Dietary fish oil reduces survival and impairs bacterial clearance in C3H/Hen mice challenged with Listeria monocytogenes.
1. To investigate the effect of dietary fat source on host resistance to intracellular pathogens, weanling female C3H/Hen mice were fed one of three experimental diets containing, 20% by weight, lard, soybean oil or 17% menhaden fish oil plus 3% corn oil. After 4 weeks, survival of mice (n = 12/treatment group) injected intraperitoneally with 2 x 10(6) colony forming units of live Listeria monocytogenes was determined. In a second study, bacterial clearance from the liver and spleen at 2, 4 and 7 days post-challenge was determined (n = 8/treatment group). 2. We found that the survival of mice fed the diets with soybean oil or menhaden fish oil was significantly lower than those fed lard (P < 0.05). Survival rates were 58% (7/12), 33% (4/12) and 100% (12/12), respectively, for mice fed soybean oil, menhaden fish oil and lard. In the second study, mice fed menhaden fish oil had approximately 1 log10 greater bacteria in their spleens at day 4 than mice fed lard or soybean oil (P < 0.001). There were no significant treatment differences in the number of bacteria recovered from liver samples. 3. In summary, dietary fat source significantly affects murine resistance to Listeria, with diets rich in n-3 polyunsaturated fatty acids, such as from fish oil, having the most detrimental effect.
Fritsche
K L
KL
Department of Animal Sciences, University of Missouri, Columbia 65211, USA.
Shahbazian
L M
LM
Feng
C
C
Berg
J N
JN
D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D003314:Corn Oil; D004041:Dietary Fats / Q000008:administration & dosage; D004042:Dietary Fats, Unsaturated / Q000009:adverse effects*; D015525:Fatty Acids, Omega-3 / Q000009:adverse effects*; D005260:Female; D005395:Fish Oils / Q000009:adverse effects*; D007113:Immunity, Innate; D008088:Listeriosis / Q000276:immunology* / Q000382:microbiology; D008099:Liver / Q000382:microbiology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D009504:Neutrophils / Q000276:immunology; D009752:Nutritional Status; D011897:Random Allocation; D013025:Glycine max; D013154:Spleen / Q000382:microbiology
D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D003314:Corn Oil