Free chlorine inactivation of fungi in drinking water sources

Pereira, Vanessa J.; Marques, Ricardo; Marques, Marta; Benoliel, Maria João; Crespo, Maria Teresa Barreto

doi:10.1016/j.watres.2012.09.052

Cited by 101 publications

(65 citation statements)

References 20 publications

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“…The tailing-off implies a shielding phenomenon in which a certain portion of the bacterial population, after inactivation by chlorine, returns the bacteria suspension into its initial state, but with a lower number of viable cells. Further reaction between the chlorine species and bacteria then results in inactivation of smaller portions of viable bacteria due to shielding by previously inactivated cells [52]. Similar observations of tailing-off effects have been reported in some inactivation experiments.…”

Section: Inactivation Of E Coli At Free Chlorine Dose Of 15 Mg/l Afsupporting

confidence: 74%

Chlorine Tolerance and Inactivation of Escherichia coli recovered from Wastewater Treatment Plants in the Eastern Cape, South Africa

2017

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Featured Application: This study examined the tolerance of Escherichia coli isolates, a fecal indicator of water contamination, to chlorine as a common water disinfectant and the effectiveness of chlorine at different concentrations in eliminating E. coli in wastewater effluent. Data obtained can be used as baseline monitoring data for future epidemiological surveillances that could further enhance the control of E. coli and some bacteria species of public health concern in wastewater treatment plants and ensure protection of public and environmental health.Abstract: This study investigated the survival of Escherichia coli (E. coli) recovered from secondary effluents of two wastewater treatment plants in the Eastern Cape Province, South Africa, in the presence of different chlorine concentrations. The bacterial survival, chlorine lethal dose and inactivation kinetics at lethal doses were examined. The bacterial isolates were identified by 16S rRNA gene sequencing. Comparison of the nucleotide sequences of 16S rRNA gene of bacteria with known taxa in the GenBank revealed the bacterial isolates to belong to Escherichia coli. At the recommended free chlorine of 0.5 mg/L, reduction of E. coli isolates (n = 20) initial bacterial concentration of 8.35-8.75 log was within a range of 3.88-6.0 log at chlorine residuals of 0.14-0.44 mg/L after 30 min. At higher doses, a marked reduction (p < 0.05) in the viability of E. coli isolates was achieved with a greater than 7.3 log inactivation of the bacterial population. Inactivation kinetics revealed a high rate of bacterial kill over time (R 2 > 0.9) at chlorine dose of 1.5 mg/L. This study indicates poor removal of bacteria at free chlorine at 0.5 mg/L and a greater efficacy of 1.5 mg/L in checking E. coli tolerance.

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Section: Inactivation Of E Coli At Free Chlorine Dose Of 15 Mg/l Afsupporting

confidence: 74%

Chlorine Tolerance and Inactivation of Escherichia coli recovered from Wastewater Treatment Plants in the Eastern Cape, South Africa

2017

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“…Chlorine also effectively removed yeasts and molds from the wash water, but did not significantly enhance the Y&M reduction on the sugar snaps compared to a water wash. Pereira et al (2013) reported fungi to be more resistant to chlorination in drinking water than bacteria and viruses, but less resistant than Cryptosporidium oocysts. Beuchat et al (1998) suggested a large abundance of chlorine resistant cell types among fungi.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Organic acid based sanitizers and free chlorine to improve the microbial quality and shelf-life of sugar snaps

Haute

Uyttendaele

Sampers

2013

International Journal of Food Microbiology

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A screening in a sugar snaps packaging company showed a converged build-up of aerobic psychrotrophic plate count (APC) (ca. 6.5 log CFU/100 mL), yeasts and molds (Y&M), and lactic acid bacteria (LAB) (both ca. 4.5 log CFU/100 mL) in the wash water in the absence of water sanitizer, and a low build-up of chemical oxygen demand (30 ± 5 mg O 2 /L) and turbidity (5.2 ± 1.1 NTU).Decontamination experiments were performed in the lab with Purac FCC 80® (80% L(+) lactic acid), two other commercial water sanitizers based on organic acids (Natraphase-ABAV®, and Natraphase-FVS®) and chlorine to evaluate their performance in reduction of the sugar snaps microbial load as well as their functionality as disinfectant of the wash water to avoid cross-contamination.An additional 1 log reduction of APC on the sugar snaps was achieved with lactic acid in the range 0.8 to 1.6 %, ABAV 0.5 %, and free chlorine 200 mg/L when compared to a water wash, while no significant difference in the numbers of Y&M was obtained when washing in sanitizer compared to water. There was no significant influence of the studied concentration and contact time on decontamination efficiency. Treatment with lactic acid 0.8% resulted in a lower APC contamination on the sugar snaps than on the untreated and water washed samples for 10 days. Chlorine 200 mg/L was the only treatment able to maintain the Y&M load lower than the untreated samples throughout the entire storage duration. The use of water sanitizers could not extend the sensorial shelf-life. Microbial loads were not indicative/predictive for visual microbial spoilage (shelf-life limiting factor), whereas maturity and amount of damage at the calyx end of the pods were.

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“…Aspergillus species are saprophytic moulds widely distributed in soil, decaying vegetation, dust, bioaerosols and different aquatic environments, in which they are expected to contribute to the degradation of pollutants (Sammon et al 2010;Pereira et al 2013;Pearson et al 2015;Ma et al 2015;Oliveira et al 2015). Aspergillus fumigatus, which is responsible for severe pathologies in humans and birds (Van Waeyenberghe et al 2013), has been isolated from hospital water systems and plumbing drains (Hayette et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Vermamoeba vermiformis-Aspergillus fumigatus relationships and comparison with other phagocytic cells

et al. 2016

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Free living amoebae (FLA) are protists ubiquitously present in the environment. Aspergillus fumigatus is a mould responsible for severe deep-seated infections, and that can be recovered in the same habitats as the FLA. By conducting coculture experiments and fungal incubation with amoebal supernatants, we report herein that Vermamoeba vermiformis, a FLA present in hospital water systems, promotes filamentation and growth of A. fumigatus. This finding is of particular importance to institutions whose water systems might harbor FLA and could potentially be used by immunocompromised patients. Also, the relationships between V. vermiformis and A. fumigatus were compared to those between this fungus and two other phagocytic cells: Acanthamoeba castellanii, another FLA, and macrophage-like THP-1 cells. After 4 h of coincubation, the percentages of the three phagocytic cell types with adhered conidia were similar, even though the types of receptors between FLA and macrophagic cell seemed different. However, the percentage of THP-1 with internalized conidia was considerably lower (40 %) in comparison with the two other cell types (100 %). Thus, this study revealed that interactions between A. fumigatus and these three phagocytic cell types show similarities, even though it is premature to extrapolate these results to interpret relationships between A. fumigatus and macrophages.

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Free chlorine inactivation of fungi in drinking water sources

Cited by 101 publications

References 20 publications

Chlorine Tolerance and Inactivation of Escherichia coli recovered from Wastewater Treatment Plants in the Eastern Cape, South Africa

Chlorine Tolerance and Inactivation of Escherichia coli recovered from Wastewater Treatment Plants in the Eastern Cape, South Africa

Organic acid based sanitizers and free chlorine to improve the microbial quality and shelf-life of sugar snaps

Vermamoeba vermiformis-Aspergillus fumigatus relationships and comparison with other phagocytic cells

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