Different types of water bodies, including lakes, streams, and coastal marine waters, are often susceptible to fecal contamination from a range of point and nonpoint sources, and have been evaluated using fecal indicator microorganisms. The most commonly used fecal indicator is Escherichia coli, but traditional cultivation methods do not allow discrimination of the source of pollution. The use of triplex PCR offers an approach that is fast and inexpensive, and here enabled the identification of phylogroups. The phylogenetic distribution of E. coli subgroups isolated from water samples revealed higher frequencies of subgroups A1 and B2(3) in rivers impacted by human pollution sources, while subgroups D1 and D2 were associated with pristine sites, and subgroup B1 with domesticated animal sources, suggesting their use as a first screening for pollution source identification. A simple classification is also proposed based on phylogenetic subgroup distribution using the w-clique metric, enabling differentiation of polluted and unpolluted sites.

Foi realizada uma avaliação sanitária das águas e areias de 16 praias do litoral do Estado de São Paulo, Brasil, durante a primavera de 1997 e verão de 1998. Cento e noventa e duas amostras de areia seca e úmida, e 96 amostras de água do mar, foram coletadas e analisadas quanto à presença de bactérias indicadoras de contaminação fecal. Também foram realizados exames parasitológicos e análises de Candida albicans nas amostras de areia, e a determinação de bacteriófagos F-específicos nas amostras de água. A análise estatística dos resultados demonstrou concentrações mais elevadas de coliformes e estreptococos fecais na areia seca, durante o verão. Observou-se uma correlação significativa (Pearson) entre as concentrações de coliformes fecais e estreptococos fecais para os dois tipos de areia, correlação esta mais elevada na areia úmida. Ovos e cistos de parasitas e C. albicans foram detectados em 4,2% e 18% das amostras, respectivamente. As elevadas densidades dos indicadores de contaminação fecal detectadas nas areias durante o verão mostram a necessidade de orientar-se adequadamente a população a respeito das doenças veiculadas pela areia e das medidas preventivas necessárias, bem como de buscar-se um critério adequado para monitorar esse risco.

A sanitary evaluation of sand and water from 16 beaches of São Paulo State, Brazil, was undertaken during spring of 1997 and summer of 1998. Ninety six samples each of wet and dry sand and seawater were collected and analysed for fecal indicator bacteria. A parasitological examination and Candida albicans analysis were also performed in sand samples and F-specific bacteriophages were determined in seawater. Statistical analysis of the results demonstrated higher concentrations of fecal coliforms and fecal streptococci in dry sand during summer. Correlation analysis indicated a significant relationship between fecal indicator densities in wet sand and seawater. There was a significant correlation between the densities of fecal coliforms and fecal streptococci for both types of sand, and this correlation was higher in wet sand. Cysts and eggs of parasites were detected in 4.2% of the samples and Candida albicans was isolated in 18% of the samples. The high concentrations of fecal indicators detected in sand during summer demonstrate that there is a health risk to the users of these recreational areas and suggest the necessity of some criteria for microbiological control. Preventive measures, such as education campaings and some management actions are important precautionary measures.