The effect of chlorine and chlorine dioxide on pathogenic free‐living amoebae (PFLA) in simulated natural conditions: The presence of bacteria and organic matter

Dawson, Mark W.; Brown, Tim

doi:10.1080/00288330.1987.9516206

Cited by 10 publications

(6 citation statements)

References 16 publications

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“…Only one experiment was conducted at each free-chlorine level, and the authors note the assertion that N. gruberi is more resistant to chlorine than N. fowleri should be interpreted in light of other studies (which generally support greater susceptibility of N. fowleri to chlorine and other disinfectants). Dawson and Brown (1987) noted greater sensitivity of N. fowleri to both chlorine and chlorine dioxide than other Naegleria spp. Dawson and Brown (1987) noted greater sensitivity of N. fowleri to both chlorine and chlorine dioxide than other Naegleria spp.…”

Section: N Fowleri Management In Drinking Water Production and Distrmentioning

confidence: 85%

“…Similarly, Cursons et al (1980) observed that at 25°C and pH 7, N. fowleri was more sensitive to chlorine, chlorine dioxide, and ozone than N. gruberi. Dawson and Brown (1987) noted greater sensitivity of N. fowleri to both chlorine and chlorine dioxide than other Naegleria spp. for demand-free suspensions and under conditions of disinfectant demand.…”

Section: N Fowleri Management In Drinking Water Production and Distrmentioning

confidence: 85%

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Naegleria fowleri: An emerging drinking water pathogen

2014

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Naegleria fowleri (N. fowleri) is a free‐living, trophic amoeba that is nearly ubiquitous in the environment and can be present in high numbers in warm waters. It is the causative agent of primary amoebic meningoencephalitis (PAM), a rare but particularly lethal disease with a very low survival incidence. Although N. fowleri was isolated from drinking water supplies in Australia in the 1980s, it was not considered a drinking water threat in the United States until recent cases were associated with a groundwater system in Arizona and surface water systems in Louisiana. N. fowleri in drinking water treatment and distribution systems can be managed using disinfectant concentrations typically encountered in well‐run plants although nitrification and attendant low disinfectant residuals may pose a challenge for some systems. The greatest challenge for N. fowleri control is in premise plumbing systems where conditions are largely outside the control of utilities, residuals might be low or nonexistent, and where water temperatures could be high enough to support rapid growth of the amoebae. This article reviews published studies describing the environmental occurrence, survival, pathogenicity, and disinfection of N. fowleri. In addition, this article provides information about this little known and poorly understood parasite with respect to its occurrence in the environment; how the amoeba amplifies in water systems such that it can cause infection; how N. fowleri has been successfully controlled for decades in water systems through treatment and distribution system management in Australia; and the knowledge gaps and information needed to address N. fowleri as an emerging pathogen in US water supplies.

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Section: N Fowleri Management In Drinking Water Production and Distrmentioning

confidence: 85%

Section: N Fowleri Management In Drinking Water Production and Distrmentioning

confidence: 85%

Naegleria fowleri: An emerging drinking water pathogen

2014

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“…Acanthamoebae are very resistant to a range of disinfectants (5,6,8,28), and bacteria within acanthamoebae are generally afforded extra protection (16). A notable example is the opportunistic pathogen Mycobacterium avium (10), which can survive within Acanthamoeba species trophozoites and cysts (4,26), resulting in increased resistance to several antimicrobials (22).…”

mentioning

confidence: 99%

Mycobacterium avium Infections of Acanthamoeba Strains: Host Strain Variability, Grazing-Acquired Infections, and Altered Dynamics of Inactivation with Monochloramine

