Last fall, Chobani recalled a number of its yogurts for mold contamination that caused packages to bloat and sour before their expiration date. More than 200 people reported becoming ill with nausea, vomiting and diarrhea after eating the yogurt. The U.S. Food and Drug Administration identified Mucor circinelloides as the contaminant, but it was initially believed that this fungus would not cause the kind of illnesses described. The company cited a statement by Randy Worobo, a professor of Food Science in Cornell University’s College of Agriculture and Life Sciences, that stated: “Mucor circinelloides is a species of mold commonly associated with fruits, vegetables and dairy that has been reported to cause spoilage like swelling and bloating in yogurt. It is not considered a disease-causing foodborne microorganism.” Research published today in mBio, the online open-access journal of the American Society for Microbiology, found otherwise. Although researchers still can’t say that the fungus directly caused the reported illnesses, their study shows that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers, posing a particular risk to immunocompromised patients. “While information disseminated in the popular press would suggest this fungal contaminant poses little or no risk to consumers, our results show instead that it is capable of causing significant infections in animals,” the study reads. The researchers obtained a plain Chobani yogurt that was within the manufacturer’s voluntary date recall range and also in the production lot subject to recall. The sample was provided by a couple in Corpus Christi, TX, who had both become sick after eating the yogurt. The team isolated a Mucor circinelloides strain and subsequently identified the isolate as belonging to the M. circinelloides f. circinelloides subgroup, the most virulent subspecies which is also commonly associated with human infections. Their tests also showed that the yogurt isolate was virulent in mice and wax moth larva. Another test found that Mucor can survive passage through the gastrointestinal tract of mice. “Compared to other food-borne pathogens, including bacteria, viruses, and parasites, less focus has been placed on the risk of fungal pathogens,” the study says. “M. circinelloides is a food-borne pathogen that can cause lethal mucormycosis and [we] suggest that caution should be exercised with respect to fungal pathogens in food, particularly for individuals who are immunocompromised.” The company responded Monday with this statement: “Chobani conducted an aggressive, statistically significant series of tests of the products voluntarily recalled in September 2013 with third party experts confirming the absence of foodborne pathogens. Chobani stands by these findings, which are consistent with regulatory agency findings and the FDA’s Class II classification of the recall on October 30, 2013,” said Alejandro Mazzotta, Chobani Vice President of Global Quality, Food Safety, and Regulatory Affairs. “In regards to this specific study, we were just made aware of it and want to take more time to review its methodology and assertions. To our knowledge, there is no evidence, including the assertions presented in this publication, that the strain in the recalled products causes illness in consumers when ingested,” he said. The statement provided by Chobani also said that the company has added new equipment for microbiological testing and conducts more than 500 of these tests a day at different stages of production. “Food quality and safety has always been and always will be paramount to Chobani,” Mazzotta said.