85株儿童感染金黄色葡萄球菌耐药性及流行病学研究

Antimicrobial resistance and epidemiology of 85 isolates of Staphylococcal aureus infection in paediatrics

目的 了解安徽省各地区近年儿童感染金黄色葡萄球菌（SA）耐药性及其流行病学特征,分析耐甲氧西林金黄色葡萄球菌（MRSA）的葡萄球菌盒式染色体（SCCmec）基因型分布特点,为临床感染和控制提供依据。方法 临床分离2010年～2013年每年9月非重复的儿童SA共85株,利用MicroscanWalk-Away-40全自动微生物分析仪进行细菌鉴定和药敏试验,MRSA经琼脂倍比稀释法进行表型筛选、聚合酶链反应（PCR）最终确定。多重PCR法检测MRSASCCmec基因分型。结果 85株SA中检出19株MRSA和66株甲氧西林敏感金黄色葡萄球菌（MSSA）,MRSA的检出率为22.35%。MRSA检出率最多的标本是痰液及咽拭子,其次为分泌物。全部SA对青霉素、克林霉素完全耐药,未发现万古霉素耐药及中介的菌株。与MSSA药敏结果比较,MR-SA对16种常用抗菌药物的耐药性更高。MRSASCCmec分型以SCCmecⅢ最多见,共12株,其次为SCCmecI5株,未分型2株,未发现SCCmecⅡ、Ⅳ、Ⅴ型。结论 本地区儿童感染SA有不同的耐药谱,儿童MRSA对同种抗菌药物耐药率均高于MSSA。儿童临床分离的MRSA菌株其SCCmec基因型以Ⅲ型为主。临床应合理使用抗菌药物,定期监测耐药性变迁,避免院内传播。

Objective To investigate the antimicrobial resistance and the epidemiological characteristics of Staphylo- coccus aureus（SA）. To analyze the methicillin-esistant SA（MRSA） staphylococcal cassette chromosome （SCCmec）genotype distribution characteristics, so as to provide evidence for clinical infection and control. Methods A total of 85 clinical isolates of SA were consecutively collected from different clinical significance specimens, and were ex- cluded the repeated isolates from the same patients. All isolates SA and drug sensitivity test were identified by the Microscan Walk-Away-40 automatic microorganism analyzer. The MRSA was made by agar dilution method for phe- notype screening and further identified by polymerase chain reaction （PCR）. The genotypes of SCCmec were deter- mined by multiplex PCR. Results Of 85 strains isolated SA, there were 19 strains MRSA and 66 strains methicil- lin sensitive SA （MSSA）. The detection rate of MRSA was 22.35%. The main detection rate of MRSA specimens was sputum and throat swab, followed by secretions. All SA were completely resistant to penicillin and childamycin, but entirely sensitive to vancomycin. Compared with MSSA, the drug resistance of 16 common antimicrobial agengts was higher than that of MRSA. SCCmec genotyping results showed that the most frequent SCCmec type was III. The 12 isolates of MRSA were SCCmec m, only 5 isolates were SCCmec I , and 2 isolates had no genotype. Type II , type IV and type V were not found in the group. Conclusion There are different resistance patterns of SA in the local area. The rates of drug resistance of MRSA for children are higher than those of MSSA. The main SCCmec genotype of MRSA in children is SCCmec III. Clinician should use antimicrobial drugs rationally, and furthermore, we should regularly monitor the change of resistance and prevent nosocomial transmission.