Listeria monocytogenes

Mon, 07/06/2020 - 06:12
Author(s): Ellen Mendez, Diane K. Walker, Jessie Vipham, Valentina Trinetta Listeria monocytogenes is one of the most concerning pathogens for the food industry due to its ability to form biofilms, particularly in difficult-to-clean sites of processing facilities. There is a current industry-wide lack of data to refer to when selecting a strategy to control L. monocytogenes biofilms in the food...
Fri, 07/03/2020 - 10:02
The aim of this research was to investigate the efficacy of the duty ratio and applied voltage in the inactivation of pathogens in soybean curd by pulsed ohmic heating (POH). The heating rate of soybean curd increased rapidly as the applied voltage increased, although the duty ratio did not affect the temperature profile. We supported this result by verifying that electrical conductivity...
Fri, 07/03/2020 - 10:02
Listeria monocytogenes is a pathogen mostly associated with the consumption of ready-to-eat foods and can cause severe disease and death. It can be introduced into food chains from raw materials, but often the contamination source is the food production environment, where certain clones can persist for years. In the meat chain, ST9 is one of the most commonly encountered L. monocytogenes sequence...
Thu, 07/02/2020 - 16:00
The inhibitory properties of novel antimicrobial proteins against food-borne pathogens such as Listeria monocytogenes offer extensive benefits to the food and medical industries. In this study, we have identified antimicrobial proteins from a milk curd–derived bacterial isolate that exhibits antilisterial activity using genome mining and mass spectrometry analysis. The analysis of the draft...
Thu, 07/02/2020 - 10:03
In this report, the draft genome sequence of Listeria monocytogenes serovar 1/2a strain IZSAM_Lm_14-16064, isolated in Italy from a cooked ham, is announced. The genome is similar to that of a clinical strain isolated in 2014.
Thu, 07/02/2020 - 06:16
Author(s): Dhafer Alshaibani, Robson A.M. Machado, Beth L. Calder, Jennifer J. Perry Survival of L. monocytogenes (LM) and shigatoxigenic Escherichia coli (STEC) during manufacture and aging of unpasteurized, farmstead-style cheese was investigated. Cheese produced with fresh, unpasteurized milk inoculated with a two-strain cocktail of LM and STEC (both ∼4.5 log cfu mL-1) was aged for 84 days at...
Thu, 07/02/2020 - 04:02
Past studies have shown that the on-farm distribution of Listeria monocytogenes is affected by environmental factors (e.g., weather). However, the majority of studies were conducted at large scales (e.g., across farms), while few studies examined drivers of L. monocytogenes prevalence at smaller scales (e.g., within a single field). This study was performed to address this knowledge gap by (i)...
Wed, 07/01/2020 - 22:16
Eudragit RS100 nanoparticles containing Baccharis dracunculifolia DC essential oil (N‐EO) was developed by the nanoprecipitation method. N‐EO presented an average diameter of 151.6 nm, zeta potential (ζ) of +51.7 mV, and encapsulation efficiency of 99.4%. The antibacterial activity of N‐EO and free essential oil (EO) was evaluated in BHI broth against Staphylococcus aureus, Bacillus cereus,...
Wed, 07/01/2020 - 08:02
by Joelle K. Salazar, Vidya Natarajan, Diana Stewart, Megan Fay, Lauren J. Gonsalves, Tanvi Mhetras, Chinmyee Sule, Mary Lou Tortorello Refrigerated ready-to-eat (RTE) dips often have pH and water activity combinations conducive to the proliferation of foodborne pathogens, including Listeria monocytogenes. This study conducted product assessments of five refrigerated RTE dips: baba ghanoush,...
Wed, 07/01/2020 - 08:02
Mycobacterium avium is a human and animal pathogen that infects the host through the mucosal surfaces. Past work has demonstrated that the bacterium can interact with both the respiratory and gastrointestinal tracts. Those surfaces in the body are covered by a bilayer of a glycoprotein, mucin, which works as a physical barrier and a gel which contains antibacterial and antivirus properties. This...
