Methods for Detecting Enterohaemorrhagic<i>Escherichia Coli</i>in Food

Sidari, Rossana; Caridi, Andrea

doi:10.1080/87559129.2010.535232

Cited by 12 publications

(6 citation statements)

References 80 publications

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“…Similarly, isolation confirmation of species identity and characterization of virulence factors present few challenges (7). The primary challenge is the cultural isolation of all VTEC strains from food samples in the presence of background microflora, a situation that has arisen partially because of the absence of simple selective factors for VTEC strains as a group but also due to the use of media originally developed for E. coli 0157:H7 (4,16,34,42,43). Successful isolation of a bacterium from enrichment broth is facilitated when the target organism constitutes a major proportion of the microflora present.…”

Section: Discussionmentioning

confidence: 99%

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Development of a Method for the Detection of Verotoxin-Producing Escherichia coli in Food

Gill

Martinez-Perez

McILWHAM

et al. 2012

Journal of Food Protection

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The growing recognition of the role of non-O157 verotoxigenic Escherichia coli (VTEC) in foodborne illness underscores the importance of developing methods to detect it in the food supply. We describe here the development of a protocol for the detection, isolation, and characterization of VTEC from foods, designed for the serotype-independent enrichment, detection, and isolation of VTEC, in combination with rapid characterization of VTEC O157, O26, O103, O111, and O145. This study examined the inhibitory concentration of six antimicrobial agents used either singly or in combination for the optimal enrichment of a panel of 18 different O serogroups of VTEC in modified tryptic soy broth. Considerable variability in resistance to the different antimicrobials tested was noted among different VTEC strains. The combination enabling growth of strains of all 18 different O serogroups was vancomycin (10 μg/ml) and cefsulodin (3 μg/ml). A similar combination of antimicrobials formulated in agar plates was found beneficial in the recovery of VTEC strains from enrichment broth cultures. The efficacy of these media in the recovery of selected VTEC (O26, O103, O111, O145, and O157) from ground beef and O157 VTEC from lettuce, spinach, and apple cider was demonstrated. The selective enrichment media described herein would appear suitable for incorporation in methods for the recovery and detection of a wide range of VTEC serogroups.

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Section: Discussionmentioning

confidence: 99%

“…Understanding the role of non-0157 VTEC in human illness and the identification of infection sources have been hampered by the shortage of validated methods for the serotype-independent detection and isolation of VTEC from foods (34). Though specific serogroups of VTEC (026, 0103, Olll, 0145, etc.)…”

mentioning

confidence: 99%

Development of a Method for the Detection of Verotoxin-Producing Escherichia coli in Food

Gill

Martinez-Perez

McILWHAM

et al. 2012

Journal of Food Protection

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“…Yet no medium or protocol has proven appropriate for all serogroups or sample types (e.g., food, feces, and water) (Durso 2013). Among current protocols, typical incubation temperatures range from 35 to 42°C, and duration from 6 to 24 h (Vimont et al 2006;Sidari and Caridi 2011). Although higher enrichment temperatures may be more selective for some STEC strains, longer incubations are sometimes applied simply for practical reasons in the laboratory such as allowing incubations to run overnight to avoid removing cultures from the incubator during non-typical work hours (Vimont et al 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, enrichment broths are frequently modified by the addition of antibiotics to suppress the growth of background microflora. However, O157 and non-O157 STEC are a diverse group, and the addition of antibiotics has been shown to inhibit the growth of some STEC strains (Sidari and Caridi 2011;Vimont et al 2007). Culture bias has been described between strains of the same species or subgroup for Listeria monocytogenes and Salmonella spp.…”

Section: Introductionmentioning

confidence: 99%

Competition during enrichment of pathogenicEscherichia colimay result in culture bias

