• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.165-168
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• 2016

Surface protein internalin (InlA) is a major virulence factor of the food-borne pathogen L. monocytogenes. It plays an important role in bacteria crossing the host's barrier by specific interaction with the cell adhesion molecule E-cadherin. Study of this protein will help to find better ways to prevent listeriosis. In this study, a monoclonal antibody against InlA was used to detect InlA. The reaction was label-free and monitored in real time with an oblique-incidence reflectivity-difference (OI-RD) technique. The kinetic constants k_on and k_off and the equilibrium dissociation constant K_d for this reaction were also obtained. These parameters indicate that the antibody is capable of detecting InlA. Additionally, the results also demonstrate the feasibility of using OI-RD for proteomics research and bacteria detection.

• 대한수의학회지
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• 제31권3호
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• pp.279-284
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• 1991

To investigate the epidemiological aspects of listeriosis, serotypes of L monocytogenes and antimicrobial susceptibilities of Listeria spp isolated from chicken carcases and chicken slaughter house environmental specimens were determined. Of 28 L monocytogenes strains, 12 strains(42.9%) were serotype 4, and the remaining 16 strains were untypable. Peak distributions of minimum inhibitory concentration$({\mu}g/ml)$ of the isolates were $0.78{\mu}g/ml$ for ampicillin, $0.39{\mu}g/ml$ for erythromycin and penicillin G, $1.56{\mu}g/ml$ for tetracycline and $6.25{\mu}g/ml$ or $12.5{\mu}g/ml$ for chloramphenicol, and $3.13{\mu}g/ml$ to > $100{\mu}g/ml$ for kanamycin and neomycin. Most of 214 isolates were sensitive to ampicillin and erythromycin, but 20. 1~78. 0% of the strains were resistant to tetracycline, kanamycin, penicillin-G and neomycin. Single or double drug resistance were observed in 75.8% of the resistant strains. The most common resistance patterns were Nm P-G(37.4%) in double pattern and P-G(23.7%) in single pattern.

• 대한수의학회지
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• 제31권3호
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• pp.271-277
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• 1991

To investigate the epidemiological trait of listeriosis, Listeria spp were isolated from poultry meat, products and environmental specimens in chicken slaughterhouse. Also determined were isolation rates by the different enrichment procedures, the biochemical properties of isolates. In a total of 307 samples including poultry meat, liver, feathers, feces, chiller water, scalding water overflow and slaughterhouse floor, Listeria spp were isolated predominantly from scalding water overflow (90.0%), body skin before washing (66.7%), liver (20.0%) and feathers(15.0%) However, few Listeria spp were isolated from body skin after washing and feces. The higher isolation rates were obtained in the secondary enrichment procedure (7.2%) than in the primary enrichment (3.9%); after stored the secondary enrichment cultures for 2 weeks at $4^{\circ}C$, Listeria spp were present in 9.8%. The majority of the isolated Listeria spp were identical to those of the standards strains in biochemical and cultural properties. Overall, Listeria spp were present in 13.4% of the specimens tested, and were in order of prevalence of L innocua(11.1%), L monocytogenes(3.3%), L grayi(0.7%) and L murrayi(0.3%).

• 한국축산식품학회지
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• 제35권5호
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• pp.669-673
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• 2015

