title: Increased intracellular calcium level and impaired nutrient absorption are important pathogenicity traits in the chicken intestinal epithelium during Campylobacter jejuni colonization.
abstract: Although a high number of chickens carry Campylobacter jejuni, the mechanistic action of colonization in the intestine is still poorly understood. The current study was therefore designed to investigate the effects of C. jejuni on glucose uptake, amino acids availability in digesta, and intracellular calcium [Ca(2+)]i signaling in the intestines of broiler chickens. For this, we compared: control birds (n = 60) and C. jejuni-infected birds (n = 60; infected orally with 1 × 10(8) CFU of C. jejuni NCTC 12744 at 14 days of age). Our results showed that glucose uptake was reduced due to C. jejuni infection in isolated jejunal, but not in cecal mucosa at 14 days postinfection (dpi). The decrease in intestinal glucose absorption coincided with a decrease in body weight gain during the 2-week post-infectious period. A reduction in the amount of the amino acids (serine, proline, valine, leucine, phenylalanine, arginine, histidine, and lysine) in ileal digesta of the infected birds at 2 and/or 7 dpi was found, indicating that Campylobacter utilizes amino acids as a carbon source for their multiplication. Applying the cell-permeable Ca(2+) indicator Fluo-4 and two-photon microscopy, we revealed that [Ca(2+)]i was increased in the jejunal and cecal mucosa of infected birds. The muscarinic agonist carbachol induced an increase in [Ca(2+)]i in jejunum and cecum mucosa of control chickens, a response absent in the mucosa of infected chickens, demonstrating that the modulation of [Ca(2+)]i by Campylobacter might be involved in facilitating the necessary cytoskeletal rearrangements that occur during the bacterial invasion of epithelial cells. In conclusion, this study demonstrates the multifaceted interactions of C. jejuni with the gastrointestinal mucosa of broiler chickens. For the first time, it could be shown that a Campylobacter infection could interfere with intracellular Ca(2+) signaling and nutrient absorption in the small intestine with consequences on intestinal function, performance, and Campylobacter colonization. Altogether, these findings indicate that Campylobacter is not entirely a commensal and can be recognized as an important factor contributing to an impaired chicken gut health.
authors.affiliation: Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria, wageha.awad@vetmeduni.ac.at.
authors.forename: Wageha A
authors.initials: WA
authors.lastname: Awad
authors.forename: Alina
authors.initials: A
authors.lastname: Smorodchenko
authors.forename: Claudia
authors.initials: C
authors.lastname: Hess
authors.forename: Jörg R
authors.initials: JR
authors.lastname: Aschenbach
authors.forename: Andor
authors.initials: A
authors.lastname: Molnár
authors.forename: Károly
authors.initials: K
authors.lastname: Dublecz
authors.forename: Basel
authors.initials: B
authors.lastname: Khayal
authors.forename: Elena E
authors.initials: EE
authors.lastname: Pohl
authors.forename: Michael
authors.initials: M
authors.lastname: Hess
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D001717:Birds; D001835:Body Weight; D002118:Calcium / Q000032:analysis*; D002169:Campylobacter Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D016123:Campylobacter jejuni / Q000472:pathogenicity*; D002353:Carrier State / Q000382:microbiology* / Q000473:pathology; D002432:Cecum / Q000382:microbiology / Q000473:pathology; D002645:Chickens; D003600:Cytosol / Q000737:chemistry*; D005766:Gastrointestinal Contents / Q000737:chemistry; D005947:Glucose / Q000378:metabolism; D054884:Host-Pathogen Interactions; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000473:pathology; D007583:Jejunum / Q000382:microbiology / Q000473:pathology; D008856:Microscopy, Fluorescence
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D005947:Glucose; D002118:Calcium