Clustering of water bodies in unpolluted and polluted environments based on Escherichia coli phylogroup abundance using a simple interaction database.

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 B23 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.

Detection of assemblages A and B of Giardia duodenalis in water and sewage from São Paulo state, Brazil.

Giardia duodenalis is a protozoan that parasitizes humans and other mammals and causes giardiasis. Although its isolates have been divided into seven assemblages, named A to G, only A and B have been detected in human faeces. Assemblage A isolates are commonly divided into two genotypes, Al and All. Even though information about the presence of this protozoan in water and sewage is available in Brazil, it is important to verify the distribution of different assemblages that might be present, which can only be done by genotyping techniques. A total of 24 raw and treated sewage, surface and spring water samples were collected, concentrated and purified. DNA was extracted, and a nested PCR was used to amplify an 890 bp fragment of the gdh gene of G. duodenalis, which codes for glutamate dehydrogenase. Positive samples were cloned and sequenced. Ten out of 24 (41.6%) samples were confirmed to be positive for G. duodenalis by sequencing. Phylogenetic analysis grouped most sequences with G. duodenalis genotype All from GenBank. Only two raw sewage samples presented sequences assigned to assemblage B. In one of these samples genotype All was also detected. As these assemblages/genotypes are commonly associated to human giardiasis, the contact with these matrices represents risk for public health.

Characterization of Enterococcus species isolated from marine recreational waters by MALDI-TOF MS and Rapid ID API® 20 Strep system.

MALDI-TOF Mass Spectrometry Biotyping has proven to be a reliable method for identifying bacteria at the species level based on the analysis of the ribosomal proteins mass fingerprint. We evaluate the usefulness of this method to identify Enterococcus species isolated from marine recreational water at Brazilian beaches. A total of 127 Enterococcus spp. isolates were identified to species level by bioMérieux's API® 20 Strep and MALDI-TOF systems. The biochemical test identified 117/127 isolates (92%), whereas MALDI identified 100% of the isolates, with an agreement of 63% between the methods. The 16S rRNA gene sequencing of isolates with discrepant results showed that MALDI-TOF and API® correctly identified 74% and 11% of these isolates, respectively. This discrepancy probably relies on the bias of the API® has to identify clinical isolates. MALDI-TOF proved to be a feasible approach for identifying Enterococcus from environmental matrices increasing the rapidness and accuracy of results.

Draft Genome Sequence of Non-O1 and Non-O139 Vibrio cholerae Strain VCC19.

Vibrio cholerae O1 is the causative agent of cholera and is ubiquitous in the aquatic environment, while V. cholerae strains non-O1 and non-O139 are recognized as causative agents of sporadic and localized outbreaks of diarrhea. Here, we report the complete sequence of a non-O1 and non-O139 V. cholerae strain (VCC19), which was isolated from the environment in Brazil. The sequence includes the integrative conjugative element (ICE). This paper is the first report of the presence of such an element in a V. cholerae strain isolated in Brazil.

Assessing the infection risk of Giardia and Cryptosporidium in public drinking water delivered by surface water systems in Sao Paulo State, Brazil.

A survey of Giardia and Cryptosporidium was conducted in surface water used as drinking water sources by public water systems in four densely urbanized regions of Sao Paulo State, Brazil. A Quantitative Microbial Risk Assessment, based on protozoa concentrations, was performed to estimate the probability of protozoa infection associated with drinking water ingestion. A total of 206 source water samples were analyzed over a 24 month period using the USEPA Method 1623. The risk of infection was estimated using an exponential dose response model, children and adults exposure and a gamma distribution for (oo)cyst concentrations with three scenarios for treating censored data. Giardia was detected in 102 of the samples, and 19 of them were also positive for Cryptosporidium, with maximum concentrations of 97.0 cysts/L and 6.0 oocysts/L, respectively. Risk distributions were similar for the three scenarios. In the four regions, the estimated risk of Giardia infection per year, for adults and children, ranged from 0.29% to 2.47% and from 0.08% to 0.70%, respectively. Cryptosporidium risk infection varied from 0.15% to 0.29% for adults and from 0.04% to 0.08% for children. In both cases, the calculated risk surpassed the risk of infection of 10(-4) (1:10,000) defined as tolerable by USEPA for a yearly exposure. The probability of Giardia infection was very close to the rates of acute diarrheic disease for adults (1% to 3%) but lower for children (2% to 7%). The daily consumption of drinking water was an important contributing factor for these differences. The Microbiological Risk Assessment carried out in this study provides an indication of infection risks by Giardia and Cryptosporidium in the population served by these source waters. Strategies for source water protection and performance targets for the water treatment should be established to achieve the required level of public health risk.

