Survival of <i>Legionella pneumophila</i> within cysts of <i>Acanthamoeba polyphaga</i> following chlorine exposure

Kilvington, Simon; Price, Jackie F.

doi:10.1111/j.1365-2672.1990.tb02904.x

Cited by 298 publications

(237 citation statements)

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“…Amoebic trophozoites probably encyst in response to the disinfecting agents resulting in greater protection for the bacteria. In an equivalent study, Kilvington and Price (1990) reported cysts produced from co-cultures of Legionella with A. polyphaga protected the bacteria from 50 mg/L free chlorine.…”

Section: Discussionmentioning

confidence: 98%

“…The minimum residual chlorine concentration and contact time of 1 mg/L chlorine for 30 min, as prescribed by potable water providers in Australia, was insufficient to reduce a B. pseudomallei population by more than 2 log 10 Intra-protozoal growth of bacterial pathogens has been associated with increased environmental survival, enhanced virulence, and resistance to biocides and antibiotics (Kilvington and Price, 1990). Protozoa may serve as reservoirs for bacteria with human pathogenic potential (Marciano-Cabral and Cabral, 2003).…”

Section: Introductionmentioning

confidence: 99%

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Disinfection of Burkholderia pseudomallei in potable water

Howard¹,

Inglis²

2005

Water Research

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The effect of chlorine, monochloramine and UV disinfection on the water-borne pathogen Burkholderia pseudomallei was assessed. Persistence of B. pseudomallei was verified by MPN involving a one-step recovery procedure. Chlorine proved the most effective disinfectant with a 99.99% reduction of a 10 6 CFU/mL pure bacterial culture followed by 99.9% reduction by monochloramine and 99% reduction by UV. Co-culture of B. pseudomallei with Acanthamoeba astronyxis was found to greatly enhance survival of B. pseudomallei in the presence of all disinfecting agents tested. For example, when amoebae were present 100 times more monochloramine was required to maintain the disinfectant efficacy. Given the results obtained from these co-culture experiments, more research is needed to investigate the role of amoeba and biofilms in survival of B. pseudomallei in potable water.

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Disinfection of Burkholderia pseudomallei in potable water

Howard¹,

Inglis²

2005

Water Research

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“…Indeed, some bacteria, collectively referred to as amoebaresistant bacteria, resist amoeba phagocytosis (11). Some of them, such as Legionella pneumophila, are even able to multiply within amoeba trophozoites (23,29) and could be found within amoeba cysts (14,27). Intracellular L. pneumophila is more resistant to biocides (3,4,14).…”

mentioning

confidence: 99%

“…Some of them, such as Legionella pneumophila, are even able to multiply within amoeba trophozoites (23,29) and could be found within amoeba cysts (14,27). Intracellular L. pneumophila is more resistant to biocides (3,4,14). Consequently, free-living amoebae, such as Acanthamoeba, have been recently described as important targets in water treatment (19,30).…”

mentioning

confidence: 99%

Cellular Response of the Amoeba Acanthamoeba castellanii to Chlorine, Chlorine Dioxide, and Monochloramine Treatments

Mogoa

Bodet

Morel

et al. 2011

Appl Environ Microbiol

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Acanthamoeba castellanii is a free-living amoebae commonly found in water systems. Free-living amoebae might be pathogenic but are also known to bear phagocytosis-resistant bacteria, protecting these bacteria from water treatments. The mode of action of these treatments is poorly understood, particularly on amoebae. It is important to examine the action of these treatments on amoebae in order to improve them. The cellular response to chlorine, chlorine dioxide, and monochloramine was tested on A. castellanii trophozoites. Doses of disinfectants leading to up to a 3-log reduction were compared by flow cytometry and electron microscopy. Chlorine treatment led to size reduction, permeabilization, and retraction of pseudopods. In addition, treatment with chlorine dioxide led to a vacuolization of the cytoplasm. Monochloramine had a dose-dependent effect. At the highest doses monochloramine treatment resulted in almost no changes in cell size and permeability, as shown by flow cytometry, but the cell surface became smooth and dense, as seen by electron microscopy. We show that these disinfectants globally induced size reduction, membrane permeabilization, and morphological modifications but that they have a different mode of action on A. castellanii.

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“…Intracellular bacteria of freeliving amoebae such as Legionella pneumophila [21], Mycobacterium avium [22] or the Chlamydia-like organism, S. negevensis [9], can survive in the cysts and are localized within the cyst or between the cyst walls. With this in mind, we made the interesting observation that a small proportion of Cp.…”

Section: Encystment Assaysmentioning

confidence: 99%