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.

scholarly journals Heavy Metal and Disinfectant Resistance of Listeria monocytogenes from Foods and Food Processing Plants

2012 ◽  
Vol 78 (19) ◽  
pp. 6938-6945 ◽  
Author(s):  
Shakir S. Ratani ◽  
Robin M. Siletzky ◽  
Vikrant Dutta ◽  
Suleyman Yildirim ◽  
Jason A. Osborne ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Listeria Monocytogenes ◽  
Food Processing ◽  
Cadmium Resistance ◽  
Content Type ◽  
Ecological History ◽  
Resistance Determinants ◽  
Processing Plants ◽  
History Of ◽  
Serotype 4B

ABSTRACTThe persistence ofListeria monocytogenesin food processing plants and other ecosystems reflects its ability to adapt to numerous stresses. In this study, we investigated 138 isolates from foods and food processing plants for resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) and to heavy metals (cadmium and arsenic). We also determined the prevalence of distinct cadmium resistance determinants (cadA1,cadA2, andcadA3) among cadmium-resistant isolates. Most BC-resistant isolates were resistant to cadmium as well. Arsenic resistance was encountered primarily in serotype 4b and was an attribute of most isolates of the serotype 4b epidemic clonal group ECIa. Prevalence of the known cadmium resistance determinants was serotype associated:cadA1was more common in isolates of serotypes 1/2a and 1/2b than 4b, whilecadA2was more common in those of serotype 4b. A subset (15/77 [19%]) of the cadmium-resistant isolates lacked the known cadmium resistance determinants. Most of these isolates were of serotype 4b and were also resistant to arsenic, suggesting novel determinants that may confer resistance to both cadmium and arsenic in these serotype 4b strains. The findings may reflect previously unrecognized components of the ecological history of different serotypes and clonal groups ofL. monocytogenes, including exposures to heavy metals and disinfectants.

Formation of Biofilm at Different Nutrient Levels by Various Genotypes of Listeria monocytogenes

2006 ◽  
Vol 69 (4) ◽  
pp. 826-834 ◽  
Author(s):  
JAMES P. FOLSOM ◽  
GREGORY R. SIRAGUSA ◽  
JOSEPH F. FRANK
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Hoechst 33258 ◽  
Genetic Subtype ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Different Strains ◽  
Element Sequence ◽  
Range Test

Strains of Listeria monocytogenes differ in their ability to form biofilms. The objectives of this study were to determine whether genetically related strains have similar biofilm-forming capacities and what effect nutrient concentration has on the ability of different strains to produce biofilms. Biofilms of 30 strains of L. monocytogenes, obtained from a variety of sources were grown on stainless steel in tryptic soy broth (TSB) or in a 1:10 dilution of TSB (DTSB) for 24 h at 32°C. The amount of biofilm formed was determined with image analysis after cells were stained with bisBenzimide H 33258 (Hoechst 33258). The strains were genetically subtyped by repetitive element sequence–based PCR (rep-PCR) with the primer set rep-PRODt and rep-PROG5. Data were analyzed with an analysis of variance and Duncan's multiple range test. Eleven strains produced the same amount of biofilm in both media. Fourteen strains produced more biofilm in TSB than in DTSB. Five strains produced more biofilm in DTSB than in TSB. Serotype 4b strains produced more biofilm in TSB than did serotype 1/2a strains, whereas serotype 1/2a strains produced more biofilm in DTSB than did serotype 4b strains. Growth in DTSB resulted in decreased biofilm accumulation for serotype 4b strains. There was no correlation between genetic subtype and the amount of biofilm accumulation. These results indicate that strains of serotype 1/2a and serotype 4b differ in the regulation of their biofilm phenotype. The poor biofilm accumulation of serotype 4b isolates when grown in DTSB could be a factor in the predominance of serogroup 1/2 strains in food processing plants, where nutrients may be limited.

