Relationship between Listeria monocytogenes and Listeria spp. in Seafood Processing Plants

The objective of this study was to evaluate the relationship between prevalence of Listeria monocytogenes as an outcome and Listeria spp. as an explanatory variable by food products, food contact surfaces, and nonfood contact surfaces in seafood processing plants by using peer-reviewed published data. Nine sets of prevalence data of L. monocytogenes and Listeria spp. were collected from published studies and used for the analyses. Based on our analysis, the relationship between L. monocytogenes prevalence and Listeria spp. prevalence in food products (incoming raw materials and finish products) was significant (P = 0.04) with (low) R2 = 0.36. Furthermore, Listeria spp. were not a good indicator for L. monocytogenes when testing food contact surfaces (R2= 0.10). Listeria spp. were a good indicator for L. monocytogenes only on nonfood contact surfaces (R2= 0.90). On the other hand, the presence of Listeria spp. on food contact surfaces (R2= 0.002) and nonfood contact surfaces (R2= 0.03) was not a good indicator for L. monocytogenes presence in food products. In general, prevalence of Listeria spp. does not seem to be a good indicator for L. monocytogenes prevalence in seafood processing plants.

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Putative Cross-Contamination Routes of Listeria monocytogenes in a Meat Processing Facility in Romania

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-539 ◽

2015 ◽

Vol 78 (9) ◽

pp. 1664-1674 ◽

Cited By ~ 17

Author(s):

ANDREI SORIN BOLOCAN ◽

ELENA ALEXANDRA ONICIUC ◽

AVELINO ALVAREZ-ORDÓÑEZ ◽

MARTIN WAGNER ◽

KATHRIN RYCHLI ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Raw Materials ◽

Meat Products ◽

Cross Contamination ◽

Meat Processing ◽

Food Contact ◽

Food Contact Surfaces ◽

Processing Facility ◽

Contact Surfaces ◽

Contamination Routes

Putative routes of Listeria monocytogenes contamination, based on the workflow of the employees, were studied in a meat processing facility by investigating 226 samples collected from food contact surfaces, non–food contact surfaces, raw materials, and ready-to-eat meat products on four occasions over a 1-year period. In total, 19.7% of non–food contact surfaces, 22.9% of food contact surfaces, 45% of raw materials, and 20% of ready-to-eat meat products were positive for L. monocytogenes (analyzed by the International Organization for Standardization standard method ISO 11290). Pulsed-field gel electrophoresis (PFGE) profiles were determined for a representative subset of these isolates, and 11 distinct pulsotypes were identified, two of which were frequently isolated (T4 and T8) and considered persistent. Strains from the various pulsotypes were screened for the presence of bcrABC and qacH, the genes responsible for tolerance responses to quaternary ammonium compounds. Two strains harbored bcrABC, and these strains had a higher benzalkonium chloride tolerance; however, they were not considered persistent strains. The frequently isolated PFGE pulsotype T8 strains were highly adhesive to abiotic surfaces at 10 and 20°C; however, the pulsotype T6 strain, which was isolated only at the last sampling time, had the highest adhesion ability, and the pulsotype T4 strain (the second most persistent pulsotype) had only modest adhesion. Four putative cross-contamination routes were confirmed by mapping the persistent and other isolates. This information could allow a food safety manager to adjust the work flow to improve the hygienic conditions in a meat processing facility. This study revealed the prevalence and persistence of L. monocytogenes strains in a meat processing facility and established the importance of developing strategies to avoid cross-contamination, recalls, and outbreaks of listeriosis.

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Mathematical Model of Listeria monocytogenes Cross-Contamination in a Fish Processing Plant

Journal of Food Protection ◽

10.4315/0362-028x-67.12.2688 ◽

2004 ◽

Vol 67 (12) ◽

pp. 2688-2697 ◽

Cited By ~ 24

Author(s):

RENATA IVANEK ◽

YRJÖ T. GRÖHN ◽

MARTIN WIEDMANN ◽

MARTIN T. WELLS

Keyword(s):

Mathematical Model ◽

Listeria Monocytogenes ◽

Food Products ◽

Raw Material ◽

Processing Plant ◽

Cross Contamination ◽

Fish Processing ◽

Food Contact ◽

Food Contact Surfaces ◽

Contact Surfaces

Listeriosis is a foodborne disease caused by the bacterium Listeria monocytogenes. The food industry and government agencies devote considerable resources to reducing contamination of ready-to-eat foods with L. monocytogenes. Because inactivation treatments can effectively eliminate L. monocytogenes present on raw materials, postprocessing cross-contamination from the processing plant environment appears to be responsible for most L. monocytogenes food contamination events. An improved understanding of cross-contamination pathways is critical to preventing L. monocytogenes contamination. Therefore, a plant-specific mathematical model of L. monocytogenes cross-contamination was developed, which described the transmission of L. monocytogenes contamination among food, food contact surfaces, employees' gloves, and the environment. A smoked fish processing plant was used as a model system. The model estimated that 10.7% (5th and 95th percentile, 0.05% and 22.3%, respectively) of food products in a lot are likely to be contaminated with L. monocytogenes. Sensitivity analysis identified the most significant input parameters as the frequency with which employees' gloves contact food and food contact surfaces, and the frequency of changing gloves. Scenario analysis indicated that the greatest reduction of the within-lot prevalence of contaminated food products can be achieved if the raw material entering the plant is free of contamination. Zero contamination of food products in a lot was possible but rare. This model could be used in a risk assessment to quantify the potential public health benefits of in-plant control strategies to reduce cross-contamination.

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Microbial contamination after sanitation of food contact surfaces in dairy and meat processing plants

Czech Journal of Food Sciences ◽

10.17221/65/2009-cjfs ◽

2010 ◽

Vol 28 (No. 5) ◽

pp. 450-461 ◽

Cited By ~ 22

Author(s):

J. Schlegelová ◽

V. Babák ◽

M. Holasová ◽

L. Konstantinová ◽

L. Necidová ◽

...

Keyword(s):

Food Products ◽

Raw Material ◽

Meat Processing ◽

Salmonella Spp ◽

Food Contact ◽

Food Contact Surfaces ◽

Heat Treated ◽

Processing Plants ◽

Contact Surfaces ◽

Staphylococcus Spp

The occurrence of Listeria monocytogenes, Salmonella spp., Bacillus cereus, Staphylococcus spp., Enterococcus spp., and Escherichia coli in raw food materials, food products, and on food contact surfaces after sanitation was investigated during the period of 2005–2006 in three dairy cattle farms (120 samples), one dairy (124 samples), and two meat processing plants (160 samples). A total of 1409 isolates were identified. The epidemiological characterisation and determination of the virulence factors and antimicrobial resistance were performed on selected isolates. The level of bacterial contamination generally decreased during the production process (the contamination of food products was lower than that of raw material). However, the contamination of food contact surfaces was relatively high even after sanitation. Moreover, specific microbiological profiles were found on the inside equipment surfaces in dairy facilities, where genetically closely related multi-resistant strains persisting in biofilm communities may occur as demonstrated for staphylococci. Although the occurrence of potentially significant pathogens was not high, the microorganisms such as L. monocytogenes, Salmonella spp., and shiga-toxin positive E. coli principally contaminated the meat processing plants. B. cereus isolates, among which 76% were positive for diarrhogenic enterotoxin, typically occurred on the inside equipment surfaces and in the heat-treated products.

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