Prevalence of plasmid-encoded carbapenemases in multi-drug resistant Escherichia coli from patients with urinary tract infection in northern Iran.

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Prevalence of plasmid-encoded carbapenemases in multi-drug resistant Escherichia coli from patients with urinary tract infection in northern Iran.

Iran J Basic Med Sci. 2020 May;23(5):586-593

Authors: Deldar Abad Paskeh M, Mehdipour Moghaddam MJ, Salehi Z

Abstract
Objectives: Resistance to carbapenems as the last line for controlling resistant bacteria is increasing due to production of carbapenemase. The aim of this study was to detect the plasmid-encoded carbapenemases using phenotypic methods and multiplex PCR among the multi-drug resistant (MDR) isolates from patients with urinary tract infection (UTI) in northern Iran.
Materials and Methods: Antimicrobial susceptibility testing and extended spectrum β-lactamase (ESBL) production test were performed for 91 MDR Escherichia coli strains by disc diffusion and double disk synergy tests (DDST), respectively. Carbapenemases production was confirmed using Hodge test, EDTA double disk synergy test (EDST) and combined disk test (CDT). The isolates were subjected to PCR targeting bla IMP, bla VIM, bla KPC and bla OXA-48 β-Lactamase genes.
Results: Resistance of isolates to 1st, 2nd, 3rd, and 4th generations of cephalosporins, carbapenems, and penicillins were 73%, 84.5%, 62%, 37.5%, 17.5%, and 76%, respectively. Based on CDT and Hodge test, 1 (3%) and based on EDST, 2 (6%) of 33 ESBL producers synthesize a type of carbapenemase. The frequency of bla IMP, bla VIM, bla KPC, and bla OXA-48 genes was 8.7%, 9.8%, 2.1%, and 15.3%, respectively. Existence of bla IMP conferred more resistance to cephalotin, fosfomycin, and piperacillin (P≤0.01) and carrying bla VIM caused more resistance to cephalotin, cefepime, and ceftazidime (P≤0.01). The presence of bla KPC conferred more resistance to cephalotin and presence of bla OXA-48 caused more resistance to chloramphenicol and piperacillin (P≤0.05).
Conclusion: Identification and controlling of this nearly low frequent ESBL and carbapenemase producing strains are important due to the presence of plasmid genes encoding carbapenemase.

PMID: 32742595 [PubMed]