Effect of Gamma Irradiation on Listeria monocytogenes in Frozen, Artificially Contaminated Sandwiches

2002 ◽  
Vol 65 (11) ◽  
pp. 1740-1744 ◽  
Author(s):  
S. CLARDY ◽  
D. M. FOLEY ◽  
F. CAPORASO ◽  
M. L. CALICCHIA ◽  
A. PRAKASH
Keyword(s):  
Listeria Monocytogenes ◽  
Gamma Irradiation ◽  
Drug Administration ◽  
Sensory Quality ◽  
Food And Drug Administration ◽  
Manufacturing Environment ◽  
Food Manufacturing ◽  
Log Reduction ◽  
Storage Study ◽  
Triangle Test

Gamma irradiation has been shown to effectively control L. monocytogenes in uncooked meats but has not been extensively studied in ready-to-eat foods. The presence of Listeria in ready-to-eat foods is often due to postprocess contamination by organisms in the food-manufacturing environment. Because gamma irradiation is applied after products are packaged, the treated foods are protected from environmental recontamination. Currently, a petition to allow gamma irradiation of ready-to-eat foods is under review by the Food and Drug Administration. This study was conducted to determine if gamma irradiation could be used to control L. monocytogenes in ready-to-eat sandwiches. Ham and cheese sandwiches were contaminated with L. monocytogenes, frozen at −40°C, and exposed to gamma irradiation. Following irradiation, sandwiches were assayed for L. monocytogenes. A triangle test was performed to determine if irradiated and nonirradiated sandwiches differed in sensory quality. We found that the D10-values ranged from 0.71 to 0.81 kGy and that a 5-log reduction would require irradiation with 3.5 to 4.0 kGy. The results of a 39-day storage study of sandwiches inoculated with 107 CFU of L. monocytogenes per g indicated that counts for nonirradiated sandwiches remained fairly constant. Counts for sandwiches treated with 3.9 kGy decreased by 5 log units initially and then decreased further during storage at 4°C. Sensory panelists could distinguish between irradiated and nonirradiated sandwiches but were divided on whether irradiation adversely affected sandwich quality. Our results suggest that manufacturers of ready-to-eat foods could use gamma irradiation to control L. monocytogenes and improve the safety of their products.

Irradiation Inactivation of Listeria monocytogenes in Low-Fat Ground Pork at Freezing and Refrigeration Temperatures

2006 ◽  
Vol 69 (12) ◽  
pp. 2955-2960 ◽  
Author(s):  
M. L. BARI ◽  
S. TODORIKI ◽  
C. SOMMERS ◽  
F. HAYAKAWA ◽  
S. KAWAMOTO
Keyword(s):  
Listeria Monocytogenes ◽  
Gamma Radiation ◽  
Lipid Oxidation ◽  
Sensory Quality ◽  
Thiobarbituric Acid ◽  
Thiobarbituric Acid Reactive Substance ◽  
Log Reduction ◽  
Pork Products ◽  
Storage Study ◽  
Ground Pork

Gamma radiation effectively controls Listeria monocytogenes in uncooked and in ready-to-eat foods. This study was conducted to determine if gamma radiation could be used to control L. monocytogenes in ground pork. Ground pork was contaminated with L. monocytogenes, kept at refrigeration (4°C), chilling (0°C), and freezing (−18°C) temperatures overnight, exposed to gamma radiation and stored at 4°C for 7 days, and at 0 and −18°C for 60 days. Following irradiation, the meat was assayed for L. monocytogenes viable counts and lipid oxidation. A triangle test was performed to determine if sausage made from the irradiated and nonirradiated ground pork differed in sensory quality. It was observed that a 5-log reduction of L. monocytogenes viable counts would require a 3.0-kGy radiation dose. The results of a 60-day storage study of ground pork inoculated with 105 to 106 CFU of L. monocytogenes per gram indicated that counts for nonirradiated meat remained fairly constant at refrigeration, chilling, and freezing temperatures. However, irradiation of ground pork at 3.0 kGy could inactivate L. monocytogenes totally in ground pork subsequently held at all the temperatures used in this study. Lipid oxidation measurements, as determined by the thiobarbituric acid–reactive substance assay, ranged from 0.16 nmol/g for nonirradiated ground pork and 0.20 nmol/g for meat irradiated at 3.0 kGy. Sensory panelists could distinguish between irradiated and nonirradiated sausage but were divided on whether irradiation adversely affected the sausage quality. Our results suggest that gamma radiation could be useful to control L. monocytogenes in ground pork and improve the safety of ground pork products.

