Detection of<i>Aeromonas hydrophila</i>in a drinking- water distribution system: a field and pilot study

Chauret, Christian; Völk, Christian; Creason, Robin; Jarosh, John; Robinson, Jeff; Warnes, Carl E.

doi:10.1139/w01-070

Cited by 69 publications

(17 citation statements)

References 19 publications

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“…However, Aeromonas species showed a seasonal distribution, as was found for chironomids (Holmes et al, 1996;Halpern et al, 2004Halpern et al, , 2006. In surface water, Aeromonas abundance peaks in the warm summer and fall months (Burke et al, 1984;Chauret et al, 2001). The seasonal increase in Aeromonas detection in the drinking water supply was found to match the peak occurrence of clinical isolates (Burke et al, 1984).…”

Section: Discussionmentioning

confidence: 91%

Vibrio cholerae and Aeromonas: do they share a mutual host?

et al. 2008

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Species of the genus Aeromonas are native inhabitants of aquatic environments and have recently been considered as an emergent human pathogen. It is estimated that aeromonads cause up to 13% of reported gastroenteritis cases in the United States. Although the autochthonous existence of Aeromonas in the aquatic environment has been established, its natural reservoir is as yet unknown. Chironomids are closely related to mosquitoes except they do not bite and they are the most widely distributed insects in freshwater. They infest drinking water systems in Israel and all over the world. Vibrio cholerae inhabit chironomids and are able to degrade their egg masses. The degradation of the egg masses is followed by failure of the eggs to hatch. In the current study, egg masses from a waste stabilization pond and a river in northern Israel were collected and cultured during a fivemonth period. Bacterial colonies were randomly chosen and checked for their egg mass degradation abilities. In addition to V. cholerae, most of the other isolates that had the ability to degrade the egg masses were identified as Aeromonas species, thus, demonstrating that Aeromonas species are natural inhabitants of chironomid egg masses. The following virulence-associated genes were detected in Aeromonas species that were isolated from chironomid egg masses: alt (78%); ahpB (76%); act/aerA/hlyA (65%); fla (59%); pla/lipH3/apl-1/lip (43%); and ast (2%). These findings indicate that the Aeromonas species inhabiting chironomid egg masses pose a potential health risk. Understanding the natural reservoir of Aeromonas will help to develop methods to monitor and control the bacteria in fresh and drinking water reservoirs and to better understand the relationships between chironomids, V. cholerae and Aeromonas populations.

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Section: Discussionmentioning

confidence: 91%

Vibrio cholerae and Aeromonas: do they share a mutual host?

et al. 2008

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“…These pathogens have been isolated from a wide variety of food and water sources and are being recovered with increasing frequency from patients with traveler's diarrhea (9,19,21). Resistance of Aeromonas spp.…”

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confidence: 99%

“…Resistance of Aeromonas spp. to water chlorination and to multiple antibiotics has resulted in this organism being placed on the "Contaminant Candidate List" by the Environmental Protection Agency (9). These ubiquitous bacteria produce a large number of virulence factors, many of which have been linked to Aeromonas-associated pathogenesis.…”

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confidence: 99%

Molecular and Functional Characterization of a ToxR-Regulated Lipoprotein from a Clinical Isolate of Aeromonas hydrophila

