Drug Resistance And Molecular Epidemiology Of CRPA Clinical Isolates In Jiangxi Province

Objective:1.To analyze the clinical characteristics of patients with Carbapenem-resistant Pseudomonas aeruginosa（CRPA）infection,to identify the death-related risk factors of infected patients,and to provide effective measures and suggestions for improving the treatment effect of CRPA infection.2.To understand the current situation and characteristics of CRPA resistance to various antibiotics in Jiangxi,and to provide a theoretical basis for the rational use of antibiotics in clinical practice.3.To analyze the drug resistance gene carrying situation of CRPA strains in Jiangxi,and to explore the related drug resistance mechanism.4.To clarify the genotype and main epidemic types of CRPA in Jiangxi,and analyze the epidemic characteristics of CRPA in Jiangxi.Methods1.From September 2018 to December 2020,CRPA-resistant non-repetitive clinical isolates were collected from 11 tertiary hospitals in 11 cities in Jiangxi Province.All strains were identified to species by VITEK-II automatic microbial analyzer.2.The clinical data of patients with CRPA infection were collected,and the clinical characteristics of patients with CRPA infection were retrospectively analyzed.Univariate chi-square test and multivariate logistic regression analysis were used to analyze the clinical characteristics and prognostic risk factors of patients.3.Imipenem,meropenem,gentamicin,tobramycin,amikacin,levofloxacin,ciprofloxacin,piperacillin/tazobactam,cefepime,ceftazidime,aztrexidine Nan et al.conducted in vitro drug susceptibility tests on 11 antibacterial drugs.4.After PFGE and MLST typing,a total of 36 cluster groups of 1-36 types and43 ST types were obtained.The dominant clonotypes were ST235,ST244,ST773,ST381 and ST274.There were 7 groups of sequences closely related to ST types.Results1.Clinical infection characteristics:The average age of 240 CRPA-infected patients was 56.73±16.71 years old;mainly male patients,accounting for 74.58%;department distribution:mainly from ICU,accounting for 42.92%.Among the 240patients,32 died within 30 days,accounting for 13.33%.ICU admission and use of immunosuppressive agents are independent risk factors for death in patients with CRPA infection.2.Specimen source and drug susceptibility results:The main source of specimens for 240 CRPA strains was sputum,accounting for 72.92%.The overall drug resistance was as follows:imipenem resistance rate was 92.5%,meropenem resistance rate was 80.00%,and other antibiotics except piperacillin/tazobactam,cefepime,gentamicin,tobu The drug resistance rates of other antibiotics,except for mycin and mikacin,were above 30%.The resistance rate of ceftazidime in different age groups was significantly different（P<0.05）,piperacillin/tazobactam,cefepime,aztreonam,gentamicin,tobramycin,adriamycin The differences of mikacin,ciprofloxacin and levofloxacin among different regions were statistically significant drug resistance rate in the eastern region was the lowest.3.Among 240 CRPA strains,the deletion rate of porin Opr D₂ gene was 56.67%（136 strains）;the detection rate of TEM,PER,GES and OXA-10 genes in-lactamase genes was 0.83%（2 strains）,0.42%（1 strain）,13.75%（33 strains）,0.42%（1 strain）,and no positive results were detected for VEB gene;the detection rates of VIM and GIM in metallo-lactamase genes were 16.25%,respectively（39strains）,0.83%（2 strains）,no positive results were detected for IMP and SIM genes.4.PFGE results showed that 240 strains of CRPA could be divided into 36 types1-36 clustering groups,the main clustering groups were type 7,type 12 and type 1;MLST results showed that there were 43 ST types,and the dominant clonotypes were ST235 and ST244,ST773,ST381 and ST274;there are seven closely related sequence groups（STs）of larger strains.Conclusion1.The study found that age?60 years old,use of immunosuppressive agents and ICU admission were independent risk factors for the death of patients with CRPA infection.Therefore,patients aged?60 years who need to use immunosuppressive agents and are admitted to ICU should be the focus of prevention and control of CRPA infection.object.2.Among the 240 CRPA strains,there are different degrees of resistance to various antibacterial drugs,and the drug resistance is serious.There were differences in drug resistance among regions,and gender and age had no statistically significant differences in bacterial resistance.3.The results of this study showed that 56.67%of the CRPA strains had deletions of the Opr D₂ gene,which indicated that one of the main reasons for the resistance of CRPA strains to carbapenems in Jiangxi was the deletion of the Opr D₂gene.4.The distribution of ST types of CRPA strains in Jiangxi is relatively scattered.ST235 is the main dominant clonotype of CRPA strains in Jiangxi,ST344 is the secondary dominant clonotype,and there are 7 closely related ST sequence groups（STs）.