• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.245-249
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• 2000

Listeria monocytogenes is one of the important causes of neonatal sepsis and listerial neonatal infection manifests in two forms : Early-onset sepsis syndrome, associated with spontaneous abortion, still birth, preterm labor, granulomatosis infantiseptica, respiratory distress, sepsis, hemodynamic compromise and late-onset listerosis mainly associated with meningitis. Cases of neonatal listerosis reported in Korea have been rare and all were full term newborns. We, herein, report a case of early-onset sepsis due to L. monocytogenes in a extremely low birth weight infant who were born in a critical condition and succumbed in the second day of life despite the intensive care.

• Journal of Mushroom
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• v.20 no.2
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• pp.78-85
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• 2022

The consumption of Flammulina velutipes mushroom imported from Korea has been associated with the cases of listeriosis in the United States, Canada, and Australia. We investigated the effect of sanitizing the plastic wrapper (used in packaging F. velutipes) with slightly acidic electrolyzed water (SAEW) and ultraviolet C waterproof light-emitting diode (UVC-W-LED) on reducing the Listeria monocytogenes. Further, the effect of UVC-LED on L. monocytogenes growth in F. velutipes at different storage temperatures (2, 4, and 10℃) was determined. The combined (SAEW+UVC-W-LED) treatment for 5-10 min reduced 99.9% of bacterial population from the contaminated plastic wrapper. In addition, the UVC-LED treatment for 3 min reduced the L. monocytogenes concentration in F. velutipes by 0.47 log CFU/g. Moreover, the growth of L. monocytogenes in the treated mushrooms was slower than that of the untreated (control) ones. L. monocytogenes concentration in F. velutipes increased over 3 log CFU/g at 2℃ and 10℃ for 60 and 10 days, respectively. The growth of L. monocytogenes at the bottom of mushrooms was faster than that at the top at both the temperatures. These results indicate that the combined SAEW+UVC-W-LED treatment of plastic wrappers and the UVC-LED treatment of mushrooms can be used as potential hurdle technologies to control the risk of L. monocytogenes in mushrooms prior to packaging at farms.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.425-429
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• 1998

Three pork fabrication processing were examined for isolation and serotyping of Listeria monocytogenes. Three hundred thirty samples were collected from gloves, knife sharpeners, knives, cutting boards, conveyer belts, skinning machines, working room air, pig carcasses, and cut meat. Among the 234 samples taken from processing environment, the isolation rates of Listeria monocytogenes and other Listeria spp. were 17.5%, 34.2% respectively. Isolation rates of Listeria monocytogenes from different specimens during processing were 20.8% in gloves, 21.3% in knife sharpeners, 14.6% in knives, 20.8% in cutting boards, 28.6% in conveyer belts, 16.7% in skinnig machines. Listeria monocytogenes and other Listeria spp. were not detected in working room air. Isolation rate of Listeria monocytogenes 14.6% in pork was increased compared to that of 8.5% in pig carcasses (p<0.05). The serovars of 41 isolates from processing environment were 4b 36.6%, 1/2a 24.4%, 4ab 17.0%, 4a 4.9%, 1/2c 2.4%, and 4c 2.4%. The serovars of 4b, 1/2a, 4ab were detected from carcassess and cut meats.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.254-259
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• 2004

Rapid detection of foodbome pathogens is becoming increasingly important. The requirement for faster, more reliable tests has lead to the development of a wide range of rapid methods. Among these methods, the use of systems based on nucleic acid based detection has been increasing since they offer advantages of reduction in test time and more reliable detection or identification. Random Amplification Polymorphic DNA(RAPD) method has been used to fingerprint foodbome microorganisms; Listeria monocytogenes. In this study, 10-mer primer OPG-13(5'-CTCTCCGCCA-3') was used to generate RAPD-PCR for detection of pathogenic L. monocytogenes of Listeria spp. Among 20 primers tested, OPG-13 showed on acceptable result for the differentiation of a pathogenic Listeria from non-pathogenic microorganisms. Pathogenic Listeria, L. monocytogenes(ATCC 15313, 19111, 19112, 19113) showed two bands for 700 bp and 1,500 bp while non-pathogenic bacteria, L. ivanovii, L. grayi, L. murrayi, L. innocua, L. welshimeri, and L. seeligeri had only one band sizing from 2,000 to 2,300 bp. This RAPD method proved to be a valuable to gain important information on sources of pathogenic bacteria in food industry.

