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.