Insights into multiple use water enterobacteria from the Brazilian semi-arid: the first approach by pyrosequencing

Thousands of people living in semi-arid regions face problems of drought and loss of water quality. In addition, high incidence of acute diarrheal diseases related to water consumption has been responsible for a high number of deaths and high economic costs for human health. Many of the diseases can be caused by the presence of enterobacteria in reservoirs that serve for multiple purposes. This study aimed to confirm the presence of potentially harmful bacteria, which was highlighted in other articles, and to reveal non-identified genera by culture-dependent methods and pyrosequencing. Twenty-three genera of the Enterobacteriaceae family were detected, with emphasis on Escherichia genus and confirmation of the presence of species such as Salmonella enterica and Enterobacter cloacae. The abundance of heterotrophic prokaryotes and the physical and chemical data show an expected average for this type of environment due to the numbers historically presented in previous articles. The unprecedented detection of the presence of some potentially pathogenic species can alert and raise awareness of the populations that use stored water in the semi-arid regions. Consequently, as a result of the peculiar characteristics of reservoirs under this climate influence, there is a cosmopolitanism of enterobacteria that may be related to the alarming numbers of infections from Waterborne Diseases.

Insights into multiple use water enterobacteria from the Brazilian semi-arid: the first approach by pyrosequencing

Thousands of people living in semi-arid regions face problems of drought and loss of water quality. In addition, high incidence of acute diarrheal diseases related to water consumption has been responsible for a high number of deaths and high economic costs for human health. Many of the diseases can be caused by the presence of enterobacteria in reservoirs that serve for multiple purposes. This study aimed to confirm the presence of potentially harmful bacteria, which was highlighted in other articles, and to reveal non-identified genera by culture-dependent methods and pyrosequencing. Twenty-three genera of the Enterobacteriaceae family were detected, with emphasis on Escherichia genus and confirmation of the presence of species such as Salmonella enterica and Enterobacter cloacae. The abundance of heterotrophic prokaryotes and the physical and chemical data show an expected average for this type of environment due to the numbers historically presented in previous articles. The unprecedented detection of the presence of some potentially pathogenic species can alert and raise awareness of the populations that use stored water in the semi-arid regions. Consequently, as a result of the peculiar characteristics of reservoirs under this climate influence, there is a cosmopolitanism of enterobacteria that may be related to the alarming numbers of infections from Waterborne Diseases.(AU)

Bacterioplankton and abiotic variables as indicators of water quality in shrimp ponds of the tropical region (Northeastern, Brazil) / Bacterioplâncton e variáveis abióticas como indicadores de qualidade da água de viveiros de camarão em região tropical (Nordeste, Brasil)

  This work aimed to determine density of the bacterioplankton in two shrimp ponds in Northeastern Brazil during complete cultivate cycles of the Litopenaeus vannamei shrimp, as well as to evaluate correlated variables that influence the water quality and the dynamics of these ecosystems. The study was carried out in two shrimp ponds: one of them with fresh water, and another with marine water. Chlorophyll-a, total phosphorus, pH, dissolved oxygen, salinity, temperature and transparency were verified. Bacterial densities were determined by fluorescence microscopy. A model of the logarithm of the mean as a linear function of observed covariates was carried out. The result is a generalized linear model with Poisson response and link log. Both ponds, characterized as eutrophic environments, presented high densities of bacterioplankton (0.51 x 108 to 1.72 x 108 org mL-1), and high concentrations of chlorophyll-a and total phosphorus. The study highlights the importance of the adequate management techniques to maintain the water quality in shrimp ponds and its effluents.

O presente trabalho objetivou determinar a densidade do bacterioplâncton em dois viveiros de camarão no Nordeste do Brasil durante ciclos completos de cultivo do camarão Litopenaeus vannamei, bem como avaliar as variáveis que influenciam a qualidade da água e a dinâmica desses ecossistemas. O estudo foi realizado em duas fazendas de camarão: uma de água doce e outra de água salgada. Foram verificados clorofila-a, fósforo total, pH, oxigênio dissolvido, salinidade, temperatura e transparência da água. A densidade bacteriana foi determinada por microscopia de fluorescência. Uma modelagem do logaritmo da média como uma função linear das covariáveis observadas foi desenvolvida. O resultado foi um modelo linear generalizado com resposta de Poisson e função de ligação logarítmica. Os viveiros estudados, caracterizados como ambientes eutrofizados, apresentaram elevada densidade do bacterioplâncton (0,51 x 108 a 1,72 x 108 org mL-1) e altas concentrações de clorofila-a e fósforo total. O estudo alerta para a necessidade de técnicas de gerenciamento adequadas visando manter a qualidade da água dos viveiros de camarão e dos seus efluentes.