Evaluation of the Incidence of Candida yeasts in Coastal Lagoon Ecosystems Puerto Rico: Ecological and Pathogenic Implications

Abstract

Coastal lagoons, located at the terrestrial-marine interface, are exposed to a series of environmental changes due to anthropogenic activity. This study evaluated the water quality of seven lagoons in Puerto Rico: Tortuguero in Vega Baja, Condado in San Juan, San José in San Juan, Torrecilla in Carolina, Piñones in Loíza, Aguas Prietas in Fajardo, and Laguna Grande in Fajardo, between February and March 2024. The objectives were to isolate yeasts from the water of each lagoon, identify the genus and species, estimate the number of yeasts through colony-forming unit (CFU) counting, and compare the isolated species among the seven water bodies. Samples were collected using sterile bags, filtering 100 mL of water in triplicate. The membranes were placed on plates with Hardy CHROM™ Candida. The incubation period for the samples was 24 to 48 hours at 35-37 °C. The colonies were counted, isolated, and macroscopically identified. The average for each lagoon was 218 CFU in Laguna Grande followed by 125 CFU in Tortuguero, 84 CFU in Piñones, 68 CFU in Condado, 50 CFU in San José, 45 CFU in Aguas Prietas, and the least was 37 CFU in Torrecilla. The yeast species identified were Candida tropicalis, Candida krusei except in Laguna Piñones, and Candida glabrata, Candida parapsilosis, Candida auris, and Candida albicans except in Laguna Tortuguero, Laguna Grande, and Laguna Piñones. The results revealed a variation in yeast types in response to environmental changes. Understanding these findings is crucial to prevent potential health risks for those who use these waters. Most of the species isolated in this study are responsible for opportunistic fungal infections. The studies indicate that patterns are being observed in the epidemiology of Candida species, such as variations in prevalence and antibiotic resistance based on geographic location.