scholarly journals Pathogens Contamination Level Reduction on Beef Using Organic Acids Decontamination Methods

2017 ◽  
Vol 74 (2) ◽  
pp. 212 ◽  
Author(s):  
Sorin Daniel DAN ◽  
Marian MIHAIU ◽  
Oana REGET ◽  
Delia OLTEAN ◽  
Alexandra TĂBĂRAN
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Organic Acids ◽  
Salmonella Enteritidis ◽  
Contamination Level ◽  
Bacterial Strains ◽  
Food Borne ◽  
Food Borne Illness ◽  
Level Reduction

In this study we aimed to assess the efficiency of organic acids in different concentrations regarding pathogens as Salmonella, Listeria and Escherichia on beef, which can cause food borne illness in humans. The samples were sterilized using UV radiation for 30 minutes, afterwards being contaminated with 1 ml of microbial suspension (0.5 MacFarland). We used reference bacterial strains for Salmonella Enteritidis, Escherichia coli and Listeria monocytogenes. The samples were subjected to decontamination procedure by introducing 25mL of solution of lactic, acetic or citric acid in concentration of 1%, 2% and 3%. The results showed a reduction of initial pathogen load, ranging from 0.32 to 7.78 log CFU/g, depending on the type of acid, concentration and pathogen sensitivity. After decontamination, standardized methods have been used for the isolation of pathogenic germs. Based on statistical analysis we conclude that pathogens have a different sensitivity to the action of acid solutions, their sensitivity in ascending order being: Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli. Among the organic acids, the most efficient was lactic acid, followed by acetic acid and less efficient citric acid. The greatest reduction of germs was determined by the concentration of 3%.

scholarly journals An Improved Cloning Vector for Construction of Gene Replacements in Listeria monocytogenes

2003 ◽  
Vol 69 (5) ◽  
pp. 3020-3023 ◽  
Author(s):  
Guojie Li ◽  
S. Kathariou
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Plasmid Vector ◽  
Gene Replacement ◽  
Direct Selection ◽  
Genetic Studies ◽  
Food Borne ◽  
Food Borne Illness ◽  
Selection For ◽  
Selection Of

ABSTRACT Listeria monocytogenes is a gram-positive, facultative intracellular bacterium implicated in severe food-borne illness (listeriosis) in humans. The construction of well-defined gene replacements in the genome of L. monocytogenes has been instrumental to several genetic studies of the virulence and other attributes of the organism. Construction of such mutations by currently available procedures, however, tends to be labor intensive, and gene replacement mutants are sometimes difficult to recover due to lack of direct selection for the construct. In this study we describe the construction and use of plasmid vector pGF-EM, which can be conjugatively transferred from Escherichia coli S17-1 to L. monocytogenes and which provides the genetic means for direct selection of gene replacements.

scholarly journals Efficacy assessment of various natural and organic antimicrobials against Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Dina H. Amin ◽  
Assem Abolmaaty
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Bactericidal Effect ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Low Concentrations ◽  
Potential Applications ◽  
Efficacy Assessment

Abstract Background Foodborne illness is a public health alarm with a deleterious effect on human health and the economy all over the world. Searching for possible solutions to beat foodborne pathogens is still a demanding concern. The scope of this study is to evaluate the antimicrobial activity of some natural and organic compounds against important pathogens including Escherichia coli O157:H7 C9490, Listeria monocytogenes Lm2 Scott A 4b, and Salmonella enteritidis 8-9-99. Results The bactericidal effect of eight compounds and their concentrations were evaluated by the tube dilution assay against the tested bacterial strains. Thymol was found to be superior to all tested compounds. Antimicrobial activities found to be highly influenced by varying pH values. Low pH 4.5 found to report higher inhibition when compared with pH 7.1. For instance, minimum inhibitory concentration (MIC) occurred at pH 7.1 with 25 ppm of thymol against Escherichia coli O157:H7 and Salmonella enteritidis, while 200 ppm against Listeria monocytogenes. However, MIC occurred at pH 4.5 with 25 ppm of thymol against all tested bacterial strains. Conclusions Thymol is the most active antimicrobial recorded in our study at low concentrations. Our results indicated thymol, benzoic acid, sodium benzoate, salicylic acid, 3-t-butyl-4-Hydroxyanisole, and acetylsalicylic acid have promising potential applications in controlling tested foodborne pathogens.

scholarly journals Microbial Profile of Fresh Beef Sold in the Markets of Ngaoundéré, Cameroon, and Antiadhesive Activity of a Biosurfactant against Selected Bacterial Pathogens

