Phenotypic and genotypic characterization of extended spectrum beta-lactamase producing E. coli harboring carbapenem and colistin-resistant genes from poultry farms in Egypt.

BACKGROUND: e Escherichia coli ( E. coli ) bacteria that produce extended spectrum beta-lactamase (ESBL) is associated with a high prevalence of human illnesses worldwide. The emergence of resistance to carbapenem and colistin compounds poses further challenges to the treatment options for these illnesses. This study aimed to evaluate the phenotypic and genotypic pattern of resistance to carbapenem and colistin in ESBL-producing E. coli . Escherichia coli isolates collected from the respiratory tract of chickens in El-Sharkia government, Egypt.

METHODS: A total of 250 lung samples were collected from 50 poultry farms. These samples were then subjected to isolation, identification, and serotyping of E. coli . The presence of antimicrobial resistance was identified by disc diffusion testing. The occurrence of ESBL phenotypes was also assessed using the double disc synergy method. PCR/sequencing techniques were employed to examine the presence of ESBL (β-lactamase (bla)-TEM , blaSHV , and blaCTX-M ), colistin (mcr-1), and carbapenem (blaNDM , blaVIM , and blaKPC ) resistance genes.

RESULTS: The findings revealed that 140 out of 250 (56%) were identified as E. coli . All E. coli isolates had a high level of multi-antimicrobial resistance (MAR) with an index value greater than 0.2, and 65.7% of them were confirmed to produce ESBL. Out of the 92 ESBL phenotypes, 55 (59.7%), 32 (34.7%), 18 (19.6%), and 37 (40.2%) isolates harbor b laTEM-3 , b laSHV-4 , b laCTX-M-1 , a nd blaCTX-M-14 genes, respectively. The blaNDM-1 gene was identified in all 40 phenotypes that exhibited resistance to carbapenem, accounting for 28.5% of all strains of E. coli and 43.4% of ESBL isolates. The VIM and KPC genes were not detected in any of the samples. Furthermore, there was a significant prevalence of the mobilized colistin resistance (mcr)-1 gene, with 64 (69.5%) of the ESBL isolates exhibiting this gene.

CONCLUSION: The prevalence of ESBL-producing E. coli , particularly those resistant to carbapenem and colistin, poses a significant public health risk in society.