Objective To investigate the antimicrobial resistance and molecular typing characteristics of Staphylococcus aureus strains isolated from sterile body fluids in Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine for improving clinical treatment.Methods The S.aureus strains isolated from sterile body fluids(excluding blood samples)of inpatients in Xinhua Hospital from December 2010 to June 2022 were collected.Antimicrobial susceptibility test was carried out by VITEK® 2 Compact automatic microbiological assay system.Multilocus sequence typing(MLST)of all strains and SCCmec typing of MRSA were performed by PCR.Results A total of 80 strains of S.aureus were collected,of which 73.8％were isolated from adults and 26.2％from children.The strains demonstrated the highest resistance rate to penicillin(93.8％),followed by oxacillin(50.0％),erythromycin(46.7％),tetracycline(30.2％)and ciprofloxacin(30.2％).No strains were found resistant to linezolid or vancomycin.The overall prevalence of MRSA was 50.0％.MRSA strains showed higher resistance rates to most antibiotics than MSSA strains.All strains were subjected to MLST typing.The most prevalent subtype was ST5(20.0％),followed by ST398(12.5％),ST7(8.8％),and ST239(8.8％).A new subtype was identified,which was isolated from pleural effusion.ST5(20.3％)was the main subtype for the strains isolated from adults while ST5(19.0％)and ST398(19.0％)were the main subtype for the strains isolated from children.MRSA strains were subjected to SCCmec typing,resulting in 4 subtypes(SCCmecⅠ,SCCmecⅢ,SCCmecⅣc and SCCmecⅤ).Most of the SCCmecⅠ strains were ST59.Most of the SCCmecⅢ strains were ST630.Most of the SCCmecⅣc strains were ST239,and most of the SCCmecⅤ strains were ST5.The remaining 10 strains were nontapable.ST5-SCCmecV and ST239-SCCmecⅣc were the main epidemic clones of MRSA.Conclusions In this study,the most prevalent subtype of S.aureus was ST5.ST5-SCCmecⅤ and ST239-SCCmecⅣc were the main epidemic clones of MRSA.MRSA strains showed significantly higher resistance rates to most antimicrobial agents than MSSA.More attention should be paid to the treatment of S.aureus infection.Meanwhile,nosocomial infection prevention and control should be strengthened.
关键词
金黄色葡萄球菌/无菌体液/耐药性/多位点序列分型/SCCmec分型
Key words
Staphylococcus aureus/sterile body fluid/antimicrobial resistance/multilocus sequence typing/SCCmec typing
维普
万方数据