• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1274-1277
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• 2008

The inactivating efficiency of alternating high-voltage pulsed (AHVP) current was investigated in brine (20 w/v% NaCl) and saline (0.9 w/v% NaCl) inoculated with $1\times10^7$ cells/ml of Listeria monocytogenes. AHVP current at 12 V with 1 pulse completely inactivated L. monocytogenes in brine within 3 ms, while the bacteria in saline were fully inactivated by 10-pulsed electric treatment at 12 V within the same time. Electron microscopic observation demonstrated substantial structural damage of electrically treated L. monocytogenes in brine. These results suggest that AHVP treatment would be effective for the rapid and complete inactivation of L. monocytogenes in brine or saline solution.

• Korean Journal of Veterinary Service
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• v.28 no.2
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• pp.113-119
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• 2005

We surveyed the distribution of Listeria spp in intestinal contents of slaughtered cattle from Daegu between March and October 2003. Fourteen Listeria spp were isolated from a total of 100 samples. Two samples contained only L innocua and other six samples contained both L monocytogenes and L innocua. Of the 99 samples positive to esculin reaction in Fraser broth, Listeria spp were isolated only from $8\%$ of the samples. Three selective plating medium were examined for detection of Listeria species including Enhanced hemolysis agar, Oxford agar and Palcam agar, It was found that Enhanced hemolysis agar was more effective than Oxford agar and Palcam agar, and that L monocytogenes needed 48 hour growth to give positive reaction.

• Clinical and Experimental Pediatrics
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• v.53 no.5
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• pp.653-656
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• 2010

$Listeria$ $monocytogenes$ is a facultative anaerobic, gram-positive bacillus that is isolated from the soil, vegetables, and wild or domestic animals. Listeria occurs predominantly in the elderly, immunocompromised patients, pregnant women and newborns. Infections by this microorganism are rare in healthy infants and children. $L.$ $monocytogenes$ may cause meningitis, meningoencephalitis, brain abscess, pyogenic arthritis, osteomyelitis, and liver abscesses in children. The course of meningoencephalitis by listeria is often severe and even fatal. Acute hydrocephalus can develop as a complication and the mortality associated with listeriosis is significantly high. We present a case of meningoencephalitis caused by $L.$ $monocytogenes$ in a previously healthy 7-year-old girl.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.324-327
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• 2006

The food-borne pathogen Listeria monocytogenes is commonly associated with meats and unpasteurized dairy products. To identify this pathogen in meats more efficiently than has been done in the past, we purchased meats from Korean markets and performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and serotyping analysis on Listeria organisms isolated from meat samples. Each Listeria species showed specific protein band patterns on SDS-PAGE. Whole-cell protein SDS-PAGE profiles indicated that the organisms isolated from meats sold in local Korean markets were L. monocytogenes with the serotypes 1/2a, 1/2b, 1/2c, and 4b. We suggest that it is possible to carry out molecular subtyping of L. monocytogenes using SDS-PAGE.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.279-283
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• 2007

Aqueous chlorine dioxide $(ClO_2)$ treatment was used for the inactivation of Listeria monocytogenes and Campylobacter jejuni in chicken. Chicken breasts and legs were inoculated with $8{\sim}9log\;CFU/g$ of Listeria monocytogenes and Campylobacter jejuni, respectively, and then treated with 0, 50, and 100 ppm of $ClO_2$ solution. Aqueous $ClO_2$ treatment decreased the populations of the pathogenic bacteria on the chicken samples. One hundred ppm $ClO_2$ treatment on the chicken breast and leg reduced the populations of Listeria monocytogenes and Campylobacter jejuni by $0.61{\sim}1.93\;and\;0.99{\sim}1.21log\;CFU/g$, respectively. Aqueous $ClO_2$ treatment affected the microbial growth during storage at $4^{\circ}C$ by decreasing the initial microbial populations. These results clearly suggest that aqueous $ClO_2$ treatment should be useful in improving the microbial safety of chicken during storage and extending the shelf life.

