RESUMO

A incidência da lesão renal aguda caracteriza-se como evento frequente em pacientes críticos internados em Unidades de Terapia Intensiva e está associada ao aumento de mortalidade, causando grande impacto à Saúde Pública. As intercorrências clínicas são minimizadas com intervenções dialíticas, acarretando a exposição do paciente a volumes expressivos de água tratada durante a terapia renal em leito. As análises microbiológicas e de determinação de endotoxinas bacterianas em amostras de água tratada e em soluções de dialisato foram executadas em dois hospitais públicos do município de São Paulo, seguindo metodologias analíticas preconizadas em compêndios oficiais. A avaliação demonstrou que a porcentagem de resultados satisfatórios no período de 2010 a 2022 variou entre 35,2 a 100% e de 40 a 100% para as unidades hospitalares I e II para a água tratada, respectivamente; e, 100% para as soluções de dialisato para a unidade hospitalar I. A eficácia de ações delineadas pelas equipes técnicas das unidades hospitalares, na adequação da água destinada à terapia dialítica, aponta para a importância em estimular outras instituições hospitalares na padronização e implantação de melhoria contínua de seus sistemas de tratamento de água para uso em procedimento dialítico, prevenindo riscos adicionais aos pacientes expostos à terapia renal.

The incidence of acute kidney is high among critically ill patients admitted to Intensive Care Units and is associated with increased mortality, having a major impact on public health. Clinical complications are minimized with dialysis interventions, which expose patients to significant volumes of treated water during in-bed renal therapy. Microbiological analyzes and determination of bacterial endotoxins were performed on treated water samples and dialysate solutions in two public hospitals in São Paulo city, using analytical methodologies recommended in official compendia. The evaluation showed that the percentage of satisfactory results for treated water ranged from 35.2% to 100% in Hospital Unit I and from 40% to 100% in Hospital Unit II between 2010 and 2022. For dialysate solutions in Hospital Unit I, the percentage of satisfactory results was 100% during the same period. The effectiveness of actions implemented by the technical hospital teams, in adapting water for dialysis therapy, points to the importance of encouraging other hospital institutions to standardize and implement a program of continuous improvement for their water treatment systems used in dialysis procedures. This will help to prevent additional risks to patients exposed to renal therapy.

Assuntos

RESUMO

Objetivo: Avaliar a qualidade microbiológica da água de bebedouros destinada ao consumo humano de uma instituição de ensino superior em Caxias do Sul-RS. Métodos: O método utilizado para bactérias heterotróficas foi o spread plate, e, para coliformes totais, Escherichia coli e Pseudomonas aeruginosa sendo que o método é a ausência ou presença com substrato enzimático. Foram coletadas oito amostras, cada uma com aproximadamente 150 mL de água em frascos esterilizados após desinfecção dos bicos dos bebedouros com álcool 70%. Resultados: Na primeira coleta, o bebedouro 4 foi o único que apresentou alterações, com presença de 4,5 x 101 de bactérias heterotróficas, no entanto, este nível estava de acordo com a quantidade permitida. Na segunda coleta, todas as amostras apresentaram positividade para bactérias heterotróficas, porém a amostra de número 3 estava no limite aceito pela legislação, e as demais mostraram resultados superiores a 500 UFC/mL. Todas as amostras foram negativas para as análises de Pseudomonas aeruginosa, coliformes totais e Escherichia coli. Conclusão: Apesar de os resultados terem sido negativos para Pseudomonas aeruginosa, coliformes totais e Escherichia coli, três amostras apresentaram valores superiores ao aceito pela portaria para bactérias heterotróficas, expondo números superiores a 500 UFC/mL. Conclui-se que esta água é considerada inadequada para consumo humano, baseando-se nos padrões de potabilidade estabelecidos pela portaria vigente.

Objective: To evaluate the microbiological quality of drinking water from drinking fountains intended for human consumption at a higher education institution in Caxias do Sul-RS. Methods: The method used for heterotrophic bacteria was spread plate and for total coliforms, Escherichia coli and Pseudomonas aeruginosa the method is absence or presence with enzyme-substrate. Eight samples were collected, each with approximately 150mL of water in sterilized bottles, after disinfection of the drinking nozzles with 70%. Results: In the first collection, the drinker 4 was the only one that presented alterations, with a presence of 4,5 x 10¹ of heterotrophic bacteria, however this level was in agreement with the quantity allowed. In the second sample, all samples were positive for heterotrophic bacteria, but the number 3 sample was within the limit accepted by the legislation, the others showed results higher than 500 CFU/mL. All Samples were negative for the analyzes of Pseudomonas aeruginosa, total coliforms and Escherichia coli. Conclusion: Although the results were negative for Pseudomonas aeruginosa, total coliforms and for Escherichia coli, three samples presented higher values than those accepted by Ministry of Health Ordinance 2914/2011 for heterotrophic bacteria. It is concluded that this water is considered inadequate for human consumption, based on the potability standards established by the aforementioned ordinance

