5 research outputs found
The occurrence of Aeromonas spp. in the bottled mineral water, well water and tap water from the municipal supplies
The aim of this work was to study the occurrence of Aeromonas sp in the bottled mineral water, well water and tap water from the municipal supplies. Positive samples were found for Aeromonas spp. 12.7% from the mineral water, 8.3% from the artesian water and 6.5% from the tap water. The recovery of Aeromonas spp. was significantly higher in the bottled mineral and artesian water than in the tap water from municipal supplies. The occurrence of the Aeromonas spp. did not correlate significantly with the contamination indicator bacteria (i.e. total coliforms) in the artesian water samples. However, a significant correlation was found between Aeromonas spp. and total coliforms in the both mineral water and tap water samples. The presence or absence of a correlation between the indicator bacteria and Aeromonas could reflect the occasional appearance of the pathogen in the drinking water and the different rates of survival and recovery of these agents compared with those fecal indicators. The finding that 41.6, 14.8 and 9.0 % of the artesian water, bottled mineral water and tap water, respectively, sampled in the current study failed to meet the Brazilian standard for total coliforms in the drinking water should therefore be of concern.<br>A porcentagem de amostras positivas para Aeromonas foi de 12.7% para água mineral, 8.3% para água de poço artesiano e 6.5% para água do sistema público de abastecimento. O isolamento de Aeromonas spp. foi significativamente maior em água mineral e água de poço artesiano do que em água do sistema público. A ocorrência de Aeromonas spp. não teve correlação significativa com os indicadores de contaminação tradicionalmente utilizados (coliformes totais) em amostras de água de poço artesiano. No entanto, esta correlação foi positiva e significativa em água mineral e água do sistema público. A presença ou ausência de correlação entre bactérias indicadoras e a presença de Aeromonas pode refletir o aparecimento ocasional de patógenos em águas para consumo humano e as diferentes taxas de sobrevivência e isolamento destes agentes comparados com os indicadores fecais de contaminação. A constatação de que 41.6%, 14.8% e 9.0% respectivamente amostras de água de poço, água mineral e água do abastecimento público utilizadas neste estudo apresentaram índices de coliformes maiores do que os aceitáveis pela legislação brasileira é um fato preocupante. Estes números mostram a necessidade de melhoria nos sistemas de monitoramento para a indústria de águas minerais e o sistema público de abastecimento. As cepas isoladas pertencentes ao gênero Aeromonas foram identificadas ao nível de espécie como A. hydrophila e A. jandaei. A significância do grande número de isolamentos de espécies de Aeromonas em saúde pública ainda não está clara. É necessário o estudo dos efeitos de cepas específicas utilizando modelos animais de infecção. Estes resultados podem contribuir para a reavaliação dos critérios empregados para a análise da qualidade microbiológica da água e a definição de limites de densidades para o gênero Aeromonas em águas destinadas ao consumo humano
Control strategies to combat dissemination of antibiotic resistance in urban water systems
The intensive use of antibiotics for medical, veterinary, or agricultural purposes results in the continuous release of antibiotics into the environment, leading to the increasingly widespread occurrence of antibiotic resistance. Although antibiotic resistance has been recognized as a major threat to human health worldwide, the related phenomenon occurring in natural and engineered environments has so far been largely overlooked. The urban (including industrial) water cycle, which connects urban life, agriculture, and the environment, is potentially a hot spot for the spread of antibiotic resistance. Therefore, better understanding of the distribution and transportation of antibiotic-resistant bacteria (ARB) and acquisition of antibiotic resistance genes (ARGs) in the urban water cycle is critically important to improve the control of this emerging environmental and human health challenge. In this book chapter, we comprehensively review the occurrence, transfer, and acquisition mechanisms of ARGs in the urban water cycle. Various methods that are used to monitor ARB and ARGs are compared in terms of their strengths and limitations. Opportunities for the development of real-time monitoring methods are discussed, along with possible control strategies for ARB and ARGs in urban water environments. We recommend that three major barriers should be developed to minimize or halt the spread of ARGs in urban water systems, including more efficient water disinfection, advanced wastewater treatment, and optimized sludge treatment processes