Listeria in Seafoods: A Review

1992 ◽  
Vol 55 (12) ◽  
pp. 1009-1015 ◽  
Author(s):  
RONDA M. DILLON ◽  
THAKOR R. PATEL
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Resistance ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Environmental Contaminant ◽  
Fresh Waters ◽  
Smoked Fish ◽  
Seafood Products ◽  
Crab Meat

Listeria is an environmental contaminant which has been isolated from marine and fresh waters, as well as various seafoods. Furthermore, Listeria, including Listeria monocytogenes, has been isolated from processed seafood products such as smoked fish, cooked and frozen seafoods, marinated fish, surimi products, etc. The pathogen, L. monocytogenes, does have a certain degree of heat resistance. It was found to survive in internally infected shrimp after boiled for up to 5 min. However, the commercial pasteurization process for crab meat was found to be sufficient to inactivate Listeria. The current recovery methodology for L. monocytogenes from seafoods is the Food and Drug Administration Listeria protocol.

scholarly journals Listeria monocytogenes-Based Antibiotic Resistance Gene-Free Antigen Delivery System Applicable to Other Bacterial Vectors and DNA Vaccines

2004 ◽  
Vol 72 (11) ◽  
pp. 6418-6425 ◽  
Author(s):  
Thorsten Verch ◽  
Zhen-Kun Pan ◽  
Yvonne Paterson
Keyword(s):  
Antibiotic Resistance ◽  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Dna Vaccines ◽  
Food And Drug Administration ◽  
Vaccine Vector ◽  
Alanine Racemase ◽  
Vaccine Platform ◽  
Vaccine Vectors ◽  
Significant Difference

ABSTRACT Plasmids represent a powerful tool to rapidly introduce genes into bacteria and help them reach high expression levels. In vaccine development, with live vaccine vectors, this allows greater flexibility and the ability to induce larger antigen amounts through multiple gene copies. However, plasmid retention often requires antibiotic resistance markers, the presence of which has been discouraged in clinical applications by the Food and Drug Administration. Therefore, we developed a Listeria monocytogenes-Escherichia coli shuttle plasmid that is retained by complementation of d-alanine racemase-deficient mutant strains both in vitro and in vivo. Our technology potentially allows the production of antibiotic resistance marker-free DNA vaccines as well as bacterial vaccine vectors devoid of engineered antibiotic resistances. As a proof of concept, we applied the d-alanine racemase complementation system to our Listeria cancer vaccine platform. With a transplantable tumor model, we compared the efficacy of the new Listeria vector to that of an established vector containing a conventional plasmid carrying a tumor-specific antigen. Both vaccine vector systems resulted in long-term regression of established tumors, with no significant difference between them. Thus, the Listeria vaccine vector presented here potentially complies with Food and Drug Administration regulations and could be developed further for clinical use.

Recovery of Heat-Stressed Listeria monocytogenes from Experimentally and Naturally Contaminated Shrimp

1990 ◽  
Vol 53 (1) ◽  
pp. 22-25 ◽  
Author(s):  
SUSAN A. McCARTHY ◽  
MILES L. MOTES ◽  
R. MERRILL McPHEARSON
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
New Method ◽  
Department Of Agriculture ◽  
The U.S ◽  
Thermally Stressed

A method was developed to enhance recovery of thermally stressed Listeria monocytogenes from internally contaminated shrimp. Shrimp tail meat was inoculated with 105 L. monocytogenes cells/g and boiled for 1–5 min. Thermally stressed L. monocytogenes cells were recovered following cold enrichment for 3 d without broth. Methods of the Food and Drug Administration and the U.S. Department of Agriculture for isolating L. monocytogenes permitted recovery of the organism from shrimp boiled for 1 min: however, with the new method, L. monocytogenes cells were recovered from shrimp boiled up to 5 min. No Listeria spp. were recovered from naturally contaminated, frozen, imported shrimp after 1 min of boiling.

