Candida species Isolated from Aquatic Ecosystems of the Arecibo region, Puerto Rico: Beach, Estuary and River

Abstract

Beaches, rivers, and estuaries are exposed to diverse environmental changes due to natural disturbances and anthropogenic pollution. The waters of pier Beach, the Caño Tiburones estuary, and the Arecibo River estuary were studied for five weeks, from February to March 2023. The objectives of this study were to isolate yeasts from different bodies of water in Arecibo, identify the genus and species, estimate the number of yeasts by counting colony-forming units (CFU), and compare the isolated species among the three bodies of water. Samples were collected at three different points equidistant from each location and placed in sterile bags. One hundred mL of water was filtered in triplicate, and the membrane was placed to grow in Hardy Chrom™ Candida culture medium. The incubation period for the samples was 2 to 3 days at 30-37°C. Colonies were counted and isolated. Macroscopic and microscopic analysis was used for yeast identification. The growth of the colonies sampled from the Caño Tiburon estuary was 171 CFU, those from the Arecibo River estuary were 215 CFU, and those from the Arecibo Pier beach were 138 CFU. The yeast species identified at the three sampling points were: Candida albicans, C. tropicalis, C. krusei, C. glabrata, C. parapsilosis, and C. auris, which was only present in the Arecibo River Estuary. The majority of species isolated in this study are responsible for opportunistic fungal infections. The study indicates the patterns that are being observed in the epidemiology of Candida species, such as variations in their prevalence and antibiotic resistance according to geographic location.