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Hippolyte T. Mouafo ◽  
Annick M. B. Baomog ◽  
Jorelle J. B. Adjele ◽  
Alphonse T. Sokamte ◽  
Augustin Mbawala ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Diversity ◽  
Salmonella Enteritidis ◽  
Meat Industry ◽  
Microbial Profile ◽  
Meat Spoilage ◽  
Food Borne ◽  
Food Borne Illness ◽  
Microbiological Criteria ◽  
Potential Use

Owing to its composition, meat is recognized as one of the best media for microbial growth leading to meat spoilage and food-borne illness. The ability of microorganisms to adhere to surfaces where meat is deposited during selling is a nonnegligible cause of meat contamination. This work was performed to assess the microbial profile of fresh beef sold in the markets of Ngaoundéré town and evaluate the antiadhesive activity of a biosurfactant derived from Lactobacillus paracasei subsp. tolerans N2 against selected pathogenic strains isolated in fresh beef. All fresh beef samples analysed were contaminated with both pathogenic and spoilage microorganisms at levels higher than the microbiological criteria set by the European Commission. A total of 151 strains belonging to 12 species (Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas sp., Escherichia coli 1, Escherichia coli, Salmonella enteritidis, Salmonella sp., Staphylococcus epidermidis, Staphylococcus xylosus, Staphylococcus aureus, Candida albicans, and Candida sp.) were isolated and identified. A specific relationship between the microbial diversity of fresh beef and the sampling sites was observed. Biosurfactant displayed antiadhesive activity against all the tested strains and the complete inhibition (100%) of Bacillus sp. BC1, S. aureus STP1, and S. xylosus STP2 was noticed at biosurfactant concentration of 10 mg/mL. This study indicates the microbial diversity of fresh beef sold in Ngaoundéré markets and suggests the potential use of biosurfactant as an antiadhesive agent in the meat industry.

scholarly journals A Rapid and Sensitive Europium Nanoparticle-Based Lateral Flow Immunoassay Combined with Recombinase Polymerase Amplification for Simultaneous Detection of Three Food-Borne Pathogens

2021 ◽  
Vol 18 (9) ◽  
pp. 4574
Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Quantitative Detection ◽  
Bacterial Strains ◽  
Food Borne Pathogens ◽  
Food Borne

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.

Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Sensory Characteristics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

Incidence of Salmonella, Campylobacter jejuni, Campylobacter coli, and Listeria monocytogenes in Poultry Carcasses and Different Types of Poultry Products for Sale on the Belgian Retail Market

1999 ◽  
Vol 62 (7) ◽  
pp. 735-740 ◽  
Author(s):  
M. UYTTENDAELE ◽  
P. DE TROY ◽  
J. DEBEVERE
Keyword(s):  
Listeria Monocytogenes ◽  
Campylobacter Jejuni ◽  
Broiler Chickens ◽  
Salmonella Enteritidis ◽  
Contamination Level ◽  
Contamination Rate ◽  
Campylobacter Coli ◽  
Retail Market ◽  
Salmonella Spp ◽  
Poultry Products

From January 1997 to May 1998, 772 samples of poultry carcasses and poultry products for sale on the retail market in Belgium were analyzed for the presence of Salmonella spp., Salmonella Enteritidis, Campylobacter jejuni, C. coli, and Listeria monocytogenes per 100 cm2 or 25 g. Poultry samples were contaminated with Salmonella (36.5%), C. jejuni and C. coli (28.5%), and L. monocytogenes (38.2%). In about 12.3% of the poultry samples, the L. monocytogenes contamination level exceeded 1 CFU per g or cm2. Significant differences in pathogen contamination rates of poultry products were noticed between the poultry products originating from Belgian, French, and U.K. abattoirs. Poultry products derived from broiler chickens running free in pine woods until slaughtering age (12 to 13 weeks) had a significantly (P < 0.05) lower contamination rate of Salmonella than poultry products from enclosed broilers slaughtered at the age of 6 to 8 weeks. A significantly (P < 0.05) lower pathogen contamination rate was noted for Salmonella, C. jejuni, and C. coli for poultry cuts without skin compared to poultry cuts with skin on. An increase in pathogen contamination rate was noticed during cutting and further processing. To diminish C. jejuni, C. coli, Salmonella, and L. monocytogenes contamination rates, hygienic rules of slaughter and meat processing must be rigorously observed. At the moment, zero tolerance for these pathogens is not feasible, and there is a need to establish criteria allowing these pathogens to be present at reasonable levels in the examined poultry samples.

scholarly journals Use of multi-locus sequencing typing as identification method for the food-borne pathogen Listeria monocytogenes: a review