Berry

Horn

et al. 2010

Appl Environ Microbiol

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Stable Mycobacterium avium infections of several Acanthamoeba strains were characterized by increased infection resistance of recent environmental isolates and reduced infectivity in the presence of other bacteria. Exposure of M. avium in coculture with Acanthamoeba castellanii to monochloramine yielded inactivation kinetics markedly similar to those observed for A. castellanii alone.Acanthamoebae are widely distributed in the environment (20) and generally function ecologically as predators of bacteria (23), although numerous types of bacteria resist predation (22). Acanthamoebae are very resistant to a range of disinfectants (5,6,8,28), and bacteria within acanthamoebae are generally afforded extra protection (16). A notable example is the opportunistic pathogen Mycobacterium avium (10), which can survive within Acanthamoeba species trophozoites and cysts (4, 26), resulting in increased resistance to several antimicrobials (22). It has been demonstrated that many Mycobacterium spp. are able to infect the laboratory strain Acanthamoeba polyphaga (1). Acanthamoeba cultures undergo many physiological changes after several passages in the laboratory (15,17,21), although it is not known if prolonged cultivation of Acanthamoeba alters their capacity to be infected by M. avium. This knowledge is important for assessing the environmental relevance of associations between Acanthamoeba and M. avium. Therefore, we studied the infectivity and infection stability of M. avium with several laboratory and environmental Acanthamoeba strains for 28 days under high-nutrient (peptone-yeast extract-glucose [PYG] medium) and low-nutrient (Page's amoeba saline [PAS]) conditions. M. avium infections in different Acanthamoeba strains. Eight Acanthamoeba strains were studied, four of which were recently isolated from the environment (biofilm from a drinking water distribution system, forest soil, and two from marsh sediment) and four "laboratory strains" which had been passaged many times on nutrient-rich medium (see Table S1 in the supplemental material). Fresh isolates (Ͻ2 months) were passaged no more than three times and were determined to be free of endosymbionts and acid-fast stained structures, by the use of methods described previously (13). The strains were classified to genotype according to the 95% sequence similarity threshold for 18S rRNA genes (27) using standard methods (11, 13). All strains were members of sequence type T4 (24), with the exception of Acanthamoeba sp. strain F2B (type T13) and Acanthamoeba hatchetii (type 11) (GenBank accession no. FJ807647 to FJ807651) (see Fig. S1 in the supplemental material). Mycobacterium avium subsp. hominissuis 104 (2) was cultured on Middlebrook 7H9/OADC (oleic acid-albumin-dextrose-catalase) broth (Sigma-Aldrich). M. avium was added to Acanthamoeba monolayers at a multiplicity of infection of 10:1 and treated with amikacin as described previously (4). Cocultures were incubated at 20°C in the dark and were washed and treated weekly with amikacin to minimize the potential for extr...

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“…11–14 Organic soils can also react with chlorine in chlorine-based disinfectants such that chlorine is sequestered and not freely available to act in a disinfecting capacity. 15 While protocols have been outlined for the sanitization process, less attention is devoted to the cloths used in this endeavor. 10,16 Recently, the appropriate wipe material selection has been identified as an essential tool to reduce food contamination related illnesses and deaths.…”

Section: Introductionmentioning

confidence: 99%

The effect of cotton fiber inclusion on the hard surface cleaning capacity of nonwoven substrates

Hron

Hinchliffe

Mattison

et al. 2019

Journal of Engineered Fibers and Fabrics

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Hard surface cleaning and disinfection is critically important in environments where microbial contamination can result in the spread of food-borne illnesses and infectious diseases. Successful disinfection of a hard surface can be impeded by the presence of a soil load in the form of protein, fat or other material. Fibrous materials used as applicators for surface disinfecting solutions require careful consideration to ensure the active ingredient remains efficacious. Of equal importance are the mechanical and surface properties of the applicator including tensile strength, cleaning efficiency, and absorbency. Therefore, the successful disinfection of a hard surface can be greatly enhanced by an applicator that also effectively removes organic contaminants, is strong enough to resist structural failure, and reduces water waste when a disinfecting solution is applied. The cleaning and physical properties of nonwoven applicators in the form of disposable wipes composed of cotton, rayon, polyester, and blends thereof were evaluated with several assays. Dynamic wiping assays, surface roughness, and tensile testing were conducted to compare the physical and surface properties of the wipes. The removal of organic contaminants was found to correlate with higher wipe surface roughness that increased with cellulosic fiber content. Tensile testing demonstrated the greige cotton, which has not been subjected to processing such as scouring or bleaching, had increased wet strength while rayon wipes lost significant strength when wet. Greige cotton wipes were also produced as a sustainable product with reduced absorbency that would minimize water usage and waste. The results indicated that inclusion of greige cotton fibers in wipes offers improvements over currently available wipes without sacrificing strength or cleaning efficiency.

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The effect of chlorine and chlorine dioxide on pathogenic free‐living amoebae (PFLA) in simulated natural conditions: The presence of bacteria and organic matter

Cited by 10 publications

References 16 publications

Naegleria fowleri: An emerging drinking water pathogen

Naegleria fowleri: An emerging drinking water pathogen

Mycobacterium avium Infections of Acanthamoeba Strains: Host Strain Variability, Grazing-Acquired Infections, and Altered Dynamics of Inactivation with Monochloramine

The effect of cotton fiber inclusion on the hard surface cleaning capacity of nonwoven substrates

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