Comparison of species and numbers of bacteria in concurrently cultured samples of proximal small intestinal fluid and endoscopically obtained duodenal mucosa in dogs with intestinal bacterial overgrowth.

Concurrent bacterial culturing of duodenal/proximal jejunal fluid and duodenal mucosa was performed on 2 occasions in each of 16 IgA-deficient German Shepherd Dogs with small intestinal bacterial overgrowth. The interval between sample collections in each dog was 74 to 78 days. Species of bacteria and numbers of bacterial colony-forming units (CFU) per milliliter of fluid were compared with species and numbers found in the concurrent duodenal mucosa sample. There was inconsistent correlation for number of CFU and minimal correlation for species of bacteria isolated from the 2 sites. Fewer bacterial CFU usually were isolated from the mucosa than from the concurrent fluid sample. When the same numeric criteria used for diagnosing small intestinal bacterial overgrowth in samples of intestinal fluid (ie, > or = 10(5) bacterial or > or = 10(4) anaerobic CFU/ml) were used to interpret results of culturing duodenal mucosa, quantitations of bacterial CFU in duodenal mucosa was found to be a specific, but insensitive test.