AUTHOR=Looft Torey , Cai Guohong , Choudhury Biswa , Lai Lisa X. , Lippolis John D. , Reinhardt Timothy A. , Sylte Matthew J. , Casey Thomas A. 

TITLE=Avian Intestinal Mucus Modulates Campylobacter jejuni Gene Expression in a Host-Specific Manner

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.03215

DOI=10.3389/fmicb.2018.03215

ISSN=1664-302X

ABSTRACT=<p><italic>Campylobacter jejuni</italic> is a leading cause of bacterial foodborne illness in humans worldwide. However, <italic>C. jejuni</italic> naturally colonizes poultry without causing pathology where it resides deep within mucus of the cecal crypts. Mucus may modulate the pathogenicity of <italic>C. jejuni</italic> in a species-specific manner, where it is pathogenic in humans and asymptomatic in poultry. Little is known about how intestinal mucus from different host species affects <italic>C. jejuni</italic> gene expression. In this study we characterized the growth and transcriptome of <italic>C. jejuni</italic> NCTC11168 cultured in defined media supplemented with or without mucus isolated from avian (chicken or turkey) or mammalian (cow, pig, or sheep) sources. <italic>C. jejuni</italic> showed substantially improved growth over defined media, with mucus from all species, showing that intestinal mucus was an energy source for <italic>C. jejuni</italic>. Seventy-three genes were differentially expressed when <italic>C. jejuni</italic> was cultured in avian vs. mammalian mucus. Genes associated with iron acquisition and resistance to oxidative stress were significantly increased in avian mucus. Many of the differentially expressed genes were flanked by differentially expressed antisense RNA asRNA, suggesting a role in gene regulation. This study highlights the interactions between <italic>C. jejuni</italic> and host mucus and the impact on gene expression, growth and invasion of host cells, suggesting important responses to environmental cues that facilitate intestinal colonization.</p><p><bold>IMPORTANCE</bold> </p><p><italic>Campylobacter jejuni</italic> infection of humans is an important health problem world-wide and is the leading bacterial cause of foodborne illnesses in U.S. The main route for exposure for humans is consumption of poultry meat contaminated during processing. <italic>C. jejuni</italic> is frequently found in poultry, residing within the mucus of the intestinal tract without causing disease. It is not clear why <italic>C. jejuni</italic> causes disease in some animals and humans, while leaving birds without symptoms. To understand its activity in birds, we characterized <italic>C. jejuni</italic> responses to poultry mucus to identify genes turned on in the intestinal tract of birds. We identified genes important for colonization and persistence within the poultry gut, turned on when <italic>C. jejuni</italic> was exposed to poultry mucus. Our findings are an important step in understanding how <italic>C. jejuni</italic> responds and interacts in the poultry gut, and may identify ways to reduce <italic>C. jejuni</italic> in birds.</p>