Conrad

Stanford²,

McAllister

et al. 2017

FACETS

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Deadly outbreaks and illnesses due to Shiga toxin-producing Escherichia coli (STEC) occur worldwide; however, the cultivation methods required for adequate monitoring and traceback investigations are inefficient at best. Detection of STEC relies heavily on enrichment; yet no standard media or protocols exist. Furthermore, whether enrichment may bias detection of multiple STEC serogroups from complex samples is unknown. Thus, 14 STEC strains of serogroups O157 and the top six non-O157s (O26, O45, O103, O111, O121, and O145) were enriched in pairs for 6-78 h in broth and evaluated by quantitative polymerase chain reaction (qPCR). Here we show that a conventional 6-h enrichment protocol did not result in intra-species culture bias for the isolates tested. However, subsequent enrichments often produced biased cultures, with differences in the qPCR gene copy number ≥2 log 10 apparent in 12%, 38%, and 52% of competitions after 30, 54, and 78 h of consecutive enrichments, respectively. Some strains were able to prevail and (or) out-compete the opponent strain in 100% of competitions. Our results suggest that culture bias should be considered and (or) evaluated further due to the potential implications during routine pathogen screening and outbreak investigations. Citation: Conrad CC, Stanford K, McAllister TA, Thomas J, and Reuter T. 2016. Competition during enrichment of pathogenic Escherichia coli may result in culture bias. FACETS 1: 114-126.

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“…This and other previous reports again emphasize the constant dangers that these pathogens can pose as they can be quickly taken in by humans and cause a variety of uncomfortable conditions ( Hoffmann et al, 2017 ; Li et al, 2019 ). Besides, prompt and rapid detection of foodborne pathogens is essential to avoid FBDs ( Sidari and Caridi, 2011 ; Kaden et al, 2018 ). The gut microbiota is a complex embodiment of a wide range of microorganisms that play vital roles in maintaining internal homeostasis.…”

Section: Introductionmentioning

confidence: 99%

Lactobacillus delbrueckii subsp. bulgaricus KLDS 1.0207 Exerts Antimicrobial and Cytotoxic Effects in vitro and Improves Blood Biochemical Parameters in vivo Against Notable Foodborne Pathogens

Evivie

Abdelazez

et al. 2020

Front. Microbiol.

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Globally, foodborne diseases (FBDs) result in millions of sicknesses and deaths annually. Cumulative evidence suggests that the use of probiotic lactic acid bacteria (LAB) strains could be a viable alternative in inhibiting the activities of foodborne pathogens. This study aims to evaluate the in vitro antimicrobial, cytotoxic, and tolerance levels of Lactobacillus bulgaricus KLDS 1.0207 against two notable foodborne pathogens-Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923. Afterward, a 48 BALB/c mice-trial was used to assess its ameliorative effects on weight and serum biochemical parameters. Results showed that the cell-free supernatant (CFS) of this strain significantly inhibited both pathogens, but these effects were abolished at pH 6.5 and 7.0 (P < 0.05). Also, 6.96 ± 0.02 log CFU mL −1 of L. bulgaricus KLDS 1.0207 was still viable after three hours in simulated gastric juice and at pH 3.0, indicating that this strain was a potential probiotic candidate. Also, inflammatory activities in RAW264.7 cells were significantly inhibited using 10 9 CFU mL −1 of L. bulgaricus KLDS 1.0207 cells (P < 0.05). Significant weight losses were also prevented in the T LBSA (from 19.42 ± 1.04 to 19.55 ± 0.55 g) and T LBEC (from 22.86 ± 0.90 to 14.77 ± 9.86 g) groups compared to their respective model groups (T SA-from 21.65 ± 1.80 to 20.14 ± 1.84, and T EC-from 21.45 ± 0.82 to 14.45 ± 9.70 g). Besides, there was a slight weight gain in the S. aureus prevention group (T LBSA) compared to the model group (T SA). Serum biochemical analyses revealed that the total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and some mineral levels were markedly increased by S. aureus and E. coli administrations but were reversed to normalcy in both prevention groups (T LBSA and T LBEC). Interestingly, high-density lipoprotein

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Methods for Detecting EnterohaemorrhagicEscherichia Coliin Food

Cited by 12 publications

References 80 publications

Development of a Method for the Detection of Verotoxin-Producing Escherichia coli in Food

Development of a Method for the Detection of Verotoxin-Producing Escherichia coli in Food

Competition during enrichment of pathogenicEscherichia colimay result in culture bias

Lactobacillus delbrueckii subsp. bulgaricus KLDS 1.0207 Exerts Antimicrobial and Cytotoxic Effects in vitro and Improves Blood Biochemical Parameters in vivo Against Notable Foodborne Pathogens

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