Abstract
Plasmid-mediated colistin resistance in food animals is a major public health concern, but longitudinal farm data remain limited. We screened 10 broiler farms in Guelma, Algeria, for mcr-1-positive colistin-resistant Escherichia coli and monitored three positive farms over 8 months. Among 186 pooled animal and environmental samples, 54 isolates were recovered, and all carried mcr-1. Positive isolates were detected in chicken feces and environmental niches, including drinking water, wastewater, wall swabs, and soil. The population was polyclonal, comprising 28 sequence types, but ST162, ST93, and ST3941 recurred across farms or sampling periods. Four ST162 isolates from farm C recovered from successive flocks differed by only 12–14 SNPs, supporting local persistence or repeated reintroduction from a common reservoir. All isolates were multidrug resistant and carried mcr-1 on an IncI2 (delta) plasmid. These findings support a mixed epidemiology combining persistence of selected clones with horizontal dissemination of a conserved mcr-1-bearing plasmid in poultry farms.
Get full access to this article
View all access options for this article.
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
