Colistin Selection of the Mcr-1 Gene in Broiler Chicken Intestinal Microbiota

Colistin has a long story of safe use in animals for the treatment and prevention certain bacterial diseases. Nevertheless, first description mcr-1 gene showed that colistin resistance can spread by horizontal transfer changed landscape. This study aimed to assess effect administration on dispersion microbiota day-old broiler chicks how presence genes influences determinants. In this study, 100 one-day-old were divided into four groups 25 (G1, G2, G3, G4). Animals from G3/G4 challenged with mcr-1-carrying Salmonella (day 7), while (600 mg/L) was administered daily G2/G4 through drinking water (from day 8 15). Two quantitative PCR assays performed compare amount present caecal samples. We observed levels higher animals, especially G4, due Salmonella. On 21, decreased reaching similar values as those but remained significantly higher, suggesting may accelerate spreading process when bacteria reach gut.