Prevalence and Genetic Diversity of Listeria monocytogenes in Vacuum-Packaged Ready-to-Eat Meat Products at Retail Markets in Latvia

2009 ◽  
Vol 72 (6) ◽  
pp. 1283-1287 ◽  
Author(s):  
AIVARS BĒRZIŅŠ ◽  
MARGARITA TERENTJEVA ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Meat Products ◽  
Processing Plant ◽  
Meat Processing ◽  
Pork Products ◽  
Beef Products ◽  
Processing Plants ◽  
Serotype 1 ◽  
Packaged Beef

Nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 Baltic meat processing plants were analyzed for presence and numbers of Listeria monocytogenes at the end of shelf life. A total of 38 (18%) of 211 samples tested positive for L. monocytogenes serotype 1/2a (88%) or 1/2c (12%). The prevalence of L. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) (P < 0.001). Enumeration of L. monocytogenes showed that 84% of the positive samples contained <100 CFU/g upon expiry of product shelf life. The numbers of L. monocytogenes exceeded 100 CFU/g only in cold-smoked, sliced, vacuum-packaged beef products. Identical pulsed-field gel electrophoresis types were recovered from different production lots of cold-smoked vacuum-packaged beef and pork products produced by the same meat processing plant, demonstrating L. monocytogenes contamination as a recurrent problem within one meat processing plant.

Contamination Patterns of Listeria monocytogenes in Cold-Smoked Pork Processing

2010 ◽  
Vol 73 (11) ◽  
pp. 2103-2109 ◽  
Author(s):  
AIVARS BĒRZIŅŠ ◽  
SANNA HELLSTRÖM ◽  
INDULIS SILIŅŠ ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Samples ◽  
Meat Products ◽  
Pulsed Field Gel Electrophoresis ◽  
Processing Plant ◽  
Environmental Sampling ◽  
Meat Processing ◽  
Pork Products ◽  
Plant Environment ◽  
Pork Samples

Contamination patterns of Listeria monocytogenes were studied in a cold-smoked pork processing plant to identify the sources and possible reasons for the contamination. Environmental sampling combined with pulsed-field gel electrophoresis (PFGE) subtyping and serotyping were applied to investigate the genetic diversity of L. monocytogenes in the plant environment and ready-to-eat (RTE) cold-smoked pork products. A total of 183 samples were collected for contamination analyses, including samples of the product at different stages during manufacture (n = 136) and environmental samples (n = 47) in 2009. L. monocytogenes isolates, previously recovered from 73 RTE cold-smoked pork samples and collected from the same meat processing plant in 2004, were included in this study. The brining machine and personnel working with brining procedures were the most contaminated places with L. monocytogenes. The overall prevalence of L. monocytogenes in raw pork (18%) increased to 60% after the brining injections. The brining machine harbored six different PFGE types belonging to serotypes 1/2a, 1/2c, 4b, and 4d, which were found on the feeding teeth, smooth surfaces, and spaces of the machine, thus potentially facilitating dissemination of L. monocytogenes contamination. Two PFGE types (2 and 8) belonging to serotypes 1/2a and 1/2c were recovered from RTE cold-smoked pork collected in 2004, and from surfaces of the brining machine sampled in 2009, and may indicate the presence of persistent L. monocytogenes strains in the plant. Due to poor hygiene design, removal of the brining machine from the production of cold-smoked meat products should be considered to reduce L. monocytogenes contamination in the finished products.

scholarly journals Occurrence of Listeria monocytogenes in Ready-to-Eat Meat Products and Meat Processing Plants in Spain

Foods ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 271-282 ◽  
Author(s):  
Diego Gómez ◽  
Laura Iguácel ◽  
Mª Rota ◽  
Juan Carramiñana ◽  
Agustín Ariño ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Meat Processing ◽  
Processing Plants

Control of Listeria monocytogenes with Combined Antimicrobials on Beef Franks Stored at 4°C

2004 ◽  
Vol 67 (10) ◽  
pp. 2296-2301 ◽  
Author(s):  
MILAGROS UHART ◽  
SADHANA RAVISHANKAR ◽  
NICOLE D. MAKS
Keyword(s):  
Listeria Monocytogenes ◽  
Safety Issue ◽  
Meat Products ◽  
Sodium Lactate ◽  
Meat Processing ◽  
Bacterial Strains ◽  
Log Reduction ◽  
Sodium Diacetate ◽  
Packaged Beef ◽  
Antimicrobial Treatments

