scholarly journals Genetic Listeria monocytogenes Types in the Pork Processing Plant Environment: From Occasional Introduction to Plausible Persistence in Harborage Sites

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 717
Author(s):  
Niels Demaître ◽  
Geertrui Rasschaert ◽  
Lieven De Zutter ◽  
Annemie Geeraerd ◽  
Koen De Reu
Keyword(s):  
Genetic Diversity ◽  
Environmental Samples ◽  
Genetic Characterization ◽  
Processing Plant ◽  
Pfge Analysis ◽  
Food Contact ◽  
Plant Environment ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Cleaning And Disinfection

The purpose of this study was to investigate the L. monocytogenes occurrence and genetic diversity in three Belgian pork cutting plants. We specifically aim to identify harborage sites and niche locations where this pathogen might occur. A total of 868 samples were taken from a large diversity of food and non-food contact surfaces after cleaning and disinfection (C&D) and during processing. A total of 13% (110/868) of environmental samples tested positive for L. monocytogenes. When looking in more detail, zone 3 non-food contact surfaces were contaminated more often (26%; 72/278) at typical harborage sites, such as floors, drains, and cleaning materials. Food contact surfaces (zone 1) were less frequently contaminated (6%; 25/436), also after C&D. PFGE analysis exhibited low genetic heterogeneity, revealing 11 assigned clonal complexes (CC), four of which (CC8, CC9, CC31, and CC121) were predominant and widespread. Our data suggest (i) the occasional introduction and repeated contamination and/or (ii) the establishment of some persistent meat-adapted clones in all cutting plants. Further, we highlight the importance of well-designed extensive sampling programs combined with genetic characterization to help these facilities take corrective actions to prevent transfer of this pathogen from the environment to the meat.

Microbiological Performance of Dairy Processing Plants Is Influenced by Scale of Production and the Implemented Food Safety Management System: A Case Study

2013 ◽  
Vol 76 (6) ◽  
pp. 975-975 ◽  
Author(s):  
BEATRICE ATIENO OPIYO ◽  
JOHN WANGOH ◽  
PATRICK MURIGU KAMAU NJAGE
Keyword(s):  
Food Safety ◽  
Environmental Samples ◽  
Safety Management ◽  
Small Scale ◽  
Microbial Quality ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
End Products ◽  
Microbiological Parameters ◽  
Contact Surfaces

The effects of existing food safety management systems and size of the production facility on microbiological quality in the dairy industry in Kenya were studied. A microbial assessment scheme was used to evaluate 14 dairies in Nairobi and its environs, and their performance was compared based on their size and on whether they were implementing hazard analysis critical control point (HACCP) systems and International Organization for Standardization (ISO) 22000 recommendations. Environmental samples from critical sampling locations, i.e., workers' hands and food contact surfaces, and from end products were analyzed for microbial quality, including hygiene indicators and pathogens. Microbial safety level profiles (MSLPs) were constructed from the microbiological data to obtain an overview of contamination. The maximum MSLP score for environmental samples was 18 (six microbiological parameters, each with a maximum MSLP score of 3) and that for end products was 15 (five microbiological parameters). Three dairies (two large scale and one medium scale; 21% of total) achieved the maximum MSLP scores of 18 for environmental samples and 15 for the end product. Escherichia coli was detected on food contact surfaces in three dairies, all of which were small scale dairies, and the microorganism was also present in end product samples from two of these dairies, an indication of cross-contamination. Microbial quality was poorest in small scale dairies. Most operations in these dairies were manual, with minimal system documentation. Noncompliance with hygienic practices such as hand washing and cleaning and disinfection procedures, which is common in small dairies, directly affects the microbial quality of the end products. Dairies implementing HACCP systems or ISO 22000 recommendations achieved maximum MSLP scores and hence produced safer products.