The aims of this study were to investigate the occurrence of Listeria species in turkey meats and to check the antimicrobial susceptibility of the isolated strains. Hundred and fifteen raw turkey meat samples were randomly collected from the supermarkets, butchers and restaurants. Strain isolation and identification were made according to the ISO11290-1 method. Antimicrobial susceptibility was determined by the standard disc diffusion method. A total of 47 Listeria spp. were isolated from 115 (40.9%) raw turkey meat samples. The isolates were distributed between L. monocytogenes (25.53%), L. innocua (34.04%), L. grayi (31.91%) and L. welshimeri (8.51%). A total of 55.3 % of Listeria spp. isolates were multi-resistant to at least 3 of the antimicrobial agent tested. The level of multi-resistance was higher in L. monocytogenes strains (66.7%) than in L. innocua (62.5%) and L. grayi (53.3%). Listeria spp. isolates were highly resistant to ampicillin, cephalothin, penicillin, meticillin, oxacillin, and trimethoprime-sulfamethoxazole. The isolates particularly L. monocytogenes are increasingly resistant to one or more antibiotics and may represent a potential risk for public health because these antibiotics are common used in treatment of listeriosis. The correct and controlled use of antibiotics in veterinary medicine is important to the emergence of resistant strains.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.157-162
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• 1998

As a part of investigation for listeriosis, we attmepted iolationof Listeria spp. from commerical frozen and refrigerated foods at the supermarket level. Seven strains of Listeria spp. were isolate from 6 samples (7.15) among 84 samples of frozen foods, and ten strains of Listeria spp. were also isolated from 8 samples (7.6%)_ among 105 samples of refrigerated foods at the supermarkets in Pusan area. From a total of 189 commerical foods, the number of isolated Listeria spp. and ratio were 6 strains(3.25) of L. grayi, one strain (0.5%) of L. welshimeri, 6 strains (3.2%) of L. innocua and 4 strains (2.15) of L monocytogenes. Listeria spp. isolates except L. monocytogenes did not show $\beta$-hemolysis on blood agar and positive reaction in CAMP test with Staphyloccccus aureus. In the antibiotic susceptibility,most isolates of Listeria spp. were susceptible to 12 antibiotics such as ampicillin , cephalotin, penicillin, amikacin, gentamicin, erythromycin, kanamycin, vancomycin, tobramycin, carbenicillin , tetracycline and trimethoprim /sulfamethoxiazole. Four strains of L. monocytogenes were susceptible to ntibiotics used in this study except nitrofurantio. The serotype of 3 strains and one strain of L. monocytogenes were classified into Listeria O serotype 1 and 4, respectively.

• 한국축산식품학회지
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• 제42권6호
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• pp.1009-1019
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• 2022

In recent years, biocontrol of foodborne pathogens has become a concern in the food industry, owing to safety issues. Listeria monocytogenes is one of the foodborne pathogens that causes listeriosis. The major concern in the control of L. monocytogenes is its viability as it can survive in a wide range of environments. The purpose of this study was to isolate lactic acid bacteria with antimicrobial activity, evaluate their applicability as a cheese starter, and evaluate their inhibitory effects on L. monocytogenes. Lactococcus lactis strain with antibacterial activity was isolated from raw milk. The isolated strain was a low acidifier, making it a suitable candidate as an adjunct starter culture. The commercial starter culture TCC-3 was used as a primary starter in this study. Fresh cheese was produced using TCC-3 and L. lactis CAU2013 at a laboratory scale. Growth of L. monocytogenes (5 Log CFU/g) in the cheese inoculated with it was monitored during the storage at 4℃ and 10℃ for 5 days. The count of L. monocytogenes was 1 Log unit lower in the cheese produced using the lactic acid bacteria strain compared to that in the cheese produced using the commercial starter. The use of bacteriocin-producing lactic acid bacteria as a starter culture efficiently inhibited the growth of L. monocytogenes. Therefore, L. lactis can be used as a protective adjunct starter culture for cheese production and can improve the safety of the product leading to an increase in its shelf-life.

• 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.

