A Preliminary Study Examining the Binding Capacity of Akkermansia muciniphila and Desulfovibrio spp., to Colonic Mucin in Health and Ulcerative Colitis.
BACKGROUND
Akkermansia muciniphila and Desulfovibrio spp. are commensal microbes colonising the mucus gel layer of the colon. Both species have the capacity to utilise colonic mucin as a substrate. A. muciniphila degrades colonic mucin, while Desulfovibrio spp. metabolise the sulfate moiety of sulfated mucins. Altered abundances of these microorganisms have been reported in ulcerative colitis (UC). However their capacity to bind to human colonic mucin, and whether this binding capacity is affected by changes in mucin associated with UC, remain to be defined.


METHODS
Mucin was isolated from resected colon from control patients undergoing resection for colonic cancer (n = 7) and patients undergoing resection for UC (n = 5). Isolated mucin was purified and printed onto mucin microarrays. Binding of reference strains and three clinical isolates of A. muciniphila and Desulfovibrio spp. to purified mucin was investigated.


RESULTS
Both A. muciniphila and Desulfovibro spp. bound to mucin. The reference strain and all clinical isolates of A. muciniphila showed increased binding capacity for UC mucin (p < .005). The Desulfovibrio reference strain showed increased affinity for UC mucin. The mucin binding profiles of clinical isolates of Desulfovibrio spp. were specific to each isolate. Two isolates showed no difference in binding. One UC isolate bound with increased affinity to UC mucin (p < .005).


CONCLUSIONS
These preliminary data suggest that differences exist in the mucin binding capacity of isolates of A. muciniphila and Desulfovibrio spp. This study highlights the mucin microarray platform as a means of studying the ability of bacteria to interact with colonic mucin in health and disease.
School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
Helen
H
Earley
School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
Grainne
G
Lennon
School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
Aine
A
Balfe
Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland; Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
Michelle
M
Kilcoyne
School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.
Marguerite
M
Clyne
Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
Lokesh
L
Joshi
College of Life Sciences, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Dublin 4, Ireland.
Stephen
S
Carrington
Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
Sean T
ST
Martin
Graduate Entry Medical School, Limerick, Ireland.
J Calvin
JC
Coffey
Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
Desmond C
DC
Winter
School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; Centre for Colorectal Disease, St Vincent's University Hospital, Dublin 4, Ireland.
P Ronan
PR
O'Connell
D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000382:microbiology*; D003106:Colon / Q000382:microbiology*; D003901:Desulfovibrio / Q000302:isolation & purification / Q000502:physiology*; D006031:Glycosylation; D006801:Humans; D037102:Lectins / Q000378:metabolism; D046228:Microarray Analysis; D009077:Mucins / Q000378:metabolism*; D061327:Verrucomicrobia / Q000302:isolation & purification / Q000502:physiology*
D037102:Lectins; D009077:Mucins