Isolation of Malassezia yeasts from dogs with gastrointestinal disease undergoing duodenal endoscopy by Aarti Kathrani and colleagues at the RVC

Evidence suggests a role for fungi in the pathogenesis of human inflammatory bowel disease, with increased numbers of Malassezia spp. documented in the intestinal mucosa of children with Crohn’s disease. Previous unpublished observations from the RVC team include the isolation of Malassezia spp. from the duodenal juice of dogs with enteropathy. They therefore applied for BSAVA PetSavers funding to determine the frequency and population density of fungi in duodenal samples from dogs with gastrointestinal disease undergoing routine endoscopic examination, using a technique that avoided the pitfalls associated with standard faecal collection, such as contamination by skin flora.

Quantitative microbial culture was performed on duodenal juice aspirated from dogs with suspected enteropathy during upper gastrointestinal endoscopy. A total of 15 fungal isolates were cultured from 14 dogs, including Malassezia pachydermatis, Candida albicans, Malassezia sympodialis, Candida glabrata, Kazachstania slooffiae, Kazachstania telluris and Pichia kudriavzevii.

To the author’s knowledge, this is the first report of isolation of M. pachydermatis, M. sympodialis, K. slooffiae and K. telluris from the canine duodenum. The method provides an alternative approach for obtaining localised samples from the duodenum of dogs during routine endoscopic diagnostic procedures, resulting in successful culturing of Malassezia. Further studies are needed to determine whether these are resident or transient fungi in the duodenum and whether yeast colonisation has a pathogenic effect on the host.

This was published in the November 2023 issue of the Journal of Small Animal Practice.

Read Aarti Kathrani’s Meet the Researcher interview with us here.