Wed, 07/01/2020 - 00:00
Antimicrobial resistance is one of today’s major public health challenges. Infections caused by multidrug-resistant bacteria have been responsible for an increasing number of deaths in recent decades. These resistant bacteria are also a concern in the food chain, as bacteria can resist common biocides used in the food industry and reach consumers. As a consequence, the search for...
Tue, 06/30/2020 - 16:00
One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through heme-oxygenase I (HO-I)-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had...
Tue, 06/30/2020 - 06:14
Author(s): Matilde D'Arrigo, Laura Mateo-Vivaracho, Eva Guillamón, Ma Fernanda Fernández-León, Daniel Bravo, Ángela Peirotén, Margarita Medina, Ana García-Lafuente The majority of cases of listeriosis are associated with the consumption of contaminated food. Some strains of Listeria monocytogenes can persist over months or years in meat processing plants increasing the risk of product...
Sun, 06/28/2020 - 06:11
Author(s): Veronica Martinez-Rios, Elissavet Gkogka, Paw Dalgaard Mathematical models were evaluated to predict growth of L. monocytogenes in mould/smear-ripened cheeses with measured dynamic changes in product characteristics and storage conditions. To generate data for model evaluation three challenge tests were performed with mould-ripened cheeses produced by using milk inoculated with L....
Sun, 06/28/2020 - 06:11
Author(s): Amaury Gérard, Soundous El-Hajjaji, Els Van Coillie, Azeddine Bentaïb, Georges Daube, Marianne Sindic Cheese potentially allowing the growth of Listeria monocytogenes must be free of the pathogen in 25 g before being put on the market, while 100 cfu/g is tolerated when the pathogen is unable to grow. Challenge tests were performed in order to assess the growth potential of L....
Fri, 06/26/2020 - 22:12
Combined washing effect of noni extract (NE) and oregano essential oil (OE) on the decontamination of Listeria monocytogenes on romaine lettuce was examined. The fractional inhibitory concentration index (FICI) between NE and three different essential oils (cinnamon leaf, thyme, and OE) was determined. Fractional inhibitory concentration index results indicated that OE only had an additive effect...
Fri, 06/26/2020 - 16:00
Listeria monocytogenes (L. monocytogenes) is a ubiquitous foodborne pathogen that comprises 14 serotypes, of which serovar 4h is a novel serotype recently reported. Serovar 4h L. monocytogenes belonging to hybrid sub-lineage II exhibit hypervirulent features. Conventional biochemical tests and widely used PCR-based serogrouping schemes could not distinguish serovar 4h strains. In this study, we...
Fri, 06/26/2020 - 06:12
Author(s): S.I. Ekonomou, S. Bulut, K.A.G. Karatzas, I.S. Boziaris High hydrostatic pressure (HHP; 200 MPa for 15 min), liquid smoke (0.50%, v/v) and freezing (−80 °C, overnight) was used to eliminate Listeria monocytogenes in BHI broth, raw and smoked trout. The bactericidal effect of liquid smoke solutions (L9 and G6), HHP and their combinations was evaluated against L. monocytogenes LO28, EGD-...
Fri, 06/26/2020 - 06:12
Author(s): Emily Forauer, Sophie Tongyu Wu, Andrea J. Etter Listeria monocytogenes has long been associated with ready-to-eat foods, particularly with deli products. A retail deli is full of potential niches for L. monocytogenes to establish, and this poses a significant sanitation challenge. Retail sliced deli meat products, also known as luncheon meat or cold cuts, are subject to long home...
Thu, 06/25/2020 - 16:00
Listeria monocytogenes is one of the major foodborne pathogens. Isolates of PCR-serogroups IIb (n = 17) and IVb (n = 31) recovered from food (n = 33) and food processing environment (n = 15) in Poland were characterized using whole genome sequencing. Most isolates belonged to Multi-Locus Sequence Type (MLST) ST2 (31.3%) and ST5 (22.9%). Core genome MLST (cgMLST) analysis classified isolates into...
