Genetic analysis of carbapenemase-producing Gram-negative bacteria isolated from a university teaching hospital in Egypt

摘要

A total of 65 non-replicate Gram-negative bacterial strains were recovered from clinical specimens between April and September 2014 at a University Hospital in Egypt. This collection was screened by PCR for carbapenemase-encoding genes, 16S rRNA methylases, and colistin resistance genes (mcr-1-mcr-8). Twenty-two strains (22/65, 33.8%) were positive for carbapenemase-encoding genes [13 NDM-1-producers (four Escherichia coli, two Klebsiella pneumoniae, and seven Providencia stuartii), two E. coli co-carrying NDM-5 and OXA-181, and seven Pseudomonas aeruginosa (three VIM-2, four VIM-24) strains]. The 16S rRNA methylase RmtC was detected in 12 NDM-1-producers for the first time in Egypt; no mcr genes were detected. A self-transmissible A/C plasmid was found to carry bla(NDM-1) in all NDM-1-producing strains. NDM-5 and OXA-181 were located on an untypeable and IncX3 plasmid, respectively. Additionally, Enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed five clonally related P. stuartii isolates collected over a 1.5-month period. Thirteen carbapenemase-producing strains were isolated from burn patients who are at a high risk of developing infections and require special medical care. To our knowledge, this is the first report of NDM-1-producing-P. stuartii strains in an African burn unit, NDM-1- and RmtC-positive non-lactose fermenting E. coli globally, VIM-24-producing P. aeruginosa in Africa, and 16S RMTase rmtC-NDM-1-producers in Egypt. This work highlights the detection of different carbapenemase-producing bacterial strains within an Egyptian teaching hospital compromising the effectiveness of carbapenems and urgently asking the Egyptian medical authorities for implementation of antimicrobial surveillance plans and infection control policies to early detect and to effectively halt the rapid spread of these superbugs.