Inhibition of food-borne pathogenic bacteria by bacteriocins from Lactobacillus gasseri

Salmonella is one of the most common food-borne pathogens. It can be transmitted between chickens, as well as to people by contaminated poultry products. In our study, we distinguished chickens with different resistances mainly based on bacterial loads. We compared the cecal tonsil transcriptomes between the susceptible and resistant chickens after Salmonella infection, aiming to identify the crucial genes participating in the antibacterial activity in the cecal tonsil. A total of 3214 differentially expressed genes (DEGs), including 2092 upregulated and 1122 downregulated genes, were identified between the two groups (fold change ≥ 2.0, padj < 0.05). Many DEGs were mainly involved in the regulation of two biological processes: crosstalk between the cecal tonsil epithelium and pathogenic bacteria, such as focal adhesion, extracellular-matrix–receptor interaction, and regulation of the actin cytoskeleton and host immune response including the cytokine–receptor interaction. In particular, the challenged resistant birds exhibited strong activation of the intestinal immune network for IgA production, which perhaps contributed to the resistance to Salmonella infection. These findings give insight into the mRNA profile of the cecal tonsil between the two groups after initial Salmonella stimulation, which may extend the known complexity of molecular mechanisms in chicken immune response to Salmonella.

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Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Biologics ◽

10.3390/biologics1020010 ◽

2021 ◽

Vol 1 (2) ◽

pp. 164-176

Author(s):

Abdallah S. Abdelsattar ◽

Anan Safwat ◽

Rana Nofal ◽

Amera Elsayed ◽

Salsabil Makky ◽

...

Keyword(s):

Pathogenic Bacteria ◽

Raw Milk ◽

Salmonella Spp ◽

Isolation And Characterization ◽

Food Borne ◽

Wide Range ◽

Almost All ◽

And Control ◽

Milk And Dairy Products

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

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

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094574 ◽

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.

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

Acta Alimentaria ◽

10.1556/066.2020.49.4.7 ◽

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.

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A novel universal nano-luciferase-involved reporter system for long-term probing food-borne probiotics and pathogenic bacteria in mice by in situ bioluminescence imaging

RSC Advances ◽

10.1039/d0ra01283a ◽

2020 ◽

Vol 10 (22) ◽

pp. 13029-13036 ◽

Cited By ~ 1

Author(s):

Ning Zhao ◽

Jing-Min Liu ◽

Shuang Liu ◽

Xue-Meng Ji ◽

Huan Lv ◽

...

Keyword(s):

Experimental Design ◽

Pathogenic Bacteria ◽

Bioluminescence Imaging ◽

Reporter System ◽

Bioluminescent Bacteria ◽

Foodborne Bacteria ◽

Food Borne

Schematic illustration of the preparation of bioluminescent bacteria and the experimental design of tracing of the foodborne bacteria in vivo.

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Behavior of Yersinia enterocolitica in the Presence of the Bacterivorous Acanthamoeba castellanii

Applied and Environmental Microbiology ◽

10.1128/aem.01915-13 ◽

2013 ◽

Vol 79 (20) ◽

pp. 6407-6413 ◽

Cited By ~ 16

Author(s):

E. Lambrecht ◽

J. Baré ◽

I. Van Damme ◽

W. Bert ◽

K. Sabbe ◽

...

Keyword(s):

Yersinia Enterocolitica ◽

Pathogenic Bacteria ◽

Acanthamoeba Castellanii ◽

Ecological Niches ◽

Free Living ◽

Content Type ◽

Food Borne ◽

Transmission Electron ◽

Set Up ◽

The Impact

ABSTRACTFree-living protozoa play an important role in the ecology and epidemiology of human-pathogenic bacteria. In the present study, the interaction betweenYersinia enterocolitica, an important food-borne pathogen, and the free-living amoebaAcanthamoeba castellaniiwas studied. Several cocultivation assays were set up to assess the resistance ofY. enterocoliticatoA. castellaniipredation and the impact of environmental factors and bacterial strain-specific characteristics. Results showed that allY. enterocoliticastrains persist in association withA. castellaniifor at least 14 days, and associations withA. castellaniienhanced survival ofYersiniaunder nutrient-rich conditions at 25°C and under nutrient-poor conditions at 37°C. Amoebae cultivated in the supernatant of oneYersiniastrain showed temperature- and time-dependent permeabilization. Intraprotozoan survival ofY. enterocoliticadepended on nutrient availability and temperature, with up to 2.8 log CFU/ml bacteria displaying intracellular survival at 7°C for at least 4 days in nutrient-rich medium. Transmission electron microscopy was performed to locate theYersiniacells inside the amoebae. AsYersiniaandAcanthamoebashare similar ecological niches, this interaction identifies a role of free-living protozoa in the ecology and epidemiology ofY. enterocolitica.

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Antibacterial Action of Vinegar against Food-Borne Pathogenic Bacteria Including Escherichia coli O157: H7 (Part 1) Examination of Bacteriostatic and Bactericidal Activities

Kansenshogaku zasshi ◽

10.11150/kansenshogakuzasshi1970.71.443 ◽

1997 ◽

Vol 71 (5) ◽

pp. 443-450 ◽

Cited By ~ 1

Author(s):

Etsuzo ENTANI ◽

Mito ASAI ◽

Shigetomo TSUJIHATA ◽

Yoshinori TSUKAMOTO ◽

Michio OHTA

Keyword(s):

Escherichia Coli ◽

Pathogenic Bacteria ◽

Antibacterial Action ◽

Escherichia Coli O157 ◽

Food Borne ◽

Bactericidal Activities

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Cloning and Characterization of a Novel N-acetylglucosaminidase (AtlD) from Enterococcus faecalis

Journal of Molecular Microbiology and Biotechnology ◽

10.1159/000486757 ◽

2018 ◽

Vol 28 (1) ◽

pp. 14-27 ◽

Cited By ~ 1

Author(s):

Carlos Eduardo Serrano-Maldonado ◽

Israel García-Cano ◽

Augusto González-Canto ◽

Eliel Ruiz-May ◽

Jose Miguel Elizalde-Contreras ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Food Industry ◽

Pathogenic Bacteria ◽

Heterologous Protein ◽

Biochemical Characterization ◽

Ph Values ◽

Food Borne ◽

Sds Page ◽

Exclusion Chromatography

The atlD gene from an Enterococcus faecalis strain isolated from a Mexican artisanal cheese was cloned, sequenced and expressed in Escherichia coli in order to perform a biochemical characterization. A partial amino acid sequence of the heterologous protein was obtained by LC-MS/MS, and it corresponded to a novel peptidoglycan hydrolase designated AtlD. Its molecular mass was 62–75 kDa, as determined by SDS-PAGE, zymography, Western blot, and exclusion chromatography. Electrofocusing rendered an isoelectric point (pI) of 4.8. It exhibited N-acetylglucosaminidase activity, with an optimal pH and temperature between 6–7 and 50°C, respectively. It retained 85% activity with NaCl at 1,000 mM, but it was susceptible to divalent ions, particularly Zn2+. It showed antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and enterococcal strains of clinical origin. Due to the fact that it showed activity versus pathogenic bacteria, and because of its capabilities under ionic strength, temperature, and pH values present in food matrices, it could be applied as an additive in the food industry. This study will aid in the design of new antibacterial agents of natural origin to combat food-borne diseases, and it could be used as an industrial or hospital hygiene agent as well.

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