Numerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750–4 400 000 population equivalents) from 13 countries spanning six continents. In addition, genetic markers were tested against 280 human and nonhuman fecal samples from domesticated, agricultural and wild animal sources. Findings revealed that all genetic markers are present in consistently high concentrations in raw (median log10 7.2–8.0 marker equivalents (ME) 100 mL–1) and biologically treated wastewater samples (median log10 4.6–6.0 ME 100 mL–1) regardless of location and population. The false positive rates of the various markers in nonhuman fecal samples ranged from 5% to 47%. Results suggest that several genetic markers have considerable potential for measuring human-associated contamination in polluted environmental waters. This will be helpful in water quality monitoring, pollution modeling and health risk assessment (as demonstrated by QMRAcatch) to guide target-oriented water safety management across the globe.
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.
Regulating recreational water exposure to pathogens within the tropics is a major public health and economic concern. Although numerous epidemiological studies estimating the risk to recreational marine water exposure have been conducted since the 1950s, few studies have been done in the tropics. Furthermore, many have suggested that the use of fecal indicator bacteria for monitoring recreational water quality in temperate regions is not appropriate in the tropics. We analyzed a large cohort study of five beaches in Sao Paulo, Brazil, conducted during consecutive weekends in the summer of 1999 that estimated risk to water, sand, and food exposures. Enterococci and Escherichia coli concentrations were measured each day of the study. Elevated risks were estimated for both swimming (OR = 1.36 95% CI: 1.05-1.58) and sand contact (OR = 1.29 95% CI 1.05-1.58). A 1 log increase in enterococci concentration was associated with an 11% increase in risk (OR = 1.11 95% CI: 1.04-1.19). For E. coli a 1-log increase in concentration was associated with 19% increase in risk (OR = 1.19 95% CI: 1.14-1.28). Most countries with beaches in the tropics are lower or middle income countries (LMIC) and rely on tourism as a major source of income. We present data that suggests fecal indicator bacteria such as enterococci are an appropriate indicator of risk in tropical urban settings where contamination is coming from predominantly human sources. Additional studies in tropical settings could help inform and refine guidelines for safe use of recreational waters.
MALDI-TOF MS enabled the identification of rare pathogens related to UTI which may represent higher risk for porcine health, especially considering high frequency of multiresistant profiles.
Aeromonads are inhabitants of aquatic ecosystems and are described as being involved in intestinal disturbances and other infections. A total of 200 drinking water samples from domestic and public reservoirs and drinking fountains located in Sã o Paulo (Brazil), were analyzed for the presence of Aeromonas. Samples were concentrated by membrane filtration and enriched in APW. ADA medium was used for Aeromonas isolation and colonies were confirmed by biochemical characterization. Strains isolated were tested for hemolysin and toxin production.Aeromonas was detected in 12 samples (6.0%). Aeromonas strains (96)
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