Wed, 06/24/2020 - 04:03
We aimed to perform serotyping and the antimicrobial resistance profile of Salmonella spp. and Listeria monocytogenes strains isolated from raw meats imported illegally into Brazil along the borders of Argentina and Uruguay. Distinct isolates of Salmonella spp. (n=6) and L. monocytogenes (n=25) obtained from 270 of these food products of earlier work were serotyped and tested for antimicrobial...
Tue, 06/23/2020 - 22:14
The objective of this study was to evaluate the possible synergistic interactions on antibacterial and antioxidant efficacy of two plant essential oils (EOs) Eucalyptus caesia Benth and Dracocephalum multicaule Montbr & Auch in vitro and in pear slices. Antibacterial combination effect was evaluated against seven important pathogenic bacteria (Bacillus cereus, Listeria monocytogenes,...
Sat, 06/20/2020 - 00:00
Listeria monocytogenes is among the best-characterized intracellular pathogens. Its virulence factors, and the way they interfere with host cells to hijack host functions and promote the establishment and dissemination of the infection, have been the focus of multiple studies over the last 30 years. During cellular infection, L. monocytogenes was shown to induce host DNA damage and delay the host...
Fri, 06/19/2020 - 04:03
The survival and virulence of Listeria monocytogenes was assessed during storage on three low-moisture foods (LMFs), chocolate liquor, corn flakes and shelled, dry-roasted pistachios (a w 0.18, 0.27, 0.20). The LMFs were inoculated with a 4-strain cocktail of L. monocytogenes at 8 log CFU/g, dried, equilibrated and then stored at 4°C, 25–81% relative humidity (RH) and 23°C, 30–35% RH for at least...
Fri, 06/19/2020 - 02:02
Sodium hypochlorite has been used in the food industry to reduce microbial contamination in food; however, the use of sodium hypochlorite is insufficient considering the human health hazards and environmental pollution. To overcome this issue, plant-derived antimicrobial agents have been developed. In our previous study, Cudrania tricuspidata leaf extract (0.4%) was used to wash fresh vegetables...
Thu, 06/18/2020 - 10:02
The Gram-positive pathogen Listeria monocytogenes can be subdivided into at least 12 different serovars, based on the differential expression of a set of somatic and flagellar antigens. Of note, strains belonging to serovars 1/2a, 1/2b, and 4b cause the vast majority of foodborne listeriosis cases and outbreaks. The standard protocol for serovar determination involves an agglutination method...
Wed, 06/17/2020 - 06:10
Author(s): Alejandro Garrido-Maestu, Sarah Azinheiro, Pablo Fuciños, Joana Carvalho, Marta Prado Dairy products have been implicated in foodborne infections caused by different bacterial pathogens. Among them, Listeria monocytogenes is of particular concern due to its ubiquity, resistance to sanitation processes and high mortality rates resulting from infection. These issues make the development...
Tue, 06/16/2020 - 06:14
Author(s): Hye Jung Shin, Hoikyung Kim, Larry R. Beuchat, Jee-Hoon Ryu This study investigated the antimicrobial activities of organic acid vapors against a phytopathogen (Acidovorax citrulli) and foodborne pathogens (Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes) on the surface of Cucurbitaceae seeds. Germination percentages of cucumber, honeydew melon and watermelon...
Sun, 06/14/2020 - 06:11
Author(s): Esmeralda Dushku, Charalampos Kotzamanidis, Kalodoti Avgousti, Antonios Zdragas, George Vafeas, Virginia Giantzi, Alexandra Staikou, Minas Yiangou Listeria monocytogenes strains were isolated from Cornu aspersum maxima snails from farm units experiencing high mortalities and were characterized by phenotypic, molecular and biochemical criteria. A high heterogeneity was observed in the...
Sat, 06/13/2020 - 18:02
In this research, first, ZnO nanorods were synthesized by hydrothermal method and characterized in terms of morphological and structural properties by means of field emission scanning electron microscopy, Fourier transform infrared, and X-ray diffraction techniques. Subsequently, polylactic acid/ZnO, polylactic acid/TiO2, and polylactic acid/ZnO/TiO2 nanocomposites with different percentages of...