Assuntos

RESUMO

Tannery wastewater is characterized by high and variable concentrations of diverse pollutants, which makes it difficult and costly to treat. In the search for sustainable treatment options for tannery effluents, two pilot-scale horizontal subsurface flow (HSF) constructed wetlands (CW) were built and operated for the treatment of synthetic water of quality similar to that of pre-treated tannery effluents. Five different loading phases were examined with gradual increase of inflow COD, NH4+-N and Cr loads until reaching and exceeding the typical composition of a tannery effluent. High COD and NH4+-N removals were observed (82 and 96%, respectively), and almost complete Cr removal in the outflow, which met the Venezuela national standards for environmental discharge. Plant uptake was measured, but microbial processes appear to be the main ammonium transformation/removal mechanism. Nitrogen, chlorophyll and Cr in the plant aerial parts and roots indicated the capacity of Phragmites sp. to grow and survive even under high loads. The measured heterotrophic bacteria in the substrate and rhizomes indicated the biofilm development and the oxidation of organic matter and nitrogen. Water losses via evapotraspiration were also measured and reached 14%. Overall, the tested CW design proved to be a sustainable and feasible alternative for the treatment of tannery wastewater in tropical climates.

Assuntos

RESUMO

O monitoramento da qualidade da água de diálise caracteriza uma importante ferramenta para a tomada de decisões quando resultados laboratoriais insatisfatórios são disponibilizados em curto período de tempo. Os inconvenientes relacionados ao tempo de espera para a obtenção dos resultados têm conduzido à busca de métodos microbiológicos alternativos que permitam obter dados exatos, precisos e em menor tempo do que os obtidos por métodos clássicos. Este projeto teve por finalidade avaliar o desempenho do método microbiológico alternativo para a contagem de bactérias heterotróficas em água tratada para diálise através da técnica de detecção microbiana pelo uso de fluorescência. Inicialmente foi realizada a determinação do tempo mínimo de incubação para obtenção de valores de contagem confiáveis pelo método alternativo, seguido pela avaliação de desempenho do método contemplando todos os parâmetros estabelecidos em compêndios nacionais e internacionais e a demonstração da equivalência do método alternativo frente ao método tradicional, através da avaliação de 23 amostras de água tratada para diálise. Os resultados demonstraram que o método alternativo permite a quantificação de bactérias heterotróficas após 40 horas de incubação, com exatidão e precisão para o range de 5 a 100 UFC/placa, resultando em uma redução de aproximadamente 67% do tempo atualmente empregado no método tradicional. Portanto, a técnica de detecção microbiana pelo uso de fluorescência se mostrou uma opção viável para a implementação de um método microbiológico rápido para a contagem de bactérias heterotróficas em amostras de água tratada para hemodiálise

Monitoring the quality of dialysis water is an important tool for decision-making when unsatisfactory results are available in a short period of time. The drawbacks related to waiting time for obtaining results have led to the search for alternative microbiological methods that allow accurate data to be obtained in less time than those obtained by classical methods. This project aimed to evaluate the alternative microbiological method performance for the heterotrophic bacteria counts in dialysis treated water through the microbial detection technique using fluorescence. Initially, the determination of the minimum incubation time to obtain reliable count values by the alternative method was performed, followed by the performance evaluation of the method, considering all the parameters established in national and international compendiums and demonstrating the equivalence of the alternative method to the traditional method, through the evaluation of 23 samples of dialysis treated water. The results demonstrated that the alternative method allows quantification of heterotrophic bacteria after 40 hours of incubation, with accuracy and precision for the range of 5 to 100 CFU/plate, resulting in a reduction of approximately 67% of the time currently used in the traditional method. Therefore, the microbial detection technique using fluorescence showed a viable option for the implementation of a rapid microbiological method for the heterotrophic bacteria counts in samples of treated water for hemodialysis

Assuntos

RESUMO

ABSTRACT: Litopenaeus vannamei is the most cultured marine shrimp in all types of systems including the Bioflocs Technology System (BFT). Bioflocs are formed by microorganisms, among these, autotrophic bacteria are responsible for the nitrification process. This study aimed to identify and promote the development of nitrifying bacteria by adding artificial substrates and biofloc inoculum in L. vannamei culture in a BFT system. The experiment consisted of four treatments with three replics (4x3) as follows: (1) Control: clear water in which bioflocs were formed; (2) IN (10%): clear water with biofloc inoculum (10%); (3) IB: clear water with substrate (immature "bioballs"); and (4) MB: clear water with mature "bioballs" inoculum from a recirculation system. Treatments were stocked with shrimp juveniles (4.92±0.45 g) in 12 tanks with 200 L working volume at a stocking density of 200 shrimp/m³. Shrimps were fed twice a day with a commercial feed (38% CP) following a feeding table, and daily observations intake were made over the four weeks of the experiment. Biofloc and "bioballs" samples were collected to detect the growth of the population of nitrifying and heterotrophic bacteria by FISH. There was no significant difference between treatments (P>0.05) for survival, obtaining mean values greater than 88%. The IN (10%) treatment had lower concentrations of ammonia and nitrite, and nitrate concentration increased, while MB had a higher weight and biomass final, productivity, weekly weight gain and lower conversion of apparent feed for production performance results.