• Journal of Food Hygiene and Safety
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• v.24 no.1
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• pp.50-55
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• 2009

Ready-to-eats fresh cut-vegetables that may be consumed without further cooking or reheating can be grouped as potentially high risk foods. The foodborne disease outbreaks associated with consumption of the fresh cut-vegetables have been related with the contamination of Listeria monocytogenes. The food survey and consumption data sets for fresh cut-vegetables and also the published dose-response models for L. monocytogenes, was used to estimate the risk of L. monocytogenes for fresh cut-vegetables in Korea. Also, the simulation model and formulas with Microsoft@ Excel spreadsheet program using these data sets and chose dose-response model was developed. The mean case of listeriosis by consumption of the fresh cut-vegetables per 10 million per year was estimated as $3.23{\times}10^{-6}$. Results suggest that additional studies were needed to allow for a more realistic and accurate microbial risk assessment (MRA) in the future.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.45-50
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• 1999

A bacteriocin-producing strain was isolated from kimchi at the early stage of kimchi fermentation. It was identified as Lactococcus lactis by morphological, cultural and physiological characteristics and partial sequence of 16S rDNA. The bacteriocin from isolate had antimicrobial activity against gram positive pathogenic bacteria, such as Listeria monocytogenes. Staphylococcus aureus and several strains of lactic acid bacteria but not to gram negative bacteria, Yersinia enterocolitica. The bacteriocin was sensitive to protease, protease ⅩⅣ, a-chymotrypsin and pepsin but not to lipase, trypsin and lysozyme. The bacteriocin activity was stable at pH 2-11 and temperature of 100 for 10 min. Thus, Listeria monocytogenes could be inhibited by Lactococcus lactis at early stage of fermentation.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.495-502
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• 2020

Processing fresh produce into fresh-cut products increases the risk of bacterial growth and contamination by breaking the exterior barrier of produce. Our objective in this study was to develop predictive models of Listeria monocytogenes in the fresh-cut salad, fresh-cut pineapple, and frozen mango. Predictive growth and survival models were developed to predict the change of L. monocytogenes populations in the fresh-cut salad (4, 10, 12, 13, 17, 25, and 36℃), fresh-cut pineapple (4, 10, 17, 25, 30, and 36℃), and frozen mango (-2, -10 and -18℃) as a function of temperature. The growth of L. monocytogenes in fresh-cut salad and pineapple was observed at above 13℃ and 10℃, respectively. The growth of L. monocytogenes in pineapple was faster than in salad. The delta value of L. monocytogenes in frozen mango increased as the storage temperature decreased. The results indicate that L. monocytogenes behave differently according to the physicochemical properties of fresh-cut fruits and vegetables. Since L. monocytogenes grow and survive well in refrigerated and frozen conditions, management programs and preventive controls for the processing of fresh-cut produce should be effectively implemented to enhance the safety of fresh-cut fruits and vegetables at retail markets.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.248-256
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• 2008

