Prevalence of yeasts in beach sand at three bathing beaches in South Florida

• Published in: Water research (Oxford) Vol. 41; no. 9; pp. 1915 - 1920
• Main Authors: Vogel, C., Rogerson, A., Schatz, S., Laubach, H., Tallman, A., Fell, J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.05.2007; Elsevier Science
• Subjects: Applied sciences; Ascomycetes; Ascomycota; Basidiomycetes; Basidiomycota; Bathing Beaches; Beach quality; beaches; Candida tropicalis; Environmental Monitoring; Exact sciences and technology; Florida; Fungi; microbial contamination; Non-traditional indicators; Other industrial wastes. Sewage sludge; Pollution; population density; recreation areas; Recreational waters; Rhodotorula mucilaginosa; Rhodotorula rubra; sand; Silicon Dioxide; temporal variation; Wastes; water content; Water Microbiology; water pollution; water quality; Water Supply; Water treatment and pollution; yeasts; Yeasts - classification; Yeasts - isolation & purification; Yeasts - pathogenicity; Florida; United States; North America; America; USA, Florida, Fort Lauderdale; ASW, USA, Florida; ASW, USA, Florida, Fort Lauderdale; Fungi; Recreational waters; Non-traditional indicators; Beach quality; Basidiomycetes; Time variation; Indicator; Intertidal zone; Health and environment; Water quality; Fungi Non-traditional indicators Recreational waters Beach quality; Candida tropicalis; Ascomycetes; Fungi Imperfecti; Bathing; Rhodotorula rubra; Bathing water; Public health; Thallophyta
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2007.02.010

The abundance and types of yeasts in the wet and dry sand of three recreational beaches in South Florida were determined. Samples were collected on 17 occasions between August 2001 and July 2002. After analyzing 102 sand samples, a total of 21 yeast species were identified by molecular methods. These isolates comprised four Basidiomycetes and 17 Ascomycetes and included eight species that had previously been reported from humans. The most frequently encountered yeasts were Candida tropicalis and Rhodotorula mucilaginosa. A greater diversity of species (16 species) was found in the dry sand above the high tide mark compared with the wet sand in the intertidal zone (11 species). Densities were also highest in the dry sand relative to wet sand (20-fold higher at Hobie beach, 6-fold higher at Fort Lauderdale Beach and 1.3-fold higher at Hollywood beach). There were no clear temporal patterns in the data and overall densities were greatest at the busiest bathing beach (Hobie Beach) where total yeasts averaged 37,720 cfu 100 g −1 dry sand and 1852 cfu 100 g −1 in the wet sand. This concentration of yeast was significantly higher than populations at the less populated beaches. Fort Lauderdale beach had a mean count of 4130 cfu 100 g −1 dry sand and 705 cfu 100 g −1 in the wet sand while the least populated beach, Hollywood Beach averaged 1945 cfu 100 g −1 dry sand and 1483 cfu 100 g −1 wet sand. While definitive statements cannot be made, high levels of yeasts may have a deleterious bearing on human health and the presence of such a diverse aggregation of species suggests that yeasts could have a role as indicators of beach health.