scholarly journals Characteristics of Listeria Monocytogenes Strains Persisting in a Meat Processing Facility over a 4-Year Period

Pathogens ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 32 ◽  
Author(s):  
Andrea Stoller ◽  
Marc Stevens ◽  
Roger Stephan ◽  
Claudia Guldimann
Keyword(s):  
Listeria Monocytogenes ◽  
Genome Sequencing ◽  
Peracetic Acid ◽  
Benzalkonium Chloride ◽  
Food Production ◽  
Whole Genome ◽  
Meat Processing ◽  
Minimal Inhibitory Concentrations ◽  
Processing Facility ◽  
Young Old

Listeria monocytogenes can persist in food production facilities, resulting in serious threats to consumers due to the high mortality associated with listeriosis, especially in the very young, old and pregnant. We subtyped 124 strains of L. monocytogenes isolated from a meat processing facility in Switzerland by serotyping, multi locus sequence typing (MLST) typing and whole genome sequencing. We then analyzed their ability to form biofilms and their resistance to the disinfectants benzalkonium chloride (BC) and peracetic acid (PAA). The genotyping results of the strains showed that several clonal populations of L. monocytogenes belonging to CC9, CC204 and CC121 had persisted in this meat processing facility for at least four years. All of the strains showed biofilm forming capacity comparable to a known high biofilm forming strain. Known efflux pumps for BC were present in CC204, CC9 (brcABC) and CC121 (qacH) strains, while strains from other CC showed very low minimal inhibitory concentrations (MICs) for BC. For PAA, minimal bactericidal concentrations of 1.2–1.6% for 20 min and minimal inhibitory concentrations between 0.1 and 0.2% were observed. These values were close to or above the recommended concentration for use (0.5–1%), suggesting that PAA might be ineffective at controlling L. monocytogenes in this and potentially other meat processing facilities.

scholarly journals Whole genome sequencing for typing and characterisation of Listeria monocytogenes isolated in a rabbit meat processing plant

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
Federica Palma ◽  
Frédérique Pasquali ◽  
Alex Lucchi ◽  
Alessandra De Cesare ◽  
Gerardo Manfreda
Keyword(s):  
Listeria Monocytogenes ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Molecular Typing ◽  
Virulence Genes ◽  
Processing Plant ◽  
Whole Genome ◽  
Meat Processing ◽  
Typing Methods ◽  
Rabbit Meat

Listeria monocytogenes is a food-borne pathogen able to survive and grow in different environments including food processing plants where it can persist for month or years. In the present study the discriminatory power of Whole Genome Sequencing (WGS)-based analysis (cgMLST) was compared to that of molecular typing methods on 34 L. monocytogenes isolates collected over one year in the same rabbit meat processing plant and belonging to three genotypes (ST14, ST121, ST224). Each genotype included isolates indistinguishable by standard molecular typing methods. The virulence potential of all isolates was assessed by Multi Virulence-Locus Sequence Typing (MVLST) and the investigation of a representative database of virulence determinant genes. The whole genome of each isolate was sequenced on a MiSeq platform. The cgMLST, MVLST, and in silico identification of virulence genes were performed using publicly available tools. Draft genomes included a number of contigs ranging from 13 to 28 and N50 ranging from 456298 to 580604. The coverage ranged from 41 to 187X. The cgMLST showed a significantly superior discriminatory power only in comparison to ribotyping, nevertheless it allows the detection of two singletons belonging to ST14 that were not observed by other molecular methods. All ST14 isolates belonged to VT107, which 7-loci concatenated sequence differs for only 4 nucleotides to VT1 (Epidemic clone III). Analysis of virulence genes showed the presence of a fulllength inlA version in all ST14 isolates and of a mutated version including a premature stop codon (PMSC) associated to attenuated virulence in all ST121 isolates.

Benzalkonium chloride tolerance of Listeria monocytogenes strains isolated from a meat processing facility is related to presence of plasmid-borne bcrABC cassette

2018 ◽  
Vol 111 (10) ◽  
pp. 1913-1923 ◽  
Author(s):  
Jana Minarovičová ◽  
Adriana Véghová ◽  
Mária Mikulášová ◽  
Romana Chovanová ◽  
Katarína Šoltýs ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Benzalkonium Chloride ◽  
Meat Processing ◽  
Processing Facility

scholarly journals Application of Whole Genome Sequencing to Aid in Deciphering the Persistence Potential of Listeria monocytogenes in Food Production Environments

