Download or read book Control of Listeria Monocytogenes in Simulated Food Processing Plant Environments written by Alexandra Thayer Spurlock and published by . This book was released on 1990 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Listeria monocytogenes in the Food Processing Environment written by Kieran Jordan and published by Springer. This book was released on 2015-04-22 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief focuses on Listeria monocytogenes, from isolation methods and characterization (including whole genome sequencing), to manipulation and control. Listeriosis, a foodborne disease caused by Listeria monocytogenes is a major concern for public health authorities. In addition, addressing issues relating to L. monocytogenes is a major economic burden on industry. Awareness of its ubiquitous nature and understanding its physiology and survival are important aspects of its control in the food processing environment and the reduction of the public health concern.

Download or read book The Role of Environmental Microbiota in the Persistence of Listeria Monocytogenes in Food Processing Facilities written by Maria Laura Rolon and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Food safety is of paramount importance for production of wholesome and nutritious food. Throughout my dissertation, I present results of four studies exploring the relationship between Listeria monocytogenes, a deadly foodborne pathogen, and environmental microbiota found in food processing facilities. L. monocytogenes can inhabit a wide range of habitats (e.g., soil, water, animals, insects) and its ability to adapt to different environmental conditions (e.g., low temperatures, high salt concentrations, low pH) allows for its survival in food processing environments, which can result in the potential for recurring contamination of food. To control the presence of L. monocytogenes, food processors rely on cleaning and sanitizing operations coupled with Environmental Monitoring Programs. While L. monocytogenes is typically susceptible to the cleaning and sanitizing protocols applied in food processing facilities, it may survive the action of sanitizers by forming, or residing inside biofilms. However, in food processing environments, L. monocytogenes resides with other environmental microorganisms that are introduced to the facilities with raw products or personnel. The presence of other microorganisms can facilitate formation of robust multi-species biofilms that may enhance the survival and persistence of L. monocytogenes. Currently, limited information is available regarding the potential associations between environmental microbiota and the presence of foodborne pathogens in food processing facilities. My dissertation research aimed to address some of the critical gaps in the understanding of the role of environmental microbiota in the survival and persistence of L. monocytogenes in food processing environments. iv To begin unraveling the role of environmental microbiota in the persistence of L. monocytogenes in food processing environments, I first sought to characterize the microbiota of three tree fruit packing facilities and statistically assess whether certain taxa co-occur with L. monocytogenes (Chapter 2). I observed a recurring presence of L. monocytogenes and a distinct microbiota composition in the monitored facilities throughout two seasons. Importantly, I found that bacterial taxa from taxonomic families Pseudomonadaceae, Xanthomonadaceae, and Microbacteriaceae were present in a significantly higher relative abundance in L. monocytogenes-positive samples, especially in the facility with a persistent L. monocytogenes contamination. While some members of these bacterial families have been studied as food spoilage organisms (e.g., Pseudomonas spp.), emerging human pathogens (e.g., Stenotrophomonas spp.), or plant pathogens (e.g., Xanthomonas spp.), there is limited information available on potential interactions between these species and L. monocytogenes. Furthermore, their role in the survival and persistence of L. monocytogenes in food processing facilities is severely understudied. In Chapter 3, I seek to understand how the detected bacterial taxa interact with L. monocytogenes. Given that the survival of L. monocytogenes under sanitizer pressure may be facilitated by biofilms formed in food processing environment, I aimed to assess the effect of biofilms formed by environmental microbiota on the survival during exposure to a commonly used sanitizer, benzalkonium chloride. I isolated environmental microbiota from families Pseudomonadaceae, Xanthomonadaceae, Microbacteriaceae, and Flavobacteriaceae from tree fruit packing environments, and tested their ability to form biofilms in single- and multi-family assemblages with L. monocytogenes. I found that microbial assemblages of v increasing complexity (i.e., increasing number of families) generally formed more biofilm and contained a greater concentration of L. monocytogenes, compared to monoculture biofilms. I further tested the effects of multi-species biofilm formation on the sanitizer tolerance of L. monocytogenes, by exposing multi-species biofilms to sanitizers and quantifying the die-off kinetics of L. monocytogenes throughout a 2-hour period. In Chapter 4, I aimed to assist fruit packers by providing practical tools to enhance the control of L. monocytogenes through traditional chemical-based cleaning and sanitizing. I tested four cleaning and sanitizing cleaning and sanitizing protocols in the fruit packing environments to determine their effectiveness in controlling L. monocytogenes and examined their effect on environmental microbiota. I found that the cleaning and sanitizing protocol that included a disinfectant with a biofilm-degrading ability was most effective in reducing the frequency of detected L. monocytogenes in the sampled areas. While the total microbial load generally decreased after the application of cleaning and sanitizing protocols, the microbiota composition did not appear to be significantly affected by the treatments. In the last research chapter (Chapter 5), I tested the ability of two lactic acid bacteria strains to inhibit L. monocytogenes in a monoculture as well as in the context of environmental microbiota from food processing facilities. Microbial strains with antilisterial activity have been previously assessed as alternative strategy to control L. monocytogenes in food processing environments, however, their performance in the context of environmental microbiota from ice cream processing facilities has not been tested before. Here, I collected environmental microbiota from three small-scale ice cream processing facilities and tested whether two lactic acid vi bacteria could attach and effectively inhibit L. monocytogenes when co-cultured with the collected environmental microbiota. I observed that the microbiota composition of ice cream processing facilities may affect the antilisterial ability of two lactic acid bacteria strains and their attachment to surfaces. In particular, the presence of Pseudomonas significantly reduced the antilisterial ability of the tested strains. The knowledge generated through my studies on the role of food processing facilities' microbiota will aid in designing tailored cleaning, sanitizing, and/or biological control protocols for control of L. monocytogenes. For example, cleaning and sanitizing could be redesigned to control taxa that facilitate Listeria's persistence, or new cleaning chemistries can be developed to improve biofilm control in food processing facilities.

