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monocytogenes listeria

Danielle R Balay, Michael G Gänzle, Lynn M McMullen
The aim of this study was to determine if different carbohydrates influence the growth of Listeria monocytogenes in the presence of carnocyclin A or leucocin A. Carnobacterium maltaromaticum ATCC PTA-5313 and Leuconostoc gelidum UAL187 were used to produce carnocyclin A and leucocin A, respectively. Growth curves were modeled for five strains of L. monocytogenes grown in basal medium supplemented with glucose, sucrose, fructose, mannose, or cellobiose, in the presence of carnocyclin A or leucocin A. The growth of L...
2018: Frontiers in Microbiology
Alexander Gluschko, Marc Herb, Katja Wiegmann, Oleg Krut, Wolfram F Neiss, Olaf Utermöhlen, Martin Krönke, Michael Schramm
The intracellular pathogen Listeria monocytogenes (L.m.) is targeted by the autophagic machinery, but the molecular mechanisms involved and consequences for anti-listerial immunity remain enigmatic. Here, we demonstrate that L.m. infection of macrophages in vivo exclusively evokes LC3-associated phagocytosis (LAP), but not canonical autophagy, and that targeting of L.m. by LAP is required for anti-listerial immunity. The pathway leading to LAP induction in response to L.m. infection emanates from the β2 integrin Mac-1 (CR3, integrin αM β2 ), a receptor recognizing diverse microbial ligands...
March 14, 2018: Cell Host & Microbe
Katherine D Hills, Daniela A Oliveira, Nicholas D Cavallaro, Carmen L Gomes, Eric S McLamore
We demonstrate a sensing mechanism for rapid detection of Listeria monocytogenes in food samples using the actuation of chitosan-aptamer nanobrush borders. The bio-inspired soft material and sensing strategy mimic natural symbiotic systems, where low levels of bacteria are selectively captured from complex matrices. To engineer this biomimetic system, we first develop reduced graphene oxide/nanoplatinum (rGO-nPt) electrodes, and characterize the fundamental electrochemical behavior in the presence and absence of chitosan nanobrushes during actuation (pH-stimulated osmotic swelling)...
March 15, 2018: Analyst
Eleni C Pappa, Thomas G Bontinis, Maria Tasioula-Margari, John Samelis
The microbiological quality of and changes in the main physicochemical parameters, together with the evolution of proteolysis, lipolysis and volatile profiles of soft Xinotyri, a traditional Greek acid-curd cheese (pH≈4.4, moisture 65%, salt 1%) made from raw (RMC) or pasteurized (PMC) goat's milk without starters, were evaluated during aerobic storage at 4o C for 60 days. No statistically significant differences between the total nitrogen (TN) and nitrogen fraction (% of TN) contents, the degradation of intact αs - or β-caseins, total free amino acid (FAA) contents, and the ratio of hydrophilic and hydrophobic peptides in the water-soluble fraction of RMC and PMC were found...
December 2017: Food Technology and Biotechnology
Partha Basu, Ajay Mehta, Minish Jain, Sudeep Gupta, Rajnish V Nagarkar, Subhashini John, Robert Petit
OBJECTIVES: A global unmet medical need exists for effective treatments for persistent, recurrent, or metastatic cervical cancer, as patients have a short life expectancy. Recently, immunotherapies have shown promising survival benefits for patients with advanced forms of cancer. Axalimogene filolisbac (ADXS11-001), a Listeria monocytogenes immunotherapy with a broad effect on the immune system, is under investigation for treatment of human papillomavirus-associated cancers including cervical cancer...
March 14, 2018: International Journal of Gynecological Cancer
Cristiana Maurella, Silvia Gallina, Giuseppe Ru, Daniela Adriano, Alberto Bellio, Daniela Manila Bianchi, Laura Chiavacci, Maria Ines Crescio, Margherita Croce, Valeria D'Errico, Maria Franca Dupont, Alessandro Marra, Ubaldo Natangelo, Francesco Pomilio, Angelo Romano, Stefano Stanzione, Teresa Zaccaria, Fabio Zuccon, Maria Caramelli, Lucia Decastelli
In May 2016, two separate clusters of febrile gastroenteritis caused by Listeria monocytogenes were detected by the local health authority in Piedmont, in northern Italy. We carried out epidemiological, microbiological and traceback investigations to identify the source. The people affected were students and staff members from two different schools in two different villages located in the Province of Turin; five of them were hospitalised. The epidemiological investigation identified a cooked beef ham served at the school canteens as the source of the food-borne outbreak...