A Survey of Microbial Contamination of Food Contact Surfaces at Broiler Slaughter Plants in Taiwan

2004 ◽  
Vol 67 (12) ◽  
pp. 2809-2811 ◽  
Author(s):  
C. P. HO ◽  
N. Y. HUANG ◽  
B. J. CHEN
Keyword(s):  
Microbial Contamination ◽  
Processing Plant ◽  
Hand Tools ◽  
Bacterial Counts ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Cleaning Procedures ◽  
Contact Surfaces ◽  
Contamination Levels ◽  
Bacterial Type

Microbial contamination levels at broiler slaughter plants were investigated at three major slaughter plants in Taiwan during the summer and winter. The microbial contamination levels in chicken carcasses and on food contact surfaces were examined using the swab method. The results indicated that the bacterial counts were affected by the slaughter processing plant, processes, and season (P < 0.05). The bacterial counts on food contact surfaces of the equipment before operation were not significantly lower than those after processing. Regardless of the bacterial type, bacterial counts of chicken carcasses generally decreased from the scalding step to the washing step before evisceration and then increased. The cleaning procedures for food contact surfaces should be evaluated, and special attention should be given to utensils used during processing, such as gloves, baskets, and hand tools.

Identification of multi-species biofilms in the meat processing environment and characterisation of involved bacteria in a mono- and multi-species biofilm model

2020 ◽  
Author(s):  
Eva M. Wagner ◽  
Nadja Pracser ◽  
Sarah Thalguter ◽  
Katharina Fischel ◽  
Nicole Rammer ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Food Processing ◽  
Extracellular Dna ◽  
Meat Processing ◽  
Food Contact ◽  
Biofilm Model ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Matrix Components ◽  
Cleaning And Disinfection

<p>Biofilms are suggested to be a source of contamination in the food producing environment leading to food spoilage or the transmission of food-borne pathogens. However, to date, research has mainly focused on the presence of (biofilm-forming) bacteria within food processing environments, without analysing the associated biofilm matrix components.</p> <p>The aim of this study was to identify biofilm hotspots in a meat processing environment by analysing the presence of microorganisms (by cultivation and targeted quantitative real-time PCR based on 16S rRNA) and the major matrix components carbohydrates, extracellular DNA and proteins. Sampling included 47 distinct food contact surfaces and 61 distinct non-food contact surfaces from eleven rooms within an Austrian meat processing plant, either during operation or after cleaning and disinfection. Additionally, we isolated and characterized bacteria found in biofilms. The biofilm forming capacity of eleven isolates, was tested, using a static biofilm model. Additionally, two different multi-species settings were tested combining three strains, each. Biofilms were grown on stainless-steel slides for seven days at 10 °C, to mimic conditions found in the food producing environment.</p> <p>Overall, we identified ten biofilm positive sites, among them seven of which were sampled during operation and three after cleaning and disinfection. Five biofilms were detected on food contact surfaces (cutters and associated equipment and a screw conveyor) and five on non-food contact surfaces (drains and water hoses) resulting in 9.3 % of the sites being classified as biofilm positive. From these sites we cultivated bacteria of 29 different genera. The most prevalent bacteria belonged to the genera <em>Brochothrix</em>, <em>Pseudomonas</em> and <em>Psychrobacter</em>. From each biofilm we isolated bacteria from four to 12 different genera, indicating the presence of multi-species biofilms.</p> <p>Culturing of eleven isolates of different species (all detected in the mentioned biofilms, representing typical residential and spoilage bacteria in the meat processing environment) showed that there are differences of individual strains to produce matrix components and biomass on stainless steel slides.  <em>Brochothrix</em>, <em>Carnobacterium</em> and <em>Kocuria</em> produced only detectable amounts of carbohydrates but neither eDNA nor proteins. The <em>Acinetobacter</em> and the <em>Flavobacterium</em> isolates were able to produce two of the measured components and six strains were capable of producing all types of analysed matrix components, among them a <em>Pseudomonas</em> <em>fragi</em> isolate. The minimal mean bacterial load detected was 5.4 log CFU/cm<sup>2</sup> formed by the <em>Psychrobacter</em> strain.</p> <p>Different isolates showed differences in matrix formation ability, possible contributing in different amounts to the matrix production in multi-species biofilms, indicating that multi-species biofilms are a key survival mechanism for microorganisms within the food processing environment.</p> <p>Currently, we are testing two different multi-species biofilms in our model. Hereby we cultivate three species detected in the cutter-associated biofilms and other three species detected in the water hose-associated biofilms together to mimic these biofilms. This work ultimately showed the presence of multi-species biofilms within the meat processing environment, thereby identifying various sources of potential contamination. Data on the presence, formation and composition of biofilms (i.e. chemical and microbiological) will help to prevent and reduce biofilm formation within food processing environments.</p>

