Molecular and Phenotypic Characterization of Listeria monocytogenes from U.S. Department of Agriculture Food Safety and Inspection Service Surveillance of Ready-to-Eat Foods and Processing Facilities†

2010 ◽  
Vol 73 (5) ◽  
pp. 861-869 ◽  
Author(s):  
TODD J. WARD ◽  
PETER EVANS ◽  
MARTIN WIEDMANN ◽  
THOMAS USGAARD ◽  
SHERRY E. ROOF ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Safety ◽  
Virulence Gene ◽  
Phenotypic Characterization ◽  
Nucleotide Polymorphisms ◽  
Department Of Agriculture ◽  
Poultry Products ◽  
Production Environments ◽  
Inspection Service

A panel of 501 Listeria monocytogenes isolates obtained from the U.S. Department of Agriculture Food Safety and Inspection Service monitoring programs for ready-to-eat (RTE) foods were subtyped by multilocus genotyping (MLGT) and by sequencing the virulence gene inlA, which codes for internalin. MLGT analyses confirmed that clonal lineages associated with previous epidemic outbreaks were rare (7.6%) contaminants of RTE meat and poultry products and their production environments. Conversely, sequence analyses revealed mutations leading to 11 different premature stop codons (PMSCs) in inlA, including three novel PMSC mutations, and revealed that the frequency of these virulence-attenuating mutations among RTE isolates (48.5%) was substantially higher than previously appreciated. Significant differences (P < 0.001) in the frequency of inlA PMSCs were observed between lineages and between major serogroups, which could partially explain differences in association of these subtypes with human listeriosis. Interrogation of single-nucleotide polymorphisms responsible for PMSCs in inlA improved strain resolution among isolates with the 10 most common pulsed-field gel electrophoresis (PFGE) patterns, 8 of which included isolates with a PMSC in inlA. The presence or absence of PMSCs in inlA accounted for significant differences (P < 0.05) in Caco-2 invasion efficiencies among isolates with identical PFGE patterns, and the proportion of PulseNet entries from clinical sources was significantly higher (P < 0.001) for PFGE patterns exclusively from isolates with full-length inlA. These results indicated that integration of PFGE and DNA sequence–based subtyping provides an improved framework for prediction of relative risk associated with L. monocytogenes strains from RTE foods.

scholarly journals Evaluation of a Chromogenic Medium for Identification and Differentiation of Listeria monocytogenes in Selected Foods

2005 ◽  
Vol 88 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Wendy F Lauer ◽  
Jean-Pierre Facon ◽  
Asmita Patel
Keyword(s):  
Listeria Monocytogenes ◽  
Food Safety ◽  
Color Change ◽  
The United States ◽  
Culture Methods ◽  
Department Of Agriculture ◽  
Chromogenic Medium ◽  
Cultural Methods ◽  
Standard Culture ◽  
Inspection Service

Abstract Listeria monocytogenes continues to be a threat to food safety in the United States despite a “zero tolerance” policy. When Listeria species are identified by standard cultural methods, confirmation of L. monocytogenes takes days to complete. RAPID'L.Mono™ agar, developed by Bio-Rad Laboratories, is a chromogenic medium that differentiates L. monocytogenes from other species of Listeria by a simple color change reaction. Differentiation is based on the specific detection of phosphatidylinositol phospholipase C activity, resulting in a blue colony, and the inability of L. monocytogenes to metabolize xylose, resulting in the absence of a yellow halo. Detection principles of standard method agars, Oxford and PALCAM, are based on the ability of all species of Listeria to hydrolyze esculin. Thus, all species of Listeria have similar colony morphology on these agars, making differentiation of pathogenic L. monocytogenes from other nonhuman pathogens difficult. RAPID'L.Mono agar has been validated with surimi, mixed salad, brie, and processed deli turkey because of the prevalence of L. monocytogenes in these foods. Sensitivity and specificity for this medium was determined to be 99.4 and 100%, respectively. Overall method agreement of RAPID'L.Mono with standard culture methods (U.S. Department of Agriculture/Food Safety and Inspection Service; U.S. Food and Drug Administration/Bacteriological Analytical Manual; and AOAC INTERNATIONAL) was excellent, with enrichment protocols 24 h shorter than those of standard methods.

