Rare Occurrence of Methicillin-Resistant Staphylococcus aureus CC130 with a Novel mecA Homologue in Humans in Germany

Abstract

MRSA CC130 containing the mecA homologue mecA_LGA251 were reported from the UK and from Denmark so far from cattle and humans. Here we report on 11 MRSA CC130 among a sample of 12691 isolates of human origin collected from January 2006 until June 2011. MRSA CC130 grew insufficiently on chromogernic agar plates for detection of MRSA; the agglutination test for presence of PBP2a was negative. We designed primers for specific detection of mecA_LGA251 as well as for concomitant detection of both, mec_LGA251 and mecA. As already described, the isolates exhibited spa-types t843, t1736, and t1773. The ccrA homologue indicated the presence SCCmec_XI. When subjected to further characterization by means of a commercially available microarray the isolates were negative for sak chp, and scn, and as expected positive for hla, untruncated hlb, and hld. They furthermore contained edinB, aur, slpA, slpB, slpE. From genes coding for surface and cell wall associated products the ica-operon, cap8, clfA, clfF, ebpS, fnbA, fnbB, sdrC were detected but not cna. The isolates were negative for enterotoxin genes and tst, as well as for eta, and etb; agr-type was III.