• 한국식품영양과학회지
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• 제29권4호
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• pp.606-614
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• 2000

Randomly Amplified Polymorphic DNA (RAPD) 기술을 이용하여 국내 식품으 로부터 분리한 Listeria sp. 분리균주에 대한 DNA polymorphism을 분석하고 유연환계를 비 교하며, 유용 marker를 개발할 목적으로 10가지 10-mer primer를 이용하여 PCR을 수행한 결과 5개의 primer(OPA-01, OP-26-01, OP-26-02, OPB-01, OP-26-10)가 선별되었고, 76개 의 DNA 단편이 증폭되었다. 이 중 OPA-01과 OP-26-10 promer에 의한 약 1.5 kb와 0.7 kb의 증폭 band는 모든 Listeria 분리균에서 관찰할수 있었으나, 이 증폭된 DNA 단편은 Listeria sp.에만 특이적인 것은 아니었다. NTSYS 프로그램을 이용해서 Listeria sp. 분리구 간의 유전적 유연관계를 알아본 결과 7개의 cluster로 나누어졌고 유사도는 대체로 0.54~ 0.93사이였으며, 특히, No.3과 No.20은 93%로 가장 높은 유사도를 나타내었고, No.7과 No.24 또는 No.7과 No.45는 54%로 가장 낮은 유사도를 나타내었다. 이러한 결과는 RAPS 기술을 이용하여 쉽게 Listeria sp.를 subspecies로 분류할 수 있음을 시사하였다.

• 한국수산과학회지
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• 제53권2호
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• pp.237-243
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• 2020

Listeria sp. is one of the pathogenic bacteria causes the infection listeriosis, through mainly raw food such as fishery food, dairy food and vegetables. Listeria sp. is a Gram-positive, non-spore-forming, motile, and facultative anaerobic bacterium. Because of the tolerance of Listeria sp. to low temperature and high salt concentration, it is very difficult to prevent them contaminated in the food, which do not require heating, especially, such as raw fishery products. So prevention and removal of bacterial contamination at the food manufacturing stage is the best method. In this study, therefore, several natural products including Psidium guajava and Geranium thunbergii were screened to investigate the antibacterial activity against Listeria sp., with expectation of fewer side effects and fewer resistance problems. Significant effects of two extracts were confirmed by well diffusion assay, MIC assay, and growth inhibition assay. P. guajava and G. thunbergii showed MIC values at 64-256 ㎍/mL meaning strong antibacterial activities against 6 kind of Listeria sp. tested. And the growth of Listeria sp. in the liquid media was actually inhibited by the addition of these two extracts.

• 한국동물위생학회지
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• 제20권1호
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• pp.69-77
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• 1997

To invastigate the epidemiological trait of listeriosis, Listeria monocytogenes were isolated from the carcasses of pigs and cattle, and environmental specimens in slaughter house. Also serotype of isolates were classified by rapid slide agglutination test. In the carcasses of pigs, Listeria sp were isolated from the carcasses after bleeding(62%), after dismemberment(60.0%) and before shipping(76.0%), and L monocytogenes were present in 8% of the carcasses after dismemberment and in 14% of the carcasses before shipping. However, few Listeria sp were isolated from the living body skin and the carcasses after scalding. In the carcasses of cattle, Listeria sp were isolated from the carcasses after bleeding(10%), after dismemberment(36.7%) and before shipping(63.3%), L monocytogenes were present in 3.3% of the carcasses after dismemberment and in 10% of the carcasses before shipping. Overall, L monocytogenes, L innocua, L welshimen, L grayi, and L murrayi were present In 4.8, 40, 2.3, 2.6 and 0.3% of all the carcasses, respectively. Prevalence of Listeria sp in environmental specimens were found to be 80% in slaughter house floors and 100% in sewage, and L monocytogenes were present in 15% of sewage. However, few Listeria sp were isolated from chilled water and from scalding water. Overall, L monocytogenes, L innocua, and L welshimeri were present in 3.8, 45 and 6.3% of all the environmental specimens, respectively. A total 27 strains of L monocytogenes were isolated from samples tested and all of the strains were classified into serotype 1.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.429-436
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• 2003