Generation of Airborne Listeria innocua from Model Floor Drains†

2012 ◽  
Vol 75 (7) ◽  
pp. 1328-1331 ◽  
Author(s):  
MARK E. BERRANG ◽  
JOSEPH F. FRANK
Keyword(s):  
Tap Water ◽  
Listeria Innocua ◽  
Cross Contamination ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Selective Agar ◽  
Poultry Processing ◽  
Contact Surfaces ◽  
Cleaning And Disinfection ◽  
Phosphate Buffered Saline

Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 108 cells per ml of phosphate-buffered saline and 104 attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

scholarly journals Occurrence of Listeria spp. and Listeria monocytogenes Isolated from PDO Taleggio Production Plants

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1636
Author(s):  
Erica Tirloni ◽  
Cristian Bernardi ◽  
Francesco Pomilio ◽  
Marina Torresi ◽  
Enrico P. L. De Santis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Genome Sequencing ◽  
Environmental Samples ◽  
The Other ◽  
Whole Genome ◽  
Strain Characterization ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Sampling Points ◽  
Contact Surfaces

The present study evaluated the presence of Listeria spp. and L. monocytogenes in four plants producing PDO Taleggio cheese. A total of 360 environmental samples were collected from different areas during production. The sampling points were identified as Food Contact Surfaces (FCS), transfer-Non Food Contact Surfaces (tr-NFCS), and non-transfer-NFCS (non-tr-NFCS). Fifty-nine ingredients/products were also analyzed. Listeria spp. was found in all the plants with a mean prevalence of 23.1%; plants that included a ripening area showed significantly higher prevalence if compared to the other plants. The positivity rate detected on FCS was moderate (~12%), but significantly lower if compared to NFCS (about 1/4 of the samples, p < 0.01). Among the FCS, higher prevalence was revealed on ripening equipment. Listeria spp. was never detected in the ingredients or products. A total of 125 Listeria spp. isolates were identified, mostly as L. innocua (almost 80%). L. monocytogenes was detected only from two FCS samples, in an area dedicated to the cutting of ripened blue cheeses; strain characterization by whole genome sequencing (WGS) evidenced a low virulence of the isolates. The results of the present study stress the importance of Listeria spp. management in the dairy plants producing PDO Taleggio and similar cheeses, mainly by the application of strict hygienic practices.

Mathematical Model of Listeria monocytogenes Cross-Contamination in a Fish Processing Plant

2004 ◽  
Vol 67 (12) ◽  
pp. 2688-2697 ◽  
Author(s):  
RENATA IVANEK ◽  
YRJÖ T. GRÖHN ◽  
MARTIN WIEDMANN ◽  
MARTIN T. WELLS
Keyword(s):  
Mathematical Model ◽  
Listeria Monocytogenes ◽  
Food Products ◽  
Raw Material ◽  
Processing Plant ◽  
Cross Contamination ◽  
Fish Processing ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces

Listeriosis is a foodborne disease caused by the bacterium Listeria monocytogenes. The food industry and government agencies devote considerable resources to reducing contamination of ready-to-eat foods with L. monocytogenes. Because inactivation treatments can effectively eliminate L. monocytogenes present on raw materials, postprocessing cross-contamination from the processing plant environment appears to be responsible for most L. monocytogenes food contamination events. An improved understanding of cross-contamination pathways is critical to preventing L. monocytogenes contamination. Therefore, a plant-specific mathematical model of L. monocytogenes cross-contamination was developed, which described the transmission of L. monocytogenes contamination among food, food contact surfaces, employees' gloves, and the environment. A smoked fish processing plant was used as a model system. The model estimated that 10.7% (5th and 95th percentile, 0.05% and 22.3%, respectively) of food products in a lot are likely to be contaminated with L. monocytogenes. Sensitivity analysis identified the most significant input parameters as the frequency with which employees' gloves contact food and food contact surfaces, and the frequency of changing gloves. Scenario analysis indicated that the greatest reduction of the within-lot prevalence of contaminated food products can be achieved if the raw material entering the plant is free of contamination. Zero contamination of food products in a lot was possible but rare. This model could be used in a risk assessment to quantify the potential public health benefits of in-plant control strategies to reduce cross-contamination.

