Detection of metallo-β-lactamase production in multi-drug resistant Pseudomonas aeruginosa in community medical institutions

Abstract

Objective To investigate the infection status and metallo-β-lactamase (MBL) production of multi-drug resistant Pseudomonas aeruginosa (MRPA) in community medical institutions.Methods A total of54 MRPA trains were isolated fron multiple community medical institutions in Guangzhou between January and December 2011.The drug-resislance to 11 types of antibioties,including imipenem,was tested by using MicroScan Walk Away 40S1 automatie bbaecteria identiffication and drug sensitivity testing system.The resistance of imipenem-sensitive and -resistant Pseudomonas aeruginosa to nine common antibioties was compared.Production of MBL in imipenem-resistant Pseudomonas aeruginosa was analyzed via modified three-dimensionalexperiment.Results Of 54 MRPA strains,29(53.7％) were resistant to imipenem.There were a total of 9 imipenem-resistant Pseudomonas aeruginosa strains (9/29,31.0％ ) that produced MBL,as revealed by three-dimensional experiment.lmipenem-resistant Pseudomonas aeruginosa yielded higher resistance rate to seven types of common antibiotics (ceftazidime:65.5％ vs 36.0％ ; cefotaxime:89.7％ vs 44.0％ ; ceftriaxone:100.0％ vs 52.0％; aztreonam:72.4％ vs 36.0％; ofloxacin:70.0％ vs 32.0％; piperacillin-tazobactam:58.6％ vs 16.0％ ;amikaein:62.1％ vs 32.0％,all P＜0.05) as compared with imipenem-sensitive Pseudomonas aeruginosa.Conclusion The ratio of MBL-production from clinical isolated MRPA is higher in community medical institutions. Key words: beta-Lactamases; Pseudomonas aeruginosa; Imipenem; Drug resistance, multiple