Pediocin K1 is a bacteriocin produced by Pediococcus sp. KCA 1303-10, isolated from traditionally fermented flatfish in Korea. Pediocin K1-dependent antibiosis and pediocin K1-independent antibiosis against Listeria monocyrogenes were investigated by comparing antibiosis potential of the ped＋ wild-type strain of Pediococcus sp. KCA1303-10 with that of the ped- mutant strain in 3 different media at 3 different temperatures. In the synthetic MRS-APT medium, bacteriocin (pediocin K1)-dependent antibiosis (BDA) acted as the major driving force of overall antibiosis at the initial stage before the pH of the media was not sufficiently lowered, while bacteriocin-independent antibiosis (BIA) took over the major role at the late stage of antibiosis by killing otherwise resistant cells in the modium. The role of BDA increased as the temperature of the system decreased. The antibiosis potential of BDA among the overall antibiosis of Pediococcus against Listeria at $37^{\circ}C$ was calculated as 46%, and as 75% at $25^{\circ}C$. In the skim milk medium, antibiosis of Pediococcus against Listeria was weakened more than 4 log cycles compared to that of the synthetic medium; however, BDA worked as the main antibiosis force regardless of the culturing temperature in the skim milk medium. In the bean soup medium, BDA also worked as the major killing mechanism against Listeria, but BIA played as another suppressing mechanism against otherwise pediocin-resistant Listeria population. These results suggest that a large portion of the inhibitory action of the ped+Pediococcus sp. KCA1303-10 was attributable to the bacteriocin produced by the strain and that viable Pediococcus sp. KCA1303-10 was superior to the purified bacteriocin in suppressing the occurrence of the bacteriocin-resistant Listeria monocytogenes in food systems.

• 한국동물위생학회지
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• 제23권4호
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• pp.341-348
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• 2000

Nowadays we continue to face challenges to the safety of our foods. It seems clear that contaminated meats provide the major route of listeria monocytogenes transmission from the environment to humans. L monocytogenes is the most important species associated with disease in humans among the listeria sp. The current incidence of symptomatic listeriosis caused by L monocytogenes is uncertain. Although the number of reports in the literature on listeriosis are increasing, it is likely that they are actually unrecognized or underreported because of a lack of awareness on the part of some laboratory workers who fail to isolate or identify these organisms. To get the information of sanitary development, we survey various meats (beef, pork, etc) in Kyongbuk area. Samples were collected from local meat shop at Kyongbuk area. Total sixty six case were isolated and identified from one hundreds and seven samples. L innocua was the most abundant in listeria sp. Among U isolates, the number of isolated L innocua was 43 (65.2%). The numbers of isolated L murrayi, L welshimeri, L monocytogenes and L seeligeri were 12(18.2%), 7(10.6%), 3(4.5%) and 1(1.5%), respectively, but L grayi, L iuanouii were not Isolated.

• 생명과학회지
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• 제13권4호
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• pp.390-399
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• 2003

본 연구는 경남지역의 해수와 해산물에서 Listeria 속을 분리하여 증균배양방법에 따른 균의 분리율, 선택배지에 따른 균의 분리율, 검체에 따른 균종 별 분리율, 생화학 시험과 분리된 L. monocytogenes에 대하여는 혈청형 시험을 실시하였다. 총 100건의 검체에서 증균배양에 따른 Listeria 속의 분리율은 1일 증균배양에서 L. monocytogenes가 4% (4건), L. innocua가 35%(35건), L. ivanovii가 4%(4건), L. welshimeri가 1%(1건)였고, 7일간 증균배양에서는 L. monocytogenes가 1%(7건), L. innocua가 38%(38건), L. ivanovii가 5%(5건), L. welshimeri가 1%(1건)로 동정되어 1일 증균배양 보다 7일간의 증균배양이 Listeria속의 분리에 휠씬 효과적이었다. 이와 함께 Oxford 선택배지나 LPM 선택 배지를 사용하였을 경우 증균배양과 비교하여 검출율이 조금 낮았다. 검체에 따른 Listeria 속의 분리율은 새우와 가재에서 80%(16/20)로 분리율이 가장 높았으며, 바지락에서 50% (10/20), 해수에서 25%(5/20), 홍합에서 20%(4/20)의 순으로 나타났다. 그리고 Listeria 속의 균종 별 분리율은 L. irnnocua가 38%(38건), L. monocytogenes가 7%(7건), L. ivanovii가 5%(5건), L. welshimeri가 1%(1건)순으로 분리되었다. 각 검체에서 Listeria 속의 균종 별 분리율은 새우에서 L. innocua가 65%(13건), L. monocytogenes가 15%(3건), 가재에서 L. innocua가 70%(14건), L. monocytogenes가 10%(2건), 바지락에서 L. innocua가 45%(9건), L. monocytogenes가 5%(1건), 홍합에서 L. innocua가 10%(2건), L. monocytogenes가 5%(1건), L. welshimeri가 5%(1건), 해수에서 L. ivanovii가 25%(5건)분리되었다. L. monocytogenes로 분리 동정된 7주에 대한 혈청형 분류는 type I이 2주, type IV가 5주로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.831-837
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• 2001

