• Korean Journal of Veterinary Research
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• v.45 no.3
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• pp.359-367
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• 2005

This study was carried out to understand the contamination patterns of Listeria in pork processing plants. A total of 402 samples were collected from carcass, pork during processing, surfaces of equipment and environment, and 238 isolates of Listeria species were identified. L. innocua was found in 64.7% of the isolates, L. monocytogenes in 33.2%, and L. welshimeri in 2.1%. Random amplified polymorphic DNA (RAPD) analysis performed to investigate the origin and routes of Listeria contamination, showed 21 composite types of L. monocytogenes and 26 composite types of L. innocua. It was confirmed that Listeria contamination begins with contaminated incoming carcass and ever-present contaminants in the processing environments. The persistence and dissemination of the same strain of L. monocytogenes and L. innocua throughout the processing line revealed that the sanitation standard operating procedure should be implemented to minimize the risk of colonization in the workplace. Molecular subtyping of L. innocua allowed us to tracing the possibility of cross-contamination during processing.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.79-86
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• 2002

Listeria spp. were isolated from the samples submitted from various seafood plants such as raw materials, products, swab samples of plants floor and conveyor belts through the whole processing procedures. All the samples were collected from 3 kinds of seafood plants such as a imitation crab meat plant, jeotgal plant and frozen seafood plant. And also serotypes of the identified L. monocytogenes were determined. Among the 301 strains of isolated Llsteria spp., 96 strains, 179 strains and 26 strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. While among the 145 strains of Listeria spp. isolated from the imitation crab meat plant, $74\;(51.0\%)$ strains, $64\;(44.1\%)$ strains and $7\;(4.8\%)$ strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. In the case of the 126 strains of Listeria spp. isolated from the frozen seafood plant, $22\;(17.5\%)$ strains of L. monocytogenes,$93\;(73.8\%)$ strains of L. innocua, and $11\;(8.5\%)$ strains of L. wdshimeri were detected. Among the 30 strains isolated from a jeotgal plant, $22\;(73.3\%)$ strains of L. innocua and $8\;(26.7\%)$ strains of L. welshimeri were detected. The detection rates of L. monocytogenes, one of the very important food poisoning bacteria especially in frozen and/or refrigerated seafoods, were relatively high as $77.1\%$ (74/96 strains) in a imitation crab meat plant and $22.9\%$ (22/96 strains) in a frozen seafood plant, but not detected from jeotgal plant. Distribution of L. monocytogenes serotypes and characterization were examined. The serotypes of 96 L. monocytogenes isolated from pork skin, pork fat, the floor and conveyor belts were 1/2a $(59.4\%)$, l/2b $(6.2\%)$, 1/2c $(12.5\%)$ and unknown serotypes $(21.9\%)$. Unknown serotypes were divided into three specific groups by the O antigen they have.

• Journal of the FoodService Safety
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• v.3 no.2
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• pp.49-58
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• 2022

The objectives of this study were to investigate the behavior characteristics of pathogenic E. coli, Salmonella Typhimurium, Campylobacter jejuni, and Listeria monocytogenes in various kinds of meat (beef, chicken, and pork) and to compare their risk using FDA-iRISK. The growth of S. Typhimurium in chicken and pathogenic E. coli in pork and beef was well supported and posed a high risk. A similar trend was observed in the risk comparison results using the iRISK. When comparing total disability adjusted life years (DALY) per year based on the kinds of meat, chicken was the highest (88.2), followed by pork (58.5) and beef for "yukhoe" (18.8). When comparing scenarios grouped by bacteria, The highest total DALYs per year was observed with pathogenic E. coli (121), followed by S. Typhimurium (44.8) and L. monocytogenes (1.67E-³). These results indicate that the risk of combining meat and foodborne pathogens varies under the same distribution environment. Thus, strict management and supervision are required to store and deliver raw meat to prevent cross-contamination among the raw meats at the processing plant and retail market.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.695-701
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• 2009