Contamination of ready-to-eat meat products such as beef franks with Listeria monocytogenes has become a major concern for the meat processing industry and an important food safety issue. The objective of this study was to determine the effectiveness of combinations of antimicrobials as aqueous dipping solutions to control L. monocytogenes on vacuum-packaged beef franks stored at 4°C for 3 weeks. Commercial beef franks were dipped for 5 min in three antimicrobial solutions: pediocin (6,000 AU), 3% sodium diacetate and 6% sodium lactate combined, and a combination of the three antimicrobials. Samples were then inoculated with 107 CFU/g of either four L. monocytogenes strains individually or a cocktail of the four strains, vacuum packaged, and stored at 4°C for 3 weeks. Sampling was carried out at day 0 and after 2 and 3 weeks of storage. Individual strains, as well as the cocktail, exhibited different responses to the antimicrobial treatments. After 2 and 3 weeks of storage at 4°C, pediocin-treated beef franks showed a less than 1-log reduction for all bacterial strains. Samples treated with the sodium diacetate–sodium lactate combination showed about a 1-log reduction after 2 weeks of storage for all strains and between a 1- and 2-log reduction after 3 weeks of storage, depending on the bacterial strain. When the three antimicrobials were combined, reductions ranged between 1 and 1.5 log units and 1.5 to 2.5 log units after 2 and 3 weeks of storage, respectively, at 4°C. These results indicate that the use of combined antimicrobial solutions for dipping treatments is more effective at inhibiting L. monocytogenes than treatments using antimicrobials such as pediocin separately.

Prediction of Persistence of Listeria monocytogenes ST451 in a Rabbit Meat Processing Plant in the Czech Republic

2019 ◽  
Vol 82 (8) ◽  
pp. 1350-1356
Author(s):  
TEREZA GELBÍČOVÁ ◽  
MARTINA FLORIANOVÁ ◽  
ZUZANA TOMÁŠTÍKOVÁ ◽  
LUCIE POSPÍŠILOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Core Genome ◽  
Sequence Type ◽  
Processing Plant ◽  
Meat Processing ◽  
Sequencing Method ◽  
Serotype 1 ◽  
Rabbit Meat ◽  
Meat Samples

ABSTRACT This study was focused on characterization of the genetic diversity of Listeria monocytogenes isolated from packed fresh rabbit meat obtained from one producer via retail outlets. The partial aim was to compare the characteristics of a suspect persistent strain with strains from human cases. The occurrence of L. monocytogenes in vacuum-packed rabbit meat was monitored during 2013 to 2016. All strains were characterized by serotyping, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Selected strains, which represented each year, were analyzed using the whole genome sequencing method. L. monocytogenes was detected in 21 (38%) of 56 originally packed rabbit meat samples from one food producer during the whole monitored period. All strains showed the identical serotype (1/2a), AscI/ApaI pulsotype (735/2), and sequence type (ST451). The clonal similarity of strains from rabbit meat was also confirmed on the basis of core genome MLST (on 1,701 loci). This fact suggests the occurrence of a suspect persistent strain in the meat processing plant. Results of core genome MLST enabled us to unambiguously exclude rabbit meat as a source of listeriosis in humans caused by the indistinguishable AscI/ApaI pulsotype and sequence type, although all strains carried all genes important for the virulence of L. monocytogenes. No specific genes that may be associated with its persistence in the food processing environment were detected among the tested strains of ST451. HIGHLIGHTS

scholarly journals Identification of Listeria monocytogenes Contamination in a Ready-to-Eat Meat Processing Plant in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Hongzhi Zhang ◽  
Fengxia Que ◽  
Biyao Xu ◽  
Linjun Sun ◽  
Yanqi Zhu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Raw Materials ◽  
Case Fatality ◽  
Etiologic Agent ◽  
Health Concern ◽  
Plate Count ◽  
Processing Plant ◽  
Meat Processing ◽  
Processing Plants

