Researchers at Duke University in the USA have been examining the genetics of a fungal isolate obtained from a sample of recalled Greek yoghurt and have concluded that it could be a foodborne pathogen.
The Greek yoghurt, produced by Chobani Inc. of Twin Falls, Idaho, was recalled in September last year after complaints of swelling packaging and claims that more than 200 people had suffered gastrointestinal symptoms, including vomiting and diarrhoea, after consuming the product.
The fungus concerned was originally identified as Mucor circinelloides and was considered to be a non-pathogenic strain present in the product as a spoilage organism. However, the Duke University team isolated a strain from a container of the recalled yoghurt and identified it using multi-locus sequence typing (MLST) and whole genome analysis.
The isolate was found to be a member of the M. circinelloides f. circinelloides subgroup, which is associated with human infections and considered the most virulent subgroup of M. circinelloides. Virulence testing in mice and insect larvae showed that the isolate caused infection and could be recovered from the faeces of the mice for 10 days, indicating survival in the gut. The authors of the study conclude that M. circinelloides can be a food spoilage organism, but could also be capable of causing gastrointestinal illness in consumers, and may be a particular risk for the immunocompromised.
A report of the study is published in the open access journal mBio® and can be found here.