Effect of Ozone on the Inactivation of Yersinia enterocolitica and the Reduction of Natural Flora on Potatoes

2006 ◽  
Vol 69 (10) ◽  
pp. 2357-2363 ◽  
Author(s):  
MARÍA VICTORIA SELMA ◽  
DAVID BELTRÁN ◽  
ELISEO CHACÓN-VERA ◽  
MARÍA ISABEL GIL

Fresh vegetables contaminated with Yersinia enterocolitica have been implicated in foodborne disease outbreaks. Surfaces of vegetables can become contaminated with pathogenic microorganisms through contact with soil, irrigation water, fertilizers, equipment, humans, and animals. One approach to reduce this contamination is to treat fresh produce with sanitizers. In this study, the ability of ozone to inactivate Y. enterocolitica inoculated in water and on potato surfaces was evaluated. Furthermore, the efficacy of ozone in reducing natural flora on whole potato was determined. Total aerobic mesophilic and psychrotrophic bacteria, total coliforms, and Listeria monocytogenes were enumerated. Finally, several disinfection kinetic models were considered to predict Y. enterocolitica inactivation with ozone. Treatments with ozone (1.4 and 1.9 ppm) for 1 min decreased the Y. enterocolitica population in water by 4.6 and 6.2 log CFU ml−1, respectively. Furthermore, ozonated water (5 ppm) for 1 min decreased Y. enterocolitica and L. monocytogenes from potato surfaces by 1.6 and 0.8 log CFU g−1, respectively. Therefore, ozone can be an effective treatment for disinfection of wash water and for reduction of potato surface contamination.

1992 ◽  
Vol 55 (5) ◽  
pp. 360-366 ◽  
Author(s):  
CATHERINE J. MOIR ◽  
MICHAEL J. EYLES

The minimum inhibitory concentrations (MICs) of methyl ρ-hydroxybenzoate (methyl paraben) and potassium sorbate for four psychrotrophic bacteria were compared at pH 5 and 6 and at 5 and 30°C. The bacteria tested were Listeria monocytogenes, Pseudomonas putida, Yersinia enterocolitica, and Aeromonas hydrophila. L. monocytogenes was generally the most resistant and A. hydrophila the least resistant to the preservatives. The differences between the bacteria were substantial. The MICs of the two preservatives were similar at pH 5, but at pH 6 the MICs of paraben were well below those of sorbate, except in the case of A. hydrophila. The MICs at 5°C were much lower than those observed at 30°C for all of the bacteria except P. putida. All four bacteria were inhibited by 1000 mg methyl paraben per L at 5°C. Exposure of the bacteria to concentrations of preservative that permitted growth at 30°C did not lead to adaptation to the preservative. The death rates of the bacteria in media containing 1000 mg methyl paraben per L varied over a wide range. At 5°C, a 3 log10 decrease in viable counts of L. monocytogenes and A. hydrophila took >4 months and a few days, respectively. Injury of L. monocytogenes, Y. enterocolitica, and A. hydrophila was detected under these conditions. Repair of the injury was demonstrated, with up to 24 h required for complete recovery. The type of buffer in which the test medium was prepared affected the preservative MICs and rate of injury of L. monocytogenes.


2012 ◽  
Vol 48 (No. 5) ◽  
pp. 126-132 ◽  
Author(s):  
M. Gulmez ◽  
A. Guven

The survival of Escherichia coli O157:H7, Listeria monocytogenes 4b and Yersinia enterocolitica O3 in traditional yogurt and kefir during fermentation, in ayran (a dairy beverage in Turkey), pasteurised (long-life) ayran, modified kefir (salted and diluted kefir) and pasteurised modified kefir during cold storage were investigated. Pasteurised samples were used to monitor the antibacterial effect of natural flora of yogurt and kefir during cold storage. Populations of all the strains were increased during fermentation, and thus pre-fermentation contamination appeared more rhisky than postfermentation contamination. Pasteurisation appeared not to be disaadventageous an application on the microbiological safety of the samples, neverthelessbiological benefits which may come from live microorganisms is lost. While E. coli O157:H7 and L. monocytogenes 4b survived for up to 21 days in all samples, Y. enterocolitica O3 survived only for 14 days in modified kefir. Yogurt microflora appeared to be more suppressive on the pathogens than that of kefir.


2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Anna Franca Sperandii ◽  
Diana Neri ◽  
Romina Romantini ◽  
Gino Angelo Santarelli ◽  
Vincenza Prencipe

Pork meat products consumed raw or after a short period of fermentation can be considered at risk for food safety (EFSA 2010). Sausages (fresh sausage made from pork meat) are produced in several Italian regions, with variation in ingredients. In some Italian Regions, including Abruzzo, these products are frequently consumed raw or undercooked, after a variable period of fermentation. The EU food regulation promotes the use of challenge tests to determinate safety levels. This study is aimed to ensure safety of Abruzzo’s sausages, compared with growth potential (δ) of <em>Listeria monocytogenes</em> and <em>Yersinia enterocolitica</em> and also aims to define an experimental standard protocol document to carry out challenge tests. Guidelines classify foods ready to eat in categories that are able to support (δ&gt;0.5 log10 ufc/g) and not support (δ≤0.5 log10 ufc/g) the growth of <em>Listeria monocytogenes</em>. The products were manufactured according to traditional recipe and were contaminated in laboratory. Results from the experiment yielded information useful to assess the ability of these products to support the growth of pathogenic microorganisms. The batches of sausages were stored at 8, 12, 18 and 20°C to get statistical evaluation. The results showed that, despite the conditioning of the storage temperature and the level of aw, both organisms remain in the product in concentrations similar to those leading or are able to increase its charge. In particular the period of greatest consumption of this product (7/8 days of preparation) corresponds to the period of greatest growth of pathogenic microorganisms studied, except for those stored at a temperature of 8° C, which are safer for the consumer.


