Bloodstream Infection Caused by Saccharomyces Cerevisiae: Case Report

Fungemias are important healthcare-associated infections. The most common are caused by yeasts of the genus Candida ; however, health services worldwide have observed an increase in infections caused by other fungi, such as those of the genus Saccharomyces . Bloodstream infections caused by Saccharomyces cerevisiae are considered rare, even in this context, and may occur in more susceptible patient groups with risk factors such as immunosuppression, central venous catheter use, broad-spectrum antibiotic therapy, parenteral nutrition, intensive care unit admission, and especially the use of probiotics containing Saccharomyces boulardii . More than one hundred cases have been reported, most associated with probiotic use, but they also occur in patients without probiotic exposure, particularly in the presence of immunosuppression or gastrointestinal tract manipulation. The following case was managed in a Brazilian tertiary hospital. A 65-year-old male, active alcohol user and smoker, had undergone gastrectomy in 2020 due to a perforated gastric ulcer, with multiple re-operations throughout 2020 due to duodenal stump fistula and adhesive small bowel obstruction. In 2021, he underwent excision of a malignant tongue lesion and, in 2022, extensive debridement of devitalized tissue due to Fournier syndrome. He presented to the emergency department with 10 days of abdominal pain associated with anorexia and vomiting of dark content, in septic shock, and underwent exploratory laparotomy for duodenal ulcer repair; a peritoniostomy was created and he was admitted postoperatively to the ICU. Two days later, he remained febrile and unstable and underwent another surgical procedure for abdominal cavity revision; a mucosal fistula in the duodenum was observed and partial colectomy with jejunostomy and terminal colostomy was performed. He progressed with worsening sepsis and died the following day. After death, the care team received the result of blood cultures collected upon ICU admission: Saccharomyces cerevisiae . There was no report of probiotic use by the patient, nor in the hospital environment. This case highlights the severity of invasive fungal infections and draws attention due to its epidemiological rarity.