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sonia Lamon ◽  
Domenico Meloni ◽  
Simonetta Gianna Consolati ◽  
Anna Mureddu ◽  
Rina Mazzette
Keyword(s):  
Listeria Monocytogenes ◽  
Detection Methods ◽  
Causative Organism ◽  
Intracellular Pathogen ◽  
Bacterial Strains ◽  
New Approach ◽  
Food Borne ◽  
Global Epidemiology ◽  
Selection Of

<em>Listeria monocytogenes</em> is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in several outbreaks of foodborne diseases. In this review, a new approach to molecular typing primarily designed for global epidemiology has been described: multi-<em>locus</em> sequencing typing (MLST). This approach is novel, in that it uses data that allow the unambiguous characterization of bacterial strains via the Internet. Our aim is to present the currently available selection of references on <em>L. monocytogenes</em> MLST detection methods and to discuss its use as <em>gold</em> <em>standard</em> to <em>L. monocytogenes</em> subtyping method.

scholarly journals Searching for Antagonistic Activity of Bacterial Isolates Derived from Food Processing Environments on Some Food-Borne Pathogenic Bacteria

2020 ◽  
Vol 49 (4) ◽  
pp. 415-423
Author(s):  
B. Baráti-Deák ◽  
Cs. Mohácsi-Farkas ◽  
Á. Belák
Keyword(s):  
Escherichia Coli ◽  
Food Processing ◽  
Pathogenic Bacteria ◽  
Inhibitory Effect ◽  
Antagonistic Activity ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Food Borne ◽  
Time Period ◽  
Growth Decline

Bacterial strains with inhibitory effect on Salmonella Hartford, Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli, respectively, were isolated. Out of the 64 bacteria originated from food processing environments, 20 could inhibit at least one of the tested pathogens, and it was proved that growth decline of the pathogenic bacteria was more remarkable by co-culturing than by using cell-free supernatants of the isolates. Seven different genera (Pseudomonas, Bacillus, Paenibacillus, Macrococcus, Staphylococcus, Serratia, and Rothia) reduced the pathogens’ growth during the time period of analysis, and the strongest inhibitory effect was observed after 24 h between 15 and 30 °C. Sensitivity of the tested human pathogenic bacteria against the inhibitory strains was distinct, as Y. enterocolitica could be inhibited by numerous isolates, while S. Hartford proved to be the most resistant. Our results reveal that the isolated bacteria or their excreted metabolites could hinder pathogen growth when used in sufficient quantities.

POTENCIAL ANTIBACTERIANO IN VITRO E TOXICOLÓGICO IN VIVO DAS FOLHAS DO JAMBO VERMELHO (Syzygium malaccensis, Myrtaceae) FRENTE A ZEBRAFISH (D. rerio) ADULTO

2021 ◽  
Author(s):  
Fernando E. T. Cunha ◽  
Maria I. C. Ferreira ◽  
Rafael S. Cruz ◽  
Maria J. G. Ferreira ◽  
Clarissa M. Aquino ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Danio Rerio ◽  
Salmonella Enteritidis

Este trabalho reporta o potencial antibacteriano in vitro e toxicológico in vivo das folhas do jambo (Syzygium malaccense) frente a zebrafish (Danio rerio) adulto (ZFa). As folhas de jambo foram submetidas a desidratação (35 ± 2°C) por 24 horas, trituração e posterior extração de metabólitos por decocção, infusão e maceração com água destilada. Os extratos obtidos foram liofilizados e submetidos a análise de atividade antibacteriana in vitro frente a Gram-negativas (Escherichia coli ATCC 25922, Salmonella Enteritidis IAL 1132) e Gram-positivas (Listeria monocytogenes ATCC 19115 e Staphylococcus aureus ATCC 27664), bem como ao potencial toxicológico in vivo frente ao ZFa. O extrato obtido por infusão se mostrou mais promissor, pois apresentou concentração mínima bactericida (CMB) e concentração mínima inibitória (CMI) com maior potencial frente às gram- positivas (CMB - 6,25 e CMI - 6,25 mg/ml), bem como às gram-negativas (CMB - 25,0 e 3,125 e CMI - 3,125 mg/ml). Todos os extratos testados não se mostraram tóxicos frente ao zebrafish adulto e não alteraram o sistema locomotor dos mesmos. Desta forma, conclui-se que o extrato aquoso das folhas do jambo vermelho (Syzygium malaccense) obtido por infusão é seguro e pode ser utilizado como conservante natural com maior ação antibacteriana. Este trabalho nos conduz a novos estudos de isolamento e caracterização de princípios bioativos.

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