The influence of media on the recovery of bacteria from the normal mouse caecum

Abstract

3 diluting fluids and 6 agar media were compared for the culture of caecal micro flora of mice. The efficiency of the media in the growth of caecal bacteria was determined by comparing the quantitative recovery (expressed as percentage of the total microscopic count) from the specimens. Of the diluting fluids saline resulted in a low yield (11·47%). Addition of potassium salts increased the yield (23·25%). A broth medium resulted in the highest recovery (44·44%). The influence of storing the caecal micro flora in 3 different diluting fluids on the yield was studied. In all diluents the viable count of caecal bacteria decreased with time, but did so least in broth medium. 6 solid agar media were tested. When saline was used as the diluting fluid, no significant differences in yields were found with all 6 media. When broth medium was used as diluting fluid and yields up to 60% were obtained, no significant differences were shown between the results with 5 media but one medium resulted in a lower yield (32·59%).