• 한국식품위생안전성학회지
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• 제16권4호
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• pp.251-257
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• 2001

Listeria monocytogenes와 L. ivanovii는 인간과 동물에 대한 식품 유래성 병원성 세균이다. Listeria 속에는 이들 병원균 외에 비병원성세균인 L. innocua, L, welshimeri, L. seeligeri, L.grayi 등 이 포함되어 있기에, 식품검사에서 배양법을 사용하는 종래의 Listeria의 검출방법은 시간과 많은 실험을 필요로 한다. 이런 이유 등으로 Literia의 종동정과 검출을 위한 신속한 검출법으로 Lis-mix multiplex PCR검출법 (Bubert et al., 1999)이 개발되었다. 본 연구에서는 식품검사에 활용하기 위한 실용적인 Lis-mix multiplex PCR 방법을 개발하고, 아울러 새로운 Siw-mixIII PCR 검출법을 개발하였다. 이 방법을 사용하여 식품에서 분리된 총 69개의 Listeria 균주를 성공적으로 종동정할 수 있었으며, Siw-mixIII multiplex PCR방법을 사용하여 L. ivanovii, L.welshimeri, L.seeligeri를 한번의 PCR로 검출 및 종동정을 할 수 있었다.

• 한국축산식품학회지
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• 제35권2호
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• pp.211-215
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• 2015

From the previous study, Enterococcus faecium SH01 was isolated from mukeunji, an over-ripened kimchi, and it produced bacteriocin SH01. Bacteriocin SH01 showed an inhibitory effect against Listeria monocytogenes ATCC 19111, a bacterial strain causing human listeriosis. Crude bacteriocin SH01 was purified by ammonium sulfate precipitation and its inhibitory activity at two concentrations (500 and 1,000 AU/g) against Listeria monocytogenes ATCC 19111 was investigated in ground beef at increasing temperatures (5, 10, 15, and 20℃) for 8 d. The number of Listeria monocytogenes ATCC 19111 significantly decreased (p<0.05) as the concentration of bacteriocin increased from 500 to 1,000 AU/g. Intrinsic crude protease activities in ground beef were examined and increased as the temperature increased. Experiments varying both the concentrations of added bacteriocin SH01 and temperature demonstrated a maximum inhibition (2.33 log reduction of bacteria) in samples containing 1,000 AU/g of bacteriocin SH01 incubated at 20℃. When the crude bacteriocin SH01 solution (1,280 AU/mL) was incubated with crude protease solutions at different temperatures, its activity decreased by only half (640 AU/mL), as assessed in an agar well diffusion assay. The finding that the antilisterial activity of bacteriocin SH01 increased with temperature can be explained by the fact that higher temperatures increase bacterial membrane fluidity, thereby promoting the cellular penetration of bacteriocin SH01 into L. monocytogenes. Bacteriocin SH01 may be an excellent candidate as a biopreservative for controlling L. monocytogenes growth in ground beef.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.259-270
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• 2020

Listeria monocytogenes is a gram-positive, facultative anaerobe food pathogen responsible for the listeriosis that mostly occurs during the low-temperature storage of a cold cut or dairy products. To understand the systemic response to a wide range of growth temperatures, L. monocytogenes were cultivated at a different temperature from 10℃ to 42℃, then whole cell proteomic analysis has been performed both exponential and stationary cells. The specific growth rate increased proportionally with the increase in growth temperature. The maximum growth rate was observed at 37℃ and was maintained at 42℃. Global protein expression profiles mainly depended on the growth temperatures showing similar clusters between exponential and stationary phases. Expressed proteins were categorized by their belonging metabolic systems and then, evaluated the change of expression level in regard to the growth temperature and stages. DnaK, GroEL, GroES, GrpE, and CspB, which were the heat&cold shock response proteins, increased their expression with increasing the growth temperatures. In particular, GroES and CspB were expressed more than 100-fold than at low temperatures during the exponential phase. Meanwhile, CspL, another cold shock protein, overexpressed at a low temperature then exponentially decreased its expression to 65-folds. Chemotaxis protein CheV and flagella proteins were highly expressed at low temperatures and stationary phases. Housekeeping proteins maintained their expression levels constant regardless of growth temperature or growth phases. Most of the growth related proteins, which include central carbon catabolic enzymes, were highly expressed at 30℃ then decreased sharply at high growth temperatures.