To investigate the epidemiological characteristics of 68 Listeria monocytogenes isolates, including 11 reference strains and 57 isolates from imported US beef, domestic meats(beef, pork, chicken meat), raw milk, and milk plants. L. monocytogenes was to evaluate the production of virulence proteins, such as hemolysin(LLO) and lecithinase(LCP), the adsorption of Congo red(CRA), and to detect virulence genes using the polymerase chain reaction(PCR). In the study of virulence protein production, 68(100%), 62(91.2%), and 54(79.4%) of the 68 L. monocytogenes strains were positive for LLO production, the LCP test, and the CRA test, respectively, while strains of other species, such as L. innocua, L. gray, L. murrayi, and L. welshimeri, were not. There were no significant differences between L. monocytogenes serotypes and the ability to produce LLO or LCP. L. monocytogenesstrains had very high hemolytic titers(2 to 16 fold), while the other Listeria species, other than L. ivanovii and L. seeligeri, did not. The hemolysin activities of L. monocytogenes, L. ivanovii, and L. seeligeri usually exceeded 1.0 HU/mg, while those of other Listeria spp. were less than 0.04 HU/mg. In the PCR assay, all of the L. monocytogenes strains contained the hlyA, plcA, plcB, inlA, and inlB virulence genes and produced a product of the expected size. In the PCR of the actA gene, the expected 385-bp product was seen in 39(57.4%) L. monocytogenesstrains, while an unexpected 268-bp product was seen in 29(42.6%) strains. Most L. monocytogenes strains isolated from Hanwoo beef produced the 385-bp actA gene product, while strains of imported US beef usually produced the 268-bp actA gene product. By contrast, no virulence gene products were amplified in the other Listeria spp.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.277-282
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• 2019

The object of this study is to compare the performance of the 3M Molecular Detection Assay 2 (3M MDA 2) and the Korea Standard Food Codex (KSFC) Method (i.e., isolation media and real-time PCR) in detecting Salmonella Typhimurium and Listeria monocytogenes in traditional Korean foods. Yuk-hwe and Yuk-sashimi (types of raw beef dishes) were artificially inoculated with $10^0-10^4CFU/25g$ of L. monocytogenes and S. Typhimurium. Citrobacter freundii and Listeria innocua were used as competitive microflora. After enrichment, the samples were analyzed using 3M MDA 2 and real-time PCR. All samples inoculated at concentrations of $10^0-10^4CFU/25g$ without competitive microflora were positive for S. Typhimurium and L. monocytogenes, as detected by 3M MDA 2 and Korea Standard Food Codex (KFSC) Method. In addition, part of the samples were positive for the presence of C. freundii and L. innocua. The 3M MDA 2 - Salmonella and Korea Standard Food Codex (KFSC) Method showed similar detection performances in Yuk-hwe and Yuk-sashimi. The 3M MDA 2 method for Salmonella and Listeria, which is a LAMP-based technology, can be used for rapid detection of S. Typhimurium and L. monocytogenes in raw beef. LAMP bioluminescence assays provide results on the subsequent day and are simple to use compared with the Korea Standard Food Codex (KFSC) Method, particularly in terms of DNA preparation.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.602-608
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• 1997

The antibacterial activity of low concentrations of clove (Eugenia caryophyllata Thumb) in culture broth against Listeria monocytogenes and Salmonella typhimurium was tested at 35, 5, and -20$^{\circ}C$. Tryptic soy broth (TSB) containing 0∼0.5% (w/v) of clove was inoculated with 10$\^$5/∼10$\^$7/ cell/ml of L. monocytogenes and S. typhimurium and incubated at each temperature. The growth of L. monocytogenes occured only after a prolonged lag period at 0.1% clove at 35$^{\circ}C$, while viabilities of the cells decreased by 1.4 and 3.3 log cycles at 0.3 and 0.5% clove, respectively. Growth of S. typhimurium occured at the presence of 0∼0.5% clove after a longer lag period with increasing concentration of clove at 35$^{\circ}C$. During refrigerated storage at 5$^{\circ}C$, the growth of L. monocytogenes occured after 6 days of lag period at 0.1% clove while viability of the cells were decreased during 24 days of storage. During frozen storage at -20$^{\circ}C$, the viability of L. monocytogenes and S. typhimurium decreased about 4 log cycles during 3 days of early period of storage at 0.1% clove. There were no major changes in the population of L. monocytogenes and S. typhimurium in TSB with different concentrations of clove during frozen storage.