Risk factors and biofilm formation analyses of hospital-acquired infection of Candida pelliculosa in a neonatal intensive care unit

BACKGROUND: Candida pelliculosa is an ecological fungal species that can cause infections in immunocompromised individuals. Numerous studies globally have shown that C. pelliculosa infects neonates. An outbreak recently occurred in our neonatal intensive care unit; therefore, we aimed to evaluate the risk factors in this hospital-acquired fungal infection. METHODS: We performed a case-control study, analysing the potential risk factors for neonatal infections of C. pelliculosa so that infection prevention and control could be implemented in our units. Isolated strains were tested for drug resistance and biofilm formation, important factors for fungal transmission that give rise to hospital-acquired infections. RESULTS: The use of three or more broad-spectrum antimicrobials or long hospital stays were associated with higher likelihoods of infection with C. pelliculosa. The fungus was not identified on the hands of healthcare workers or in the environment. All fungal isolates were susceptible to anti-fungal medications, and after anti-fungal treatment, all infected patients recovered. Strict infection prevention and control procedures efficiently suppressed infection transmission. Intact adhesin-encoding genes, shown by genome analysis, indicated possible routes for fungal transmission. CONCLUSIONS: The use of three or more broad-spectrum antimicrobials or a lengthy hospital stay is theoretically associated with the risk of infection with C. pelliculosa. Strains that we isolated are susceptible to anti-fungal medications, and these were eliminated by treating all patients with an antifungal. Transmission is likely via adhesion to the cell surface and biofilm formation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-021-06295-1.