scholarly journals Genetic and phenotypic characterization of Listeria monocytogenes lineage III

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 685-693 ◽  
Author(s):  
Angela Roberts ◽  
Kendra Nightingale ◽  
Greg Jeffers ◽  
Esther Fortes ◽  
Jose Marcelino Kongo ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Phylogenetic Analyses ◽  
Plaque Assay ◽  
Virulence Gene ◽  
Phenotypic Characterization ◽  
Ecological Niches ◽  
Phenotypic Characteristics ◽  
Putative Virulence Gene ◽  
Clinical Cases

Listeria monocytogenes has been previously grouped into three evolutionary groups, termed lineages I, II and III. While lineages I and II are commonly isolated from various sources, lineage III isolates are rare and have several atypical and unique phenotypic characteristics. Relative to their prevalence in other sources, lineage III strains are overrepresented among isolates from food-production animals, and underrepresented among isolates from human clinical cases and foods. This work describes an extensive genotypic and phenotypic characterization of 46 lineage III isolates. Phylogenetic analyses of partial sigB and actA sequences showed that lineage III represents three distinct subgroups, which were termed IIIA, IIIB and IIIC. Each of these lineage III subgroups is characterized by differentiating genotypic and phenotypic characteristics. Unlike typical L. monocytogenes, all subgroup IIIB and IIIC isolates lack the ability to ferment rhamnose. While all IIIC and most IIIB isolates carry the putative virulence gene lmaA, the majority of subgroup IIIA isolates lack this gene. All three lineage III subgroups contain isolates from human clinical cases as well as isolates that are cytopathogenic in a cell culture plaque assay, indicating that lineage III isolates have the potential to cause human disease. The identification of specific genotypic and phenotypic characteristics among the three lineage III subgroups suggests that these subgroups may occupy different ecological niches and, therefore, may be transmitted by different pathways.

scholarly journals Occurrence of Listeria monocytogenes in Ready-to-Eat Meat and Poultry Product Verification Testing Samples from U.S. Department of Agriculture–Regulated Producing Establishments, 2005 through 2017

2020 ◽  
Vol 83 (9) ◽  
pp. 1598-1606 ◽  
Author(s):  
STEPHEN W. MAMBER ◽  
TIM B. MOHR ◽  
CARRIE LEATHERS ◽  
EVELYNE MBANDI ◽  
PHILIP A. BRONSTEIN ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Geographic Location ◽  
Positive Sample ◽  
Production Volume ◽  
Sample Collection ◽  
Department Of Agriculture ◽  
Poultry Products ◽  
Inspection Service ◽  
Low Prevalence ◽  
Product Verification

ABSTRACT Ready-to-eat (RTE) meat and poultry product samples collected between 2005 and 2017 from RTE-producing establishments for the U.S. Department of Agriculture, Food Safety and Inspection Service (FSIS) ALLRTE/RTEPROD_RAND (random) and RTE001/RTEPROD_RISK (risk-based) sampling projects were tested for Listeria monocytogenes (Lm). Data for 45,897 ALLRTE/RTEPROD_RAND samples collected from 3,607 distinct establishments and 112,347 RTE001/RTEPROD_RISK samples collected from 3,283 distinct establishments were analyzed for the presence of Lm. These data were also analyzed based upon the percentages of establishments with positive samples, annual production volume, sanitation control alternatives, geographic location, and season or month of sample collection. Results revealed low occurrence of Lm-positive samples from the random and risk-based sampling projects, with 152 (0.33%) positive samples for ALLRTE/RTEPROD_RAND and 403 (0.36%) positive samples for RTE001/RTEPROD_RISK. The percentage of positive samples significantly decreased over time, from about 0.7% in 2005 and 2006 to about 0.2% in 2017 (P < 0.05). From 2005 to 2017, 3.9% of establishments sampled under the ALLRTE/RTEPROD_RAND sampling project had at least one Lm-positive sample. Similarly, 10.0% of establishments sampled under the RTE001/RTEPROD_RISK sampling project had at least one positive sample. Samples positive for Lm were found in all geographic regions in all months. Thus, in 13 years of RTE product sampling in FSIS-regulated establishments (2005 through 2017), <0.4% of samples were positive for Lm in both risk-based and random sampling projects. The low prevalence of Lm in these products suggests that the combination of FSIS policies and industry practices may be effective for controlling Lm contamination. Information obtained from these sampling projects is relevant to the ongoing prevention of foodborne Lm illnesses from RTE meat and poultry products. HIGHLIGHTS