RESUMO: Litopenaeus vannamei é o camarão marinho mais cultivado em todos os tipos de sistemas, incluindo o Sistema de Tecnologia de Bioflocos (BFT). Os bioflocos são formados por microorganismos, entre estes, bactérias autotróficas que são responsáveis pelo processo de nitrificação. Este estudo teve como objetivo identificar e promover o desenvolvimento de bactérias nitrificantes pela adição de substratos artificiais e inóculo de bioflocos no cultivo de L. vannamei em sistema BFT. O experimento consistiu de quatro tratamentos com três repetições (4x3), sendo: (1) Controle: água limpa, na qual foram formados os bioflocos; (2) IN (10%): água limpa com inóculo de bioflocos (10%); (3) BI: água limpa com substrato ("bioballs" imaturos); e (4) BM: água limpa com inóculo de "bioballs" maduros de um sistema de recirculação. Para tanto, os tratamentos foram estocados com juvenis de camarão (4,92±0,45 g) em 12 tanques com 200 L de volume útil com densidade de 200 camarões/m³. Os camarões foram alimentados duas vezes ao dia com ração comercial (38% PB) seguindo uma tabela de alimentação, e observações diárias foram feitas ao longo das quatro semanas de experimento. Amostras de bioflocos e "bioballs" foram coletadas para detectar o crescimento da população de bactérias nitrificantes e heterotróficas por FISH. Não houve diferença significativa entre os tratamentos (P>0,05) para sobrevivência, obtendo-se valores médios superiores a 88%. O tratamento com IN (10%) apresentou menores concentrações de amônia e nitrito, e a concentração de nitrato aumentou, enquanto o BM apresentou maior peso e biomassa final, produtividade, ganho de peso semanal e menor conversão alimentar aparente para resultados de desempenho zootécnico.

RESUMO

Litopenaeus vannamei is the most cultured marine shrimp in all types of systems including the Bioflocs Technology System (BFT). Bioflocs are formed by microorganisms, among these, autotrophic bacteria are responsible for the nitrification process. This study aimed to identify and promote the development of nitrifying bacteria by adding artificial substrates and biofloc inoculum in L. vannamei culture in a BFT system. The experiment consisted of four treatments with three replics (4x3) as follows: (1) Control: clear water in which bioflocs were formed; (2) IN (10%): clear water with biofloc inoculum (10%); (3) IB: clear water with substrate (immature bioballs); and (4) MB: clear water with mature bioballs inoculum from a recirculation system. Treatments were stocked with shrimp juveniles (4.92±0.45 g) in 12 tanks with 200 L working volume at a stocking density of 200 shrimp/m³. Shrimps were fed twice a day with a commercial feed (38% CP) following a feeding table, and daily observations intake were made over the four weeks of the experiment. Biofloc and bioballs samples were collected to detect the growth of the population of nitrifying and heterotrophic bacteria by FISH. There was no significant difference between treatments (P>0.05) for survival, obtaining mean values greater than 88%. The IN (10%) treatment had lower concentrations of ammonia and nitrite, and nitrate concentration increased, while MB had a higher weight and biomass final, productivity, weekly weight gain and lower conversion of apparent feed for production performance results.(AU)

Litopenaeus vannamei é o camarão marinho mais cultivado em todos os tipos de sistemas, incluindo o Sistema de Tecnologia de Bioflocos (BFT). Os bioflocos são formados por microorganismos, entre estes, bactérias autotróficas que são responsáveis pelo processo de nitrificação. Este estudo teve como objetivo identificar e promover o desenvolvimento de bactérias nitrificantes pela adição de substratos artificiais e inóculo de bioflocos no cultivo de L. vannamei em sistema BFT. O experimento consistiu de quatro tratamentos com três repetições (4x3), sendo: (1) Controle: água limpa, na qual foram formados os bioflocos; (2) IN (10%): água limpa com inóculo de bioflocos (10%); (3) BI: água limpa com substrato (bioballs imaturos); e (4) BM: água limpa com inóculo de bioballs maduros de um sistema de recirculação. Para tanto, os tratamentos foram estocados com juvenis de camarão (4,92±0,45 g) em 12 tanques com 200 L de volume útil com densidade de 200 camarões/m³. Os camarões foram alimentados duas vezes ao dia com ração comercial (38% PB) seguindo uma tabela de alimentação, e observações diárias foram feitas ao longo das quatro semanas de experimento. Amostras de bioflocos e bioballs foram coletadas para detectar o crescimento da população de bactérias nitrificantes e heterotróficas por FISH. Não houve diferença significativa entre os tratamentos (P>0,05) para sobrevivência, obtendo-se valores médios superiores a 88%. O tratamento com IN (10%) apresentou menores concentrações de amônia e nitrito, e a concentração de nitrato aumentou, enquanto o BM apresentou maior peso e biomassa final, produtividade, ganho de peso semanal e menor conversão alimentar aparente para resultados de desempenho zootécnico.(AU)

