铜绿假单胞菌毒力基因与耐药性关系分析

Analysis of the relationship the virulence genes and antibiotic resistance in Pseudomonas aeruginosa

目的:了解临床分离铜绿假单胞菌Ⅲ型分泌系统毒力基因exoT、exoY、exoS和exoU的携带情况及其与细菌耐药性的关系。方法:收集上海市奉贤区中心医院2016年4月-2018年4月临床样本中非重复分离的157株铜绿假单胞菌,使用Phoenix 100全自动微生物分析仪进行细菌鉴定和药敏试验,PCR检测毒力基因exoS、exoU、exoT和exoY,并分析不同毒力基因型组合与细菌耐药性的关系。结果:157株铜绿假单胞菌中,携带exoT、exoY、exoS和exoU基因的阳性率分别为100.00%(157/157)、95.54%(150/157)、70.06%(110/157)和28.03%(44/157)。共检测出6种毒力基因型组合,以exoT+/exoY+/exoS+/exoU-(68.79%,108/157)和exoT+/exoY+/exoS-/exoU+(25.48%,40/157)为主。多重耐药菌株以exoT+/exoY+/exoS+/exoU-型为主,耐碳青霉烯类铜绿假单胞菌以exoT+/exoY+/exoS-/exoU+型为主。exoT+/exoY+/exoS-/exoU+型菌株对亚胺培南、环丙沙星、左氧氟沙星的耐药率高于exoT+/exoY+/exoS+/exoU-型菌株。结论:exoT和exoY基因普遍存在于铜绿假单胞菌中,不同毒力基因型组合与铜绿假单胞对常用抗菌药物的耐药率密切相关。

Objective:To study the relationship with the typeⅢsecretion system virulence genes exoS,exoU,exoT and exoY carrying rate in clinical isolates of Pseudomonas aeruginosa and drug resistance.Methods:A total of 157 clinical isolates of P.aeruginosa strains were collected from April 2016 to April 2018,the drug susceptibility testing and strains identification was performed using a Phoenix 100 automatic microbiological analyzer.The virulence genes exoS,exoU,exoT,and exoY were detected by using PCR,and analyze the relationship between different virulence genotype combinations and bacterial resistance.Results:Among 157 strains of clinical isolated P.aeruginosa,the positive rates of carrying exoT,exoY,exoS and exoU genes were 100.00%(157/157),95.54%(150/157),70.06%(110/157)and 28.03%(44/157).A total of 6 virulence genotype combinations were detected,mainly exoT+/exoY+/exoS+/exoU-(68.79%,108/157)and exoT+/exoY+/exoS-/exoU+(25.48%,40/157).The multidrug-resistant strains are mainly exoS+/exoT+/exoY+/exoU-,and the carbapenem-resistant P.aeruginosa strains are mainly exoT+/exoY+/exoU+/exoS-.The resistance rate of exoT+/exoY+/exoS-/exoU+strains to imipenem,ciprofloxacin,and levofloxacin were higher than that of exoT+/exoY+/exoS+/exoU-type strains.Conclusion:The exoT and exoY genes are universally present in P.aeruginosa.The combination of different virulence genotypes is closely related to the resistance rate of P.aeruginosa to commonly used antibacterial drugs.