Genetic Characterization of Carbapenemase-Producing <i>Enterobacter cloacae</i> Complex and <i>Pseudomonas aeruginosa</i> of Food of Animal Origin from Egypt

Abstract

The increasing spread of carbapenem resistance is a serious global public health concern that negatively affects human and animal health. In this study we characterized the carbapenemase production in gram-negative bacteria isolated from different meat and meat products in Egypt. Phenotypic and genotypic susceptibility testing were investigated. Two <i>Enterobacter cloacae</i> complex strains, isolated from kofta and beef burger, and one <i>Pseudomonas aeruginosa</i> isolated from minced meat, were found to harbor VIM-1 and VIM-2, respectively. These isolates showed multidrug resistance phenotype. The phenotypic carbapenemase production was confirmed with Carba NP test in addition to modified Hodge test, modified carbapenem inactivation method, and ethylenediaminetetraacetic acid inhibition test. The <i>bla</i>_VIM-1 gene in both non-clonally related <i>E. cloacae</i> complex strains was part of a class 1 integron that also carried other resistance gene cassettes such as <i>aacA7</i>, <i>dfrA1</i>, <i>ΔaadA</i>, and <i>smr</i>. This integron was uncommonly disrupted by the insertion sequence IS<i>Pa</i>21, located on a self-conjugative plasmid of either the A/C or HI2 incompatibility group with a size of >93 kb. The <i>bla</i>_VIM-2 gene was identified within a class 1 integron, followed downstream by resistance genes <i>aadB</i> and <i>bla</i>_OXA-10. The transfer of <i>bla</i>_VIM-2 gene from <i>P. aeruginosa</i> failed, suggesting that this gene was located on the chromosome. Further studies are needed to screen the dissemination of carbapenemase-producing bacteria in both the environment and food chain.