Assuntos

RESUMO

RESUMO A quantidade e a qualidade da água potável ingerida estão diretamente relacionadas com a saúde humana. A garantia de segurança e potabilidade depende do funcionamento adequado de etapas que vão desde o tratamento até a distribuição; e, caso alguma delas apresente falhas, pode haver processo de contaminação. Partindo desse pressuposto, objetivou-se com o presente trabalho verificar a qualidade microbiológica da água fornecida em bebedouros de escolas públicas e privadas de ensino fundamental e infantil da cidade de Santa Rita, na Paraíba. As análises de coliformes totais, termotolerantes e bactérias heterotróficas foram realizadas segundo os padrões e metodologias da American Public Health Association. Por meio dos resultados deste trabalho, baseados nos padrões contidos na Portaria nº 2.914, de 12 de dezembro de 2011, do Ministério da Saúde, em relação à contagem de coliformes totais, verificou-se que 100% das amostras apresentavam-se impróprias para consumo, enquanto coliformes termotolerantes foram detectados em 33,33% das amostras). A contagem de bactérias heterotróficas variou entre 1,5x102 e 1,6x103 UFC.mL-1, sendo assim, todas as amostras foram consideradas impróprias ao consumo humano. Sugere-se um rigoroso controle de qualidade e a adoção de boas práticas, tais como tratamento da água, limpezas periódicas e manutenção dos reservatórios, filtros e bebedouros, bem como medidas preventivas e corretivas para manutenção da higiene e do controle microbiológico dos reservatórios de água, de forma a ser disponibilizada água com qualidade.

ABSTRACT The quantity and the quality of drinking water intake are directly related to human health. In order to guarantee the safety and potability of drinking water, a series of steps ranging from treatment to distribution must work properly, and if any of them fails, contamination can occur. Based on this assumption, the aim of the present work was to check the microbiological water quality in drinking fountains from pre-school and elementary public and private schools in the city of Santa Rita, Paraíba, Brazil. The analyzes of total coliforms, thermotolerant bacteria and heterotrophic bacteria were carried out according to the standards and methodologies of the American Public Health Association. Based on the standards from Decree 2,914 of December 12, 2011, from the Brazilian Health Ministry, of the total coliforms, 12 samples (100%) were unfit for consumption, and thermotolerant coliforms were detected in 33.33% of the samples. The heterotrophic bacteria count ranged from 1.5x102 to 1.6x103 CFU.mL-1, and as such, all of the samples were unsuitable for human consumption. Thus, we suggest the implementation of a rigorous maintenance process that monitors and controls hygiene and microbiological contamination in the drinking fountains at these locations. Additionally, we recommend the adoption of preventive and corrective measures such as water treatment, regular cleaning and the maintenance of reservoirs, filters and drinking fountains, in order to provide quality water at these schools.

RESUMO

Abstract The diversity and abundance of retrievable pelagic heterotrophic bacteria in Kongsfjorden, an Arctic fjord, was studied during the summer of 2011 (June, August, and September). Retrievable bacterial load ranged from 103 to 107 CFU L−1 in June, while it was 104-106 CFU L−1 in August and September. Based on 16S rRNA gene sequence similarities, a higher number of phylotypes was observed during August (22 phylotypes) compared to that during June (6 phylotypes) and September (12 phylotypes). The groups were classified into four phyla: Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Bacteroidetes was represented only by a single member Leewenhoekiella aequorea during the three months and was dominant (40%) in June. However, this dominance changed in August to a well-known phytopathogenic species Rhodococcus fascians (32%), which could be a result of decrease in the phytoplankton biomass following the secondary bloom. It is the first report of Halomonas titanicae isolation from the Arctic waters. It showed an increase in its abundance with the intrusion of Atlantic water into Kongsfjorden. Increased abundance of Psychrobacter species in the late summer months coincided with the presence of cooler waters. Thus, the composition and function of heterotrophic bacterial community was fundamentally different in different months. This could be linked to the changes in the water masses and/or phytoplankton bloom dynamics occurring in Arctic summer.

Assuntos

RESUMO

The diversity and abundance of retrievable pelagic heterotrophic bacteria in Kongsfjorden, an Arctic fjord, was studied during the summer of 2011 (June, August, and September). Retrievable bacterial load ranged from 10³ to 107 CFU L1 in June, while it was 104-106 CFU L1 in August and September. Based on 16S rRNA gene sequence similarities, a higher number of phylotypes was observed during August (22 phylotypes) compared to that during June (6 phylotypes) and September (12 phylotypes). The groups were classified into four phyla: Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Bacteroidetes was represented only by a single member Leewenhoekiella aequorea during the three months and was dominant (40%) in June. However, this dominance changed in August to a well-known phytopathogenic species Rhodococcus fascians (32%), which could be a result of decrease in the phytoplankton biomass following the secondary bloom. It is the first report of Halomonas titanicae isolation from the Arctic waters. It showed an increase in its abundance with the intrusion of Atlantic water into Kongsfjorden. Increased abundance of Psychrobacter species in the late summer months coincided with the presence of cooler waters. Thus, the composition and function of heterotrophic bacterial community was fundamentally different in different months. This could be linked to the changes in the water masses and/or phytoplankton bloom dynamics occurring in Arctic summer.(AU)

