First Isolation of Candida parapsilosis from Water-Related Domestic Environments in Colombia: A Public Health...

Candida parapsilosis is an opportunistic yeast of increasing clinical importance, with fluconazole resistance rates rising globally and reaching concerning levels in clinical settings across several countries, including Colombia. However, the occurrence of antifungal-resistant Candida species in domestic water systems in the country remains largely unexplored.

This cross-sectional study assessed the occurrence and antifungal susceptibility of Candida spp. in intradomiciliary water from 104 households in Villavicencio, Colombia, during two monitoring periods. Water samples were filtered, and yeast-like colonies were identified using MALDI-TOF mass spectrometry. Susceptibility to fluconazole, amphotericin B, and anidulafungin was determined using the CLSI broth microdilution method. The ERG11 gene was sequenced in the fluconazole-resistant isolate.

C. parapsilosis was recovered from 16 of 104 households (15.4%), yielding 22 isolates distributed across six communes. Most isolates (72.7%) were obtained from household water storage tanks. One isolate was resistant to fluconazole (MIC = 8 µg/mL) and harbored a nonsynonymous R398I substitution in ERG11.

To our knowledge, this is the first report of C. parapsilosis, including a fluconazole-resistant isolate carrying an ERG11 substitution, recovered from domestic water in Colombia. These findings suggest that household water storage tanks may serve as environmental reservoirs for this opportunistic yeast. The implications for human exposure remain to be determined and highlight the need for integrated One Health surveillance.