• YAKHAK HOEJI
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• v.22 no.2
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• pp.59-71
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• 1978

사람에게 병을 일으키는 수 많은 세균이 분비하는 다수의 외독소중, 이곳에서는 Corynebacterium diphtheriae의 외독소인 디프테리아 독소와 Vibrio cholerae가 분비하는 콜레라 장내 독소에 관해 주로 논하기로 하며, 디프테리아 독소와 생화학적 병인성 기전이 비슷한 Pseudomonas aeruginosa가 분비하는 pseudomnas외독소와 콜레라 장내독소와 병인성기전이 유사한 Escherichia coli의 장내독소에 관하여는 간략하게 언급하고져 한다.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.9-14
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• 2002

This survey was conducted to evaluate the microbiological quality and to detect of pathogenic microorganisms on the surface of slaughtered beef and pork products in two abattoirs located in Seoul from January 2001 through December 2001. Two hundred and twenty-five beef and 215 hog were surveyed for microbiological quality and 630 beef and 625 hog were detected for pathogenic microorgainsms. 1. The prevalence level on number of standard plate count(SPC) less than $10^4$cfu/$cm^2$in beef and hog were 89.8% and 90.7%, respectively. 2. Escherichia coli less than $10^2$cfu/$cm^2$ in beef and less than $10^3$cfu/$cm^2$ in hog were 98.2% and 99% 3. E coli 0157:H7 was recovered from 2 beef carcasses(0.32%), and Staphylococcus aureus from 12 pork carcasses(1.90%), Listeria monocytogenes from 1 beef and 4 pork carcasses (0.15%, 0.64%) and clostridium perfringens from 14 beef and 11 pork carcasses(2.22%, 1.76%), respectively.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.130-133
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• 2005

The growth inhibitiory effect of chaff vinegar against various food-borne pathogenic bacteria was evaluated. Bacterial growth was evaluated in chaff vinegar at concentrations of 15, 30, 50, 65, 80, and $100\%$ using the paper disc diffusion method and 0.5, 1.0, 1.5, 1.8, 2.0, 2.2 and $2.5\%$ in broth. In the paper disc diffusion assay, chaff vinegar showed a clear zone on both the Gram-positive bacteria; Listeria monocytogenes, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli O157:H7, Salmonella Typhimurium, and Vibrio parahaemolyticus. Chaff vinegar exhibited the greatest growth inhibition for V. parahaemolyticus. The bactericidal effect of chaff vinegar on the E. coli O157:H7 was tested at concentrations ranging from 0.5 to $2.5\%$ (v/v) in the LB broth media. Chaff vinegar retarded the lag phase time of the growth curve in proportion in a concentration-dependent manner. Chaff vinegar at $2.5\%$ completely inhibited the growth of E. coli O157:H7.

• Journal of fish pathology
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• v.24 no.3
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• pp.279-287
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• 2011

Transcriptional response patterns of mud loach (Misgurnus mizolepis; Cypriniformes) hepcidin, a potential ortholog to human hamp1, in response to experimental challenges with non-pathogenic and pathogenic bacterial species were analyzed based on the semi-quantitative reverse transcription-PCR assay. Mud loach hepcidin transcripts were much more preferentially induced by pathogenic bacterial species (Edwardsiella tarda and Vibrio anguillarum) causing apparent pathological symptoms than by non-pathogenic species (Escherichia coli and Bacillus thuringiensis) displaying neither clinical signs nor mortality. However in overall, the induced amounts of hepcidin transcripts were positively related with the number of bacterial cells delivered in both pathogenic and non-pathogenic bacterial species. Inducibility of hepcidin transcripts were variable among three tissues examined (liver, kidney and spleen) in which kidney and spleen were more responsive to the bacterial challenge than liver. Time course expression patterns of hepcidin mRNAs after challenge were different between groups challenged with pathogenic and non-pathogenic species, although the overall pattern of hepcidin expression was in accordance with that generally observed in battery genes appeared during early phase of inflammation. Fish challenged with E. coli (non-pathogenic) showed the significant induction of hepcidin transcripts within 24 hr post injection (hpi) but the level was rapidly declined to the basal level either at 48 or 96 hpi. On the other hand, hepcidin transcript levels in E. tarda (pathogenic)-challenged fish were continuously elevated until 48 hpi, then downregulated at 96 hpi, although the level at 96 hpi was still significantly higher than control level observed in non-challenged fish. This expression pattern was consistent in all the three tissues examined. Taken together, our data indicate that hepcidin is tightly in relation with pathological and/or inflammation status during bacterial challenge, consequently providing useful basis to extend knowledge on the host defensive roles of hepcidin under infectious conditions in bony fish.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.278-282
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• 2004

Compost is used mainly as an organic fertilizer, but it is also used as bedding material for cattle. Dairy cattle have been identified as a main reservoir of pathogenic Escherichia coli O157:H7. Further, E. coli is regarded as an environmental pathogen that causes bovine clinical mastitis. Hence, its growth in compost spread or compost bedding should be avoided. Physical and chemical conditions, available nutrients and microflora in compost change greatly during the composting process. Since pathogen growth in compost seems to be related to these changes, we assessed the possibility of E. coli growth in compost samples collected at 0, 7, 13, 22, 41, 190 and 360 d. Cattle waste composts with and without added tofu residue were collected from static piles and immediately air-dried. Compost samples were inoculated with a pure culture of E. coli, the moisture content was adjusted to 50%, and the samples were incubated for 5 d at $30^{\circ}C$. The numbers of E. coli in compost before and after incubation were determined by direct plating on Chromocult coliform agar. Almost all compost samples supported E. coli growth. Samples collected during or immediately after the thermophilic phase (day 7) showed the highest growth. Growth in samples more than 13 d old were not significantly different from those of aged compost samples. The addition of tofu residue gave a higher growth than its absence in younger samples collected prior to 13 d. To minimize the risk of environmental mastitis, the use of compost in the initial stage of the process is better avoided.