Assuntos

RESUMO

The diversity and abundance of retrievable pelagic heterotrophic bacteria in Kongsfjorden, an Arctic fjord, was studied during the summer of 2011 (June, August, and September). Retrievable bacterial load ranged from 103 to 107CFUL-1 in June, while it was 104-106CFUL-1 in August and September. Based on 16S rRNA gene sequence similarities, a higher number of phylotypes was observed during August (22 phylotypes) compared to that during June (6 phylotypes) and September (12 phylotypes). The groups were classified into four phyla: Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Bacteroidetes was represented only by a single member Leewenhoekiella aequorea during the three months and was dominant (40%) in June. However, this dominance changed in August to a well-known phytopathogenic species Rhodococcus fascians (32%), which could be a result of decrease in the phytoplankton biomass following the secondary bloom. It is the first report of Halomonas titanicae isolation from the Arctic waters. It showed an increase in its abundance with the intrusion of Atlantic water into Kongsfjorden. Increased abundance of Psychrobacter species in the late summer months coincided with the presence of cooler waters. Thus, the composition and function of heterotrophic bacterial community was fundamentally different in different months. This could be linked to the changes in the water masses and/or phytoplankton bloom dynamics occurring in Arctic summer.

Assuntos

RESUMO

Pico and nanoplankton communities from the Southwest Atlantic Ocean along the Brazilian Bight are poorly described. The hydrography in this region is dominated by a complex system of layered water masses, which includes the warm and oligotrophic Tropical Water (TW), the cold and nutrient rich South Atlantic Central Water (SACW) and the Coastal Water (CW), which have highly variable properties. In order to assess how pico- and nanoplankton communities are distributed in these different water masses, we determined by flow cytometry the abundance of heterotrophic bacteria, Prochlorococcus, Synechococcus and autotrophic pico and nanoeukaryotes along three transects, extending from 23°S to 31°S and 39°W to 49°W. Heterotrophic bacteria (including archaea, maximum of 1.5 × 106 cells mL-1) were most abundant in Coastal and Tropical Water whereas Prochlorococcus was most abundant in open-ocean oligotrophic waters (maximum of 300 × 103 cells mL-1). Synechococcus(up to 81 × 103 cells mL-1), as well as autotrophic pico and nanoeukaryotes seemed to benefit from the influx of nutrient-rich waters near the continental slope. Autotrophic pico and nanoeukaryotes were also abundant in deep chlorophyll maximum (DCM) layers from offshore waters, and their highest abundances were 20 × 103 cells mL-1 and 5 × 103 cells mL-1, respectively. These data are consistent with previous observations in other marine areas where Synechococcus and autotrophic eukaryotes dominate mesotrophic waters, whereas Prochlorococcus dominate in more oligotrophic areas. Regardless of the microbial community structure near the surface, the carbon stock dominance by autotrophic picoeukaryotes near the DCM is possibly linked to vertical mixing of oligotrophic surface waters with the nutrient-rich SACW and their tolerance to lower light levels.

RESUMO

Abstract:Community structure and composition are dictated by evolutionary and ecological assembly processes which are manifested in signals of, species diversity, species abundance and species relatedness. Analysis of species coexisting relatedness, has received attention as a tool to identify the processes that influence the composition of a community within a particular habitat. In this study, we tested if microbialite genetic composition is dependent on random events versus biological/abiotical factors. This study was based on a large genetic data set of two hypervariable regions (V5 and V6) from previously generated barcoded 16S rRNA amplicons from nine microbialite communities distributed in Northeastern, Central and Southeastern Mexico collected in May and June of 2009. Genetic data of the most abundant phyla (Proteobacteria, Planctomycetes, Verrucomicrobia, Bacteroidetes, and Cyanobacteria) were investigated in order to state the phylogenetic structure of the complete communities as well as each phylum. For the complete dataset, Webb NTI index showed positive and significant values in the nine communities analysed, where values ranged from 31.5 in Pozas Azules I to 57.2 in Bacalar Pirate Channel; meanwhile, NRI index were positive and significant in six of the nine communities analysed with values ranging from 18.1 in Pozas Azules I to 45.1 in Río Mesquites. On the other hand, when comparing each individual phylum, NTI index were positive and significant in all groups, except in Cyanobacteria for which positive and significant values were only found in three localities; finally, NRI index was significant in only a few of the comparisons performed. The results suggest that habitat filtering is the main process that drives phylogenetic structure in bacterial communities associated to microbialites with the exception of Cyanobacteria where different lineages can contribute to microbialite formation and growth. Rev. Biol. Trop. 64 (3): 10571065. Epub 2016 September 01.