scholarly journals Identification and Spoilage Potential of the Remaining Dominant Microbiota on Food Contact Surfaces after Cleaning and Disinfection in Different Food Industries

2019 ◽  
Vol 82 (2) ◽  
pp. 262-275 ◽  
Author(s):  
SHARON MAES ◽  
MARC HEYNDRICKX ◽  
THIJS VACKIER ◽  
HANS STEENACKERS ◽  
ALEX VERPLAETSE ◽  
...  
Keyword(s):  
Food Contamination ◽  
Surface Contamination ◽  
Food Spoilage ◽  
Production Environment ◽  
Food Industries ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Cleaning And Disinfection ◽  
Rrna Sequences

ABSTRACT After cleaning and disinfection (C&D), surface contamination can still be present in the production environment of food companies. Microbiological contamination on cleaned surfaces can be transferred to the manufactured food and consequently lead to foodborne illness and early food spoilage. However, knowledge about the microbiological composition of residual contamination after C&D and the effect of this contamination on food spoilage is lacking in various food sectors. In this study, we identified the remaining dominant microbiota on food contact surfaces after C&D in seven food companies and assessed the spoilage potential of the microbiota under laboratory conditions. The dominant microbiota on surfaces contaminated at ≥102 CFU/100 cm2 after C&D was identified based on 16S rRNA sequences. The ability of these microorganisms to hydrolyze proteins, lipids, and phospholipids, ferment glucose and lactose, produce hydrogen sulfide, and degrade starch and gelatin also was evaluated. Genera that were most abundant among the dominant microbiota on food contact surfaces after C&D were Pseudomonas, Microbacterium, Stenotrophomonas, Staphylococcus, and Streptococcus. Pseudomonas spp. were identified in five of the participating food companies, and 86.8% of the isolates evaluated had spoilage potential in the laboratory tests. Microbacterium and Stenotrophomonas spp. were identified in five and six of the food companies, respectively, and all tested isolates had spoilage potential. This information will be useful for food companies in their quest to characterize surface contamination after C&D, to identify causes of microbiological food contamination and spoilage, and to determine the need for more thorough C&D.

Use of One-Ply Composite Tissues in an Automated Optical Assay for Recovery of Listeria from Food Contact Surfaces and Poultry-Processing Environments

2007 ◽  
Vol 70 (5) ◽  
pp. 1263-1266 ◽  
Author(s):  
ZHINONG YAN ◽  
KEITH L. VORST ◽  
LEI ZHANG ◽  
ELLIOT T. RYSER
Keyword(s):  
Stainless Steel ◽  
Environmental Samples ◽  
Culture Method ◽  
Predictive Values ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Poultry Processing ◽  
Contact Surfaces ◽  
Analysis System ◽  
Sensitivity Specificity

A novel one-ply composite tissue (CT) method using the Soleris (formerly BioSys) optical analysis system was compared with the conventional U.S. Department of Agriculture (USDA) environmental sponge enrichment method for recovery of Listeria from food contact surfaces and poultry-processing environments. Stainless steel and high-density polyethylene plates were inoculated to contain a six-strain L. monocytogenes cocktail at 104, 102, and 10 CFU per plate, whereas samples from naturally contaminated surfaces and floor drains from a poultry-processing facility were collected with CTs and environmental sponges. CT samples were transferred into Soleris system vials, and presumptive-positive samples were further confirmed. Sponge samples were processed for Listeria using the USDA culture method. L. monocytogenes recovery rates from inoculated stainless steel and polyethylene surfaces were then compared for the two methods in terms of sensitivity, specificity, and positive and negative predictive values. No significant differences (P &gt; 0.05) were found between the two methods for recovery of L. monocytogenes from any of the inoculated stainless steel and polyethylene surfaces or environmental samples. Sensitivity, specificity, and overall accuracy of the CT-Soleris for recovery of Listeria from environmental samples were 83, 97, and 95%, respectively. Listeria was detected 2 to 3 days sooner with the CT-Soleris method than with the USDA culture method, thus supporting the increased efficacy of this new protocol for environmental sampling.

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