The Potential Diversity of Intestinal Enterobacteriaceae in Broiler Chickens is Associated with Infectious Bursal Disease Virus Infection

THE aim of this work is to study the Enterobacteriaceae-related bacteria of the gut microbiota with infectious bursal disease virus infection (IBDV) in naturally and experimentally infected broiler chickens. From the field, samples were collected from 20 suspected Gumboro-infected and 5 apparently healthy farms. For the experimental study, 36-day-old chicks were allocated to 2 groups of 18 birds each, then at 14 days old, G1 was challenged via eye drop with IBDV strain MK088026, and G2 was kept as control negative. RT-PCR revealed that 75% of farms were IBD-positive. The aerobic bacterial counts in positive farms were significantly higher than in apparently healthy individuals. The bacterial counts on MacConkey, IBD-positive farms were significantly higher than apparently healthy. Also, positive farms showed significantly higher lactose and non -lactose fermenter counts than apparently healthy ones. Serologically, the bacterial isolates from positive farms were 5 serotypes of E. coli identified as E. coli O78, O127H6, O91H21, O159, and O1H7. On apparently healthy, 3 E. coli serotypes were recorded as O128 H2, O146H21, and O2H6. Also, in positive farms, the non-lactose fermenter was Proteus mirabillus, Provedencia rettgeri, Salmonella kentacy. and Salmonella typhemurium while, in apparently healthy, 3 isolates were Salmonella entritedis, Salmonella larochella, and Salmonella typhemurium. On the experimental level, the bacterial counts on different media in challenged birds were higher than control. The serologically identified bacteria in G1 were 3 E. coli serotypes (O26H11, O78, and O128H2) while in G2, 3 E. coli (O26H11, O78, and O55H7). Our results indicated that IBDV infection was associated with an increased number of Enterobacteriaceae-related bacteria in the chicken gut.