ResumenLa estructura y composición de las comunidades son determinadas por procesos evolutivos y ecológicos que se manifiestan en señales de diversidad, abundancia y la relación de especies. El análisis de la relación de especies que coexisten ha recibido atención como una herramienta para identificar los procesos que influyen en la composición de una comunidad dentro de un hábitat particular. En este estudio, evaluamos si la composición genética de bacterias microbialíticas depende de acontecimientos al azar vs factores biológicos/ abióticos. Este estudio se basa en un conjunto de datos genéticos de dos regiones hipervariables (V5 y V6) de gen 16S rRNA generados previamente de nueve comunidades de microbialitos distribuidos en el Noreste, Centro y Sureste de México, recolectados en mayo y junio 2009. Los datos genéticos de los filos más abundantes (Proteobacteria, Planctomycetes, Verrucomicrobia, Bacteroidetes y Cyanobacteria) fueron analizados para determinar la estructura filogenética de la comunidad y de cada filo por separado. Para el análisis conjunto, el índice NTI de Webb mostró valores positivos y significativos en las nueve comunidades analizadas, en donde los valores oscilaron entre 31.5 en Pozas Azules I y 57.2 en el Canal Pirata en Bacalar; en contraste, los valores del índice NRI fueron positivos y significativos en seis de las nueve comunidades analizadas con valores oscilando desde 18.1 en Pozas Azules I hasta 45.1 en Río Mezquites. Por otro lado, en la comparación de cada filo individual, el índice NTI fue positivo y significativo en todos los grupos excepto en Cyanobacteria, en donde valores positivos y significativos fueron encontrados sólo en tres localidades; finalmente, el índice NRI fue significativo sólo en unas cuantas de las comparaciones realizadas. Los resultados sugieren que el filtrado del hábitat es el proceso principal que determina la estructura filogenética de las comunidades bacterianas asociadas a microbialitos con la excepción de las cianobacterias en donde diferentes linajes pueden contribuir a la formación y crecimiento del microbialito.

Assuntos

RESUMO

Oxygen minimum zones (OMZs), characterized by depleted dissolved oxygen concentration in the intermediate depth of the water column, are predicted to expand under the influence of global warming. Recent studies in the Eastern Tropical South Pacific Ocean and Arabian Sea have reported that heterotrophic nitrogen fixation is active in the OMZs. In this study, we investigated the community structure of diazotrophs in the OMZ of the Costa Rica Dome (CRD) upwelling region in the Eastern Tropical North Pacific Ocean, using 454-pyrosequencing of nifH gene amplicons. Comparing diazotroph assemblages in different depth strata of the OMZ (200-1000 m in depth), we found a unique diazotroph community in the OMZ core, which was mainly dominated by methanotroph-like diazotrophs, suggesting a potential coupling of nitrogen cycle and methane assimilation. In addition, some OTUs revealed in this study, especially those belonging to the large sub-cluster Vibrio diazotrophicus, were reported to be abundant and expressing the nifH gene in other OMZs. Our results suggest that the unique hydrographic conditions in OMZs may support similar assemblages of diazotrophs, and heterotrophic nitrogen fixation could also be occurring in our studied region. Our study provides the first insight into the composition and distribution of putative diazotrophs in the CRD OMZ.

RESUMO

Coastal areas may be impacted by human and industrial activities, including contamination by wastewater, heavy metals and hydrocarbons. This study aimed to evaluate the impact of hydrocarbons (TPH) and metals on the microbiota composition and abundance in two estuarine systems in the coast of São Paulo: the Santos (SE) and Itanhaém (IE) estuaries. The SE was found to be chronically contaminated by heavy metals and highly contaminated by hydrocarbons. This finding was correlated with the increased density of cyanobacteria in sediments and suggests the possible use of cyanobacteria for bioremediation. These contaminants influence the density and composition of estuarine microbiota that respond to stress caused by human activity. The results are troubling because quantitative and qualitative changes in the microbiota of estuarine sediments may alter microbiological processes such as decomposition of organic matter. Moreover, this pollution can result in damage to the environment, biota and human health.

Assuntos

RESUMO

Infectious diseases in renal patients may be associated with the dialysis water quality, which may be contaminated with microorganisms. In Brazil, the water quality is evaluated by analyzing total coliforms, heterotrophic bacteria, and bacterial endotoxin, but not Pseudomonas sp. and fungi. Water samples from haemodialysis units in Curitiba/PR were investigated on their conformity with the standard established by the Brazilian Health Ministry. Total coliforms, heterotrophic bacteria,P. aeruginosa and fungi counts were performed according to APHA, and LAL methodology for detecting bacterial endotoxin. All of the samples showed the total coliforms counts ≤1.1 MPN/100 mL,and ≥ 95 % of analyzed samples complied with the standards for heterotrophic bacteria counting.P. aeruginosa was recovered from 4 % of samples. In 15 % of samples, bacterial endotoxin was detected in values above the limit established by legislation. Yeasts were isolated from 26 % samples and filamentous fungi from 58 %, being 46 % characterized as melanized fungi. The fungi genera were Cladosporium spp., Penicillium spp., Beauveria spp., Exophiala spp., Fusarium spp., Aspergillus spp., Trichoderma spp, Acremonium spp. and Rinocladiella spp.. The study highlights the significance ofP. aeruginosa and fungi detection in those systems, as these microorganisms are potentially pathogenic to immunocompromised patients...