Download or read book Listeria Monocytogenes written by Monde Alfred Nyila and published by BoD – Books on Demand. This book was released on 2018-08-29 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book "Listeria monocytogenes" describes different topics that deal with L. monocytogenes in medical research, modelling the behaviour of the organism in meat, quality assurance of raw food material and food products, the impact of environmental stresses in virulence traits of L. monocytogenes relevant to food safety, contamination, prevention and control in food processing and food service environments. The aim of this book is to introduce the reader to different approaches, methods, and tools in understanding the pathogen, Listeria monocytogens, with regard to primary and public health, food safety, pathogenicity, virulence, and its ubiquity. Topics covered in this book deal with L. monocytogenes in medical research. modelling the behaviour of the organism in meat, quality assurance of raw food material and food products, the impact of environmental stresses in virulence traits of L. monocytogenes relevant to food safety, contamination, prevention and control in food processing and food services environments.

Download or read book Tracking and Control Strategies of Listeria Monocytogenes in Seafood Processing Plants written by Joanne Thimothe and published by . This book was released on 2002 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contamination Prevention and Control of Listeria Monocytogenes in Food Processing and Food Service Environments written by Frederick Tawi Tabit and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter reviews issues related to the occurrence and growth of Listeria monocytogenes in food processing and food service environments. L. monocytogenes is a food-borne pathogen with the capacity to contaminate raw or minimally processed foods such as chilled ready-to-eat (RTE) foods. The consumption of food contaminated with L. monocytogenes can result in a disease known as listeriosis among vulnerable groups of people such as pregnant women and fetuses, newborns, adults between the ages of 65 and 75, and people with weakened immune systems. L. monocytogenes is ubiquitous and has been isolated from soil, vegetation, sewage, water, animal feed, fresh and frozen meat including poultry, slaughterhouse wastes and the feces of healthy animals and humans. The bacterium is both acid tolerant and salt tolerant. It is able to grow at refrigerator temperature, and is therefore often associated with the consumption of raw or minimally processed and often chilled RTE foods. L. monocytogenes is able to form biofilms on food processing and preparation surfaces, which protects it from antimicrobial action. Continuous education of vulnerable groups regarding food safety will increase their awareness of the importance of practicing safer food handling practices such as hand washing and safe storage of RTE foods as a means to prevent listeriosis.

Download or read book Behavior of Listeria Monocytogenes Biofilms in a Simulated Food Processing SFP Ecosystem written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the research has been to develop an experimental biofilm ecocystem for the characterization of Listeria monocytogenes biofilms in a simulated food processing (SFP) environment. Individual strains of L. monocytogenes were initially surveyed for their ability to attach to surfaces and form biofilms under a variety of conditions. Five strains of L. monocytogenes were then screened for optimal cell attachment and biofilm formation. Significant differences in surface attachment and biofilm formation were observed among the different strains of L. monocytogenes. The biofilms of the five-strain mixture of L. monocytogenes were formed on surfaces that are commonly used in food processing facilities, such as stainless steel and Teflon®. The biofilms were subjected to the SFP system in sequential 24-h daily cycles. Conditions of the SFP system included: starvation, washing, rinsing, and sanitation that routinely occur in a food processing plant. Cell survival in biofilms was determined during the time course of the experiment. The susceptibility of the cells in biofilms and detached cells to different sanitizers was measured. The morphology of the cells in biofilms and the planktonic cells detached from biofilms was observed. The study indicated that the progressive resistance developed by L. monocytogenes biofilms to a sanitizer could protect the cells in biofilms from this and other sanitizing agents. The progressive resistance and cross protection was observed in biofilms, but not in detached cells. These findings could provide a basis for further research on the mechanism of progressive resistance to stresses by L. monocytogenes in biofilms under food processing conditions. The data may help to establish effective sanitation programs for food processing and related industries.

