Immune protection mediated by the probiotic Lactobacillus rhamnosus HN001 (DR20) against Escherichia coli O157:H7 infection in mice.
This study investigated the protective effects of feeding the immunoenhancing probiotic Lactobacillus rhamnosus HN001 against Escherichia coli O157:H7 infection in murine (BALB/c and C57BL/6 mice) challenge infection models. Mice were fed milk-based diets supplemented with L. rhamnosus HN001 (3 x 10(8) cfu g(-1)) for 7 days prior to and following oral challenge with E. coli O157:H7. Morbidity and feed intake were measured for 1 week following challenge; pathogen translocation to spleen, liver and blood, and humoral and cellular immunological responses (specific antibody and phagocytosis) were measured in a sub-sample of ostensibly healthy animals 1 week post-challenge. Results showed that, after challenge, L. rhamnosus HN001-fed mice exhibited lower cumulative morbidity and bacterial translocation rates, compared to non-probiotic-fed control mice. Significantly higher intestinal anti-E. coli IgA responses and blood leucocyte phagocytic activity were recorded among probiotic-fed mice compared to controls. These results demonstrate that feeding the probiotic L. rhamnosus HN001 to mice can reduce the severity of E. coli O157:H7 infection, and suggest that this reduction may be associated with enhanced humoral and cellular immune responses.
Milk and Health Research Centre, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand. shuq@crop.cri.nz
Quan
Q
Shu
Harsharnjit S
HS
Gill
D000818:Animals; D000907:Antibodies, Bacterial / Q000378:metabolism; D001770:Blood Bactericidal Activity; D004435:Eating; D004927:Escherichia coli Infections / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*; D019453:Escherichia coli O157 / Q000276:immunology* / Q000472:pathogenicity*; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007422:Intestines / Q000276:immunology; D007778:Lactobacillus / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010586:Phagocytes / Q000276:immunology; D019936:Probiotics
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G