Biofilm formation and antimicrobial resistance of coagulasenegative staphylococcus

Abstract:

ObjectiveTo analyze the biofilm forming ability and antimicrobial resistance of  coagulasenegative staphylococcus（CNS）isolated from  blood culture.Methods126 strains of CNS from blood culture in a hospital were collected, biofilm formation was analyzed with  96well polystyrene plates, and polymerase chain reaction (PCR) was applied to detect mecA gene, antimicrobial resistance was analyzed.ResultsAmong 126 CNS isolates, 87(69.04%) were positive for biofilm,105 （83.33%）carried mecA gene. The resistant rates of CNS to penicillin, oxacillin, and erythromycin were all＞ 80%, none of the strains were resistant to linezolid, quinupristin / dalfopristin, vancomycin, and tigecycline; resistant rates of methicillinresistant CNS (MRCNS) to ciprofloxacin, gentamicin,levofloxacin, penicillin, rifampicin, and compound sulfamethoxazole were all higher than  methicillinsusceptible CNS(MSCNS) (all P＜0.05). Of MSCNS, 2 carried mecA gene.ConclusionCNS isolated from blood have strong biofilm forming ability, most are MRCNS and with multidrug resistance; there are strains with inconsistence of drugresistant  phenotype and genotype.