南京地区不同人群呼吸道耐甲氧西林金黄色葡萄球菌耐药性及五种耐药基因分析

Analysis of drug resistance and five drug resistance genes in MRSA from different populations in Naning district

目的探讨南京地区成年健康人群鼻咽部携带的耐甲氧西林金黄色葡萄球菌(MRSA)和医院下呼吸道感染患者痰液中分离的MRSA的耐药性及耐药基因分布特点。方法收集南京地区成年健康人群(健康组)鼻咽部分离的19株MRSA和医院下呼吸道感染患者(临床组)痰液中分离的51株MRSA,K-B法测定其药敏情况,多重PCR法检测mecA基因,氨基糖苷修饰酶基因aacA-aphD,大环内酯类23srRNA甲基化酶基因ermA、ermC,四环素类核糖体保护蛋白基因tetM、tetK。结果所有菌株对万古霉素、替考拉宁和利奈唑胺敏感,对多种抗生素的耐药率在90%以上,携带mecA基因;aacA-aphD、ermA、ermC、tetM、tetK五种耐药基因的MRSA菌株在健康组和临床组的检出率分别为94.8%、100.0%、21.0%、100.0%、10.5%和98.0%、96.1%、19.6%、96.1%、23.5%。结论南京地区成年健康人群鼻咽部携带的MRSA和医院下呼吸道感染患者分离的MRSA均表现出多重耐药,相关耐药基因检出率高。

Objective To investigate the drug resistance and drug resistance genes in methicillin-resistant Staphylococcus aureus（MRSA） isolated from nasopharyngeal carriage of healthy adults and sputum of hospital respiratory infection patients in Nanjing district. Methods A total of 19 MRSA strains isolated from nasopharyngeal samples of healthy adults（group A） and 51 MRSA strains isolated from sputum of hospital respiratory infection patients （group B） was collected. The susceptibility to antibiotics was tested by K-B method. Multiplex PCR was used to detect the methicillin-resistant gene mecA, aminoglycoside-resistant gene aacA-aphD, macrolide-lincosamidestretogramin B-resistant genes ermA and ermC, and tetracycline-resistant genes tetM and tetK. Results All MRSA strains were sensitive to vancomycin, teicoplanin and linezolid. The resistant rates of all strains to many kinds of drugs were greater than 90%. MecA gene was detected in all MRSA strains. The positive rates of aacA-aphD, ermA, ermC, tetM, and tetK genes were 94. 8%, 100. 0%, 21. 0%, 100.0%,and 10.5% in group A and 98. 0%, 96.1%,19. 6%, 96.1%, and 23.5% in group B. Conclusion Multiple drug resistances of MRSA are serious with high detection rates in healthy adults and hospital infection patients in Nanjing district.