Sat, 06/13/2020 - 06:13
Author(s): Anna Kristina Witte, Birgit Bromberger, Patrick Mester, Christian Robben, Dagmar Schoder, Eva Streit, Peter Rossmanith Diagnostic strategies to detect foodborne pathogens such as L. monocytogenes in food processing environments are cost- and time-consuming necessities to ensure safe food. In this study we present in-house monitoring data of a relatively novel direct enrichment PCR (DEP...
Fri, 06/12/2020 - 00:00
Listeria monocytogenes is a foodborne pathogen responsible for about 1600 illnesses each year in the United States (US) and about 2500 confirmed invasive human cases in European Union (EU) countries. Several technologies and antimicrobials are applied to control the presence of L. monocytogenes in food. Among these, the use of natural antimicrobials is preferred by consumers. This is due to their...
Thu, 06/11/2020 - 02:03
Pomegranate peel extract (PGE) is a new promising natural alternative control substance with large spectrum of activity against wide range of pathogenic microorganisms. In the present study, PGE was firstly investigated as natural antimicrobial against Listeria monocytogenes both in vitro and on fresh-cut fruits. The in vitro results showed quick and strong bactericidal and bacteriostatic...
Wed, 06/10/2020 - 06:10
Author(s): Yun Fan, Jiaju Qiao, Zhaoxin Lu, Zhiyang Fen, Yang Tao, Fengxia Lv, Haizhen Zhao, Chong Zhang, Xiaomei Bie In a food-processing environment, bacterial cells often adhere to surfaces and form biofilms to protect themselves from external adverse influences. Our study aimed to identify the influence of environmental factors and cell properties on Listeria monocytogenes biofilm formation....
Wed, 06/10/2020 - 04:03
In relation to milk hygiene and safety, the milking phase is considered a critical moment since it represents a probable pathway for the introduction of unwanted microorganisms in the dairy chain. In particular, Listeria monocytogenes (L. monocytogenes) and Escherichia coli ( E. coli ) are known as possible microbial contaminants of raw sheep milk although extensive knowledge regarding their...
Tue, 06/09/2020 - 22:16
The enterocin P‐producing Enterococcus lactis strain Q1 was directly added at 107 CFU/g in refrigerated raw beef to evaluate its effectiveness in the control of Listeria monocytogenes EGDe 107776 proliferation. Furthermore, sensorial evaluation of the quality of treated beef meat samples with the enterococcal protective culture was performed basing on color, odor, and appearance parameters for 14...
Tue, 06/09/2020 - 16:00
Gut organoids are stem cell derived 3D models of the intestinal epithelium that are useful for studying interactions between enteric pathogens and their host. While the organoid model has been used for both bacterial and viral infections, this is a closed system with the luminal side being inaccessible without microinjection or disruption of the organoid polarization. In order to overcome this...
Tue, 06/09/2020 - 06:13
Author(s): Ligia E. Prezzi, Sarah H.I. Lee, Valéria M.R. Nunes, Carlos H. Corassin, Tatiana C. Pimentel, Ramon S. Rocha, Gustavo L.P. Ramos, Jonas T. Guimarães, Celso F. Balthazar, Maria Carmela K.H. Duarte, Mônica Q. Freitas, Erick A. Esmerino, Marcia C. Silva, Adriano G. Cruz, Carlos A.F. Oliveira This study aimed to evaluate the effect of Lactobacillus rhamnosus GG on growth of Staphylococcus...
Mon, 06/08/2020 - 06:11
Author(s): Andrew Green, Vladimir Popović, Keith Warriner, Tatiana Koutchma The inactivation efficacies of low pressure mercury (LPM) lamps (253.7 nm) and UVC LEDs (277 nm) were compared for Escherichia coli O157:H7 on lettuce leaves and Listeria monocytogenes on apple skin. Reductions ranging from 1.19 ± 0.59 to 1.58 ± 0.27 log CFU per sample at 4 and 25 °C were achieved. At 4 °C, UVC LEDs...
Sat, 06/06/2020 - 06:11
LWT
Author(s): Minjung Shin, Sang-Soon Kim, Dong-Hyun Kang The purpose of this study was to identify the combined effect of a 222-nm krypton-chlorine (KrCl) excilamp and a 280-nm light-emitting-diode (LED-UVC) on inactivation of Salmonella Typhimurium and Listeria monocytogenes. Distilled water samples inoculated with pathogens were subjected to KrCl excilamp, LED-UVC, and combined treatment. The...
