Listeria monocytogenes Isolates Carrying Virulence-Attenuating Mutations in Internalin A Are Commonly Isolated from Ready-to-Eat Food Processing Plant and Retail Environments

2016 ◽  
Vol 79 (10) ◽  
pp. 1733-1740 ◽  
Author(s):  
A. VAN STELTEN ◽  
A. R. ROBERTS ◽  
C. S. MANUEL ◽  
K. K. NIGHTINGALE
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Food Production ◽  
Stop Codon ◽  
Significant Proportion ◽  
Premature Stop Codon ◽  
Processing Plant ◽  
Contact Surfaces ◽  
Internalin A ◽  
Food Processing Plant

ABSTRACT Listeria monocytogenes is a human foodborne pathogen that may cause an invasive disease known as listeriosis in susceptible individuals. Internalin A (InlA; encoded by inlA) is a virulence factor that facilitates crossing of host cell barriers by L. monocytogenes. At least 19 single nucleotide polymorphisms (SNPs) in inlA that result in a premature stop codon (PMSC) have been described worldwide. SNPs leading to a PMSC in inlA have been shown to be causally associated with attenuated virulence. L. monocytogenes pathogens carrying virulence-attenuating (VA) mutations in inlA have been commonly isolated from ready-to-eat (RTE) foods but rarely have been associated with human disease. This study was conducted to determine the prevalence of VA SNPs in inlA among L. monocytogenes from environments associated with RTE food production and handling. More than 700 L. monocytogenes isolates from RTE food processing plant (n = 409) and retail (n = 319) environments were screened for the presence of VA SNPs in inlA. Overall, 26.4% of isolates from RTE food processing plant and 32.6% of isolates from retail environments carried a VA mutation in inlA. Food contact surfaces sampled at retail establishments were significantly (P < 0.0001) more likely to be contaminated by a L. monocytogenes isolate carrying a VA mutation in inlA (56% of 55 isolates) compared with nonfood contact surfaces (28% of 264 isolates). Overall, a significant proportion of L. monocytogenes isolated from RTE food production and handling environments have reduced virulence. These data will be useful in the revision of current and the development of future risk assessments that incorporate strain-specific virulence parameters.

scholarly journals Hypo- and Hyper-Virulent Listeria monocytogenes Clones Persisting in Two Different Food Processing Plants of Central Italy

2021 ◽  
Vol 9 (2) ◽  
pp. 376
Author(s):  
Fabrizia Guidi ◽  
Massimiliano Orsini ◽  
Alexandra Chiaverini ◽  
Marina Torresi ◽  
Patrizia Centorame ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Stop Codon ◽  
Genetic Relationships ◽  
Central Italy ◽  
Premature Stop Codon ◽  
Small Scale ◽  
Processing Plant ◽  
Cadmium Resistance

A total of 66 Listeria monocytogenes (Lm) isolated from 2013 to 2018 in a small-scale meat processing plant and a dairy facility of Central Italy were studied. Whole Genome Sequencing and bioinformatics analysis were used to assess the genetic relationships between the strains and investigate persistence and virulence abilities. The biofilm forming-ability was assessed in vitro. Cluster analysis grouped the Lm from the meat plant into three main clusters: two of them, both belonging to CC9, persisted for years in the plant and one (CC121) was isolated in the last year of sampling. In the dairy facility, all the strains grouped in a CC2 four-year persistent cluster. All the studied strains carried multidrug efflux-pumps genetic determinants (sugE, mdrl, lde, norM, mepA). CC121 also harbored the Tn6188 specific for tolerance to Benzalkonium Chloride. Only CC9 and CC121 carried a Stress Survival Islet and presented high-level cadmium resistance genes (cadA1C1) carried by different plasmids. They showed a greater biofilm production when compared with CC2. All the CC2 carried a full-length inlA while CC9 and CC121 presented a Premature Stop Codon mutation correlated with less virulence. The hypo-virulent clones CC9 and CC121 appeared the most adapted to food-processing environments; however, even the hyper-virulent clone CC2 warningly persisted for a long time. The identification of the main mechanisms promoting Lm persistence in a specific food processing plant is important to provide recommendations to Food Business Operators (FBOs) in order to remove or reduce resident Lm.

