Estudo microbiológico de águas de poços artesianos para consumo humano na região de Santa Maria, RS / Microbiological study of artesian wells water for human consumption in the region of Santa Maria, RS

Objetivo: A água é de extrema importância para a saúde humana e essencial para a sobrevivência dos seres vivos. Águas subterrâneas de poços artesianos são menos contaminadas por não estarem expostas aos poluentes. Este estudo efetuou a análise microbiológica de águas de poços artesianos para o consumo humano. Métodos: As análises foram realizadas no Laboratório de Análises Microbiológicas, Departamento de Microbiologia e Parasitologia, Centro de Ciências da Saúde da Universidade Federal de Santa Maria. Através da técnica dos tubos múltiplos e do número mais provável por mililitro de amostra se obteve a contagem de coliformes totais e coliformes termotolerantes. A contagem de bactérias heterotróficas foi realizada em placas de Petri com meio Ágar Padrão Contagem. E a pesquisa e confirmação de Escherichia coli por Ágar Eosina Azul de Metileno e testes bioquímicos, respectivamente. Resultados: Verificou-se que 68% das amostras estavam próprias para consumo humano, em 21% foi emitido um alerta e 11% estavam impróprias. Foi confirmada E. coli em 96% das amostras impróprias. Além disso, Pseudomonas aeruginosa foi encontrada em oito das amostras analisadas. Em relação ao tratamento com cloro, 85% das amostras cloradas estavam próprias. Dividiu-se o estudo em quatro períodos para efetuar um comparativo da potabilidade, o último período do estudo demonstrou um maior nível de potabilidade quando comparado ao primeiro. Conclusão: Estes dados são de grande relevância para a população e a conscientizam sobre um controle microbiológico frequente a fim de obter níveis menores ou isentos de bactérias, evitando contaminações que podem ser nocivas à saúde humana.

Objective: Water is very important for human health and essential to survival of living beings. Groundwater from artesian wells is the least contaminated because it is not exposed to pollutants. This study performed the microbiological analysis of artesian well water to human consumption. Methods: These analyses were performed at the Microbiological Analysis Laboratory, Department of Microbiology and Parasitology, Health Sciences Center of the Federal University of Santa Maria. Using the multiple tube technique and the Most Probable Number per milliliter of the sample, the Total Coliform and Thermotolerant Coliform counts were obtained. Heterotrophic Bacteria counts were performed in Plate Count Agar Petri dishes. And the research and confirmation of Escherichia coli by Methylene Blue Eosin Agar and biochemical tests, respectively. Results: Checked that 68% of the samples were found to be safe to human consumption, 21% were alerted and 11% were inappropriate. E. coli was confirmed in 96% of improper samples. In addition, Pseudomonas aeruginosa was found in eight of the samples analyzed. Regarding chlorine treatment, 85% of chlorinated samples were safe to human consumption. The study was divided into four periods to make a potability comparison, the last period of the study showed a higher level of potability when compared to the first one. Conclusion: These data are of great relevance to the population and make them aware of frequent microbiological control in order to obtain lower or bacteria-free levels. This avoids contamination that can be harmful to human health.

E-ADA activity in lymphocytes of an experimental model of pythiosis treated with immunotherapy.

Pythiosis is a life-threatening disease caused by the oomycete Pythium insidiosum. Some authors have suggested the involvement of a Th2-like immune response in the infected host, which leads to extensive tissue damage. The switch from a Th2 to a Th1 response pattern is one hypothesis to explain the curative properties of immunotherapy. Taking into account the importance of immunotherapy for pythiosis treatment and the contribution of adenine nucleotides in the immunoregulation of the host, we evaluated the ecto-adenosine deaminase (E-ADA; EC 3·5.4·4) activity in lymphocytes from rabbits inoculated with P. insidiosum. Rabbits were inoculated with 1 milliliter of zoospores subcutaneously injected into the lateral thorax; after developing lesions, the rabbits received eight doses of immunotherapy. E-ADA activity was measured in lymphocytes and the adenine nucleotides and adenosine levels were quantitatively determined in serum. Rabbits with characteristic lesions of pythiosis showed a decreased E-ADA activity (82·36%), a decreased adenosine triphosphate concentration (54·04%) and a higher adenosine concentration (2·51 fold), when compared with controls, after 28 days of inoculation. However, after the immunotherapy, the rabbits showed an increase in the E-ADA activity when compared with control (78·62%), contributing for the change in the immune response. Our results reinforce the hypothesis that the change from a Th2 to a Th1 immune response with the participation of the purinergic system could be responsible for the curative properties of immunotherapy.

Immunotherapy for pythiosis: Effect on NTPDase activity in lymphocytes of an experimental model.

NTPDase (EC 3.6.1.5) occurs in lymphocytes and plays an important role in immune function, in that hydrolyzes extracellular nucleoside tri- and/or diphosphates to form AMP. Pythium insidiosum causes the disease pythiosis, a pyogranulomatous disease of horses, dogs, cattle, cats and humans. Most antifungal drugs are ineffective against this pathogen, and immunotherapy, a treatment approach that relies on the injection of P. insidiosum antigen, has been successfully used in humans and horses to manage this disease. In this study, we investigated NTPDase activity in lymphocytes from rabbits inoculated with zoospores of P. insidiosum. After immunotherapy, we investigated the relationship between enzymatic activity and the pattern of the immune response. One milliliter of zoospores was inoculated subcutaneously into the coastal region of each rabbit. An average of 17,500 viable mobile zoospores/mL of induction medium was administered. Inoculated rabbits were checked weekly, and the subcutaneous nodular area (cm²) was measured 28 days after inoculation. Rabbits that developed lesions received four doses of immunotherapy at intervals of 14 days. Blood samples were collected by heart puncture twice a month for the determination of NTPDase activity. The results demonstrated that NTPDase activity in lymphocytes was increased in relation to ATP hydrolysis (by about 100%) in pythiosis and returned to normal values after immunotherapy. The data demonstrating NTPDase activity before and after immunotherapy reinforce the previously elaborated hypothesis that the change from a Th2 to a Th1 immune response is responsible for the curative properties of immunotherapy.