Drug resistance and genotype of methicillin-resistant Staphylococcus in Tianjin / 中华临床感染病杂志

ABSTRACT

Objective To investigate the drug resistance and genotype of methicillin-resistant Staphylococcus (MRS), and to study the epidemiology of drug resistance in Staphylococcus. Methods Drug susceptibility tests were performed for 138 Staphylococcus strains clinically isolated, and mecA gene was detected with PCR. For mecA positive strains, Staphylococcal cassette chromosome mec (SCCmec) gene was detected by two multiplex PCR assays. Results Seven (10.8%) out of 65 Staphylococcus aureus strains were methicillin-resistant Staphylococcus aureus (MRSA) strains, and 44 (60.3%) out of 73 coagulase negative Staphylococcus strains were methicillin-resistant coagulase negative Staphylococcus (MRCNS)strains. There was statistical significance on the difference of isolation rates (x2 = 37. 05, P ＜0.01). No vancomycin or nitrofurantoin resistant strain was found. There were 52 (52/138, 37.7%) mecA positive strains, including 16 SCCmec type Ⅰ strains, 1 type Ⅱ strain, 13 type Ⅲ strains, 9 type Ⅳ strains and 4 type Ⅴ strains. Conclusions Drug resistance in MRS is increasingly serious. MRCNS strains are more popular than MRSA in clinic, and SCCmec Ⅰ and Ⅲ may account for most infections.