尿路感染分离金黄色葡萄球菌的耐药性研究

A study of drug resistance genes of Staphylococcus aureus isolated from urinary tract infections

目的研究金黄色葡萄球菌的耐药情况及耐药基因检出情况,为菌株感染的防治提供指导。方法收集尿路感染者送检标本,进行金黄色葡萄球菌培养及分离纯化,鉴定菌株,并采用PCR检测耐药基因。结果共分离金黄色葡萄球菌174株,K-B法测定金黄色葡萄球菌对阿米卡星、苯唑西林、四环素、红霉素、万古霉素、环丙沙星、替考拉宁、克林霉素、利福平、庆大霉素的耐药率分别为14.94%、39.08%、37.93%、59.20%、0、31.03%、0、47.70%、17.82%和45.98%,中介率分别为10.92%、0、5.17%、1.72%、0、2.87%、0、9.20%、0和6.90%,敏感率分别为74.14%、60.92%、56.90%、39.08%、100.00%、66.09%、100.00%、43.10%、82.18%和47.13%。PCR扩增金黄色葡萄球菌ermA基因为421bp、ermC基因为572bp、qacA基因为629bp、ermB基因为359bp、aac(6')/aph(2')基因为220bp、mecA基因为162bp,检出率分别为21.26%、10.92%、16.09%、35.06%、29.89%和43.10%。结论分离自尿路感染者尿液的金黄色葡萄球菌对常用抗生素有一定耐药性,在抗感染治疗中可优先考虑使用万古霉素和替考拉宁,但仍应合理选用。为控制菌株耐药性发生及发展,应及时分析菌株耐药基因分布情况。

Objectives To study the drug resistance of Staphylococcus aureus and to study the prevalence of its drug re-sistance genes in order to guide the prevention and treatment of infections with S. aureus. Methods Samples were col-lected from patients with a urinary tract infection and S. aureus was cultured, isolated, and purified. Strains of S. aureus were identified. Drug resistance genes were detected with PCR. Results One hundred and seventy-four strains of Staphylococcus aureus were isolated from clinical specimens from inpatients. The drug resistance of S. aureus was ana-lyzed using the K-B method. Results indicated that the resistance of S. aureus to amikacin was 14.94%, its resistance to oxacillin was 39.08%, its resistance to tetracycline was 37.93%, its resistance to erythromycin was 59.20%, its resist-ance to vancomycin was 0.00%, its resistance to ciprofloxacin was 31.03 %, its resistance to teicoplanin was 0.00 0%, its resistance to clindamycin was 47.70%, its resistance to rifampicin was 17.82%, and its resistance to gentamicin was 47. 70%. The intermediate resistance of S. aureus to amikacin was 10.92%, its intermediate resistance to oxacillin was 0. 00%, its intermediate resistance to tetracycline was 5.17%, its intermediate resistance to erythromycin was 1.72%, its intermediate resistance to vancomycin was 0.00%, its intermediate resistance to ciprofloxacin was 2.87%, its intermedi-ate resistance to teicoplanin was 0.00 %, its intermediate resistance to clindamycin was 9.20 %, its intermediate resistance to rifampicin was 0.00%, and its intermediate resistance to gentamicin was 6.90%. The sensitivity of S. aureus to ami-kacin was 74.14%, its sensitivity to oxacillin was 60.92%, its sensitivity to tetracycline was 56.90%, its sensitivity to erythromycin was 39.08%, its sensitivity to vancomycin was 100.00%, its sensitivity to ciprofloxacin was 66.09%, its sensitivity to teicoplanin was 100.00%, its sensitivity to clindamycin was 43.10%, its sensitivity to rifampicin was 82. 18%, and its sensitivity to gentamicin was 47.13%. Amplification with PCR revealed that the ermA gene was 421 bp in length, the ermC gene was 572 bp in length, the qacA gene was 629 bp in length, the ermB gene was 359 bp in length, the aae （6 ＇）/aph （2 ＇） gene was 220 bp in length, and the mecA gene was 162 bp in length. The mecA gene was detected at a rate of 21.26%/00, the qacA gene was detected at a rate of 10.92%, the ermA gene was detected at a rate of 16.09%, the ermB gene was detected at a rate of 10.92%, the ermC gene was detected at a rate of 29.89%, and the aac （6 ＇）/aph （2 ＇） gene was detected at a rate of 43.10%. Conclusion S. aureus isolated from patients with a urinary tract infection had a certain level of resistance to common drugs. Vaneomycin and teicoplanin should be the drug of choice in treating an infection with S. aureus, but drugs should be used rationally. The distribution of drug resistance genes should be promptly analyzed in order to control the occurrence and development of drug-resistant strains.