Resistance testing of 76 mucoid pseudomonas aeruginosa strains to commonly used antimicrobial drugs and distribution of virulence genes
Objective To investigate the antibiotic resistance of 76 mucoid Pseudomonas aeruginosa(PA)strains against common antibiotics and to analyze the distribution of their virulence genes.Methods A total of 76 strains of mucous PA were isolated from patients admitted to the Ninghai County Hospital of Traditional Chinese Medicine between January 2017 and December 2021.The strains were identified by the full-automatic microbiological analyzer.The sensitivity of PA to imipenem(IPM),amikacin(AK),tobramycin(TOB),gentamicin(CN),cefepime(FEP),piperacillin/tazobactam(TZP),levofloxacin(LEV),ceftazidime(CAZ),ciprofloxacin(CIP)and meropenem(MEM)was detected by disc diffusion test.The distribution of genes exoS,exoT,exoU and exoY in effector protein of type Ⅲ secretion system(T3SS)was detected using polymerase chain reaction(PCR).The sources of 76 strains of mucous PA,drug resistance to common antibiotics and distribution characteristics of T3SS virulence genes were analyzed.The relationship between ExoT+/ExoY+/ExoS+/ExoU-,ExoT+/ExoY+/ExoS-/ExoU+genotypes and common antibiotics was compared.Results The 76 strains of mucous PA were primarily isolated from sputum,accounting for 68％.The resistance rates of mucous PA were low to AK,TOB,CN,TZP,LEV and CAZ,but resistance rates were high to IPM,MEM,FEP and CIP.The resistance rate of mucous PA to common antibiotics at 48 h was 7％-14％,the difference was statistically significant compared with drug sensitivity results at 24 h(0-9％,P＜0.05).In PA strains,positive rate of ExoT virulence gene was the highest(100％),followed by ExoY(92％),ExoS(70％)and ExoU(26％).In T3SS virulence genotypes,proportions of ExoT+/ExoY+/ExoS+/ExoU-and ExoT+/ExoY+/ExoS-/ExoU+were the highest(67％,22％).The resistance rates to LEV,IPM and CIP in ExoT+/ExoY+/ExoS+/ExoU-genotype were 37％,22％and 41％,respectively.These rates were lower than those observed in the ExoT+/ExoY+/ExoS-/ExoU+genotype,which had resistance rates of 100％,76％,and 100％(P＜0.05).Conversely,the resistance rates to FEP and TZP were 84％and 78％in ExoT+/ExoY+/ExoS-/ExoU+genotype,which were higher than those in the ExoT+/ExoY+/ExoS-/ExoU+genotype(35％and 41％,P＜0.05).Conclusion The resistance rates of mucous PA towards carbapenem antibiotics are significantly high,such as IPM and MEM.Additionally,virulence genes ExoT and ExoY are frequently observed in mucous PA,which are associated with the T3SS.The resistance rates of mucous PA to commonly used antibiotics are influenced by the various combinations of virulence genotypes
万方数据
维普
