Outbreak of Kodamaea ohmeri fungemia in neonates: case series and literature review

Introduction Kodamaea ohmeri is an emerging opportunistic yeast pathogen associated with high mortality yet reports of nosocomial outbreaks—particularly in neonatal intensive care units—remain scarce. Methods We retrospectively identified five cases of K. ohmeri fungemia occurring within a 2-month period in the NICU of a tertiary general hospital in China. Clinical and epidemiological data were collected. Isolates were identified by MALDI-TOF MS and characterized by CHROMagar™ Candida chromogenic medium, antifungal susceptibility testing (Sensititre YeastOne™), and microsatellite genotyping. A systematic literature review of K. ohmeri bloodstream infections was also performed. Results All five neonates (median age 1 month) had indwelling catheters, received mechanical ventilation and broad-spectrum antibiotics, and all survived following antifungal therapy and catheter removal. Seven isolates from the five patients exhibited identical microsatellite genotypes across three highly polymorphic loci, confirming clonal transmission and a common nosocomial origin. Morphological dimorphism (smooth/rough colony types) was observed in one isolate. Fluconazole MICs were elevated (4–8 μg/mL), whereas echinocandins and amphotericin B showed low MICs. The literature review identified 30 sporadic cases and two prior outbreaks (total 38 patients; mortality 32%), with prematurity, indwelling catheters, and broad-spectrum antibiotic use as predominant risk factors. Conclusion This cluster describes an outbreak of K. ohmeri fungemia in neonates. Microsatellite genotyping proved valuable for confirming nosocomial transmission. Accurate identification (MALDI-TOF MS), prompt catheter removal, and appropriate antifungal therapy are crucial. Enhanced hand hygiene and environmental disinfection remain essential for NICU infection control.