Pediocin K1, a bacteriocin produced by Pediococcus sp. K1 isolated from Korean traditional fermented flatfish, inhibited certain strains of Lactobacillus, Streptococcus, and Listeria monocytogenes. Pediocin K1 was found to be stable at $90^{\circ}C$ for 30 min. Among the organisms tested, Listeria monocytogenes was the most sensitive to pediocin K1 and was completely killed when the initial inoculum size of L.monocytogenes cells was equal to or less than $10^3 CFU/ml$. The degree of inibition of Listeria monocytogenes by pediocin K1 increased 10-fold on the addition of citric acid ($0.2\%$) to the medium, thereby showing the synergistic effect of citric acid. Listeria monocytogenes cells resistant to pediocin K1 appeared at a frequency of about $10^-4$/cells. Once developed after exposure to pediocin K1, the resistant phenotype still persisted in the absence of pediocin K1 in successive cultures. This infers that resistance may be attributable to genetic change(s) in the resistant cells.

• 한국수산과학회지
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• 제56권5호
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• pp.721-727
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• 2023

This study was conducted to evaluate the level of microbial contamination in smoked salmon products sold in hypermarkets in major metropolitan cities in Korea. Listeria monocytogenes is the primary cause of smoked and raw salmon product recalls. Here, we used L. monocytogenes as a bacterial hygiene indicator and investigated the microbial contamination level of frozen/refrigerated smoked salmon products collected from hyper markets. Contamination levels were analyzed by seasons, manufacturers, and consumption regions. For hygiene indicator bacteria, total bacteria count, coliforms, and Escherichia coli were examined according to the food code established by the Ministry of Food and Drug Safety, and polymerase chain reaction (PCR) was performed to detect Listeria sp. The highest contamination level was observed in spring in Busan among five consumption regions. Listeria was detected at a level of 2.1% among all samples collected. And especially L. monocytogenes was detected in two cases from the samples collected from Daegu and Daejeon. Sanitary standards and specifications should be established according to the contamination level of smoked salmon products investigated in this study, and continuous monitoring is necessary.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.680-686
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• 2003

This study was carried out to characterize the antilisterial substances produced by Leuconostoc sp. W65 and to evaluate the effects of pH, temperature, and time on inhibitory activity using response surface methodology. Leucocin W65, an antilisterial substance produced by Leuconostoc sp. W65, markedly inhibited the growth of Listeria monocytogenes, L. innocua, and L. ivanovii, whereas other pathogens including Gram-negative bacteria were not susceptible. The pH was the most effective factor with regard to bacteriocin activity, while temperature and time of heat treatment had no significant effect. Fifty percent of inhibitory activity remained after 22.8 min at pH 4.2 and $121^{\circ}C$. Leucocin W65 was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, and tricine-SDS-PAGE. Compositional analysis originally estimated the peptide to be 56 amino acids in length without asparagine, glutamine, and tryptophane. The sequence of partial N-terminal amino acid residues of purified bacteriocin was identified as follows: $NH_{2}-XGXAGVXPXGGQQPXVPLXYP$.

• 한국환경농학회지
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• 제28권1호
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• pp.75-81
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• 2009

This study was carried out to assess the antilisterial potential of ethyl acetate (EtOAc) extract of a marine isolate of Aspergillus sp. The in vitro antilisterial efficacy of ethyl acetate extract was examined using disc diffusion, minimum inhibitory concentration (MIC) determination, cell viable count and scanning electron microscopic (SEM) methods against the employed strains of Listeria monocytogenus. The ethyl acetate extract ($300{\mu}g\;disc^{-1}$) exhibited a promising antilisterial effect as diameters of inhibition zones against L. monocytogenes ATCC 19111, 19116, 19118, 19166 and 15313, which were found in the range of 11-17 mm along with their MIC values ranging from 125 to $1000{\mu}g\;ml^{-1}$ respectively. Also the EtOAc extract had strong detrimental effect on the viable count of the tested L. monocytogens ATCC 19166. Furthermore, scanning electron microscopic (SEM) study demonstrated potential detrimental effect of ethyl acetate extract on the morphology of L. monocytogenes ATCC 19116 at the used MIC concentration. These findings strongly support the role of ethyl acetate extract of a marine isolate of Aspergillus sp. as an antiliterial potential.