ENTERAL FORMULA COMPOSITION DOES NOT AFFECT RESPONSE TO LETHAL INFECTIOUS CHALLENGE IN MICE

The effects of enteral formulations on the response of mice to infecti ous challenge with Listeria monocytogenes, influenza A or Candida albi cans were studied to test the efficacy of specialized ingredients. CF- 1 outbred female mice (12-15 g) were fed nonpurified diet (Purina No. 5002) or commercially available liquid formulas: Osmolite HN(R), Perat ive(R) Impact(R). There were no differences between the groups fed the liquid formulas with regards to mean survival time of percentage of s urvivors in any of these models of infection. Examination of spleens f rom the groups challenged with L. monocytogenes, lungs from mice infec ted with Influenza A and kidneys from the groups challenged with C. al bicans revealed no differences in cure rate of survivors. Pre-feeding periods of up to 8 d before infection produced similar results for mic e fed enteral formulations compared to nonpurified diet. Contrary to p revious reports, the use of Impact(R) did not improve resistance to di sease in mice challenged with lethal doses of L. monocytogenes, as com pared with mice fed Osmolite HN. Additionally, mice fed lmpact(R), Per ative(R), or nonpurified diet responded similarly to challenge with L. monocytogenes, C. albicans or influenza A. The results indicate that these acute lethal animal models of infectious challenge may be of lim ited use to distinguish effects of modified nutrient composition of en teral formulas.