March 2018: Euro Surveillance: Bulletin Européen sur les Maladies Transmissibles, European Communicable Disease Bulletin
Lisa Milazzo, Stefan Hofbauer, Barry D Howes, Thomas Gabler, Paul G G Furtmüller, Christian Obinger, Giulietta Smulevich
Coproheme decarboxylases (ChdC) catalyse the hydrogen peroxide-mediated conversion of coproheme to heme b. This work compares the structure and function of wild-type (WT) coproheme decarboxylase from Listeria monocytogenes and its M149A, Q187A, and M149A/Q187A mutants. The UV-vis, resonance Raman and electron paramagnetic resonance spectroscopies clearly show that the ferric form of the WT protein is a pentacoordinate quantum mechanically mixed-spin state, which is very unusual in biological systems. Exchange of the Met149 residue to Ala dramatically alters the heme coordination, which becomes a 6 coordinate low spin species with the amide nitrogen atom of the Q187 residue bound to the heme iron...
March 14, 2018: Biochemistry
Fulai Li, Fan Li, Dan Luo, Weihua Lai, Yonghua Xiong, Hengyi Xu
Infectious diseases caused by Listeria monocytogenes pose a great threat to public health worldwide. Therefore, a rapid and efficient method for L. monocytogenes detection is needed. In this study, a biotin-exposure-based immunomagnetic separation (IMS) method was developed. That is, biotinylated antibody was first targeted to L. monocytogenes. Then, streptavidin-functionalized magnetic nanoparticles were added and anchored onto L. monocytogenes cells indirectly through the strong noncovalent interaction between streptavidin and biotin...
August 9, 2018: Analytica Chimica Acta
Ester Meles, Caterina De Carlini, Gaetano Gentile, Alberto Roghi, Stefano Maggiolini
We report the case of a 56-year-old man showing numerous cardiovascular manifestations of Listeria infection (myo-pericarditis, coronary vasospasm, intracavitary vegetations/thrombus, sinoatrial blocks). Cardiac magnetic resonance and echocardiography images provided an unexpected picture of this infection, and were relevant for the appropriate clinical management. Transthoracic and transesophageal echocardiography were useful for assessing the presence of an endocavitary mass. Tissue characterization by cardiac magnetic resonance confirmed the presence of a thrombus and revealed signs of active inflammation in the myocardial wall, pericardium and vascular pedicle...
February 2018: Giornale Italiano di Cardiologia
Christopher J Anderson, John Satkovich, Volkan K Köseoğlu, Hervé Agaisse, Melissa M Kendall
Ethanolamine is a ubiquitous and essential molecule within a host. Significantly, bacterial pathogens exploit ethanolamine during infection to promote growth and regulate virulence. The ethanolamine permease EutH is dispensable for growth in vitro under standard conditions, whereas EutH is required for ethanolamine utilization at low pH. These findings suggested a model in which EutH facilitates diffusion of ethanolamine into the bacterial cell in acidic environments. To date, the ecological significance of this model has not been thoroughly investigated, and the importance of EutH to bacterial growth under physiologically relevant conditions is not known...
March 12, 2018: Infection and Immunity
Stephanie M Prezioso, Kevin Xue, Nelly Leung, Scott D Gray-Owen, Dinesh Christendat
Listeria monocytogenes is a common food-borne bacterial pathogen that contaminates plant and animal consumable products. The persistent nature of L. monocytogenes is associated with millions of food recalls annually. Here, we describe the role of shikimate in directly modulating the expression of genes encoding enzymes for the conversion of quinate and shikimate metabolites to protocatechuate. In L. monocytogenes these genes are found within two operons, named qui1 and qui2. Additionally, a gene named quiR, encoding a LysR-Type Transcriptional Regulator (QuiR), is located immediately upstream of the qui1 operon...
March 9, 2018: Journal of Molecular Biology
Moran Brenner, Lior Lobel, Ilya Borovok, Nadejda Sigal, Anat A Herskovits
Listeria monocytogenes (Lm) is a saprophyte and intracellular pathogen. Transition to the pathogenic state relies on sensing of host-derived metabolites, yet it remains unclear how these are recognized and how they mediate virulence gene regulation. We previously found that low availability of isoleucine signals Lm to activate the virulent state. This response is dependent on CodY, a global regulator and isoleucine sensor. Isoleucine-bound CodY represses metabolic pathways including branched-chain amino acids (BCAA) biosynthesis, however under BCAA depletion, as occurs during infection, BCAA biosynthesis is upregulated and isoleucine-unbound CodY activates virulence genes...
March 12, 2018: PLoS Genetics
Fernanda B Campagnollo, Larissa P Margalho, Bruna A Kamimura, Marcelo D Feliciano, Luisa Freire, Letícia S Lopes, Verônica O Alvarenga, Vasco A P Cadavez, Ursula Gonzales-Barron, Donald W Schaffner, Anderson S Sant'Ana
Artisanal raw milk cheeses are highly appreciated dairy products in Brazil and ensuring their microbiological safety has been a great need. This study reports the isolation and characterization of lactic acid bacteria (LAB) strains with anti-listerial activity, and their effects on Listeria monocytogenes during refrigerated shelf-life of soft Minas cheese and ripening of semi-hard Minas cheese. LAB strains (n = 891) isolated from Minas artisanal cheeses (n = 244) were assessed for anti-listerial activity by deferred antagonism assay at 37 °C and 7 °C...
