Abstract

BACKGROUND: New Delhi metallo-beta-lactamase-1 (NDM-1) is one of the most important emerging antibiotic resistance. Co-harboring three or four carbapenemases is rare and only a few reports exist in the literature. We described the characteristics of the large epidemic outbreaks and reports co-producing bla(NDM-1) with the other carbapenemase genes in P. aeruginosa isolates. METHODS: This present cross-sectional research was conducted on 369 P. aeruginosa isolates obtained from burn and general hospitals within years 2013 to 2016. Beta-lactamase classes A, B and D genes were identified by PCR method. Modified hodge test (MHT), double-disk potentiation tests (DDPT) and double disk synergy test (DDST) were performed for detection carbapenemase and metallo beta-lactamase (MBL) production of bla(NDM-1) positive P. aeruginos isolates. RESULTS: From 236 carbapenem-resistant P. aeruginosa (CRPA), 116 isolates have had MBL genes and twenty-nine isolates were found positive for bla(NDM-1) . In CRPA isolates, bla(IMP-1) , bla(VIM-2) and bla(OXA-10) were identified in 27.5, 21.1 and 32.2 of isolates respectively, while co-producing bla(NDM-1) , bla(IMP-1) , bla(OXA-10) , co-producing bla(NDM-1) , bla(VIM-2) , bla(OXA-10) and co-producing bla(IMP-1) , bla(VIM-2) were determined in 11 (4.6), 8 (3.4) and 27 (11.4) of isolates respectively. CONCLUSION: The finding of this co-existence of multiple carbapenemase resistance genes is threating for public health. Dipicolinic acid is a superior MBL inhibitor in DDPT antique than EDTA in DDST method for the detection of MBL-bla(NDM-1) producing P. aeruginosa.