Use of Pulsed-Field Gel Electrophoresis To Monitor a Five-Strain Mixture of Listeria monocytogenes in Frankfurter Packages†

2003 ◽  
Vol 66 (8) ◽  
pp. 1465-1468 ◽  
Author(s):  
ANNA C. S. PORTO ◽  
LAURA WONDERLING ◽  
JEFFREY E. CALL ◽  
JOHN B. LUCHANSKY
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Processing Plant ◽  
Refrigerated Storage ◽  
Pork Sausage ◽  
Pulsed Field ◽  
Potassium Lactate ◽  
Serotype 1 ◽  
Serotype 4B

In a previous study, the viability of a five-strain mixture of Listeria monocytogenes (including Scott A [serotype 4b, clinical isolate], 101M [serotype 4b, beef-pork sausage isolate], F6854 [serotype 1/2a, turkey frankfurter isolate], H7776 [serotype 4b, frankfurter isolate], and MFS-2 [serotype 1/2a, pork plant isolate]) was monitored during refrigerated storage of frankfurters prepared with and without 3.0% added potassium lactate. Throughout a 90-day period of storage at 4°C, the initial inoculum level of 20 CFU per package remained relatively constant in packages containing frankfurters prepared with potassium lactate, but pathogen counts increased to 4.6 log10 CFU in packages containing frankfurters prepared without added potassium lactate. To determine which of the five strains persisted under these conditions, randomly selected colonies obtained after 28 and 90 days of refrigerated storage of frankfurters were analyzed by pulsed-field gel electrophoresis (PFGE) with the restriction enzyme SmaI to generate distinct banding patterns for each of the five strains. Then, with the use of PFGE as a tool for identification, the percentages of the strains on days 28 and 90 of the growth study were compared. In the absence of any added potassium lactate in the product, 43% of the 58 isolates recovered on day 28 were identified as strain Scott A, 12% were identified as strain 101M, 22% were identified as strain F6854, 10% were identified as strain H7776, and 12% were identified as strain MFS-2. However, by day 90, an appreciable number (83%) of the 60 isolates analyzed were identified as strain MFS-2. In packages containing frankfurters formulated with 3.0% potassium lactate, all five strains were present at frequencies of 5 to 36% among the 19 isolates tested on day 28; however, by day 90, strain MFS-2 made up the statistical majority (63%) of the 27 isolates tested. The results of this study indicate that strain MFS-2, a serotype 1/2a isolate recovered from a pork processing plant, was more persistent than strains Scott A, 101M, F6854, or H7776 during the extended refrigerated storage of frankfurters.

scholarly journals An outbreak of listeriosis linked to turkey meat products in the Czech Republic, 2012–2016

2018 ◽  
Vol 146 (11) ◽  
pp. 1407-1412 ◽  
Author(s):  
T. Gelbíčová ◽  
M. Zobaníková ◽  
Z. Tomáštíková ◽  
I. Van Walle ◽  
W. Ruppitsch ◽  
...  
Keyword(s):  
Czech Republic ◽  
Food Processing ◽  
Meat Products ◽  
Processing Plant ◽  
Outbreak Strain ◽  
The Czech Republic ◽  
Turkey Meat ◽  
Close Relationship ◽  
Serotype 1 ◽  
Food Processing Plant

AbstractSince 2012–2016 an increased number of listeriosis cases, especially from one region of the Czech Republic, were observed. Most of them were caused by strains of serotype 1/2a, clonal complex 8, indistinguishable by pulsed-field gel electrophoresis. Twenty-six human cases were reported, including two neonatal cases in twins. Three cases were fatal. The typing of Listeria monocytogenes isolates from food enabled to confirm a turkey meat delicatessen as the vehicle of infection for this local outbreak in the Moravian-Silesian Region. The food strains belonging to identical pulsotype were isolated from ready-to-eat turkey meat products packaged by the same producer between 2012 and 2016. This fact confirms that the described L. monocytogenes outbreak strain probably persisted in the environment of the aforementioned food-processing plant over several years. Whole-genome sequencing confirmed a very close relationship (zero to seven different alleles) between isolates from humans, foods and swabs from the environment of the food-processing plant under investigation.

scholarly journals Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants

2008 ◽  
Vol 74 (5) ◽  
pp. 1464-1468 ◽  
Author(s):  
S. Mullapudi ◽  
R. M. Siletzky ◽  
S. Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Food Processing ◽  
Benzalkonium Chloride ◽  
The United States ◽  
Limited Information ◽  
Chloride Resistance ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B

ABSTRACT The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes.

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.

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.

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
Sign in / Sign up

Export Citation Format

Share Document