Pathogenicity of Staphylococcus epidermidis Causing Urinary Tract Infection / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To understand the pathogenicity of Staphylococcus epidermidis causing urinary tract infection. METHODS Thirty five isolates were collected in the patients with urinary tract infection during 2003-2004 to test the minimal inhibitory concentration(MIC) to erythromycin,ampicillin,cefoxitin,ceftriaxone,teicoplanin,ciprofloxacin,tetracycline,trimethoprim-sulfamethoxazole and vancomycin.The genes of ermA,ermB,ermC,msrA,mecA,and icaA were amplified by PCR.The biofilm producing of the isolates was determined by the quantitative method.The pulsed-field gel electrophoresis(PFGE) was used to discriminate the homology among the isolates. RESULTS Among the isolates,MRSE accounted for 71.4%.The antibiotic susceptibility to erythromycin,ampicillin,ceftriaxone,ciprofloxacin,tetracycline and trimethoprim-sulfamethoxazole were 22.8%,6.34%,34.9%,26.9%,44.4% and 62.2%,respectively,whereas to teicoplanin and vancomycin were 99.2% and 100%.All the isolates resistant to cefoxitin carried mecA.ermC Was the predominant determinant among the erythromycin resistant isolates.Among the 14 icaA positive isolates,10 isolates were biofilm producing.All the isolates were classified into 18 types by PFGE. CONCLUSIONS The high and multiple antibiotic resistance of S.epidermidis isolates causing urinary tract infection were shown.The detection of icaA gene in clinical S.epidermidis isolates was a signal of their pathogenicity.