected from the northern Caribbean during African dust events (Griffin et al 2003).…”

Genetic determinants and biofilm formation of clinicalStaphylococcus epidermidisisolates from blood cultures and indwelling devises

“…All isolates were analyzed by three MLST protocols, as previously described by Wisplinghoff et al [28]. The sequences of both strands of all PCR products were resolved with an ABI 3700 automated sequencer (PE Applied Biosystems) with BigDye fl uorescent terminators and the primers used in the initial PCR amplifi cation.…”

“…A number of isolates were also non-typeable. Wisplinghoff et al [28] determined a different distribution of SCCmec types in methicillin-resistant S. epidermidis isolates as well. They detected SCCmec IV as the most dominant type followed by types II and III, rarely SCCmec type I.…”

Novel Non- mecA -Containing Staphylococcal Chromosomal Cassette Composite Island Containing pbp4 and tagF Genes in a Commensal Staphylococcal Species: a Possible Reservoir for Antibiotic Resistance Islands in Staphylococcus aureus

“…Three relatively large SCCmec elements, types I, II, and III, were initially described for MRSA isolates, which were mostly obtained from patients frequenting health care environments (10). A smaller SCCmec element, type IV, was first identified in community-acquired MRSA (CA-MRSA) isolates from Chicago (4,16) and was subsequently found in MRSA isolates from other geographic locales (3,6,18) and in Staphylococcus epidermidis (22).…”