Infection with Campylobacter jejuni reduces the number of muc2 and muc5ac goblet cells in the gastrointestinal tract of White Leghorn chickens

Campylobacter jejuni is highly pathogenic in people and is the most common cause of food poisoning. In contrast, C. jejuni is commensal in the chicken gastrointestinal tract. Understanding the properties of the chicken mucosal barrier and how it inhibits C. jejuni invasion may help develop interventions to reduce food poisoning. We examined whether infection with C. jejuni changed the number of muc2 and muc5ac goblet cells in the gastrointestinal tract in chickens. Twenty day-old specific-pathogen-free White Leghorn chicks were housed under experimental conditions. At 21 days of age, chicks were randomly separated into control (C, n=10) and infected (I, n=10) groups and received 0.2ml of sterile media (C) or 105 cells of C. jejuni M1 in 0.2ml of media (I) orally. Five chicks in each group were killed at 5 and 14 days post-treatment. From each bird, tissue samples from the proventriculus, duodenum, ileum, caeca and large intestine were obtained, fixed in 4% paraformaldehyde and embedded in paraffin wax before sectioning. Sections were probed with rabbit polyclonal antibodies against chicken muc2 and muc5ac. For each tissue section, five random fields at 400x magnification were blindly assessed, a linear segment of villous and crypt epithelium was measured and within each length the number of positively stained goblet cells was counted. Data were analysed using maximum likelihood generalized mixed effects models for Poisson distributions. The staining profile of muc2 and muc5ac differed. The anatomical location of the tissue section had a strong influence for both muc2 and muc5ac staining. C. jejuni infection, but not number of days post-treatment, had a significant influence, reducing the number of muc2 stained and muc5ac stained goblet cells by 16% and 9% respectively (both p