Analysis Of Resistance And MexA,mexB,oprM Genes Of Pseudomonas Aeruginosa

Objectives:Analyzing resistance of pseudomonas aeruginosa and infectious risk factors of multiple drug resistant pseudomonas aeruginosa isloted from First Affiliated Hospital of Kunming Medical University to provide laboratory evidence for reasonable antibiotics usage and prevention of multiple drug resistant pseudomonas aeruginosa infection;Detecting mexA,mexB and oprM genes which code MexAB-OprM efflux system to provide evidence for learning more about drug resistance mechanism of pseudomonas aeruginosa.Methods:Pseudomonas aeruginosa were collected from patients suffered from infection caused by pseudomonas aeruginosa and hospitalized in First Affiliated Hospital of Kunming Medical University during January 1,2015 to December 31,2016.Drug sensitivity assay was taken by VIETK-2 automatic susceptibility analyzer.According to the results of drug sensitive experiment,patients were divided into multiple drug resistant pseudomonas aeruginosa group(MDRPA)and non-multiple drug resistance pseudomonas aeruginosa group(NMDRPA).Clinical data of patients was collected to analyze risk factors of infection caused by pseudomonas aeruginosa.mexA,mexB and oprM genes of isolates collected during January 1,2016 to December 31,2016 were detected by reverse transcription fluorescence quantitative polymerase chain reaction(RT-qPCR)to analyze the relationship between overexpression of these genes and antibiotics resistance,multiple drug resistance of pseudomonas aeruginosa.Results:242 strains of pseudomonas aeruginosa were collected,of which 68(28.1%)strians were multiple drug resistant pseudomonas aeruginosa.The major specimen of pseudomonas aeruginosa was respiratory tract specimen(59.9%)and the second was urine specimen(11.2%).ICU was the major department where pseudomonas aeruginosa distributed in,accounted for 24.4%,followed by neurosurgery,which accounted for 16.1%.Drug resistance of pseudomonas aeruginosa to antibiotics from high to low in turn was:Imipenem(36.7%),Meropenem(30.4%),Ceftazidime(23.8%),Piperacillin(23.3%),Ciprofloxacin(20.4%),Tobramycin(19.9%),Gentamycin(19.5%),Cefepime(18.8%),Piperacillin-tazobactam(17.8%),Levofloxacin(17.6%)and Amikacin(12.1%).Resistant rate of pseudomonas aeruginosa from ICU was from 15.5%to 57.6%,resistant rate of isolates from non-ICU was from 11%to 29.8%.Resistant rate of strains from children,adult and elderly patients was 0-25%,18.0%-41.4%and 4.6%-33:3%,respectively.Univariate analysis show that ICU admission,hospitalization days,fluoroquinolone antibiotics use,carbapenems use,glycopeptide antibiotics use,drug combination,time of antibiotic use,urinary catheter,stomach tube,central venous catheter,endotracheal intubation,sputum suction,breathing machine,external drainage,chronic renal failure and granulocytopenia in MDRPA and NMDRPA had statistically significant(P<0.05).Multivariate analysis indicated that the distribution of carbapenems use and chronic renal failure did different in MDRPA and NMDRPA(P<0.05).At the same time,102 strains of pseudomonas aeruginosa were collected during January 1,2016 to December 31,2016.Detection rate of strains show overexpression of mexA,mexB or oprM genes was 65.7%,39.2%and 35.3%,respectively.Overexpression of mexA was related to the resistance of pseudomonas aeruginosa to Piperacillin,Piperacillin/tazobactam,Ceftazidime and Cefepime,overexpression of mexA,mexB was related to multiple drug resistance of pseudomonas aeruginosa.Conclusions:As the resistance of pseudomonas aeruginosa to each antibiotic was different,so as to isolates from different departments and different patients,clinicians should choose rational antibiotic according to results of drug sensitive experiment.carbapenems use and chronic renal failure were independent risk factors of pseudomonas aeruginosa infection.Overexpression of mexA was related to resistance of pseudomonas aeruginosa to ?-lactamase antibiotics and overexpression of mexA,mexB made contribution to multiple drug resistance of pseudomonas aeruginosa.