Effects of prevalent freshwater chemical contaminants on in vitro growth of Escherichia coli and Klebsiella pneumoniae

Higgins, James; Hohn, Christina

doi:10.1016/j.envpol.2007.06.049

Cited by 9 publications

(9 citation statements)

References 23 publications

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“…These same results were also found by Koutsotoli et al (2005) and Higgins and Hohn (2007). In the work by Koutsotoli et al (2005), the growth of NCTC 9001 Escherichia coli and Enterococcus faecalis was not affected by up to 0.1 mg/L atrazine concentrations.…”

Section: Herbicidesupporting

confidence: 77%

“…In the work by Koutsotoli et al (2005), the growth of NCTC 9001 Escherichia coli and Enterococcus faecalis was not affected by up to 0.1 mg/L atrazine concentrations. Higgins and Hohn (2007) also exposed Escherichia coli to atrazine concentrations and did not observe bacterial growth inhibition. In this study, the same atrazine concentration (in all commercial formulations) used in Koutsotoli et al (2005) was applied (0.1 mg/L) and although authors have used different strains of Escherichia coli in these two studies, the herbicide was not toxic to their growth.…”

Section: Herbicidementioning

confidence: 99%

“…Although various studies have evaluated the toxicity promoted by pesticides to the environment using bacteria as a test organism, reports on the Escherichia coli use are minimal (Bálague et al, 2001;Higgins and Hohn, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…However, bacteria represent important members of the fresh water flora and are presumably vulnerable to alterations in their growth and reproduction due to exposure to chemical contaminants (Higgins and Hohn, 2007).…”

Section: Introductionmentioning

confidence: 99%

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Toxicity of herbicides on Escherichia coli growth

2012

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Agriculture uses a huge variety and quantity of chemicals. If, on one hand, the goal is to increase productivity, on the other hand these products contaminate aquatic environments. Among these products, herbicides deserve greater attention in relation to contamination of aquatic environments due to their extensive use to weed control. This study was carried out because the effects of these molecules on aquatic microorganisms such as Escherichia coli, is still unclear. Using microdilution plate assays, Escherichia coli were exposed to various commercial formulations of herbicides widely used in Brazil. The herbicide paraquat was the only one able to prevent the growth of Escherichia coli and is characterized as bacteriostatic.Keywords: aquatic ecosystem, bacteriostatic, paraquat. Toxicidade de herbicidas sobre o crescimento de Escherichia coli ResumoA agricultura utiliza uma enorme variedade de produtos químicos, e se por um lado a meta é aumentar a produtividade, por outro lado estes produtos contaminam ambientes aquáticos. Entre estes produtos, herbicidas merecem maior atenção em relação à contaminação de ecossistemas aquáticos, devido a seu amplo emprego para controlar plantas daninhas. Este estudo foi realizado porque os efeitos destas moléculas em micro-organismos aquáticos, tais como Escherichia coli, ainda são pouco estudados. Através de ensaios de microdiluição, E. coli foi exposta a várias formulações comerciais de herbicidas amplamente utilizados no Brasil e foi verificado que o herbicida paraquat foi o único capaz de impedir o crescimento de E. coli, caracterizando-se assim como bacteriostático.Palavras-chave: ecossistemas aquáticos, bacteriostático, paraquat.

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Section: Herbicidesupporting

confidence: 77%

Section: Herbicidementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Toxicity of herbicides on Escherichia coli growth

2012

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“…Essa bactéria pode causar diarréia quando em número muito elevado no intestino. A concentração de E. coli em amostras de água é um dos principais indicadores biológicos de contaminação fecal utilizados pelo homem (Higgins & Hohn, 2008).…”

Section: Relação Entre Co 2 Livre E Concentração De Escherichia Coliunclassified

Correlação entre Escherichia coli e variáveis limnológicas em amostras de água da Lagoa da Parangaba

Sá

Barbosa

Gomes

2010

Braz. J. Aquat. Sci. Technol.

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The present work aimed at evaluating the possible relationship between the Escherichia coli counts and the concentrations of free CO 2 , dissolved oxygen, reactive phosphorus, total ammonia, nitrite and pH in water samples of the Lagoa da Parangaba (Fortaleza, Ceará). Eight campaigns were carried out every fifteen days to collect sub-superficial water samples in three sampling spots. Regression analyses were performed upon the variable with the greatest linear Pearson coefficients looking for the curve that best fitted to the observed data. The correlation between the water free CO 2 and E. coli was best represented by the equation y = 17.74 -1.16*10 -3 x + 6.76*10 -8 x² (R² = 0.75; P = 0.06), where x is the E. coli count (MPN 100 mL -1 ) and y is the water carbon dioxide concentration (mg L -1 ). It was concluded that the rich organic matter inflows of the Lagoa da Parangaba, mainly of fecal origin, have increased not only the sanitary risk to the population that use this water source, but also affected the life of the animal populations that live in it. It was also observed that the Lagoa da Parangaba's waters are highly contaminated by E. coli. Besides, they are acidic and suffer eventual episodes of hypoxia.

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Ecotoxicological characterization of a tropical soil after diazinon spraying

et al. 2012

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The impact of diazinon spraying in an agricultural tropical soil through the evaluation of both the habitat and retention functions of the soil system was never reported. To fill this gap, five times the recommended dose of a commercial diazinon formulation was sprayed in an agricultural area of Costa Rica, and dilution gradients of the sprayed soil were prepared in the laboratory. Avoidance and reproduction tests with soil organisms (Eisenia andrei, Enchytraeus crypticus and Folsomia candida) to evaluate losses in terrestrial habitat function, and growth and reproduction tests with aquatic organisms (Chlorella vulgaris and Daphnia magna, respectively) to evaluate the retention function of soil were performed. Results demonstrated that regarding habitat function, F. candida reproduction was the most sensitive endpoint (EC(50) = 0.288 mg a.i./kg), followed by avoidance behaviour of E. andrei (EC(20) = 1.75 mg a.i./kg). F. candida avoidance and the reproduction of E. andrei and E. crypticus were not affected by diazinon. The toxicity tests with aquatic organisms showed that the soil retention function was insufficient to prevent effects of diazinon either on microalgae growth (EC(50) ≤ 0.742 mg/L and EC(20) ≤ 0.223 mg/L) and on the reproduction of the cladoceran (EC(50) ≤ 0.00771 mg/L and EC(20) ≤ 0.00646 mg/L). Results suggested that diazinon exerted toxic effects even at the dilution corresponding to the recommended dose, fact which makes its misuse an issue of environmental concern. Furthermore, the present study highlighted the importance and complementary nature of the assessment of both habitat and retention functions to an ecological risk assessment in tropical systems.

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Effects of prevalent freshwater chemical contaminants on in vitro growth of Escherichia coli and Klebsiella pneumoniae

Cited by 9 publications

References 23 publications

Toxicity of herbicides on Escherichia coli growth

Toxicity of herbicides on Escherichia coli growth

Correlação entre Escherichia coli e variáveis limnológicas em amostras de água da Lagoa da Parangaba

Ecotoxicological characterization of a tropical soil after diazinon spraying

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