The development of antimicrobial resistance in broilers affected by veterinary antimicrobials and a probiotic administration

Relevance. The broad use of antimicrobials by agriculture and consumers motivation to buy antibiotic-free production form a basis to development of substitutes to antimicrobials. The goal of research was the analysis of antimicrobial resistance caused by veterinary antimicrobials administration to broilers, as well as the effect of metaprobiotic “Probiocid-Ultra” on antimicrobial resistance in dynamic.Methods. Three groups of broiler chickens were formed: I — control, who received the main diet, II — experimental, who received veterinary antibiotics enrofloxacin and colistin in addition to the diet of group I, III — experimental, who received the metaprobiotic “Probiocide-Ultra” in addition to the diet of group II. Gene expression analysis was performed using quantitative reverse transcription PCR. With inoculation to different media the antimicrobial resistance was examined with classical microbiological methods.Results. The dynamic of accumulation of antimicrobial resistance determinants caused by enrofloxacin and colistin administration to broilers was examined. Under the influence of enrofloxacin the increase in antimicrobial resistance to enrofloxacin itself, as well as to beta-lactams, tetracycline and colistin was observed. Under the influence of colistin the increase in antimicrobial resistance to colistin itself, as well as to enrofloxacin and beta-lactams was observed. The feed administration with metaprobiotic “Probiocid-Ultra” promoted noticeable decrease of the antimicrobial resistance genes amount, when analyzed with growth medium led to antimicrobial resistant enterobacteria vanished.