铜绿假单胞菌致病毒力基因的表达与耐药性相关分析

Correlation analysis on the expression of virulence genes with drug resistance in Pseudomonas aeruginosa

目的:探讨铜绿假单胞菌(PA)Ⅲ型分泌系统(T3SS)4种致病毒力基因exoT、exoY、exoS、exoU的表达情况及其与耐药性的相关性。方法:收集安徽医科大学附属安庆第一人民医院2022年9月~2023年9月临床检出的不同标本来源的PA 144株,使用Vitek2-Compact仪器进行细菌鉴定并分析药敏结果,PCR检测T3SS系统致病毒力基因exoT、exoY、exoS、exoU携带表达情况,分析不同致病毒力基因型组合与细菌耐药性之间的关系。结果:144株PA携带exoT(144/144)和exoY(144/144)基因的阳性率为100%,exoS基因占84.72%(122/144),exoU基因占20.14%(29/144)。总共检出4种致病毒力基因型组合,以exoT+/exoY+/exoS+/exoU-(79.17%,114/144)基因型组合为主,其次是exoT+/exoY+/exoS-/exoU+(14.58%,21/144)。药敏结果显示exoT+/exoY+/exoS-/exoU+基因型菌株对常见抗菌药物如妥布霉素、头孢他啶、左旋氧氟沙星、环丙沙星、哌拉西林、替卡西林/克拉维酸、美洛培南、粘菌素耐药率高于exoT+/exoY+/exoS+/exoU-基因型(P<0.05)。结论:本研究检出T3SS致病毒力基因以exoT+/exoY+/exoS+/exoU-型为主,不同毒力基因型组合的PA对常见抗生素的耐药性有差异。

Objective:To investigate the correlation of virulence gene exoT,exoY,exoS and exoU expressed in Pseudomonas aeruginosa(P.aeruginosa)typeⅢsecretion system(T3SS)with drug resistance.Methods:A total of 144 strains of P.aeruginosa were harvested from different specimens detected in clinic from September 2022 to September 2023 in Anqing First People′s Hospital of Anhui Medical University.Vitek2-compact instrument was used to identify the bacteria and analyze the drug sensitivity.PCR was performed to detect the expression of T3SS virulence genes exoT,exoY,exoS and exoU,and the relationship between the combination of different virulence genotypes and bacterial resistance was analyzed.Results:The 144 P.aeruginosa strains carried 100%positivity for exoT(144/144)and exoY(144/144)genes,84.72%(122/144)for the exoS gene,and 20.14%(29/144)for the exoU gene.Four virulence genotypes combination were detected,which were dominated by exoT+/exoY+/exoS+/exoU-(79.17%,114/144),followed by exoT+/exoY+/exoS-/exoU+(14.58%,21/144).The drug sensitivity results showed that the resistance rate of exoT+/exoY+/exoS-/exoU+genotype to tobramycin,ceftazidme,levofloxacin,ciprofloxacin,piperacillin,ticarcillin/clavulanic acid,meropenem and colistin were higher than that of exoT+/exoY+/exoS+/exoU-genotype(P<0.05).Conclusion:The virulence genes detected in our hospital were mainly exoT+/exoY+/exoS+/exoU-type,and the resistance of P.aeruginosa to common antibiotics was different among different virulence genotypes.