Peptidoglycan Acetylation of Campylobacter jejuni Is Essential for Maintaining Cell Wall Integrity and Colonization in Chicken Intestines
ABSTRACTPeptidoglycan (PG) acetylation of Gram-positive bacteria confers lysozyme resistance and contributes to survival in the host. However, the importance of PG acetylation in Gram-negative bacteria has not been fully elucidated. The genes encoding putative PG acetyltransferase A (PatA) and B (PatB) are highly conserved inCampylobacter jejuni, the predominant cause of bacterial diarrhea worldwide. To evaluate the importance of PatA and PatB ofC. jejuni, we constructedpatAandpatBisogenic mutants and compared their phenotypes with those of the parental strains. Although transmission electron microscopy did not reveal morphological changes, both mutants exhibited decreased motility and biofilm formationin vitro. The extent of acetylation of the PG purified from thepatAandpatBmutants was significantly lower than the PG acetylation in the parental strains. Both mutants exhibited decreased lysozyme resistance and intracellular survival in macrophage cells. In a chick colonization experiment, significant colonization deficiency was observed for both mutants. These results suggest that PatA and PatB ofC. jejuniplay important roles in maintaining cell wall integrity by catalyzing PGO-acetylation and that the loss of these enzymes causes decreased motility and biofilm formation, thus leading to colonization deficiency in chicken infection.IMPORTANCEThe importance of peptidoglycan (PG) acetylation in Gram-negative bacteria has not been fully elucidated. The genes encoding putative PG acetyltransferase A (PatA) and B (PatB) are highly conserved inCampylobacter jejuni, the predominant cause of bacterial diarrhea worldwide. We evaluated the importance of these enzymes using isogenic mutants. The results of this study suggest that PatA and PatB ofC. jejuniplay important roles in maintaining cell wall integrity. The loss of these factors caused multiple phenotypic changes, leading to colonization deficiency in chicken infection. These data should be useful in developing novel control measures to prevent chicken colonization byC. jejuni. Inhibitors of the PG acetylation enzymes PatA and PatB might serve as potent anti-C. jejuniagents.