Microbiological Quality and Antibiotic Resistance Analysis of a Brazilian Water Supply Source

Abstract

Water samples of the Passaúna River, Curitiba/Paraná (Brazil), were analyzed to determine total and thermotolerant coliform counts and Escherichia coli in order to provide information on human impacts on the water supply. Samples were collected and analyzed monthly, from March 2006 to February 2007, at five different locations along the river, and the multiple tube method was used to obtain total and thermotolerant coliform counts. The results varied from 130 MPN/100 mL to 1.6×10 6 MPN/100 mL for total coliforms, while for thermotolerant coliforms the variation was between 40 MPN/100 mL and 5× 10 5 MPN/100 mL. The E. coli strains isolated from the samples were tested with 13 different antibiotics to determine their antibiotic resistance. The isolated strains were constantly sensitive to seven of the 13 antibiotics tested, and resistant to at least one of the other antibiotics. The results indicated that two factors could influence the increased contamination on this river, viz., seasonality parameters and domestic wastewater discharges. The determination of antibiotic resistance indices aimed to provide information on the anthropogenic influence. Only one of the locations investigated was considered critical due to the anthropogenic influence, with significant impacts from irregular domestic wastewater discharges.

Characterization of bacterial pathogens in rural and urban irrigation water

“…Therefore, irrigation water sources may serve as reservoirs of antibiotic-resistant pathogens thereby posing a food safety and public health threat in the case that new pathogens emerge. Multiple resistances to antibiotics were noted in E. coli isolated from rivers close to urban/densely populated areas (Olaniran et al 2009;Da Silva et al 2011). Antibiotic resistance can be used to determine relatedness of environmental E. coli as well as the source of contamination (Wiggins et al 1999).…”

“…Additionally, 18 isolates (selected from aerobic plate counts) were identified using the Omnilog® system referred to following isolation on plate count agar (Oxoid) and subsequently Biolog Universal Growth medium (BUG) (Biolog). Eleven (11) antibiotics (Oxoid) at single concentrations were selected according to Da Silva et al (2011). Antimicrobial susceptibility was done using multiple antibiotic resistance (MAR) analysis (Vantakaris et al 2006).…”

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“…As amostras de água foram coletadas em cinco pontos do Rio Passaúna (Figura 1), mensalmente dos meses de outubro de 2014 a janeiro de 2015, próximo aos mesmos pontos utilizados por Silva et al (2011) e Bocalon (2007, cujas coordenadas geográficas e localização estão informadas na Tabela 1.…”

“…Saunitti et al, já em 2004, destacavam que a falta de esgotamento sanitário e a expansão urbana irregular na região gerava fontes de poluição prejudiciais à qualidade ambiental da bacia hidrográfica desse rio. Essa influência foi, posteriormente, também observada por Silva et al (2011), que isolaram cepas de Escherichia coli multirresistentes a antibióticos em amostras de água da área.…”

Water quality indicators for environmental and resistance profile of Escherichia coli strains isolated in Rio Cascavel, Paraná, Brazil

“…The main groups of bacteria used to indicate pollution levels in water are total coliform (CT) and thermotolerant (CTe), and more specifically Escherichia coli (PLUMMER & LONG, 2007;SILVA et al, 2010.). Besides the presence of coliforms, the evaluation of the resistance of microorganisms against various antimicrobial suitable for human population, has been indicated to evaluate the anthropogenic contamination of a wellspring (SILVA et al, 2010).…”