Assuntos

RESUMO

Infectious diseases in renal patients may be associated with the dialysis water quality, which may be contaminated with microorganisms. In Brazil, the water quality is evaluated by analyzing total coliforms, heterotrophic bacteria, and bacterial endotoxin, but not Pseudomonas sp. and fungi. Water samples from haemodialysis units in Curitiba/PR were investigated on their conformity with the standard established by the Brazilian Health Ministry. Total coliforms, heterotrophic bacteria, P. aeruginosa and fungi counts were performed according to APHA, and LAL methodology for detecting bacterial endotoxin. All of the samples showed the total coliforms counts 1.1 MPN/100 mL,and 95 % of analyzed samples complied with the standards for heterotrophic bacteria counting. P. aeruginosa was recovered from 4 % of samples. In 15 % of samples, bacterial endotoxin was detected in values above the limit established by legislation. Yeasts were isolated from 26 % samples and filamentous fungi from 58 %, being 46 % characterized as melanized fungi. The fungi genera were Cladosporium spp., Penicillium spp., Beauveria spp., Exophiala spp., Fusarium spp., Aspergillus spp., Trichoderma spp, Acremonium spp. and Rinocladiella spp.. The study highlights the significance of P. aeruginosa and fungi detection in those systems, as these microorganisms are potentially pathogenic to immunocompromised patients(AU)

Doenças infecciosas em pacientes renais podem ser associadas à qualidade da água de diálise, que pode apresentar contaminação com microrganismos. Pelos padrões brasileiros, a qualidade da água é avaliada analisando-se coliformes totais, bactérias heterotróficas e endotoxinas bacterianas. Pseudomonas sp. e fungos não são investigados. Amostras de água de clínicas de hemodiálise em Curitiba/PR foram avaliadas quanto à conformidade com os padrões do Ministério da Saúde. Contagens de coliformes totais, bactérias heterotróficas, Pseudomonas aeruginosa e fungos foram realizadas seguindo-se APHA e detecção de endotoxina pela metodologia LAL. Todas as amostras tiveram contagens de coliformes totais abaixo de 1,1 MPN/100 mL e 95 % das amostras apresentaram padrões aceitáveis para bactérias heterotróficas. P. aeruginosa foi encontrada em quatro amostras. Em 15 % das amostras, endotoxinas bacterianas foram detectadas em valores acima dos permitidos pela legislação. Leveduras foram isoladas em 26 % das amostras e fungos filamentosos em 58 %, sendo 46 % melanizados e 27 % hialinos. Os gêneros fúngicos detectados foram Cladosporium spp., Penicillium spp., Beauveria spp., Exophiala spp., Fusarium spp., Aspergillus spp., Trichoderma spp, Acremonium spp. e Rinocladiella spp.. Foi evidenciada a importância da detecção de P. aeruginosa e fungos nestes sistemas, uma vez que estes podem ser potencialmente patogênicos para pacientes imunocomprometidos(AU)

Assuntos

RESUMO

Heterotrophic CaCO3-precipitating bacteria were isolated from biofilms on deteriorated ignimbrites, siliceous acidic rocks, from Morelia Cathedral (Mexico) and identified as Enterobacter cancerogenus (22e), Bacillus sp. (32a) and Bacillus subtilis (52g). In solid medium, 22e and 32a precipitated calcite and vaterite while 52g produced calcite. Urease activity was detected in these isolates and CaCO3 precipitation increased in the presence of urea in the liquid medium. In the presence of calcium, EPS production decreased in 22e and 32a and increased in 52g. Under laboratory conditions, ignimbrite colonization by these isolates only occurred in the presence of calcium and no CaCO3 was precipitated. Calcium may therefore be important for biofilm formation on stones. The importance of the type of stone, here a siliceous stone, on biological colonization is emphasized. This calcium effect has not been reported on calcareous materials. The importance of the effect of calcium on EPS production and biofilm formation is discussed in relation to other applications of CaCO3 precipitation by bacteria.

Assuntos

RESUMO

A qualidade microbiológica e físico-química de amostras de água fora dos padrões legais permitidos tem contribuído para o aumento do consumo de água envasada por parte da população. Objetivou-se verificar a qualidade microbiológica e físico-química de quatro marcas de água mineral comercializadas no município de São Mateus, ES. Para a detecção de coliformes totais, Escherichia coli e Salmonella spp. utilizou-se kit microbiológico Tecnobac® e para contagem de bactérias heterotróficas utilizou-se a técnica de semeadura em profundidade. Para as análises físicoquímicas utilizou-se kit analítico Ecokit®. Verificou-se o pH, a condutividade, além da análise de ferro. Os resultados das análises microbiológicas demonstraram que todas as marcas de água mineral investigadas estavam em conformidade com a Portaria 2914/2011 em relação aos coliformes totais e E. coli. Constatou-se a ausência de Salmonella spp. em todas as amostras. Com relação à contagem de bactérias heterotróficas, 5 amostras (13,89%) excederam o limite máximo permitido, estando em desacordo com a legislação vigente. As análises físico-químicas demonstraram que 25 amostras (55,56%) obtiveram valores fora dos padrões preconizados pela portaria. Sugere-se a implementação de Boas Práticas de Fabricação (BPF) e de ações conjuntas com os responsáveis pelas empresas, de forma a garantir a saúde da população.

