Variations of the Escherichia coli population in the digestive tract of broilers.

Variations of the Escherichia coli population in the digestive tract of broilers. Avian Pathol. 2020 Aug 24;:1-41 Authors: Mourand G, Le Devendec L, Delannoy S, Fach P, Keita A, Amelot M, Jaunet H, Dia MEH, Kempf I Abstract The aim of this study was to explore the between-group and temporal variations in the intestinal Escherichia coli populations of broilers under experimental conditions, taking both antimicrobial resistance and virulence into consideration. Four replicates of 45 commercial chicks were reared in four animal facilities. On their first day of life (Day 0), they were orally inoculated with two extended-spectrum-cephalosporin-resistant (ESCR) E. coli (2.72 log10 CFU of a bla CMY-2- and 2.55 log10 CFU of a bla CTX-M-carrying E. coli). Faecal samples were then collected weekly and caecal samples were obtained from birds sacrificed on Days 21 or 42. The total, ESCR, ciprofloxacin- and gentamicin-resistant E. coli populations were enumerated on MacConkey (MC) and MC-supplemented media, and eight virulence-associated genes (VAGs) (iroN, iutA, iss, ompT, hlyF, vat, frzorf4 , and fyuA) were sought by PCR on isolates obtained on MC agar. The results showed significant between-group differences in the size of the resistant sub-populations and the presence of VAGs. Contrary to bla CTX-M-positive strains, bla CMY-positive strains persisted up to Day 42, but represented only a minor fraction of the total E. coli population. The ESC...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research