2021 ◽  
Vol 9 (9) ◽  
pp. 1856
Author(s):  
Natalia Unrath ◽  
Evonne McCabe ◽  
Guerrino Macori ◽  
Séamus Fanning
Keyword(s):  
Listeria Monocytogenes ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Biofilm Formation ◽  
Food Production ◽  
Mortality Rates ◽  
Foodborne Illness ◽  
Whole Genome ◽  
Bioinformatic Tools ◽  
Production Environments

Listeria monocytogenes is the etiological agent of listeriosis, a foodborne illness associated with high hospitalizations and mortality rates. This bacterium can persist in food associated environments for years with isolates being increasingly linked to outbreaks. This review presents a discussion of genomes of Listeria monocytogenes which are commonly regarded as persisters within food production environments, as well as genes which are involved in mechanisms aiding this phenotype. Although criteria for the detection of persistence remain undefined, the advent of whole genome sequencing (WGS) and the development of bioinformatic tools have revolutionized the ability to find closely related strains. These advancements will facilitate the identification of mechanisms responsible for persistence among indistinguishable genomes. In turn, this will lead to improved assessments of the importance of biofilm formation, adaptation to stressful conditions and tolerance to sterilizers in relation to the persistence of this bacterium, all of which have been previously associated with this phenotype. Despite much research being published around the topic of persistence, more insights are required to further elucidate the nature of true persistence and its implications for public health.

scholarly journals In-Depth Longitudinal Study of Listeria monocytogenes ST9 Isolates from the Meat Processing Industry: Resolving Diversity and Transmission Patterns Using Whole-Genome Sequencing

2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Annette Fagerlund ◽  
Solveig Langsrud ◽  
Trond Møretrø
Keyword(s):  
Listeria Monocytogenes ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Raw Materials ◽  
Source Tracking ◽  
Common Source ◽  
Whole Genome ◽  
Meat Processing ◽  
Production Environment ◽  
Content Type

ABSTRACT 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 types, and for effective source tracking, the divergence and spread of ST9 must be understood. In this study, whole-genome sequencing (WGS) was used to characterize and track 252 L. monocytogenes ST9 isolates collected from four Norwegian meat processing plants between 2009 and 2017. The isolates formed distinct clusters relative to genomes found in public databases, and all but three isolates clustered into two major clonal populations. Different contamination patterns were revealed, e.g., evidence of contamination of two factories with a clone that diverged from its ancestor in the late 1990s through a common source of raw materials; breach of hygienic barriers within a factory, leading to repeated detection of two clones in the high-risk zone during a 4- to 6-year period; entry through the purchase and installation of second-hand equipment harboring a previously established clonal population; and spreading and diversification of two clones from two reservoirs within the same production room over a 9-year period. The present work provides data on the diversity of ST9, which is crucial for epidemiological investigations and highlights how WGS can be used for source tracking within food processing factories. IMPORTANCE Listeria monocytogenes is a deadly foodborne pathogen that is widespread in the environment, and certain types can be established in food factories. The sequence type ST9 dominates in meat processing environments, and this work was undertaken to obtain data needed for the tracking of this subtype. By using whole-genome sequencing (WGS), we revealed the presence of cross-contamination routes between meat factories as well as within a single factory, including the spread from different reservoirs within the same room. It was also possible to estimate the time frame of persistence in the factory, as well as when and how new clones had entered. The present work contributes valuable information about the diversity of ST9 and exemplifies the potential power of WGS in food safety management, allowing the determination of relationships between strains both in an international context and locally between and within factories.

scholarly journals HrcA and DnaK are important for static and continuous-flow biofilm formation and disinfectant resistance in Listeria monocytogenes

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3782-3790 ◽  
Author(s):  
Stijn van der Veen ◽  
Tjakko Abee
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Peracetic Acid ◽  
Continuous Flow ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Wild Type ◽  
Shock Response ◽  
Disinfectant Resistance

The food-borne pathogen Listeria monocytogenes is able to form biofilms in food processing environments. Since biofilms are generally difficult to eradicate during clean-up procedures, they pose a major risk for the food industry. Stress resistance mechanisms involved in L. monocytogenes biofilm formation and disinfectant resistance have, to our knowledge, not been identified thus far. In this study, we investigated the role of hrcA, which encodes the transcriptional regulator of the class I heat-shock response, and dnaK, which encodes a class I heat-shock response chaperone protein, in static and continuous-flow biofilm formation and resistance against benzalkonium chloride and peracetic acid. Induction of both hrcA and dnaK during continuous-flow biofilm formation was observed using quantitative real-time PCR and promoter reporters. Furthermore, in-frame deletion and complementation mutants of hrcA and dnaK revealed that HrcA and DnaK are required to reach wild-type levels of both static and continuous-flow biofilms. Finally, disinfection treatments of planktonic-grown cells and suspended static and continuous-flow biofilm cells of wild-type and mutants showed that HrcA and DnaK are important for resistance against benzalkonium chloride and peracetic acid. In conclusion, our study revealed that HrcA and DnaK are important for L. monocytogenes biofilm formation and disinfectant resistance.