Avaliação da performance de metodologias de detecção de Cryptosporidium spp. e Giardia spp. em água destinada ao consumo humano, para o atendimento às demandas da Vigilância em Saúde Ambiental no Brasil / Performance evaluation of different methodologies for detection of Cryptosporidium spp. and Giardia spp. in water for human consumption to meet the demands of the Environmental Health Surveillance in Brazil

Objetivo: avaliar a performance de três protocolos de concentração de cistos e oocistos em amostras de água bruta de rios brasileiros. Métodos: os protocolos estudados foram precipitação química, filtração em membranas de 47mm de diâmetro e 3μm de porosidade nominal e filtração com o sistema Filta-Max®. Amostras de água bruta coletadas de rios nos estados de São Paulo e Minas Gerais foram analisadas após contaminação artificial. Os resultados de precisão inicial e recuperação de organismos marcados (Color-Seed®) foram comparados com os critérios da Agencia de Proteção Ambiental dos Estados Unidos da Améri¬ca (USEPA). Resultados: Nos ensaios de precisão inicial para cistos de Giardia, a filtração em membranas e com Filta-Max® atingiram os critérios da USEPA para recuperação de cistos. Para Cryptosporidium, somente o procedimento com Filta-Max® alcançou os critérios. Conclusão: o sistema Filta-Max® foi o único método que atingiu todos os critérios para identificação de Cryptosporidium e Giardia em água.

Objective: this study aimed to evaluate three different concentration protocols of cysts and oocysts in raw water samples in Brazilian rivers. Methods: the protocols studied were chemical precipitation, filtration in membranes of 47mm of diameter versus nominal porosity of 3µm and filtration using Filta-Max® system. The raw water samples collectedfrom rivers in the states of São Paulo andMinas Gerais were analyzed after being seeded with Color-Seed®. The results of initial precision using filtration in membranes and recovery of Color-Seed® organisms were compared to the acceptance criteria established by the United States Environmental Protection Agency (USEPA). Results: The study of initial precision to Giardia using filtration in membranes and recovery of Color-Seed® met the USEPA criteria; for Cryptosporidium only the Filta-Max® achieved the established criteria. Conclusion: Filta-Max® system showed to be the only method that achieved all the performance criteria for identification of Giardia and Cryptosporidium in water.

Sanitary quality of sands from marine recreational beaches of São Paulo, Brazil

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 percent of the samples and Candida albicans was isolated in 18 percent 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.

Avaliaçäo da presença dos protozoários Giardia sp e Cryptosporidium sp em águas superficiais destinadas a captaçäo e tratamento para consumo humano no Estado de Säo Paulo / Evaluation of Giardia sp and Cryptosporidium sp in source water from Säo Paulo State, Brazil

Objetivo. Avaliar a presença dos protozoários Giardia sp e Cryotosporidium sp em águas destinadas a captaçäo e tratamento para consumo humano no Estado de Säo Paulo, como parte do projeto da CETESB (Companhia de Tecnologia e Saneamento Básico do Estado de Säo Paulo) "Avaliaçäo da Qualidade das Aguas Interiores do Estado de Säo Paulo". Trata-se de importantes agentes etiológicos de gastroenterites de veiculaçäo hídrica, amplamente disseminados no ambiente e com características que favorecem a transmissäo pela água. Métodos. Durante 19 meses foram analisadas 278 amostras de águas superficiais provenientes de 28 pontos de captaçäo de 10 bacias hidrográficas. Foi utilizada a técnica de imonofluorescência, após concentraçäo das amostras por floculaçäo por carbonato de cálcio. Foram igualmente , analisados para verificar-se eventual correlaçäo com esses protozoários, coliformes fecais, estreptococos fecais e Clostridium perfrigens. Resultados. Os resultados obtidos indicaram a presença da Giardia sp e Cryptosporidium sp, respectivamente em 27 por cento e 2,5 por cento das amostras analisadas, uma porcentagem de positividade inferior àquela relatada na literatura, principalmente para o Cryptosporidium sp. O teste de postos de Spearman revelou uma correlaçäo significativa, entre as concentraçöes de Giardia sp e os três indicadores de contaminaçäo fecal. Conclusöes. Segundo a Legislaçäo Americana de Monitoramento - ICR ( Information Collection Rule), em 16 dos 28 pontos de captaçäo avaliados seria necessário realizar análise da água tratada para avaliar a eficiência do tratamento na remoçäo dos parasitas. A complexidade dos métodos de analise requer rigoroso programa de Controle de Qualidade Analítica. Algumas deficiências técnicas do método ainda limitam a utilizaçäo os resultados do monitoramento em Saúde Pública.