Colonization of mice by Campylobacter jejuni

Both streptomycin-treated and untreated Swiss white mice were irregularly colonized when challenged orogastrically with between 1 and 10(11) viable organisms of either of two strains of Campylobacter jejuni. The organisms were occasionally recovered from portions of the intestinal tracts of these animals in numbers ranging from 10(1) to 10(3)/g when the challenge doses were 10(10) or more. When germfree mice were challenged with 10(8) organisms of either strain, the entire intestinal tracts of all the animals were colonized with C. jejuni in numbers ranging from 10(4) to 10(9)/g. The ceca were most heavily colonized. Both strains of C. jejuni multiplied anaerobically in brucella broth, except when the broth contained 60.80 mu eq of total volatile fatty acids (VFA) per ml at pH 6.75, simulating conditions in the ceca of untreated mice, or when it contained 21.63 mu eq/ml at pH 7.04, simulating conditions in the ceca of streptomycin-treated mice. Active multiplication occurred, however, in brucella broth without VFA at pH 7.02 that was incubated microaerobically, simulating conditions in the ceca of germfree mice. The results suggest that VFA operating under anaerobic conditions present in the intestinal tract of both streptomycin-treated and untreated conventional mice interfere with the multiplication of C. jejuni. The organisms actively multiply, on the other hand, in the absence of VFA at the higher oxidation-reduction potential of the intestinal tract of germfree mice.