et al. 2006

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Human diseases caused by species of Aeromonas have been classified into two major groups: septicemia and gastroenteritis. In this study, we reported the molecular and functional characterization of a new virulence factor, ToxR-regulated lipoprotein, or TagA, from a diarrheal isolate, SSU, of Aeromonas hydrophila. The tagA gene of A. hydrophila exhibited 60% identity with that of a recently identified stcE gene from Escherichia coli O157:H7, which encoded a protein (StcE) that provided serum resistance to the bacterium and prevented erythrocyte lysis by controlling classical pathway of complement activation by cleaving the complement C1-esterase inhibitor (C1-INH). We purified A. hydrophila TagA as a histidine-tagged fusion protein (rTagA) from E. coli DE3 strain using a T7 promoter-based pET30 expression vector and nickel affinity column chromatography. rTagA cleaved C1-INH in a time-dependent manner. The tagA isogenic mutant of A. hydrophila, unlike its corresponding wild-type (WT) or the complemented strain, was unable to cleave C1-INH, which is required to potentiate the C1-INH-mediated lysis of host and bacterial cells. We indeed demonstrated colocalization of C1-INH and TagA on the bacterial surface by confocal fluorescence microscopy, which ultimately resulted in increased serum resistance of the WT bacterium. Likewise, we delineated the role of TagA in contributing to the enhanced ability of C1-INH to inhibit the classical complement-mediated lysis of erythrocytes. Importantly, we provided evidence that the tagA mutant was significantly less virulent in a mouse model of infection (60%) than the WT bacterium at two 50% lethal doses, which resulted in 100% mortality within 48 h. Taken together, our data provided new information on the role of TagA as a virulence factor in bacterial pathogenesis. This is the first report of TagA characterization from any species of Aeromonas.Aeromonas hydrophila represents one of the most predominant species within the family Aeromonadaceae that leads to human diseases, such as gastroenteritis, wound infections, and septicemia (21). These pathogens have been isolated from a wide variety of food and water sources and are being recovered with increasing frequency from patients with traveler's diarrhea (9,19,21). Resistance of Aeromonas spp. to water chlorination and to multiple antibiotics has resulted in this organism being placed on the "Contaminant Candidate List" by the Environmental Protection Agency (9). These ubiquitous bacteria produce a large number of virulence factors, many of which have been linked to Aeromonas-associated pathogenesis. Among them are matrix-binding proteins, elastases, proteases, cytotonic and cytotoxic enterotoxins, hemolysins, aldolase, chitinase, lipases/phospholipases, and the ability to form a capsule-like outer layer (10,30,35,45). Aeromonas spp. also possess type IV pili and bundle-forming pili, the latter of which has been shown to be associated with gastroenteritis (23, 29).Our laboratory purified and extensively characterized the cytotoxi...

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“…It was reported that the number of Aeromonas sp. are temperature dependent with highest numbers recorded in the summer (Chauret et al 2001).…”

Section: Discussionmentioning

confidence: 99%

Effect of temperature and arsenic on Aeromonas hydrophila growth, a modelling approach

Goswami

Mandal²,

Mandal

et al. 2014

Biologia

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Aeromonas hydrophila is frequently reported from arsenic affected areas. Present study was aimed to determine the effect of arsenic and temperature on growth of A. hydrophila. The bacteria were isolated from naturally infected fish from a water body in Birbhum, West-Bengal, India, which is reported to be an arsenic-free area. Arsenic concentration in natural aquatic reservoirs (e.g., pond, lake or river) varies from 0-6 mg/L. No significant change in bacterial growth was observed within this range of arsenic exposure. However, variation in temperature impacted the growth of A. hydrophila. A single dimension model was constructed using simple logistic equation. Rate parameters of the model were derived from the experimental observations. Comparison of model results and laboratory observations gives a good conformity regarding the effect of variation of arsenic concentration and temperature change on growth of this bacterium. From the analysis of this model we further get the idea that the maximum growth of A. hydrophila is supposed to be at 31.4• C in absence of arsenic, whereas at 477 mg/L arsenic concentration, the growth of the bacteria totally stops at 30• C.

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Detection ofAeromonas hydrophilain a drinking- water distribution system: a field and pilot study

Cited by 69 publications

References 19 publications

Vibrio cholerae and Aeromonas: do they share a mutual host?

Vibrio cholerae and Aeromonas: do they share a mutual host?

Molecular and Functional Characterization of a ToxR-Regulated Lipoprotein from a Clinical Isolate of Aeromonas hydrophila

Effect of temperature and arsenic on Aeromonas hydrophila growth, a modelling approach

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