• 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 Microbiology and Biotechnology
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• v.2 no.2
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• pp.73-77
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• 1992

The effect of a nisin-producing Lactococcus lactis spp. lactis (L. lactis) on the growth and attachment of Listeria monocytogenes Scott A and Brie 1 on stainless steel and their growth in Brain Heart Infusion broth was determined. Viable cells of Listeria decreased rapidly after 9~12 hr of incubation at $21^{\circ}C$ and after 6~9 hr of incubation at $32^{\circ}C$ in the presence of L. lactis. The number of L. monocytogenes Scott A attached to stainless steel in pure culture was $2.5{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.3{\times}10^3/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ after 48 hr of incubation, but was only $10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}1.1{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ in the presence of L. lactis. Results from L. monocytogenes strain Brie 1 were similar to those from strain Scott A. The population of L. monocytogenes Scott A which attached to stainless steel with previously adherent L. lactis was $1.8{\times}10^2/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}8.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, whereas the population attached to sterile stainless steel was $1.2{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.1{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. For L. monocytogenes Brie 1, the attached population of the control was $1.6{\times}10^4/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}3.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, and on stainless steel with adherent L. lactis, it was $1.1{\times}10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}6.9{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. Surface adherent L. lactis was less inhibitory to attachment of L. monocytogenes on stainless steel than a liquid culture inoculum. Listeria attached to stainless steel survived dry storage for 20 days both in the presence and absence of adherent lactococci.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1016-1024
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• 2000

The study was conducted to develop a rapid method for the detection of Listeria monocytogenes in foods via polymerase chain reaction (PCR) technique using hemolysin gene (hlyA) primers. Specificity and sensitivity of PCR, optimal conditions for PCR and application of hlyA gene primers for the detection of L. monocytogenes from milk and beef were investigeted. Each of the 20 L. monocytogenes strains gave a single 713 bp band, but other Listeria sup. and other bacteria did not show any bands. As few as 1 pg of L. monocytogenes DNA or 2.4$\times$10$^4$L. monocytogenes cells could be detected with hlyA gene primers. PCR product was most improved at 20~30 cycle in terms of removal of tailing and sensitivity. Also, the sensitivity was significantly improved by the further 10~15 cycle after 20 cycle PCR amplication. Milk (10 mL) and beef (10 g) samples were inoculated with L. monocytogenes at the concentrations ranging from 0 to 10$^{7}$ CFU/mL or g to determine the best sensitivity of PCR for the rapid detection of L. monocytogenes. PCR assay could detect 2 cells in milk with repeating PCR amplication and 2.6$\times$10$^2$cells in beef sample after 24 hr enrichment growth at 35$^{\circ}C$ in LEB.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.634-644
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• 1989

Listeria monocytogenes, one of five species in the genus Listeria and the only one currently believed to be pathogenic for humans, is a small gram-positive, nonsporeforming, aerobic, motile and hemolytic rod-shaped bacterium. The bacterium is widespread in the environment, having been isolated from soil, dust, animal feed, water, sewage, almost every type of animal that has been cultured, and asymptomatic humans. L. monocytogenes causes listeriosis, a disease which most often affects humans with a compromised immune system. Included are pregnant woman, infants and adults suffering from such diseases as cancer, cirrhosis of liver or AIDS or are being treated with drugs such as corticosteroids. Listeriosis is manifested by such syndromes as pregnancy infections, granulomatosis infantiseptica, sepsis, meningoencephalitis, and focal infections. Infections, can be treated successfully with penicillin, ampicillin, or erythromycin. However, a mortality rate of about 30％ has occurred in outbreaks of listeriosis. Food-associated outbreaks of listeriosis have been attributed to coleslaw (Canada, 1981), pasteurized milk (U.S., 1983), and soft cheese (U.S., 1985). Presence of L. monocytogenes in various dairy foods has prompted recall of such products from the U.S. market-place. L. monocytogenes also has been found in raw meats and seafood.

• Korean Journal of Veterinary Research
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• v.49 no.4
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• pp.319-328
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• 2009

This study investigated the epidemiology of Listeria (L.) monocytogenes, a food-borne pathogen. The epidemiology of food-borne pathogens is of great importance for clarifying bacterial origin and preventing bacterial contamination and infection. This work examined 68 L. monocytogenes strains, including 11 reference strains and 57 isolates from imported US beef, domestic meats (beef, pork, chicken meat), raw milk, and milk plants. The random amplified polymorphic DNA (RAPD) techniques were optimized to develop a standard molecular epidemiological analysis of L. monocytogenes. There was great genetic variability among the isolates, which produced 24 and 34 RAPD patterns with primer HLWL85 and HLWL74, respectively. The discriminatory power of the RAPD methods with HLWL85 and HLWL74 primer were very high (DI = 0.957; S ${\geq}$ 80%, S ${\geq}$ 95%). Some RAPD types were specific to origin. A few RAPD types were specific for L. monocytogenes strains belonging to a particular serotype. Using the HLWL85 primer, the strains isolated from milk plants could be distinguished from the other strains. And using the HLWL74 primer, the strains isolated from imported beef (US) could be distinguished completely from the other strains.