EFFECT OF MALNUTRITION ON THE ADHERENCE OF SALMONELLA TYPHIMURIUM (ST) TO RAT ENTEROCYTE

Abstract

The adherence of bacteria to intestinal mucosa is an important initial event in the pathogenesis of enteric infections. Such infections occur frequently in association with undernutrition. We investigated the adherence of two strains of ST to enterocytes from ad-libitum fed and nutrient restricted rats in order to study the effects of nutrient restriction on the adherence of ST to enterocytes. An animal model of malnutrition was produced by feeding young male adult rats 50% of the daily intake in control ad-libitum fed rats. Enterocytes were isolated from proximal and distal small intestinal segments by agitation in isolation medium. Adherence was studied using fimbriated (S7471F) and non-fimbriated (S7471N) strains of ST labelled with 3H-adenine. Labelled bacteria were incubated with freshly isolated enterocytes for 30 min. at 37 C. and the free bacteria were separated from those bound to enterocytes by membrane filtration and washing. The bound bacteria was quantitated by liquid scintillation. Adherence was significantly higher with S7471F both with proximal and distal intestinal enterocytes. There was no significant difference between the malnourished and control rats with respect to degree of adherence despite significant differences in body and organ weights and serum albumin. Prolongation of the period of nutrient restriction (to 12 wks) did not produce any change in pattern of adherence. We conclude that the adherence patterns of these strains of ST to enterocytes are not significantly altered by malnutrition.