Emerge of NDM-1-Producing Multidrug-Resistant Pseudomonas aeruginosa and Co-Harboring of Carbapenemase Genes in South of Iran

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 bum 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