Isolation and characterization of Escherichia coli O157 from retail beef and bovine feces in Thailand

Vuddhakul, V

doi:10.1016/s0378-1097(99)00615-1

Cited by 14 publications

(20 citation statements)

References 19 publications

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“…It has been shown that E. coli O157:H7 is prevalent in domestic animals, especially cattle (11,12,40,44). Previous studies evaluated the reduction of E. coli O157:H7 in cattle and sheep prior to slaughter when using microbial feeds (21,43) and a change of diet (14).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a Cocktail of Three Bacteriophages for Biocontrol of Escherichia coli O157:H7

O'Flynn

Ross

Fitzgerald

et al. 2004

Appl Environ Microbiol

401

285

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Escherichia coli O157:H7 is an endemic pathogen causing a variety of human diseases including mild diarrhea, hemorrhagic colitis, hemolytic-uremic syndrome, and thrombotic thrombocytopenic purpura. This study concerns the exploitation of bacteriophages as biocontrol agents to eliminate the pathogen E. coli O157:H7. Two distinct lytic phages (e11/2 and e4/1c) isolated against a human strain of E. coli O157:H7, a previously isolated lytic phage (pp01), and a cocktail of all three phages were evaluated for their ability to lyse the bacterium in vivo and in vitro. Phage e11/2, pp01, and the cocktail of all three virulent phages resulted in a 5-log-unit reduction of pathogen numbers in 1 h at 37°C. However, bacteriophage-insensitive mutants (BIMs) emerged following the challenge. All tested BIMs had a growth rate which approximated that of the parental O157 strain, although many of these BIMs had a smaller, more coccoid cellular morphology. The frequency of BIM formation (10 ؊6 CFU) was similar for e11/2, pp01, and the phage cocktail, while BIMs insensitive to e4/1c occurred at the higher frequency (10 ؊4 CFU). In addition, BIMs commonly reverted to phage sensitivity within 50 generations. In an initial meat trial experiment, the phage cocktail completely eliminated E. coli O157:H7 from the beef meat surface in seven of nine cases. Given that the frequency of BIM formation is low (10 ؊6 CFU) for two of the phages, allied to the propensity of these mutants to revert to phage sensitivity, we expect that BIM formation should not hinder the use of these phages as biocontrol agents, particularly since low levels of the pathogen are typically encountered in the environment.

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Section: Discussionmentioning

confidence: 99%

Evaluation of a Cocktail of Three Bacteriophages for Biocontrol of Escherichia coli O157:H7

O'Flynn

Ross

Fitzgerald

et al. 2004

Appl Environ Microbiol

401

285

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“…For example, the Thai government has established a policy to develop Thailand as the "Kitchen of the World". However, various types of spoilage and pathogenic bacteria have been found in Thai foods (Indrawattana et al, 2011;Keeratipibul et al, 2010;Minami et al, 2010;Padungtod et al, 2006;Suthienkul et al, 1990;Vindigni et al, 2007;Vuddhakul et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Bacterial Contamination in Retail Foods Purchased in Thailand