Listeria monocytogenes strains encoding premature stop codons in inlA invade mice and guinea pig fetuses in orally dosed dams

2013 ◽  
Vol 62 (12) ◽  
pp. 1799-1806 ◽  
Author(s):  
Anne Holch ◽  
Hanne Ingmer ◽  
Tine Rask Licht ◽  
Lone Gram
Keyword(s):  
Listeria Monocytogenes ◽  
Guinea Pig ◽  
Food Processing ◽  
Guinea Pigs ◽  
Stop Codon ◽  
Fetal Liver ◽  
Fatal Case ◽  
Premature Stop Codon ◽  
Tissue Samples ◽  
Pregnant Mice

Listeria monocytogenes is an important food-borne bacterial pathogen and listeriosis can result in abortions in pregnant women. The bacterium can colonize food-processing environments, where specific molecular subtypes can persist for years. The purpose of this study was to determine the virulence potential of a group of food-processing persistent L. monocytogenes strains encoding a premature stop codon in inlA (encoding internalin A) by using two orally dosed models, pregnant mice and pregnant guinea pigs. A food-processing persistent strain of L. monocytogenes invaded placentas (n = 58; 10 % positive) and fetuses (3 % positive) of pregnant mice (n = 9 animals per strain), similar to a genetically manipulated murinized strain, EGD-e InlA m* (n = 61; 3 and 2 %, respectively). In pregnant guinea pigs (n = 9 animals per bacterial strain), a maternofetal strain (from a human fetal clinical fatal case) was isolated from 34 % of placenta samples (n = 50), whereas both food-processing persistent strains were found in 5 % of placenta samples (n = 36 or 37). One of the food-processing persistent strains, N53-1, was found in up to 8 % of guinea pig fetal liver and brain samples, whereas the maternofetal control was found in 6 % of fetal tissue samples. As the food-processing persistent strains carry a premature stop codon in inlA but are invasive in orally dosed pregnant mice and guinea pigs, we hypothesize that listerial crossing of the placental barrier can occur by a mechanism that is independent of an interaction between E-cadherin and InlA.

scholarly journals Plant Location Selection for Food Production by Considering the Regional and Seasonal Supply Vulnerability of Raw Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jin Woo Park ◽  
Ha Young Oh ◽  
Duck Young Kim ◽  
Yong Ju Cho
Keyword(s):  
Food Processing ◽  
Food Production ◽  
Raw Materials ◽  
Plant Location ◽  
Raw Material ◽  
Processing Plant ◽  
Production Volume ◽  
Market Demand ◽  
Decision Support Model ◽  
Food Processing Plant

A production capacity analysis considering market demand and raw materials is very important to design a new plant. However, in the food processing industry, the supply uncertainty of raw materials is very high, depending on the production site and the harvest season, and further, it is not straightforward to analyze too complex food production systems by using an analytical optimization model. For these reasons, this study presents a simulation-based decision support model to select the right location for a new food processing plant. We first define three supply vulnerability factors from the standpoint of regional as well as seasonal instability and present an assessment method for supply vulnerability based on fuzzy quantification. The evaluated vulnerability scores are then converted into raw material supply variations for food production simulation to predict the quarterly production volume of a new food processing plant. The proposed selection procedure is illustrated using a case study of semiprocessed kimchi production. The best plant location is proposed where we can reduce and mitigate risks when supplying raw material, thereby producing a target production volume steadily.

scholarly journals An 8-Year Surveillance of the Diversity and Persistence of Listeria monocytogenes in a Chilled Food Processing Plant Analyzed by Amplified Fragment Length Polymorphism

2007 ◽  
Vol 70 (8) ◽  
pp. 1866-1873 ◽  
Author(s):  
RIIKKA KETO-TIMONEN ◽  
RIINA TOLVANEN ◽  
JANNE LUNDÉN ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Food Processing ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Aflp Analysis ◽  
Processing Plant ◽  
Production Lines ◽  
Food Processing Plant

Contamination routes of Listeria monocytogenes were examined in a chilled food processing plant that produced ready-to-eat and ready-to-reheat meals during an 8-year period by amplified fragment length polymorphism (AFLP) analysis. A total of 319 L. monocytogenes isolates were recovered from raw materials (n = 18), the environment (n = 77), equipment (n = 193), and products (n = 31), and 18 different AFLP types were identified, five of which were repeatedly found to be persistent types. The three compartments (I to III) of the plant showed markedly different contamination statuses. Compartment I, which produced cooked meals, was heavily contaminated with three persistent AFLP types. AFLP type A1 dominated, and it comprised 93% of the isolates of the compartment. Compartment II, which produced uncooked chilled food, was contaminated with four persistent and five nonpersistent AFLP types. The equipment of compartment III, which produced cooked ready-to-reheat meals, was free of contamination. In compartments that produced cooked meals, the cleaning routines, product types, and lack of compartmentalization seemed to predispose production lines to persistent contamination. The most contaminated lines harbored L. monocytogenes in coolers, conveyors, and packing machines. Good compartmentalization limited the flow of L. monocytogenes into the postheat-treatment area and prevented the undesired movement of equipment and personnel, thus protecting the production lines from contamination. In compartment II, grated cheese was shown to cause product contamination. Therefore, special attention should be paid to continuous quality control of raw ingredients when uncooked ready-to-eat foods are produced. In compartment II, reconstruction of the production line resulted in reduced prevalence rates of L. monocytogenes and elimination of two persistent AFLP types.