scholarly journals Formación de biopelículas por Listeria monocytogenes aisladas de queso fresco de mercados del Cercado de Lima

2017 ◽  
Vol 78 (3) ◽  
pp. 322 ◽  
Author(s):  
Diego Villanueva ◽  
María Salazar
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
San Marcos ◽  
Para Determinar

Introducción. Listeria monocytogenes, bacteria de importancia en salud pública por causar la listeriosis y sus graves consecuencias, se asocia al consumo de alimentos que durante su producción se pueden contaminar con bacterias que se liberan de biopelículas formadas en tuberías, superficies y equipos. Objetivo. Analizar muestras de queso fresco con el fin de aislar e identificar L. monocytogenes y evaluar su capacidad formadora de biopelículas en dos medios de cultivo. Diseño. Estudio experimental, prospectivo. Institución. Instituto de Investigación en Química Biológica, Microbiología y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material. 75 muestras de queso fresco provenientes de diez mercados del Cercado de Lima. Métodos. En el análisis microbiológico se empleó metodologías del Manual de Bacteriología Analítica de la Food and Drug Administration (FDA). Para determinar la capacidad formadora de biopelículas se aplicó el método de microplaca descrito por Djordjevic modificado por Borucki. Se usó la prueba de Kruskal-Wallis. Principales medidas de resultados. Identificación de L. monocytogenes. Resultados. Se identificó L. monocytogenes en 14 muestras (18,7%), valor que representó un riesgo potencial para la salud de los consumidores. Se halló nueve cepas con capacidad de formar biopelículas que, según la densidad óptica a 595 nm, fueron clasificadas en formadoras débiles y moderadas, con diferencias significativas dependiendo del medio de cultivo utilizado, siendo el caldo infusión cerebro corazón (BHI) el más efectivo para esta bacteria. Conclusiones. Se identificó L. monocytogenes en 18,7% (14/75) de las muestras de quesos frescos adquiridas en 10 mercados del Cercado de Lima. De estas cepas, 64,3% (9/14) tuvieron capacidad formadora de biopelículas.

Characterization of Listeria monocytogenes Recovered from Imported Cheese Contributed to the National PulseNet Database by the U.S. Food and Drug Administration from 2001 to 2008

2010 ◽  
Vol 73 (8) ◽  
pp. 1511-1514 ◽  
Author(s):  
BABGALEH B. TIMBO ◽  
CHRISTINE KEYS ◽  
KARL KLONTZ
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Genetic Relatedness ◽  
Tracking System ◽  
Food And Drug Administration ◽  
The United States ◽  
Surveillance Network ◽  
Imported Foods ◽  
The U.S

Imported foods must meet the same U.S. Food and Drug Administration (FDA) standards as domestic foods. The FDA determines whether an imported food is in compliance with the Federal Food, Drug, and Cosmetic Act. Pursuant to its regulatory activities, the FDA conducts compliance surveillance on imported foods offered for entry into the U.S. commerce. The National PulseNet Database is the molecular surveillance network for foodborne infections and is widely used to provide real-time subtyping support to epidemiologic investigations of foodborne diseases. FDA laboratories use pulsed-field gel electrophoresis to subtype foodborne pathogens recovered from imported foods and submit the molecular patterns to the National PulseNet Database at the Centers for Disease Control and Prevention. There were 60 isolates of Listeria monocytogenes in the FDA Field Accomplishment and Compliance Tracking System from 2001 to 2008 due to cheese imported from the following countries: Mexico (n = 21 isolates), Italy (19), Israel (9), Portugal (5), Colombia (3), Greece (2), and Spain (1). We observed genetic diversity of L. monocytogenes isolates and genetic relatedness among strains recovered from imported cheese products coming to the United States from different countries. Consistent characterization of L. monocytogenes isolates recovered from imported cheeses, accompanied by epidemiologic investigations to ascertain human illness associated with these strains, could be helpful in the control of listeriosis acquired from imported cheeses.

scholarly journals Prevalence of Listeria in ice creams in Baghdad province

2010 ◽  
Vol 34 (2) ◽  
pp. 39-44
Author(s):  
Ali Hassan Ahmed AL-Shamary
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Potential Risk ◽  
Dairy Products ◽  
Food And Drug Administration ◽  
Ice Cream ◽  
International Organization ◽  
Powdered Milk ◽  
Ice Creams ◽  
Different Origins