scholarly journals Whole-Genome Sequencing Allows for Improved Identification of Persistent Listeria monocytogenes in Food-Associated Environments

2015 ◽  
Vol 81 (17) ◽  
pp. 6024-6037 ◽  
Author(s):  
Matthew J. Stasiewicz ◽  
Haley F. Oliver ◽  
Martin Wiedmann ◽  
Henk C. den Bakker
Keyword(s):  
Listeria Monocytogenes ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Genetic Determinants ◽  
Single Nucleotide ◽  
Content Type ◽  
Food Borne ◽  
Clonal Spread

ABSTRACTWhile the food-borne pathogenListeria monocytogenescan persist in food associated environments, there are no whole-genome sequence (WGS) based methods to differentiate persistent from sporadic strains. Whole-genome sequencing of 188 isolates from a longitudinal study ofL. monocytogenesin retail delis was used to (i) apply single-nucleotide polymorphism (SNP)-based phylogenetics for subtyping ofL. monocytogenes, (ii) use SNP counts to differentiate persistent from repeatedly reintroduced strains, and (iii) identify genetic determinants ofL. monocytogenespersistence. WGS analysis revealed three prophage regions that explained differences between three pairs of phylogenetically similar populations with pulsed-field gel electrophoresis types that differed by ≤3 bands. WGS-SNP-based phylogenetics found that putatively persistentL. monocytogenesrepresent SNP patterns (i) unique to a single retail deli, supporting persistence within the deli (11 clades), (ii) unique to a single state, supporting clonal spread within a state (7 clades), or (iii) spanning multiple states (5 clades). Isolates that formed one of 11 deli-specific clades differed by a median of 10 SNPs or fewer. Isolates from 12 putative persistence events had significantly fewer SNPs (median, 2 to 22 SNPs) than between isolates of the same subtype from other delis (median up to 77 SNPs), supporting persistence of the strain. In 13 events, nearly indistinguishable isolates (0 to 1 SNP) were found across multiple delis. No individual genes were enriched among persistent isolates compared to sporadic isolates. Our data show that WGS analysis improves food-borne pathogen subtyping and identification of persistent bacterial pathogens in food associated environments.

scholarly journals Persistent Listeria monocytogenes Isolates from a Poultry-Processing Facility Form More Biofilm but Do Not Have a Greater Resistance to Disinfectants than Sporadic Strains

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 250 ◽  
Author(s):  
Daniel Rodríguez-Campos ◽  
Cristina Rodríguez-Melcón ◽  
Carlos Alonso-Calleja ◽  
Rosa Capita
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Bacterial Persistence ◽  
Crystal Violet Assay ◽  
Processing Facility ◽  
Poultry Processing ◽  
Sessile Cells ◽  
Selection Of

Some strains of Listeria monocytogenes can persist in food-processing environments, increasing the likelihood of the contamination of foodstuffs. To identify traits that contribute to bacterial persistence, a selection of persistent and sporadic L. monocytogenes isolates from a poultry-processing facility was investigated for biofilm-forming ability (crystal violet assay). The susceptibility of sessile cells to treatments (five minutes) with sodium hypochlorite having 10% active chlorine (SHY: 10,000 ppm, 25,000 ppm, and 50,000 ppm) and benzalkonium chloride (BZK: 2500 ppm, 10,000 ppm, and 25,000 ppm) was also studied. All isolates exhibited biofilm formation on polystyrene. Persistent strains showed larger (p < 0.001) biofilm formation (OD580 = 0.301 ± 0.097) than sporadic strains (OD580 = 0.188 ± 0.082). A greater susceptibility to disinfectants was observed for biofilms of persistent strains than for those of sporadic strains. The application of SHY reduced biofilms only for persistent strains. BZK increased OD580 in persistent strains (2500 ppm) and in sporadic strains (all concentrations). These results indicate that the use of BZK at the concentrations tested could represent a public health risk. Findings in this work suggest a link between persistence and biofilm formation, but do not support a relationship between persistence and the resistance of sessile cells to disinfectants.

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