scholarly journals Procedure for microbiological baseline surveys conducted by US Department of Agriculture Food Safety and Inspection Service

Food Control ◽  
2020 ◽  
Vol 111 ◽  
pp. 107083
Author(s):  
Hans D. Allender ◽  
Stephanie Buchanan ◽  
Naser Abdelmajid ◽  
Ilene Arnold ◽  
Jeanetta Tankson ◽  
...  
Keyword(s):  
Food Safety ◽  
Department Of Agriculture ◽  
Inspection Service

Use of Octanoic Acid as a Postlethality Treatment To Reduce Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products

2007 ◽  
Vol 70 (2) ◽  
pp. 392-398 ◽  
Author(s):  
SCOTT L. BURNETT ◽  
JOCELYN H. CHOPSKIE ◽  
TERESA C. PODTBURG ◽  
TIMOTHY A. GUTZMANN ◽  
STEFANIE E. GILBRETH ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Sensory Evaluation ◽  
Sensory Quality ◽  
Octanoic Acid ◽  
Minimal Impact ◽  
Poultry Products ◽  
Trained Panel ◽  
Regulatory Guidelines ◽  
Inspection Service ◽  
Whole Muscle

The antilisterial efficacy and organoleptic impact of an octanoic acid (OA)–based treatment for ready-to-eat (RTE) meat and poultry products were investigated. Whole-muscle and comminuted RTE products were inoculated with a five-strain mixture of Listeria monocytogenes. The OA treatments were applied to the surface of RTE products by dispensing a specific volume of solution directly into the final package prior to vacuum sealing. Once sealed, the vacuum-packaged RTE products containing OA were immersed in water heated to 93.3°C (200°F) for 2 s to effect adequate film shrinkage. Extending the time at which the packaged, treated RTE products were exposed to water heated to 93.3°C was also evaluated with a commercial cascading shrink tunnel fitted with a modified drip pan. Once treated, RTE products were examined for survivor populations of L. monocytogenes after 24 h of storage at 5°C. Sensory evaluation was conducted with a 60-member trained panel on 11 uninoculated, treated RTE products. The OA treatment of RTE products reduced L. monocytogenes numbers to between 0.85 log CFU per sample (oil-browned turkey) and 2.89 log CFU per sample (cured ham) when compared with controls. The antilisterial activity of OA was improved by increasing the duration of the heat shrink exposure. Specifically, reductions of L. monocytogenes ranged from 1.46 log CFU per sample (oil-browned turkey) to 3.34 log CFU per sample (cured ham). Results from the sensory evaluation demonstrated that 10 of the 11 treated RTE products were not perceived as different (P ≤ 0.05) from the untreated controls. Panelists detected reduced (P ≤ 0.05) smoke flavor intensity with treated mesquite turkey, although the treated product was viewed as acceptable. Results demonstrate the effectiveness of OA as a postlethality treatment meeting U.S. Food Safety and Inspection Service regulatory guidelines for RTE meat and poultry products with minimal impact on sensory quality.