The aim of this study was concerned on the prevalence of Listeria spp.in the ice cream samples collected from the different pastry shops and downtown stores of Baghdad province during December 2009 till April 2010. A total of 50 ice cream samples (25 locally produced samples from raw and imported powdered milk and 25 imported samples from different origins) were analyzed and processed according to the standard protocols of Food and Drug Administration (FDA) and International Organization for Standardization (ISO) with some modifications. Growth of Listeria spp. was determined in 7 (14%) of total samples as 4 (16%) isolates from locally produced ice creams , from which one isolate was confirmed as Listeria monocytogenes, and 3 (12%) isolates from imported ice creams. The findings of this study suggest that Listeriacontaminates some dairy products and Listeria infections are not a potential risk in Baghdad province, but it is strongly recommended that these products are monitored carefully.

scholarly journals PESQUISA DE Listeria monocytogenes EM QUEIJO MUÇARELA FATIADO COMERCIALIZADO EM ESTABELECIMENTOS VAREJISTAS NA CIDADE DE GOIÂNIA, GO.

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
Virgínia Alves ◽  
Ana Clara Melo Lima ◽  
Luiza Chaul Toubas ◽  
Aline Neves Pereira ◽  
Geovanna Bárbara henrique correia da Silva ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration

Listeria monocytogenes é o agente causal da listeriose, uma doença de caráter oportunista e grave, que afeta especialmente gestantes, neonatos, idosos e imunodeprimidos. Os alimentos são os principais veículos de transmissão da bactéria, sendo considerados de alto risco especialmente os prontos para consumo, que apresentam longa vida de prateleira sob refrigeração e são consumidos sem aquecimento prévio, como é o caso de diversos derivados lácteos. O objetivo deste trabalho foi verificar a presença de L. monocytogenes em amostras queijo muçarela fatiado, adquiridas no comércio varejista de Goiânia (GO). 34 amostras do produto foram analisadas no Laboratório de Pesquisa em controle de Qualidade de Alimentos e Medicamentos da Faculdade de Farmácia da Universidade Federal de Goiás. As análises foram conduzidas de acordo com o protocolo preconizado pelo Food and Drug Administration. Os resultados foram confirmados com o kit API Listeria. A presença de L. monocytogenes foi detectada em quatro (11,75%) das 34 amostras de queijo muçarela avaliadas, e a presença de L. innocua em uma (2,9%) das amostras. Apesar de, no Brasil, ainda não ter sido possível estabelecer a relação entre alimentos e doença, os resultados do presente estudo evidenciam que o queijo muçarela fatiado pode atuar como importante veículo para transmissão da bactéria, constituindo, dessa forma, risco para os consumidores.

scholarly journals Competitive Fitness of Listeria monocytogenes Serotype 1/2a and 4b Strains in Mixed Cultures with and without Food in the U.S. Food and Drug Administration Enrichment Protocol

2006 ◽  
Vol 72 (1) ◽  
pp. 776-783 ◽  
Author(s):  
Lisa Gorski ◽  
Denise Flaherty ◽  
Robert E. Mandrell
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Mixed Cultures ◽  
Genetic Lineage ◽  
Processing Plants ◽  
Serotype 1 ◽  
Enrichment Protocol ◽  
Serotype 4B ◽  
The U.S

ABSTRACT Thirteen different serotypes of the food-borne pathogen Listeria monocytogenes have been described. Serotype 4b strains are most often associated with illness, and serotype 1/2a strains are most often isolated from foods and processing plants. Different abilities to respond to stresses have been described for serotype 4b and 1/2a strains. One of the common enrichment protocols used to test foods for the presence L. monocytogenes is described in the U.S. Food and Drug Administration (FDA) Bacterial Analytical Manual (BAM). We compared three strains of L. monocytogenes serotype 4b and five strains of serotype 1/2a in direct competition with each other in two-strain mixed cultures by using the FDA BAM enrichment protocol, which includes both enrichment broth and selective agar, with and without added food to mimic the conditions that occur during attempts to isolate Listeria species from contaminated foods. Using a colony immunoblot procedure and analyzing over 112,000 colonies, we observed differences in strain fitness, but these differences were not attributable to serotype or genetic lineage.

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