Genetic analysis of mecA gene and detection of homologue pbpD in Stahylococcus sciuri group

Abstract

Oxacillin/methicillin-resistance is related to the mecA and its regulatory genes mecR1 and mecI. Its origin is still unknown, although evidences support that it is related to CNS, once mecA and a homologue gene, pbpD, were both detected in Staphylococcus sciuri species group. The present work evaluated 210 samples of skin and ear swabs from rodents and 60 nasal swabs from equines of Army Biologic Institute, Rio de Janeiro. Pheno- and genotypic characterization provided 59.52% (25/42) and 78.57% (11/14) S. lentus and S. sciuri, respectively. It was observed that although all S. sciuri isolates tested positive for pbpD, there was no correlation with oxacillin-resistance. On the other hand, isolates tested positive for mecA gene also presented phenotypic oxacillin-resistance in at least one assay. The alignment of the mecA gene showed that the nucleotide sequences were sorted into 2 different groups, one comprising the bovine strains and the other containing human and equine strains.