THE STUDY ON THE SURVIVAL SKILLS OF LISTERIA MONOCYTOGENES INHABITING A 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.

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

Journal of Food Protection ◽

10.4315/0362-028x.jfp-16-145 ◽

2016 ◽

Vol 79 (10) ◽

pp. 1733-1740 ◽

Cited By ~ 12

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.

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

Applied and Environmental Microbiology ◽

10.1128/aem.70.4.2193-2203.2004 ◽

2004 ◽

Vol 70 (4) ◽

pp. 2193-2203 ◽

Cited By ~ 54

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.

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

ILR Review ◽

10.1177/001979391006300403 ◽

2010 ◽

Vol 63 (4) ◽

pp. 606-626 ◽

Cited By ~ 39

Author(s):

Derek C. Jones ◽

Panu Kalmi ◽

Antti Kauhanen

Keyword(s):

Food Processing ◽

Productive Efficiency ◽

Incentive Pay ◽

Processing Plant ◽

Food Processing Plant

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

Epidemiology and Infection ◽

10.1017/s0950268811001610 ◽

2011 ◽

Vol 140 (5) ◽

pp. 906-915 ◽

Cited By ~ 16

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.

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