The microbiological and physicochemical quality of water samples out of permitted legal standards has contributed to the increased consumption of bottled water by the population. It has been our objective to verify the microbiological and physicochemistry quality of four brands of bottled water sold in the town of São Mateus-ES. We have used microbiological sekit Tecnobac® for detection of total coliforms, Escherichia coli and Salmonella spp and; for counting heterotrophic bacteria we have used the pour plate technique. For physical and chemical analyzes we have used Ecokit sekit ®. We have verified the pH and conductivity as well as analysis of iron. The microbiological analysis showed that all brands of mineral water were investigated in accordance with Ordinance 2914/2011 in relation to total coliforms and E.coli. We have noted the absence of Salmonella spp. in all samples. In relation to the count of heterotrophic bacteria, five samples (13.89%) exceeded the maximum allowed, which is in disagreement with the current legislation. The physical-chemical analyzes showed that 25 samples (55.56%) had values outside the standards recommended by the Ordinance. It is suggested the implementation of Good Manufacturing Practices (GMP) and joint actions with the companies and their staff to ensure the health of the population.

Assuntos

RESUMO

Substantial amounts of organic matter (OM) from terrestrial ecosystems are buried as sediments in inland waters. It is still unclear to what extent this OM constitutes a sink of carbon, and how much of it is returned to the atmosphere upon mineralization to carbon dioxide (CO2). The construction of reservoirs affects the carbon cycle by increasing OM sedimentation at the regional scale. In this study we determine the OM mineralization in the sediment of three zones (river, transition, and dam) of a tropical hydroelectric reservoir in Brazil as well as identify the composition of the carbon pool available for mineralization. We measured sediment organic carbon mineralization rates and related them to the composition of the OM, bacterial abundance and pCO2 of the surface water of the reservoir. Terrestrial OM was an important substrate for the mineralization. In the river and transition zones most of the OM was allochthonous (56 and 48%, respectively) while the dam zone had the lowest allochthonous contribution (7%). The highest mineralization rates were found in the transition zone (154.80 ± 33.50 mg C m(-) (2) d(-) (1)) and the lowest in the dam (51.60 ± 26.80 mg C m(-) (2) d(-) (1)). Moreover, mineralization rates were significantly related to bacterial abundance (r (2) = 0.50, p < 0.001) and pCO2 in the surface water of the reservoir (r (2) = 0.73, p < 0.001). The results indicate that allochthonous OM has different contributions to sediment mineralization in the three zones of the reservoir. Further, the sediment mineralization, mediated by heterotrophic bacteria metabolism, significantly contributes to CO2 supersaturation in the water column, resulting in higher pCO2 in the river and transition zones in comparison with the dam zone, affecting greenhouse gas emission estimations from hydroelectric reservoirs.

RESUMO

The study verified sanitary aspects in fish ponds with sequential disposal and the effect of the tanks effluent in parallel in the system. Six fish ponds were studied in the dry and the rainy periods and were analyzed microbiological aspects (thermo tolerant coliforms, total coliforms and heterotrophic bacteria), DBO5 and DQO. It had contamination in the water of supplying for thermo tolerant coliforms, either of human or animals, compromising all the fish ponds studied with sanitary indices undesirable and representing risk in the cultivation of fish. It was found a great contamination of thermo tolerant coliforms, total coliforms, and heterotrophic bacteria in the period of rains with significant differences for DBO5 and total coliforms variables in relation to the showed periods. The high temperatures and the waters of draining had favored the high level of coliforms and heterotrophic bacteria in the period of rains. Through the results was concluded that the parallel tanks and the rainy period had had greater influence that the proper sequential disposal of the fisheries.

O estudo verificou aspectos sanitários em viveiros de criação de peixes com disposição seqüencial e o efeito dos efluentes de tanques em paralelo no sistema. Foram estudados seis viveiros de criação de peixes nos períodos de chuva e seca e analisados aspectos microbiológicos (coliformes termotolerantes, totais e bactérias heterotróficas), DBO5 e DQO. Houve contaminação na água de abastecimento por coliformes termotolerantes, seja de origem humana ou animal, comprometendo todos os viveiros estudados com índices sanitários indesejáveis e representando risco na criação de peixes. Foi encontrado um maior aporte de coliformes totais e bactérias heterotróficas no período de chuvas com diferenças significativas nos períodos amostrados em relação à DBO5 e coliformes totais. As altas temperaturas e as águas de escoamento favoreceram as concentrações elevadas de coliformes e bactérias heterotróficas no período de chuvas. Através dos resultados obtidos concluiu-se que os tanques paralelos e o período chuvoso tiveram maior influência que a própria disposição seqüencial dos viveiros.

Assuntos