Habituation to normally lethal acidity by prior growth of Escherichia coli at a sub-lethal acid pH value

Goodson, Margaret; Rowbury, R. J.

doi:10.1111/j.1472-765x.1989.tb00227.x

Cited by 154 publications

(111 citation statements)

References 13 publications

(11 reference statements)

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“…fruit juice) or in the stomach and subsequently cause infection after ingestion (Goodson & Rowbury, 1989). In an environment with changing pH, acid sensitive E. coli O157 cultures can become acid-resistant within 17 min (de Jonge, Takumi, Ritmeester & van Leusden, 2003).…”

Section: Discussionmentioning

confidence: 99%

Inactivation of Escherichia coli in orange juice using ozone

Patil¹,

Bourke²,

Frias³

et al. 2009

Innovative Food Science & Emerging Technologies

112

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This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (10 6 CFU mL -1 ) as a challenge microorganism was treated with ozone at 75-78µg mL -1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500m or 1mm sieves. Fast inactivation rates for total reduction of E. coli were achieved in model orange juice (60 seconds) and in juice with low pulp content (6 min). However, in unfiltered juice inactivation was achieved after 15-18 min. This indicated that juice organic matter interferes with antibacterial activity of gaseous ozone. The effect of prior acid (pH 5.0) exposure of E. coli strains on the inactivation efficacy of ozone treatment was also investigated. There was a strain effect observed, where prior acid exposure resulted in higher inactivation times in some cases by comparison with the control cells.However, the overarching influence on inactivation efficacy of ozone was related to the pulp content. Generally, the applied gaseous ozone treatment of orange juice resulted in a population reduction of 5 log cycles.Key words: Escherichia coli, ozone, non-thermal inactivation, acid exposure, orange juice, microbial kinetics Industrial relevance: To facilitate the preservation of unstable nutrients many juice processors have investigated alternatives to thermal pasteurisation, including unpasteurised short shelf life juices with high retail value. This trend has continued within the European Union. However within the US recent regulations by the FDA have 3 required processors to achieve a 5-log reduction in the numbers of the most resistant pathogens in their finished products. Pathogenic E. coli may survive in acid environments such as fruit juices for long periods. This study demonstrates that the use of ozone as a non-thermal technology is effective for inactivation of E. coli and acid exposed E. coli in orange juice. Information on the design of the ozone treatment for inactivation of E. coli which results into safe juice products is also among the main outputs of this work. Ozone auto-decomposition makes this technology safe for fruit juice processing.4

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Section: Discussionmentioning

confidence: 99%

Inactivation of Escherichia coli in orange juice using ozone

Patil¹,

Bourke²,

Frias³

et al. 2009

Innovative Food Science & Emerging Technologies

112

View full text Add to dashboard Cite

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“…exposed to acid conditions in the urinary tract and in the phagolysosome (Goodson & Rowbury, 1989b ; Raja e t al., 1991). Adaptation and survival in a low pH environment may be an important prerequisite toward the production of disease by many gastrointestinal pathogens.…”

Section: Introductionmentioning

confidence: 99%

Adaptive acid tolerance response (ATR) in Aeromonas hydrophila

1994

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Aeromonas hydrophila, a gastrointestinal pathogen of humans, was shown t o exhibit a significant adaptive acid tolerance response (ATR) capable of protecting cells from severe acid at a pH of 3.5. The ATR was induced by exposure t o a relatively mild pH level of 5-0 for 20 min. Adaptation required protein Synthesis since treatment with chloramphenicol during adaptation t o pH 5-0 prevented the development of acid tolerance. The adaptation t o acid environment was found t o be a non-transient phenomenon. Also, iron was not required for acid adaptation in A. hydrophila. Two-dimensional protein analyses revealed an increased production of 28 proteins and decreased synthesis of 10 following pH shifts from 7.2 t o 5.0. The mild pH treatment must act as a signal t o A. hydrophila t o adapt and survive in acid environments by producing 'protective proteins. The adaptation and survival of this pathogen in low pH may provide valuable information about i t s ability t o withstand acid environments in nature and in the human gastrointestinal tract.

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“…However, many bacteria have been shown to develop acid tolerance on exposure to acid shock. Therefore the ability of food-borne pathogens, including Salmonella typhimurium (Foster and Hall, 1990), Escherichia coli (Goodson and Rowbury, 1989), and Listeria monocytogenes (Kroll and Patchett, 1992), to adapt to acidic conditions is a concern in food safety (Brown and Booth, 1991). Adaptation enhances tolerance to stresses and may promote survival in adverse environments.…”

mentioning

confidence: 99%

Acid adaptation induces cross-protection against some environmental stresses in Vibrio parahaemolyticus.

Koga

Sakamoto

Yamoto

et al. 1999

J. Gen. Appl. Microbiol.

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The relationship of acid adaptation to the resistance of other environmental stresses was examined in Vibrio parahaemolyticus. Acid-adapted cells were found to have increased resistance to various stresses, including heat, crystal violet, bile, and deoxy cholic acid. However, heat-adapted cells showed no increased resistance against acid stress. Adaptation required protein synthesis, since treatment with chloramphenicol during adaptation to pH 5.3 prevented the development of acid resistance. Acid-adapted cells showed an increased amount of outer membrane protein with an apparent molecular weight of 27,000. These results show that acid-induced cross-protection involved changes in outer membrane protein composition and the known enhancement of intracellular pH homeostasis.

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Habituation to normally lethal acidity by prior growth of Escherichia coli at a sub-lethal acid pH value

Cited by 154 publications

References 13 publications

Inactivation of Escherichia coli in orange juice using ozone

Inactivation of Escherichia coli in orange juice using ozone

Adaptive acid tolerance response (ATR) in Aeromonas hydrophila

Acid adaptation induces cross-protection against some environmental stresses in Vibrio parahaemolyticus.

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