A Health Threat from Farm to Fork: Shiga Toxin-Producing Escherichia coli Co-Harboring bla NDM-1 and mcr-1 in Various Sources of the Food Supply Chain

The dissemination of resistant pathogens through food supply chains poses a significant public health risk, spanning from farm to fork. This study analyzed the distribution of Shiga toxin-producing (STEC) across various sources within the animal-based food supply chain. A total of 500 samples were collected from livestock, poultry, the environment, fisheries, and dairy. Standard microbiological procedures were employed to isolate and identify isolates, which were further confirmed using MALDI-TOF and virulence-associated genes (VAGs) such as . The phenotypic resistance patterns of the isolates were determined using the disc diffusion method, followed by molecular identification of antibiotic resistance genes (ARGs) through PCR. STEC were subjected to PCR-based O typing using specific primers for different O types. Overall, 154 (30.5%) samples were confirmed as , of which 77 (50%) were multidrug-resistant (MDR) . Among these, 52 (67.53%) isolates exhibited an array of VAGs, and 21 (40.38%) were confirmed as STEC based on the presence of and . Additionally, 12 out of 52 (23.07%) isolates were identified as non-O157 STEC co-harbouring and . O26 STEC was found to be the most prevalent among the non-O157 types. The results suggest that the detection of STEC in food supply chains may lead to serious health consequences, particularly in developing countries with limited healthcare resources.