Occurrence of Salmonella in Ready-to-Eat Meat and Poultry Product Samples from U.S. Department of Agriculture–Regulated Producing Establishments. I. Results from the ALLRTE and RTE001 Random and Risk-Based Sampling Projects, from 2005 to 2012

2018 ◽  
Vol 81 (10) ◽  
pp. 1729-1736 ◽  
Author(s):  
STEPHEN W. MAMBER ◽  
TIM MOHR ◽  
CARRIE LEATHERS ◽  
EVELYNE MBANDI ◽  
PHIL BRONSTEIN ◽  
...  
Keyword(s):  
Hazard Analysis ◽  
Control Point ◽  
Geographic Location ◽  
Positive Sample ◽  
Risk Category ◽  
Sample Collection ◽  
Department Of Agriculture ◽  
Critical Control Point ◽  
Poultry Products ◽  
Inspection Service

ABSTRACT Ready-to-eat (RTE) meat and poultry product samples collected from RTE-producing establishments for the ALLRTE (random) and RTE001 (risk-based) sampling projects of the Food Safety and Inspection Service (FSIS) were tested for both Salmonella and Listeria monocytogenes. The FSIS analyzed Salmonella results for RTE meat and poultry product samples collected for the two sampling projects from 2005 to 2012. Data for 24,385 ALLRTE samples collected from 3,023 establishments and 66,653 RTE001 samples collected from 2,784 establishments were evaluated for the percentages of Salmonella-positive samples, product types of positive samples, and Salmonella serotypes. There also were descriptive summaries with respect to establishment hazard analysis and critical control point (HACCP) size, production volumes, L. monocytogenes control alternatives, geographic location, and season or month of sample collection. Results showed low occurrences of Salmonella-positive samples from the ALLRTE and RTE001 sampling projects, with 14 positive samples (0.06%) for ALLRTE and 33 positive samples (0.05%) for RTE001. Percentages of establishments with at least one Salmonella-positive sample averaged 0.46% for ALLRTE and 1.11% for RTE001. Three product types—sausage products, pork barbecue, and head cheese—accounted for 62% of all positive samples. There were 27 distinct serotypes from 48 Salmonella isolates, with serotypes Infantis and Typhimurium being the most common (5 isolates each). All but one of the Salmonella-positive samples were obtained from establishments with HACCP sizes of small or very small. More than half of the positive samples were obtained from establishments using L. monocytogenes control alternative 3 (sanitation only, highest-risk category). Positive Salmonella samples were found in all geographic regions at all times of the year. Information obtained from these sampling projects is relevant to the prevention of foodborne Salmonella illnesses from RTE meat and poultry products.

Determination of Pentachlorophenol in Animal Tissues: A Canadian Perspective

1990 ◽  
Vol 73 (6) ◽  
pp. 838-841
Author(s):  
James D Macneil ◽  
John R Patterson ◽  
Adrian C Fesser ◽  
Valerie K Martz
Keyword(s):  
Food Safety ◽  
Animal Tissue ◽  
Animal Tissues ◽  
Department Of Agriculture ◽  
National Surveys ◽  
Relative Standard ◽  
Canadian Perspective ◽  
Inspection Service ◽  
The U.S

Abstract Analytical methods for pentachlorophenol (PCP) residues In edible animal tissue have been reviewed, with particular reference to gas chromatographic methods of analysis. Results of analyses demonstrate that significant residues of PCP can persist for several weeks In animals exposed to contaminated bedding. National surveys In Canada have found that the incidence of PCP residues In pork in excess of 0.1 ppm was reduced from 32% of survey samples In 1981- 1982 to 6.6% of samples tested In 1987-1988. An Interlaboratory sample exchange among Canadian laboratories demonstrated that the PCP analytical method currently used by Agriculture Canada could be successfully transferred to other laboratories. An exchange of samples between regulatory laboratories of Agriculture Canada and the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) demonstrated equivalency of results for the 2 methods currently used in the respective laboratories, with relative standard deviations for analytical results ranging from 4.4 to 22.2%.