Listeria monocytogenes is the etiologic agent of listeriosis, which remains a significant public health concern in many countries due to its high case-fatality rate. The constant risk of L. monocytogenes transmission to consumers remains a central challenge in the food production industry. At present, there is very little known about L. monocytogenes contamination in ready-to-eat (RTE) processing plants in China. In this study, L. monocytogenes in an RTE meat processing plant in Shanghai municipality was characterized using pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Furthermore, the biofilm formation ability of the pathogen was also tested. Results revealed that L. monocytogenes isolates were present in 12 samples out of the 48 samples investigated. Most of them (66.7%, 8/12) were identified from the processing facilities irrespective of observed hygiene levels of aerobic plate count (APC) and coliforms. Coliforms were present in only one processing area. ST5 (1/2b) isolates were predominant (83.3%, 10/12) and were identified in two dominant pulsotypes (PTs) (three in PT3 and seven in PT4, respectively). Results of the core-genome multi-locus sequence typing (cgMLST) showed that ST5 in three PTs (PT1, PT3, and PT4) had 0–8 alleles, which confirmed that clonal transmission occurred in the RTE meat processing facilities. In addition, the biofilm formation test confirmed that the isolates from the processing facilities could form biofilms, which helped them colonize and facilitate persistence in the environment. These results indicated that common sanitation procedures regularly applied in the processing environment were efficient but not sufficient to remove L. monocytogenes isolates, especially biofilm of L. monocytogenes. Furthermore, the ST5 isolates in this study exhibited 12 alleles with one ST5 clinical isolate, which contributes to the understanding of the potential pathogenic risk that L. monocytogenes in RTE meat processing equipment posed to consumers. Therefore, strong hygienic measures, especially sanitation procedures for biofilms eradication, should be implemented to ensure the safety of raw materials. Meanwhile, continuous surveillance might be vital for the prevention and control of listeriosis caused by L. monocytogenes.

scholarly journals The Connection between Persistent, Disinfectant-Resistant Listeria monocytogenes Strains from Two Geographically Separate Iberian Pork Processing Plants: Evidence from Comparative Genome Analysis

2015 ◽  
Vol 82 (1) ◽  
pp. 308-317 ◽  
Author(s):  
Sagrario Ortiz ◽  
Victoria López-Alonso ◽  
Pablo Rodríguez ◽  
Joaquín V. Martínez-Suárez
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Pfge Type ◽  
Processing Plant ◽  
Content Type ◽  
Pork Products ◽  
Processing Plants ◽  
Pork Product ◽  
Ammonium Compounds ◽  
Insight Into

ABSTRACTThe aim of this study was to investigate the basis of the putative persistence ofListeria monocytogenesin a new industrial facility dedicated to the processing of ready-to-eat (RTE) Iberian pork products. Quaternary ammonium compounds, which included benzalkonium chloride (BAC), were repeatedly used as surface disinfectants in the processing plant. Clean and disinfected surfaces were sampled to evaluate if resistance to disinfectants was associated with persistence. Of the 14 isolates obtained from product contact and non-product contact surfaces, only five different pulsed-field gel electrophoresis (PFGE) types were identified during the 27-month study period. Two of these PFGE types (S1 and S10-1) were previously identified to be persistent and BAC-resistant (BACr) strains in a geographically separate slaughterhouse belonging to the same company. The remaining three PFGE types, which were first identified in this study, were also BACr. Whole-genome sequencing andin silicomultilocus sequence typing (MLST) analysis of five BACrisolates of the different PFGE types identified in this study showed that the isolate of the S1 PFGE type belonged to MLST sequence type 31 (ST31), a low-virulence type characterized by mutations in theinlAandprfAgenes. The isolates of the remaining four PFGE types were found to belong to MLST ST121, a persistent type that has been isolated in several countries. The ST121 strains contained the BAC resistance transposon Tn6188. The disinfection-resistantL. monocytogenespopulation in this RTE pork product plant comprised two distinct genotypes with different multidrug resistance phenotypes. This work offers insight into theL. monocytogenessubtypes associated with persistence in food processing environments.