Download or read book Listeria Monocytogenes in Ready to eat Food Processing Plants written by Thomas James Vincent Malley and published by . This book was released on 2012 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Listeria monocytogenes can persist in food processing environments, resulting in the predominant source of L. monocytogenes post-processing ready-to-eat (RTE) food contamination. Butt's "Seek and Destroy" strategy is a systematic method for finding sites of persistent growth ("niches"); it may reduce L. monocytogenes prevalence in RTE food and expedite detection and response to L. monocytogenes outbreaks. Applying this strategy, we sampled environments at two smoked fish plants to identify persistent L. monocytogenes ribotypes, and to identify and eliminate or manage niches. Persistence was measured with binomial statistics: one statistic compared ribotype recurrences to reference distributions; the second measured ribotype occurrences as a risk factor. Persistent ribotypes and persistence sites were identified to guide interventions. Poisson regression showed borderline decreases in L. monocytogenes isolation at both plants (p=0.026 and p=0.076). One niche on a food contact surface was eliminated; others were not. These methods should facilitate identification of microbial persistence. ii.

Download or read book Genotypic and Phenotypic Evaluation of Antimicrobial Resistance of Listeria Monocytogenes and Environmental Microbiota Obtained from Food Processing Environments written by Katie Bartlett and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L. monocytogenes is a pathogenic Gram-positive microorganism found in food processing and packaging facilities. The risk of food contamination with L. monocytogenes increases when L. monocytogenes withstands cleaning and sanitizing procedures designed to control foodborne pathogens. Failure to control L. monocytogenes in food processing environments can result in outbreaks of fatal disease listeriosis. Furthermore, L. monocytogenes has been found to co-exist in food packing environments with non-pathogenic bacterial families, including Xanthomonadaceae, Pseudomonadaceae, Microbacteriaceae and Flavobacteriaceae. These non-pathogenic microorganisms may contribute to biofilm formation and increased tolerance to sanitizers, if not effectively controlled with sanitizers. Not only have L. monocytogenes strains shown resistance to industrial sanitizers, but resistance has also become a concern with clinically relevant antibiotics that are used to treat human listeriosis. In order to effectively control L. monocytogenes in food processing environments and to effectively treat listeriosis, it is important to monitor the resistance of L. monocytogenes and food processing environmental microbiota to industrially and clinically relevant antimicrobials (i.e., sanitizers, antibiotics). Better understanding of the resistance of L. monocytogenes and environmental microbiota to sanitizers can inform proper cleaning and sanitizing procedures to prevent food contamination. Furthermore, understanding of the resistance of L. monocytogenes can inform the selection of antimicrobials for treatment of foodborne listeriosis. In this thesis, we measured the prevalence of antimicrobial resistance among L. monocytogenes and environmental microbiota isolates obtained from tree fruit packing facilities. We utilized broth microdilution assay to test the resistance to clinically relevant antibiotics (i.e., ampicillin, ceftriaxone, and gentamicin), as well as commonly used sanitizers (i.e., benzyl alkanium chloride and peracetic acid). Furthermore, we whole-genome sequenced the environmental isolates and analyzed sequences to study the association between antimicrobial resistance genes and phenotypic antimicrobial resistance.

Download or read book Listeria Monocytogenes written by Monde Alfred Nyila and published by . This book was released on 2018 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book ""Listeria monocytogenes"" describes different topics that deal with L. monocytogenes in medical research, modelling the behaviour of the organism in meat, quality assurance of raw food material and food products, the impact of environmental stresses in virulence traits of L. monocytogenes relevant to food safety, contamination, prevention and control in food processing and food service environments. The aim of this book is to introduce the reader to different approaches, methods, and tools in understanding the pathogen, Listeria monocytogens, with regard to primary and public health, food safety, pathogenicity, virulence, and its ubiquity. Topics covered in this book deal with L. monocytogenes in medical research. modelling the behaviour of the organism in meat, quality assurance of raw food material and food products, the impact of environmental stresses in virulence traits of L. monocytogenes relevant to food safety, contamination, prevention and control in food processing and food services environments.

