Purpose Plasmids of the incompatibility group X type 3 (IncX3) were described carrying various carbapenemase genes in carbapenemase-producing Enterobacteriaceae (CPE) worldwide and in the United Arab Emirates (UAE), as well. To understand the driving force behind the emergence of such plasmids in the UAE, the relationship between IncX3 plasmids encountered locally and globally was investigated. Methods CPE strains isolated in the UAE during 2009–2014 were screened by X3 PCR-based replicon typing. The clonal relationship of CPE carrying IncX3 plasmids was determined by multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Complete sequence of selected IncX3 plasmids was determined. Phylogenetic relationship between the carbapenemase carrying IncX3 plasmids from the UAE and of those reported worldwide was established by comparing the plasmid backbones. Results 10.2% of the 295 CPE tested were identified to carry IncX3 plasmids: 13 Escherichia coli , 13 Klebsiella pneumoniae , two Enterobacter cloacae , one Citrobacter freundii and one Morganella morganii isolate, respectively. Most of them were non-clonal; with small clusters of triplets and pairs of E. coli and K. pneumoniae , and a cluster of five K. pneumoniae ST11 exhibiting >90% similar PFGE patterns, respectively. The 30 isolates harbored either bla NDM-1 , bla NDM-4 , bla NDM-5 , bla NDM-7 , bla OXA-181 or bla KPC-2 carbapenemase genes on IncX3 plasmids. Phylogenetic analysis of the backbone region of IncX3 plasmids carrying various beta-lactamase genes from the UAE (n=23) and that of North-America, Europe, Asia and Australia (n=35) revealed three clusters based on the carbapenemase genes carried: plasmids harboring bla OXA-181 and bla NDM-5 formed two distinct groups, whereas backbones of plasmids with bla NDM-1 , bla NDM-4 and bla NDM-7 clustered together. Each cluster contained plasmids of diverse geographical origin. Conclusion The findings suggest that different carbapenemase gene carrying IncX3 plasmids encountered in the UAE do not evolve locally, rather are subtypes of this epidemic plasmid emerging in this country due to international transfer.

Our findings show that IncX3 type plasmids play an important role in the spread of the currently rare NDM-7 variant in the Arabian Peninsula. This association of bla with the IncX3-type plasmid is particularly worrisome, as this type of plasmid was proved to spread other carbapenemases in various species of Enterobacteriaceae worldwide at a high efficiency.

Our aim was to assess the susceptibility of carbapenem-resistant Enterobacterales (CRE) from the Arabian Peninsula to a broad spectrum of antibiotics, including fosfomycin, ceftazidime-avibactam, and aztreonam-avibactam. Methods: 1192 non-repeat CRE isolated in 2009-2017 from 33 hospitals in five countries of the Arabian Peninsula were tested. The minimum inhibitory concentration of 14 antibiotics was determined. Carbapenemase and 16S methylase genes were detected by PCR. Clonality was assessed by PFGE. Results: The highest rate of susceptibility was detected to aztreonam-avibactam (95.5%) followed by colistin (79.8%), fosfomycin (71.8%) and tigecycline (59.9%). Isolates co-producing two carbapenemases (12.4%) were the least susceptible. Aminoglycoside susceptibility was affected by the frequent production of a 16S methylase. Susceptibility to ceftazidime-avibactam was impacted by the high rate of metallobeta-lactamase producers (46.3%), while aztreonam-avibactam resistance occurred mostly in clonally unrelated, carbapenemase non-producing Escherichia coli. Conclusion: Of the currently available drugs: colistin, tigecycline, and ceftazidime-avibactam coadministered with aztreonam appear to be the most effective to treat CRE infections. However, the presence of non-clonal CRE isolates, in which avibactam does not lower the aztreonam MIC below the clinical breakpoint, is of notable concern. Based on the relatively high rate of fosfomycin susceptibility, it would be desirable to license parenteral fosfomycin in the region.

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.

No abstract