Fri, 06/05/2020 - 22:15
The objective of this study was to investigate the antibacterial activity of propolis at different doses and combinations of the same with nisin against Listeria monocytogenes in ice cream. Experimental groups were prepared with propolis in three concentrations (400, 800, and 1,600 mg/L) and combinations of the same with 250 ppm nisin. L. monocytogenes was inhibited in the ice cream which...
Fri, 06/05/2020 - 22:12
Aim of the study Effect of internalized phthalyl starch nanoparticles (PSNs) on the antimicrobial ability of Lactococcus lactis (LL) KCTC 2013. Methods and results Phthalyl starch nanoparticles (PSNs) were prepared by self‐assembly of phthalyl starch and the amount of the hydrophobic phthalic moieties were characterized by nuclear magnetic resonance (NMR), PSN1 (DS: 14.3 mol.‐%), PSN2 (DS: 17.8...
Thu, 06/04/2020 - 03:50
Author(s): Alberto Garre, Marcel H. Zwietering, Heidy M.W. den Besten Variability is inherent in biology and also substantial for microbial populations. In the context of food safety risk assessment, it refers to differences in the response of different bacterial strains (between-strain variability) and different cells (within-strain variability) to the same condition (e.g. inactivation treatment...
Wed, 06/03/2020 - 03:52
ABSTRACT Consumer demand for "fresh food" with no chemical preservatives has prompted researchers to pay more attention to natural antimicrobial peptides such as bacteriocins. Nisin is currently the most widely used food biopreservative among the bacteriocins; however, its applications are restricted due to its low stability at neutral and alkaline pH values. Circular bacteriocins have potent...
Wed, 06/03/2020 - 03:43
Listeria monocytogenes is a foodborne pathogen causing systemic infection with high mortality. To allow efficient tracing of outbreaks a clear definition of the genomic signature of a cluster of related isolates is required, but lineage specific characteristics call for a more detailed understanding of evolution. In our work we used core genome MLST (cgMLST) to identify new outbreaks combined to...
Wed, 06/03/2020 - 03:39
Here we report a sensing method for Listeria monocytogenes based on the agglutination of all-liquid Janus emulsions. This two-dye assay enables the rapid detection of trace Listeria in less than 2 h via an emissive signal produced in response to Listeria binding. The biorecognition interface between the Janus emulsions is...
Sat, 05/30/2020 - 03:40
Programmed cell death plays crucial roles in organismal development and host defense. Recent studies have highlighted mechanistic overlaps and extensive, multifaceted crosstalk between pyroptosis, apoptosis, and necroptosis, three programmed cell death pathways traditionally considered autonomous. The growing body of evidence, in conjunction with the identification of molecules controlling the...
Fri, 05/29/2020 - 03:48
Author(s): Gabriella Centorotola, Romolo Salini, Anna Franca Sperandii, Diana Neri, Patrizia Tucci, Gino Angelo Santarelli, Violeta Di Marzio, Romina Romantini, Luca Candeloro, Annamaria Conte, Giacomo Migliorati, Francesco Pomilio, Luigi Iannetti
Fri, 05/29/2020 - 03:38
Whole genome sequencing (WGS) analyses have been instrumental in traceback investigations of Listeria monocytogenes (Lm). To demonstrate how long-read sequencing analysis can capture and describe relationships among isolates from clinical, food, and environmental sources, we analyzed 366 long-read- and shotgun-sequenced isolates from 16 Lm outbreak strains associated with cantaloupe, leafy green...
Thu, 05/28/2020 - 03:48
Antimicrobial effect of oregano and thyme essential oils (1%) in minced pork was assessed after storage at 3°C/7 days in a vacuum. The inhibition of S. Typhimurium depended mainly on the fat content (logarithmic dependence) and to a lesser degree on the pH, whereas pH was not found to be a significant predictor in the case of L. monocytogenes. The results show that only lean minced meat (up to 5...

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