Abstract:
Objective To analyze the antimicrobial resistance, distribution of resistance genes and staphylococcal chromosome cassette mec (SCCmec) typing in 166 strains of Staphylococcus epidermidis isolated from early pregnancy cervical swabs in Chaoyang district of Beijing during 2015–2017, and provide evidence for rational medication and infection prevention.
Methods A retrospective analysis on antibiotic resistance of 166 strains of S. epidermidis isolated from early pregnancy cervical swabs in Chaoyang during 2015–2017 was conducted. K-B disk diffusion method was used to detect the susceptibility to cefoxitin. Microbroth dilution method was used to detect the susceptibility to 11 antibiotics. PCR was performed to detect drug resistance genes to erythromycin, quinolone, sulfa, aminoglycoside, macrolide and tetracycline and the genotypes and subtypes of all currently described SCCme. SPSS 22.0 was used for data analysis.
Results The results showed that the sensitivity rate of 166 strains of S. epidermidis was 100% to vancomycin and 93.37% to daptomycin. The resistance rates to penicillin, oxacillin and erythromycin were above 90%, and the resistance rates to other antibiotics were different. For the 166 strains, the multi-drug resistance rate was 72.89%, the detection rate of mecA gene was 45.78%. The carriage rates of resistance genes norA1 (100%) and norA2 (95.78%) were highest, followed by msrA (71.08%). Among 76 strains of mecA gene-positive S. epidermidis, the major genotype was SCCmecⅢ (40.79%), followed by SCCmeⅤ (22.37%) .
Conclusion The carrying rate of S. epidermidis in cervical swabs of healthy population was more than 50%, the detection rate of methicillin resistant S. epidermidis (MRSE) was 24.70%. It is necessary to trace back the typing and drug resistance of strain from cervical secretion of pregnant women. Long-term enhanced antibiotic supervision for multi-drug resistant strains is needed to reduce drug-resistant strains and reduce the risk for neonatal sepsis infection.