scholarly journals Multilocus Sequence Typing of Listeria monocytogenes by Use of Hypervariable Genes Reveals Clonal and Recombination Histories of Three Lineages

2004 ◽  
Vol 70 (4) ◽  
pp. 2193-2203 ◽  
Author(s):  
Richard J. Meinersmann ◽  
Robert W. Phillips ◽  
Martin Wiedmann ◽  
Mark E. Berrang
Keyword(s):  
Listeria Monocytogenes ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Food Processing ◽  
Genomic Sequence ◽  
Processing Plant ◽  
Serotype 1 ◽  
History Of ◽  
Serotype 4B ◽  
Food Processing Plant

ABSTRACT In an attempt to develop a method to discriminate among isolates of Listeria monocytogenes, the sequences of all of the annotated genes from the fully sequenced strain L. monocytogenes EGD-e (serotype 1/2a) were compared by BLASTn to a file of the unfinished genomic sequence of L. monocytogenes ATCC 19115 (serotype 4b). Approximately 7% of the matching genes demonstrated 90% or lower identity between the two strains, and the lowest observed identity was 80%. Nine genes (hisJ, cbiE, truB, ribC, comEA, purM, aroE, hisC, and addB) in the 80 to 90% identity group and two genes (gyrB and rnhB) with approximately 97% identity were selected for multilocus sequence analysis in two sets of L. monocytogenes isolates (a 15-strain diversity set and a set of 19 isolates from a single food-processing plant). Based on concatenated sequences, a total of 33 allotypes were differentiated among the 34 isolates tested. Population genetics analyses revealed three lineages of L. monocytogenes that differed in their history of apparent recombination. Lineage I appeared to be completely clonal, whereas representatives of the other lineages demonstrated evidence of horizontal gene transfer and recombination. Although most of the gene sequences for lineage II strains were distinct from those of lineage I, a few strains with the majority of genes characteristic of lineage II had some that were characteristic of lineage I. Genes from lineage III organisms were mostly similar to lineage I genes, with instances of genes appearing to be mosaics with lineage II genes. Even though lineage I and lineage II generally demonstrated very distinct sequences, the sequences for the 11 selected genes demonstrated little discriminatory power within each lineage. In the L. monocytogenes isolate set obtained from one food-processing plant, lineage I and lineage II were found to be almost equally prevalent. While it appears that different lineages of L. monocytogenes can share habitats, they appear to differ in their histories of horizontal gene transfer.

Teams, Incentive Pay, and Productive Efficiency: Evidence from a Food-Processing Plant

ILR Review ◽  
2010 ◽  
Vol 63 (4) ◽  
pp. 606-626 ◽  
Author(s):  
Derek C. Jones ◽  
Panu Kalmi ◽  
Antti Kauhanen
Keyword(s):  
Food Processing ◽  
Productive Efficiency ◽  
Incentive Pay ◽  
Processing Plant ◽  
Food Processing Plant

Outbreak ofNeisseria meningitidisC in workers at a large food-processing plant in Brazil: challenges of controlling disease spread to the larger community

2011 ◽  
Vol 140 (5) ◽  
pp. 906-915 ◽  
Author(s):  
B. P. M. ISER ◽  
H. C. A. V. LIMA ◽  
C. De MORAES ◽  
R. P. A. De ALMEIDA ◽  
L. T. WATANABE ◽  
...  
Keyword(s):  
Food Processing ◽  
Purpura Fulminans ◽  
Control Measures ◽  
Disease Spread ◽  
Processing Plant ◽  
Sterile Site ◽  
Matched Case ◽  
Epidemiological Link ◽  
Control Study ◽  
Food Processing Plant

SUMMARYAn outbreak of meningococcal disease (MD) with severe morbidity and mortality was investigated in midwestern Brazil in order to identify control measures. A MD case was defined as isolation ofNeisseria meningitidis, or detection of polysaccharide antigen in a sterile site, or presence of clinical purpura fulminans, or an epidemiological link with a laboratory-confirmed case-patient, between June and August 2008. In 8 out of 16 MD cases studied, serogroup C ST103 complex was identified. Five (31%) cases had neurological findings and five (31%) died. The attack rate was 12 cases/100 000 town residents and 60 cases/100 000 employees in a large local food-processing plant. We conducted a matched case-control study of eight primary laboratory-confirmed cases (1:4). Factors associated with illness in single variable analysis were work at the processing plant [matched odds ratio (mOR) 22, 95% confidence interval (CI) 2·3–207·7,P<0·01], and residing <1 year in Rio Verde (mOR 7, 95% CI 1·11–43·9,P<0·02). Mass vaccination (>10 000 plant employees) stopped propagation in the plant, but not in the larger community.

Sign in / Sign up

Export Citation Format

Share Document