High incidence of New Delhi metallo-beta-lactamase-producing Klebsiella pneumoniae isolates in Sharjah, United Arab Emirates.

The purpose of this study was to identify carbapenem-resistant Klebsiella pneumoniae in a tertiary care hospital in Sharjah Emirate, to identify the plasmids carrying the carbapenemase genes and to reveal clonal relationships among the isolates. Two hundred and two clinically relevant isolates collected between September 2011 and October 2012 at Al-Qassimi hospital, Sharjah, were investigated for meropenem resistance. Strains with decreased susceptibility were further tested with the modified Hodge test, by EDTA and phenylboronic acid synergy and by E-test. The genes of New Delhi metallo-β-lactamase (NDM), IMP, VIM, OXA-48, and KPC beta-lactamases were targeted by polymerase chain reaction and the genes were located on plasmids by Southern blotting. Clusters of the isolates were revealed by macrorestriction analysis. Seven percent of the isolates were originally found to be meropenem resistant, one isolate have lost its resistance during storage. All of the 13 resistant isolates were positive for the NDM-1 gene located on plasmids of 125 to >170 kb, while three isolates also carried the blaOXA-48-like genes. Clusters having repeatedly been isolated over the study period were identified. Carbapenem-resistant Klebsiella pneumoniae carrying the blaNDM-1 gene is a fast emerging problem, emphasizing the potential role of the Middle East as a secondary reservoir for these organisms.