Ananchaipattana

Hosotani

Kawasaki

et al. 2012

FSTR

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The loss of quality or quantity of raw foods caused by spoilage bacteria is a major problem, especially in developing countries. Evaluation of the frequency and level of bacterial contamination and/or identification of the contaminating bacteria are keys to solving this problem. The objective of this study was to evaluate the prevalence and types of contaminating bacteria in retail foodstuffs in Thailand. Foods in four categories (137 samples total) including meat (51 samples), vegetables (38 samples), fish or seafood (37 samples) and fermented food (11 samples) were purchased randomly from seven different open markets and seven supermarkets in Thailand from August 2010 to March 2011. Indicator bacteria of fecal contamination or other naturally contaminating bacteria were isolated and identified. More than 90% of each category of collected retail meat, vegetables and fish or seafood was contaminated with coliform bacteria. The contamination rate of fecal coliform bacteria, Staphylococcus spp. and lactic acid bacteria was higher in vegetables from open markets than those from supermarkets, and the contamination rate of Staphylococcus spp. was likewise higher in fish or seafood samples purchased from open markets than those from supermarkets. Improvement in hygienic practices throughout the food distribution may reduce the risk of food poisoning and spoilage of foods purchased in Thai markets.Keywords: spoilage, food hygiene, Thailand *To whom correspondence should be addressed. E-mail: inatu@affrc.go.jp IntroductionSpoilage can be defined as any change in a food product that makes it unacceptable to the consumer from a sensory point of view. It is mainly ascribable to the undesired growth of microorganisms to unacceptable levels. For example, in the case of raw meat or fish, microbial spoilage leads to the development of off-odors and often slime formation, which make the product undesirable for human consumption, consequently leading to the loss of foodstuff.Finding ways to prevent food spoilage is important to assure a sufficient and stable supply of food, especially in developing countries. Production and processing of high quality foods for export are now making an important contribution to the economy in developing countries. For example, the Thai government has established a policy to develop Thailand as the "Kitchen of the World". However, various types of spoilage and pathogenic bacteria have been found in Thai foods (Indrawattana et al., 2011;Keeratipibul et al., 2010;Minami et al., 2010;Padungtod et al., 2006;Suthienkul et al., 1990;Vindigni et al., 2007;Vuddhakul et al., 2000).There are two types of retail markets, supermarkets and open markets, in many South-East Asian countries including Thailand. Supermarkets are indoors, often air conditioned, typically offering controlled-temperature environments and have displays of prepackaged products under refrigeration.In contrast, open markets are traditional open-air markets where foodstuffs are sold by individual vendors or farmers and are usually displaye...

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“…The production of Stx 1 and Stx 2 in E. coli is conferred by toxin-converting lysogenic bacteriophages [1][2][3][4]. The natural reservoirs of EHEC are cattle and other domestic animals [5]. The presence of phages carrying the Stx 2 gene is also common in sewage from developed countries [6,7].…”

Section: Introductionmentioning

confidence: 99%

Seasonal change and fate of coliphages infected to Escherichia coli O157:H7 in a wastewater treatment plant

et al. 2003

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Seasonal change of virulent phage infected to two E. coli O157:H7 strains (O:157-phage) in the influent of a domestic wastewater treatment plant in the central part of Japan and fate of O:157-phage in the plant were monitored almost monthly from March 2001 to February 2002. Coliphage infected to nonpathogenic E. coli O157:H7 ATCC43888 (43888-phage) was detected for 1 year. On the other hand, phage infected to pathogenic E. coli O157:H7 EDL933 (EDL-phage) was detected intermittently. Concentration of EDL-phage was almost one-tenth of that of 43888-phage. The progressive decrease in phage concentration with the treatment steps was observed. No phage was detected in the supernatant from the secondary settling tank and effluent. PCR amplification of the Stx 2 gene that encodes Shiga toxin (Stx) was observed when O:157-phage concentration in the influent was high Â 10 3 PFU/ml order. Concentration and percentage of suspended O:157-phage decreased with the progress of the wastewater treatment. 933W phage, which encodes Stx 2 gene, was more fragile and sensitive to chlorination than T4 phage. However, addition of 0.02 mg/l chlorine, in conformance with the required concentration of the plant, did not affect the viability of T4 and 933W phages. On the other hand, 1 mg/l chlorine inactivated the 933W phage significantly. r

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Isolation and characterization of Escherichia coli O157 from retail beef and bovine feces in Thailand

Cited by 14 publications

References 19 publications

Evaluation of a Cocktail of Three Bacteriophages for Biocontrol of Escherichia coli O157:H7

Evaluation of a Cocktail of Three Bacteriophages for Biocontrol of Escherichia coli O157:H7

Bacterial Contamination in Retail Foods Purchased in Thailand

Seasonal change and fate of coliphages infected to Escherichia coli O157:H7 in a wastewater treatment plant

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