This study was performed to evaluate the effectiveness of biological critical control points using the genetic profile of Escherichia coli isolates from pork cutting plants. Samples were collected from carcasses, equipment (knife, table, glove, transport belt, boning and skinning machine), the environment (wall and floor), and meat cuts during the cutting process from two plants. Pulsed-field gel electrophoresis (PFGE) was used to characterize the E. coli isolates. An identical genotype was detected from the carcasses, equipment, environment, and final meat cuts, and showed that the incoming carcasses, which were contaminated during transportation from slaughterhouses, were a major source of E. coli that was spread throughout processing. Also, consistent cross-contamination due to improper cleaning and disinfection procedures was another possibility. As a result, incoming carcasses and cleaning procedures should be considered critical control points in pork cutting plants, since a heating step is not used to inactivate microorganisms. Furthermore, the high rate (59.6%) of E. coli isolation indicates E. coli can be a good indicator in livestock processing plants even though it has genetic diversity.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.67-72
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• 2003

Random amplified Polymorphic DNA (RAPD) analysis Is based on the amplification of random DNA segment using a single arbitrary primer. Polymorphic DNA patterns identified by this method can be used for typing Listeria monocytogenes. To select the primers for RAPD typing Listeria spp., the performance of 31 primers were compared by analyzing 13 Listeria spp. reference strains. Reproducible electrophoresis patterns were obtained. Among 31 primers, 6 primers (primer 6, HLWL74, UBC155, UBC127, Lis5, Lis11) showed better differentiation, when discrimination index, band clarity, band number, difficulty of band scoring were considered than the others. These primers will be useful far typing Listeria spp. in the future. Currently, we are under investigation for the RAPD typing of contaminated L. monocytogenes for the risk analysis of pork processing plant using these primers.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.224-228
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• 2003

Random amplified polymorphic DNA (RAPD) analysis is based on the amplification of random DNA segment using a single arbitratrary primer. For typing Salmonella spp., polymorphic DNA patterns identified by this method can be used. To select the primers for RAPD typing Salmonella spp., the performances of 20 primers were compared by analyzing 16 Salmonella spp. reference strains. Reproducible electrophoresis patterns were obtained. Among the 20 primers tested, 4 primers (A, OPG04, OPG10, OPL03) showed better differentiation than the others. At the time discrimination index, band clarity, band number and difficulty of band scoring were considered. These primers will be useful for typing Salmonella spp. in the future. Curretly, we are under investigation for the RAPD typing of contaminated Slmonella spp. for the risk analysis of pork processing plant using the primers.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.103-107
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• 2012

We compared between an automated most-probable-number technique $TEMPO^{(R)}$TVC and traditional plating methods $Petrifilm^{TM}$ for estimating populations of total aerobic bacteria in various livestock products. 257 samples randomly selected in local retail stores and 87 samples inoculated with $E.$ $coli$ ATCC 25922, $Staphylococcus$ $aureus$ ATCC 12868 were tested in this study. The degree of agreement was estimated according to the CCFRA (Campden and Chorleywood Food Research Association Group) Guideline 29 and the agreement indicates the difference of two kinds methods is lower than 1 log base 10($log_{10}$). The samples of hams, jerky products, ground meat products, milks, ice creams, infant formulas, and egg heat formed products were showed above 95% in the agreement of methods. In contrast, proportion of agreement on meat extract products, cheeses and sausages were 93.1%, 92.1%, 89.1%, respectively. One press ham and five sausages containing spice and seasoning, two pork cutlets containing spice and bread crumbs, two meat extract product and two natural cheeses and one processing cheese with a high fat content, and one ice cream containing chocolate of all samples showed the discrepancy. Our result suggest that $TEMPO^{(R)}$TVC system is efficient to analyses total aerobic bacteria to compare manual method in time-consuming and laborious process except livestock products having limit of detection.