2021 ◽  
pp. 1-24
Author(s):  
Qihua Qiu ◽  
Daniel Dewey-Mattia ◽  
Sanjana Subramhanya ◽  
Zhaohui Cui ◽  
Patricia M. Griffin ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 397
Author(s):  
Dimitra Kostoglou ◽  
Parthena Tsaklidou ◽  
Ioannis Iliadis ◽  
Nikoletta Garoufallidou ◽  
Georgia Skarmoutsou ◽  
...  

Fresh vegetables and salads are increasingly implicated in outbreaks of foodborne infections, such as those caused by Listeria monocytogenes, a dangerous pathogen that can attach to the surfaces of the equipment creating robust biofilms withstanding the killing action of disinfectants. In this study, the antimicrobial efficiency of a natural plant terpenoid (thymol) was evaluated against a sessile population of a multi-strain L. monocytogenes cocktail developed on stainless steel surfaces incubated in lettuce broth, under optimized time and temperature conditions (54 h at 30.6 °C) as those were determined following response surface modeling, and in comparison, to that of an industrial disinfectant (benzalkonium chloride). Prior to disinfection, the minimum bactericidal concentrations (MBCs) of each compound were determined against the planktonic cells of each strain. The results revealed the advanced killing potential of thymol, with a concentration of 625 ppm (= 4 × MBC) leading to almost undetectable viable bacteria (more than 4 logs reduction following a 15-min exposure). For the same degree of killing, benzalkonium chloride needed to be used at a concentration of at least 20 times more than its MBC (70 ppm). Discriminative repetitive sequence-based polymerase chain reaction (rep-PCR) also highlighted the strain variability in both biofilm formation and resistance. In sum, thymol was found to present an effective anti-listeria action under environmental conditions mimicking those encountered in the salad industry and deserves to be further explored to improve the safety of fresh produce.


2011 ◽  
Vol 4 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Jeffrey Blazar ◽  
Marc Allard ◽  
E. Kurt Lienau

AbstractFood safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published <abs>Food safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published literature. We highlight at least eleven different species of insects, including the lesser mealworm, Alphitobius diaperinus (Panzer); secondary screwworm, Cochliomyia macellaria (Fabricius); synanthropic flies [flesh fly, Sarcophaga carnaria (L.); house fly, Musca domestica (L.); fruit fly, Drosophila melanogaster (Meigen); and stable fly, Stomoxys calcitrans (L.)], American cockroach, Periplaneta americana (L.); German cockroach, Blatella germanica (L.); Oriental cockroach, Blatta orientalis (L.); Pacific beetle cockroach, Diploptera punctata (Eschscholtz); and Speckled feeder cockroach, Nauphoeta cinerea (Olivier), which act as vectors for Salmonella spp. or Escherichia coli and illustrate how these insects are successful vectors of foodborne disease outbreaks. We propose that insects be considered as one of the latest issues in food safety initiatives. Not only are some insects extremely important contributors to diseases, but now we suggest that more research into insects as potential carriers of E. coli and Salmonella spp., and therefore as contributing to foodborne disease outbreaks, is granted.


1999 ◽  
Vol 62 (9) ◽  
pp. 1059-1070 ◽  
Author(s):  
JOAN B. ROSE ◽  
THERESA R. SLIFKO

While the risk from pathogenic microorganisms in foods has been recognized for hundreds of years, bacterial agents are generally implicated as the contaminants. Although many outbreaks of gastroenteritis caused by protozoan pathogens have occurred, it is only in the last 3 years that attention has focused on protozoan association with foodborne transmission. Recognized as waterborne parasites, Giardia, Cryptosporidium, and Cyclospora have now been associated with several food-borne outbreaks. The oocysts and cysts of these organisms can persist and survive for long periods of time both in water and on foods. While Cyclospora oocysts require a maturation period, Cryptosporidium oocysts and Giardia cysts are immediately infectious upon excretion from the previous host. As a result, these parasites have emerged as public health risks and have become a concern to the food industry. More than 200 cases of foodborne giardiasis (seven outbreaks) were reported from 1979 to 1990. Four foodborne Cryptosporidium outbreaks (with a total of 252 cases) have been documented since 1993. Cyclospora caused a series of sporadic outbreaks of cyclosporasis throughout North America that have affected over 3,038 people since 1995. Control and prevention of protozoan foodborne disease depends upon our ability to prevent, remove, or kill protozoan contaminants. This review will address the biology, foodborne and waterborne transmission, survival, and methods for detection and control of Giardia, Cryptosporidium, and Cyclospora.


2010 ◽  
Vol 97 (2) ◽  
pp. 213-227 ◽  
Author(s):  
Maitri Thakur ◽  
Sigurdur Olafsson ◽  
Jong-Seok Lee ◽  
Charles R. Hurburgh

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