August 2018: Food Microbiology
E Cabrera-Díaz, L Martínez-Chávez, J Sánchez-Camarena, J A Muñiz-Flores, A Castillo, P Gutiérrez-González, S M Arvizu-Medrano, D G González-Aguilar, N E Martínez-Gonzáles
Simultaneous and individual enumeration of Salmonella, Shigella and Listeria monocytogenes was compared on inoculated Roma tomatoes and Serrano peppers using an Most Probable Number (MPN) technique. Samples consisting of tomatoes (4 units) or peppers (8 units) were individually inoculated with a cocktail of three strains of Salmonella, Shigella or L. monocytogenes, or by simultaneous inoculation of three strains of each pathogen, at low (1.2-1.7 log CFU/sample) and high (2.2-2.7 log CFU/sample) inocula. Samples were analyzed by an MPN technique using universal pre-enrichment (UP) broth at 35 °C for 24 ± 2 h...
August 2018: Food Microbiology
Alejandro Garrido-Maestu, Sarah Azinheiro, Joana Carvalho, Marta Prado
Listeria monocytogenes continues to be one of the most important foodborne pathogens worldwide, either due to its incidence and/or to its high mortality rate. In the present study, a filtration-based protocol was applied for the screening of viable bacteria. Additionally, a complete method (enrichment, filtration, DNA extraction and real-time PCR detection) was evaluated in order to determine the capacity of this protocol to detect viable L. monocytogenes in food samples. A new multiplex qPCR detection system was designed, including an internal amplification control, both targets were detected with hydrolysis probes...
August 2018: Food Microbiology
Ioannis-Angelos I Thamnopoulos, Georgios F Michailidis, Dimitrios J Fletouris, Anastasia Badeka, Michael G Kontominas, Apostolos S Angelidis
Propolis is a natural bee-product with documented antimicrobial properties in vitro. The objective of this study was to develop a protocol for adding propolis into milk and to determine whether the addition of propolis can confer anti-listerial activity during the storage of milk under optimal or improper refrigeration conditions. Upon dissolving propolis ethanolic extract (PEE) into glycerol, the PEE-glycerol mixture contained no visible insoluble particles and could be dispersed evenly into milk, without leaving any insoluble material...
August 2018: Food Microbiology
Rita Rahmeh, Abrar Akbar, Mohamed Kishk, Thanyan Al Onaizi, Aisha Al-Shatti, Anisha Shajan, Batool Akbar, Salwa Al-Mutairi, Awatef Yateem
Food safety has become an issue of great interest worldwide. Listeria monocytogenes is a food-borne pathogen that causes listeriosis and is difficult to control in the dairy industry. The use of lactic acid bacteria (LAB) and their antimicrobial substances against Listeria is promising in food applications. Here, we report the isolation from raw camel milk of LAB displaying antilisterial activity. Two isolates were selected for their secretion of bacteriocin(s) and identified by 16S rRNA sequencing as Enterococcus faecium S6 and R9...
March 7, 2018: Journal of Dairy Science
Olfa Ben Braïek, Paola Cremonesi, Stefano Morandi, Slim Smaoui, Khaled Hani, Taoufik Ghrairi
This study aims to characterise a potential bacteriocinogenic lactic acid bacterial strain isolated from a raw pink shrimp (Palaemon serratus) and evaluate its safety aspect. The strain designated as 4CP3 was noted to display antibacterial activities (P < 0.05) against Gram-positive and Gram-negative foodborne pathogens (Listeria monocytogenes and Pseudomonas aeruginosa) and some filamentous fungi (e.g. Aspergillus niger A79). Phenotypic and molecular techniques as well as phylogenetic analysis identified the isolate 4CP3 as Enterococcus lactis...
March 7, 2018: Microbial Pathogenesis
Xin-Jun Du, Yu-Xuan Zang, Hai-Bin Liu, Ping Li, Shuo Wang
Listeria monocytogenes is an important food-borne pathogenic bacterium that causes human disease, resulting in economic losses worldwide. The current detection methods for L. monocytogenes are not well suited for direct field testing because they involve complicated, time-consuming operations. A simple, efficient method is vital for L. monocytogenes detection. In this study, we combined isothermal recombinase polymerase amplification (RPA) with a lateral flow (LF) strip to rapidly and reliably detect L. monocytogenes...
March 10, 2018: Journal of Food Science
Michael J Rothrock, Peixin Fan, Kwangcheol C Jeong, Sun Ae Kim, Steven C Ricke, Si Hong Park
Investigation of Listeria monocytogenes transmission from environmental sources associated with pasture-raised chickens to poultry products is needed to determine ways to prevent potential foodborne illness. Here, we report the complete genome sequence of Listeria monocytogenes MR310, one of the isolates from a pastured-flock poultry management system.
March 8, 2018: Genome Announcements
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