Download or read book Foodborne Bacterial Pathogens written by Michael Doyle and published by CRC Press. This book was released on 1989-02-24 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacteria are estimated to cause some 24 million cases of diarrheal disease annually in the US. These papers have wide importance providing background information and recent research findings and giving a comprehensive, current understanding of bacterial pathogens associated with foods and their role

Download or read book Development of Listeria Monocytogenes Biofilms in a CDC Biofilm Reactor and Investigation of Effective Strategies for Biofilm Control in Food Processing Environments written by Ellen Andrea Mendez Sosa and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Listeria monocytogenes is one of the most concerning threat for the food industry. This pathogen has shown niche adaptation and ability to form biofilms. Even if sanitation practices can minimize the risk of pathogen survival, difficult-to-clean sites remain high-risk areas. Chemical sanitizers combined with non-thermal processing technologies might represent an effective way to control L. monocytogenes biofilm formation. The main objectives of this study were to: 1) understand L. monocytogenes biofilm formation ability under different conditions of material, temperature, and nutrients; 2) evaluate the effect of several chemical sanitizers alone or in combination with UV light to control biofilms; and 3) study the transcriptional response of L. monocytogenes biofilm to sublethal conditions of chemical sanitizers. A CDC Biofilm Reactor was used to grow 4-days-old multi-strain L. monocytogenes biofilms on stainless steel and polycarbonate coupons under dynamic conditions using TSBYE (Tryptic Soy Broth + 0.6% Yeast Extract) or BHI (Brain Heart Infusion) as media culture at 30 °C or 37 °C incubation temperature. Biofilms grown at 30 °C in TSBYE on stainless steel reached higher cell counts (8.14 log CFU/cm2). These conditions were selected for subsequent experiments. Biofilm survivability was investigated after 10 min exposure to lactic acid (4%), peracid (200 ppm), quaternary-ammonium (400 ppm) alone or in combination with UV light (254 nm) for 15 or 30 min. Sequential treatments effect was also evaluated. Control biofilms reached 6 log CFU/cm2 . Reductions ranging from 2.6 to 3.6 log CFU/cm2 were observed with chemical sanitizers, while a maximum of 1.8 log CFU/cm2 reduction was recorded after UV-C treatment alone. Combined treatments showed enhanced effect and their application sequence was significant for lactic acid and peroxyacid (P

Download or read book Investigating the Prevalence and Control of Listeria Monosytogenes in Food Facilities written by Cyril Nsom Ayuk Etaka and published by . This book was released on 2021 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small and very small food facilities in the ready-to-eat food industry face difficulties complying with the Food Safety Modernization Act-Preventive Controls for Human Food rule (FSMA-PCHF). This regulation highlights the need for sanitation to control environmental pathogens like Listeria monocytogenes. The main goal of this project was to investigate the prevalence and control of Listeria monocytogenes in food facilities. This study provides technical assistance to facilities to comply with the PCHF rule and addresses sanitation alternatives for food contact surfaces like aqueous ozone. First, the prevalence of Listeria spp and L. monocytogenes in small and very small food manufacturing facilities in Nebraska was determined. In this study, environmental samples were collected from three participating facilities. Overall, Listeria spp were detected in 14 of 266 (5.3%) samples with sites like floors and drains having the highest prevalence. No significant difference in prevalence across all three facilities was observed. Listeria monocytogenes was not detected in any of the facilities. This study highlights the importance of management and sanitation of non-food-contact surfaces like drains and floors. Our data was provided to participating facilities to assist in starting their environmental monitoring program and overall, contributing to their compliance with the PCHF rule. Next, we determined the efficacy of ozonated water for the decontamination of Listeria on food contact surfaces. For this study, stainless steel and polypropylene coupons constructed to 10 x 10 cm were conditioned with organic matter made from uncured deli turkey breast and inoculated with Listeria monocytogenes. Other experiments were performed with Listeria innocua separately. Clean coupons were also included for experiments with L. innocua. Inoculated surfaces were exposed to 10 ppm of ozonated water for 15, 30, and 45 seconds. Tap water was included as a treatment. There were no significant differences in reductions attributed to ozonated water compared to tap water washing. However, reductions of L. innocua on soiled stainless steel were significantly higher than on clean surfaces(P = 0.01). Similarly, L. innocua reductions were numerally higher on soiled polypropylene though not significantly different from clean coupons. Spraying applications may have influenced bacterial reduction from surfaces by dislodging rather than actual inactivation. In addition, the soil system with deli turkey may have not provided sufficient soil (grease) to reduce the efficacy of ozonated water resulting in similar reductions on both soiled and clean surfaces. Overall, data suggest that cleaning may be effective at reducing transiently attached Listeria from FCS.