Assessing the Impact of Retailer Disclosure on the Effectiveness of U.S. Meat and Poultry Recalls

2020 ◽  
Vol 83 (12) ◽  
pp. 2095-2101
Author(s):  
JIANBIN YU ◽  
NEAL H. HOOKER
Keyword(s):  
Food Safety ◽  
Plant Size ◽  
Policy Debate ◽  
Recovery Rates ◽  
Disclosure Policy ◽  
Poultry Products ◽  
Inspection Service ◽  
The Impact ◽  
The U.S ◽  
Lower Recovery

ABSTRACT In August 2008, the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) launched a new policy that required publication of a list of retail consignees for the meat and poultry products part of class I recalls, those with the greatest potential impact on public health. In this study, two recall effectiveness measures (recovery rate and completion time) and a difference-in-difference method were used to examine the effects of retailer disclosures. When controlling for factors previously determined to impact recall effectiveness, including product type, reasons for recall, the amount of food recalled, plant size, and the way the problem was discovered, no significant impact on recall effectiveness was discerned under the current disclosure policy. Recalls for bacterial contamination had higher recovery rates. Larger recalls had lower recovery rates and longer completion times. Recalls issued by very small plants had lower recovery rates. Compared with other stakeholders, government agency discovery of the problem was associated with lower recovery rates. As the U.S. Food and Drug Administration considers a similar retailer disclosure policy for foods regulated under the Food Safety Modernization Act, such lessons from the USDA experience should inform the policy debate. HIGHLIGHTS

Genetic and Phenotypic Characterization of Listeria monocytogenes from Human Clinical Cases That Occurred in Portugal Between 2008 and 2012

2014 ◽  
Vol 11 (11) ◽  
pp. 907-916 ◽  
Author(s):  
Rui Magalhães ◽  
Vânia Ferreira ◽  
Isabel Santos ◽  
Gonçalo Almeida ◽  
Paula Teixeira ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Phenotypic Characterization ◽  
Clinical Cases

scholarly journals Listeria monocytogenes Isolates from Foods and Humans Form Distinct but Overlapping Populations

2004 ◽  
Vol 70 (10) ◽  
pp. 5833-5841 ◽  
Author(s):  
Michael J. Gray ◽  
Ruth N. Zadoks ◽  
Esther D. Fortes ◽  
Belgin Dogan ◽  
Steven Cai ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Plaque Assay ◽  
Virulence Gene ◽  
The United States ◽  
Polymorphism Analysis ◽  
Genetic Lineages ◽  
The Public ◽  
Cell Spread ◽  
Specific Food

ABSTRACT A total of 502 Listeria monocytogenes isolates from food and 492 from humans were subtyped by EcoRI ribotyping and PCR-restriction fragment length polymorphism analysis of the virulence gene hly. Isolates were further classified into genetic lineages based on subtyping results. Food isolates were obtained through a survey of selected ready-to-eat food products in Maryland and California in 2000 and 2001. Human isolates comprised 42 isolates from invasive listeriosis cases reported in Maryland and California during 2000 and 2001 as well as an additional 450 isolates from cases that had occurred throughout the United States, predominantly from 1997 to 2001. Assignment of isolates to lineages and to the majority of L. monocytogenes subtypes was significantly associated with the isolate source (food or human), although most subtypes and lineages included both human and food isolates. Some subtypes were also significantly associated with isolation from specific food types. Tissue culture plaque assay characterization of the 42 human isolates from Maryland and California and of 91 representative food isolates revealed significantly higher average infectivity and cell-to-cell spread for the human isolates, further supporting the hypothesis that food and human isolates form distinct populations. Combined analysis of subtype and cytopathogenicity data showed that strains classified into specific ribotypes previously linked to multiple human listeriosis outbreaks, as well as those classified into lineage I, are more common among human cases and generate larger plaques than other subtypes, suggesting that these subtypes may represent particularly virulent clonal groups. These data will provide a framework for prediction of the public health risk associated with specific L. monocytogenes subtypes.

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