Direct Detection and Identification of Lactic Acid Bacteria in a Food Processing Plant and in Meat Products Using Denaturing Gradient Gel Electrophoresis

2004 ◽  
Vol 67 (11) ◽  
pp. 2515-2520 ◽  
Author(s):  
HAJIME TAKAHASHI ◽  
BON KIMURA ◽  
MIWAKO YOSHIKAWA ◽  
SEITARO GOTOU ◽  
ITARU WATANABE ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Meat Products ◽  
Pcr Amplification ◽  
Processing Plant ◽  
Meat Processing ◽  
Processing Plants ◽  
Gradient Gel Electrophoresis

We established a novel system using denaturing gradient gel electrophoresis (DGGE) to quickly identify bacteria known to be responsible for spoilage in meat processing plants and meat products. We extracted bacterial DNA from swabbed samples at various locations in the plant and from meat products and performed PCR amplification, targeting 16S rDNA from the dominant organisms. The amplification products were subjected to DGGE, and the contaminating bacteria in the meat products and the plant were analyzed. This analysis indicated that lactic acid bacteria and spoilage-causing bacteria are widely distributed within the meat processing plant. We developed molecular size markers to identify the dominant organisms obtained from the plant and meat products. The establishment of the present method allows quick and simple identification of bacteria causing the possible deterioration of products and contamination and thus permits constant monitoring of any harmful bacteria within meat processing plants.

scholarly journals Retail Survey of Brazilian Milk and Minas Frescal Cheese and a Contaminated Dairy Plant To Establish Prevalence, Relatedness, and Sources of Listeria monocytogenes Isolates

2008 ◽  
Vol 74 (15) ◽  
pp. 4954-4961 ◽  
Author(s):  
J. Renaldi F. Brito ◽  
Emilia M. P. Santos ◽  
Edna F. Arcuri ◽  
Carla C. Lange ◽  
Maria A. V. P. Brito ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Samples ◽  
Minas Gerais ◽  
Processing Plant ◽  
Contamination Source ◽  
Milk Samples ◽  
Dairy Processing ◽  
Processing Plants ◽  
Serotype 1 ◽  
Dairy Plant

ABSTRACT A study was designed to recover Listeria monocytogenes from pasteurized milk and Minas frescal cheese (MFC) sampled at retail establishments (REs) and to identify the contamination source(s) of these products in the corresponding dairy processing plant. Fifty milk samples (9 brands) and 55 MFC samples (10 brands) were tested from REs located in Juiz de Fora, Minas Gerais, Brazil. All milk samples and 45 samples from 9 of 10 MFC brands tested negative for L. monocytogenes; however, “brand F” of MFC obtained from REs 119 and 159 tested positive. Thus, the farm/plant that produced brand F MFC was sampled; all samples from the milking parlor tested negative for L. monocytogenes, whereas several sites within the processing plant and the MFC samples tested positive. All 344 isolates recovered from retail MFC, plant F MFC, and plant F environmental samples were serotype 1/2a and displayed the same AscI or ApaI fingerprints. Since these results established that the storage coolers served as the contamination source of the MFC, plant F was closed so that corrective renovations could be made. Following renovation, samples from sites that previously tested positive for the pathogen were collected from the processing environment and from MFC on multiple visits; all tested negative for L. monocytogenes. In addition, on subsequent visits to REs 159 and 119, all MFC samples tested negative for the pathogen. Studies are ongoing to quantify the prevalence, levels, and types of L. monocytogenes in MFC and associated processing plants to lessen the likelihood of listeriosis in Brazil.

scholarly journals Complete Genome Sequences of Six Listeria monocytogenes Sequence Type 9 Isolates from Meat Processing Plants in Norway

2018 ◽  
Vol 6 (7) ◽  
Author(s):  
Annette Fagerlund ◽  
Solveig Langsrud ◽  
Birgitte Moen ◽  
Even Heir ◽  
Trond Møretrø
Keyword(s):  
Listeria Monocytogenes ◽  
Complete Genome ◽  
Foodborne Pathogen ◽  
Sequence Type ◽  
Nanopore Sequencing ◽  
Meat Processing ◽  
Sequencing Data ◽  
Genome Sequences ◽  
Fatal Disease ◽  
Processing Plants

ABSTRACT Listeria monocytogenes is a foodborne pathogen that causes the often-fatal disease listeriosis. We present here the complete genome sequences of six L. monocytogenes isolates of sequence type 9 (ST9) collected from two different meat processing facilities in Norway. The genomes were assembled using Illumina and Nanopore sequencing data.

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