Biological roles of the O-methyl phosphoramidate capsule modification in Campylobacter jejuni.
Campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide, and the capsular polysaccharide (CPS) of this organism is required for persistence and disease. C. jejuni produces over 47 different capsular structures, including a unique O-methyl phosphoramidate (MeOPN) modification present on most C. jejuni isolates. Although the MeOPN structure is rare in nature it has structural similarity to some synthetic pesticides. In this study, we have demonstrated, by whole genome comparisons and high resolution magic angle spinning NMR, that MeOPN modifications are common to several Campylobacter species. Using MeOPN biosynthesis and transferase mutants generated in C. jejuni strain 81-176, we observed that loss of MeOPN from the cell surface correlated with increased invasion of Caco-2 epithelial cells and reduced resistance to killing by human serum. In C. jejuni, the observed serum mediated killing was determined to result primarily from activation of the classical complement pathway. The C. jejuni MeOPN transferase mutant showed similar levels of colonization relative to the wild-type in chickens, but showed a five-fold drop in colonization when co-infected with the wild-type in piglets. In Galleria mellonella waxmoth larvae, the MeOPN transferase mutant was able to kill the insects at wild-type levels. Furthermore, injection of the larvae with MeOPN-linked monosaccharides or CPS purified from the wild-type strain did not result in larval killing, indicating that MeOPN does not have inherent insecticidal activity.
Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Lieke B
LB
van Alphen
Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Cory Q
CQ
Wenzel
Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Michele R
MR
Richards
Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Christopher
C
Fodor
Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.
Roger A
RA
Ashmus
Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
Martin
M
Stahl
School of Life Sciences, Kingston University, London, United Kingdom.
Andrey V
AV
Karlyshev
London School of Hygiene and Tropical Medicine, London, United Kingdom.
Brendan W
BW
Wren
Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
Alain
A
Stintzi
Produce Safety and Microbiology Research Unit, Agricultural Research Service, US Department of Agriculture, Albany, California, United States of America.
William G
WG
Miller
Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.
Todd L
TL
Lowary
Alberta Glycomics Centre, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Christine M
CM
Szymanski
D000577:Amides / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D016667:Bacterial Capsules / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D018938:Caco-2 Cells; D002169:Campylobacter Infections / Q000382:microbiology; D016123:Campylobacter jejuni / Q000201:enzymology* / Q000235:genetics; D002645:Chickens; D055786:Gene Knockout Techniques; D006801:Humans; D007306:Insecticides / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000382:microbiology; D050296:Microbial Viability; D009036:Moths / Q000187:drug effects / Q000382:microbiology; D010756:Phosphoric Acids / Q000378:metabolism*; D010802:Phylogeny; D011135:Polysaccharides, Bacterial / Q000494:pharmacology / Q000502:physiology*; D034421:Sus scrofa; D014166:Transferases / Q000235:genetics
D000577:Amides; D001426:Bacterial Proteins; D007306:Insecticides; D010756:Phosphoric Acids; D011135:Polysaccharides, Bacterial; C011067:phosphoramidic acid; D014166:Transferases