抄録
Lactose-positive bacteria facilitate the colonization in the intestine in mono-associated quails fed a lactose-containing diet, because the quail does not possess intestinal lactase. We examined the influence of the overgrowth of various human intestinal lactose-positive bacteria on pathological change of mono-associated quails fed a lactose-containing diet. The strains used in this study included Bacteroides fiagilis Bifldobacterium breve, Clostidium butyrwwn, Esherichia coll. Enterococcus faecaliss, and Lactobacillus casei. Gas cysts, hemorrhage, and erosion were observed in the cecum of the quails mono-associated with E. coil or C. butyricum Necrotic areas were not observed in the lesion. These lesions were diagnosed as typical pneumatosis cystoides intestinalis (PCI), and the findings were benign, neither fulminant nor fatal. Weak-gas-producing mutants (gasw) derived from C. butyricum were compared as to incidence of lesion with parent strain. The biochemical characters of the mutants were consistent with the parent strain except for less than half gas production. The incidence of lesion was significantly lower in the quails mono-associated with gasw mutant than in those of mono-associated with the parent strain. These results suggest that a large amount of gas produced by C. butyricum might be mainly related to the onset of cecal PCI.
