The presence of microorganisms in potable water can alter its quality and cause public health issues when ingested or after contact with skin and mucous membranes, especially in individuals with impaired immune system. The aim of this study was to assess the occurrence and seasonality of potentially pathogenic yeast in the public water supply of a municipality in the state of São Paulo, Brazil. In addition, to evaluate the in vitro susceptibility profiles of the isolates against four antifungal drugs. Water samples (n = 1923) were collected from distinct points of the public water system, 15 days after the beginning of each climatic season. They were filtered through a cellulose membrane, which was subsequently upturned on an agar plate. Results show that 11.5% of the samples were positive for yeasts. After identification of the isolates, Rhodotorula minuta was the most prevalent in spring (48.6%), fall (35.2%), and summer (46.3%); and Candida spp. in winter (68.2%). Resistant phenotypes were observed in 54.2% of the isolates, mainly because of Rhodotorula spp. As conclusions, yeasts are present in the water supply during all seasons of the year with great species variability and significant rates of resistance. These results indicate a health concern, suggesting that water quality control protocols require changes to minimize exposure to potentially pathogenic microorganisms and selection of resistant strains.

食入水中或与皮肤和粘膜接触后，饮用水中微生物的存在会改变其质量并引起公共卫生问题，特别是在免疫系统受损的个体中。这项研究的目的是评估巴西圣保罗州一个城市的公共供水中潜在致病性酵母菌的发生和季节性。另外，为了评估分离物对四种抗真菌药物的体外敏感性概况。水样（n = 1923年）是在每个气候季节开始后15天从公共供水系统的不同地点收集的。将它们通过纤维素膜过滤，随后将其在琼脂平板上翻转。结果显示11.5％的样品中的酵母呈阳性。鉴定出分离株后，在春季（48.6％），秋季（35.2％）和夏季（46.3％），红景天最普遍。和念珠菌属 冬季（68.2％）。在54.2％的分离物中观察到抗性表型，主要是由于红斑杜鹃spp。结论是，一年中所有季节的水源中都存在酵母菌，其物种变异性很大，耐药率也很高。这些结果表明对健康的关注，表明水质控制方案需要进行更改，以最大程度地减少对潜在病原微生物的接触以及对耐药菌株的选择。