Download or read book Control Strategies for Listeria Monocytogenes in Ready to eat Foods and on Food Contact Surfaces written by Jasdeep Kaur Saini and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ubiquitous nature and continued presence in food processing environments makes Listeria monocytogenes a significant threat in ready-to-eat (RTE) food products. This study was performed in two phases; Phase 1 studied lauric arginate (LAE) as an antimicrobial on food contact surfaces and shredded mozzarella cheese, and use of glucose oxidase (GOX), sodium lactate (SL), and acidified calcium sulfate (ACS) as preservatives in mozzarella cheese; Phase 2 evaluated efficacy of Photohydroionization (PHI) technology to control L. monocytogenes on food contact surfaces, sliced American cheese, and ready-to-eat turkey. Stainless steel coupons, mozzarella cheese, American cheese, and turkey were surface inoculated with a three- or five-strain cocktail of L. monocytogenes. Coupons were treated with 100 and 200 ppm solution of lauric arginate for 5 and 15 min. Mozzarella cheese was treated with different combinations of treatments comprising LAE, GOX, SL, ACS, dextrose, and anticaking agents (free flow 1031 and cellulose). Results indicated up to 2.5 log CFU/coupon reductions and it was concluded that LAE was effective in controlling low levels of contamination of L. monocytogenes on food contact surfaces. In mozzarella cheese, results indicated that lauric arginate provided no additional antimicrobial effect (P> 0.05) as compared to GOX + dextrose. The antimicrobial blends with GOX, SL, and ACS were different (P 0.05) from the controls but showed no differences (P 0.05) in their effect in controlling bacterial populations. Results from treatment with PHI unit showed significant (P 0.05) reduction in bacterial populations. L. monocytogenes populations reduced by 4.37 log CFU/coupon on stainless steel surfaces after 15 min of treatment; 2.16 and 2.52 log CFU/sample reduction on American cheese and ready-to-eat turkey, respectively, after short treatment time of 5 min. Lipid oxidation analyses performed on cheese and turkey samples indicated that the PHI treatment did not affect (P 0.05) TBAR values. These studies suggest that LAE and GOX as antimicrobials and PHI treatment can be used as intervention strategies in an integrated process to ensure safe production of food. Further research is needed to evaluate applicability of SL and ACS in mozzarella cheese.

Download or read book Risk Assessment of Listeria Monocytogenes in Ready to eat Foods written by World Health Organization and published by . This book was released on 2004 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cases of listeriosis appear to be predominantly associated with ready-to-eat products. FAO and WHO have undertaken a risk assessment of Listeria monocytogenes in ready-to-eat foods, prepared and reviewed by an international team of scientists. Input was received from several international fora including expert consultations and Codex Alimentarius committee meetings as well as via public and peer review. This interpretative summary provides an overview of how the risk assessment was undertaken and the results. In particular, it provides information relevant to risk managers addressing problems posed by this pathogen in ready-to-eat foods. It includes answers to the specific risk management questions posed by the Codex Committee on Food Hygiene and outlines the issues to be considered when implementing control measures, including the establishment of microbiological criteria.

Download or read book Behavior of Listeria Monocytogenes Biofilms in a Simulated Food Processing SFP Ecosystem written by Youwen Pan and published by . This book was released on 2005 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: ywpan, food science.

Download or read book Microbiological Analysis of Foods and Food Processing Environments written by Osman Erkmen and published by Academic Press. This book was released on 2021-12-09 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbiological Analysis of Foods and Food Processing Environments is a well-rounded text that focuses on food microbiology laboratory applications. The book provides detailed steps and effective visual representations with microbial morphology that are designed to be easily understood. Sections discuss the importance of the characteristics of microorganisms in isolation and enumeration of microorganisms. Users will learn more about the characteristics of microorganisms in medicine, the food industry, analysis laboratories, the protection of foods against microbial hazards, and the problems and solutions in medicine and the food industry. Food safety, applications of food standards, and identification of microorganisms in a variety of environments depend on the awareness of microorganisms in their sources, making this book useful for many industry professionals. Includes basic microbiological methods used in the counting of microbial groups from foods and other samples Covers the indicators of pathogenic and spoilage microorganisms from foods and other samples Incorporates identification of isolated microorganisms using basic techniques Provides expressed isolation, counting and typing of viruses and bacteriophages Explores the detection of microbiological quality in foods