• Korean Journal of Veterinary Research
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• v.53 no.3
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• pp.163-167
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• 2013

Avian pathogenic Escherichia coli (APEC) are known to cause extraintestinal disease in poultry, leading to substantial losses in the industry. IutA, iron-regulated aerobactin receptor is firmly associated with APEC. To assess the potential of IutA to induce protective immune responses, attenuated Salmonella Typhimurium strain expressing IutA was constructed and administered orally to BALB/c mice. The IutA-specific immune responses were measured with sera, vaginal and fecal samples by an enzyme-linked immunosorbent assay. We found that the Salmonella-IutA vaccine induced significantly higher immune responses as compared to the control inoculated with the attenuated S. Typhimurium containing the plasmid only. The IutA-specific immune responses were increased by second immunization at third week after initial immunization, whereas triple immunization induced lower immune responses than those induced by the double immunization. The Salmonella-IutA vaccine induced a nature of immunity biased to the Th1-type, as judged by the ratio of IutA-specific IgG isotypes (IgG2a/IgG1). Overall, these results suggest that the Salmonella-IutA vaccine appear to be suitable candidate for a vaccine against APEC.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.647-651
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• 2013

Animal manure compost is a commonly used fertilizer in organic vegetable and fruit production in Korea. However, livestock manure compost produced from animal feces can contain a lot of the non-pathogenic and pathogenic bacteria. Of particular concern are bacteria causing human food-borne illness such as Escherichia coli O157:H7 and Listeria monocytogenes. The objective of this study was to investigate effect of temperature on survival of E. coli O157:H7 and L. monocytogenes in livestock manure compost. Commercial livestock manure compost (manure 60%, sawdust 40%) was inoculated with E. coli O157:H7 and L. monocytogenes. Compost was incubated at four different temperatures (10, 25, 35, and $55^{\circ}C$) for 20 weeks. Samples were taken every week during incubation depending on the given conditions. E. coli O157:H7 persisted for up to 1 day in livestock manure compost at $55^{\circ}C$, over 140 days at $10^{\circ}C$, 140 days at $25^{\circ}C$, and 120 days at $35^{\circ}C$, respectively. L. monocytogenes persisted for up to 1 day in livestock manure compost at $55^{\circ}C$ and 140 days at $10^{\circ}C$, 70 days at $25^{\circ}C$, and 40 days at $35^{\circ}C$, respectively. The results indicated that E. coli O157:H7 and L. monocytogenes persisted longer under low temperature condition. E. coli O157:H7 survived longer than L. monocytogenes at three different temperatures (10, 25, and $35^{\circ}C$). The results are being used to develop guidelines on the management of manure to reduce the risks of E. coli O157:H7 and L. monocytogenes transmission to foods produced in the presence of animal waste.

• Food Science and Preservation
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• v.17 no.2
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• pp.301-306
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• 2010

We identified microorganisms causing skin disease in slaughtered chickens. Ten microbial strains were isolated from skin wound regions on the back and legs of chickens. Fatty acid composition analysis of the cell membranes of isolated bacteria identified five isolates of Shigella sonnei, Proteus mirabilis (2), and Escherichia coli (2). In addition, 16S rRNA sequencing indicated that S. sonnei (99%), P. mirabilis (99%), and E. coli (99%) were the strains responsible for skin wounds in chickens. Therefore, these three species may be the major pathogenic bacteria causing skin wounds on the back and legs of chickens.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.139-145
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• 1987

Adherence to HEp-2 cells has been proposed as a virulence characteristic of enteropathogenic E. coli (EPEC). The role of the HEp-2 adherent E. coli was evaluated in a group of children with endemic diarrhea admitted to Hanyang University Hospital in Seoul, Korea. HEp-2-adherent E. coli was detected in fecal samples of 59 (59%) of 100 cases and ten (22.7%) of 44 concurrent control children (p<0.0005). Adherence was exhibited by 15 serogroups and subgroups, but within these groups more than one adherence pattern was frequently observed. Of 17 strains belonging to traditional infantile EPEC serogroups, 12(70.6%) gave a positive adherence. Of 45 enterotoxin producing strains, 24 (53.3%) gave a positive adherence. HEp-2-adherent strains that did not belong to classic EPEC serogroups and did not produce heat-stable and/or heat-labile enterotoxins(referred as enteroadherent E. coli, EAEC) was found in 29 (29%) of the patients with diarrhea and in six (13.6%) of the well children (p<0.05). From 22 of the 29 cases, no pathogen other than EAEC was isolated. These findings strongly implicate EAEC as the cause of diarrhea in the children. Our study supports the concept that EAEC may be an important cause of endemic diarrhea in Korean children.

• Korean journal of food and cookery science
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• v.16 no.1
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• pp.40-46
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• 2000

The sensitivity of various pathogenic bacteria(Listeria monocytogenes, Staphylococcus aureus, Aeromonas hydrophila, Escherichia coli O157:H7 and Salmonella typhimurium) to the pine needle and green tea extracts was tested. Water extract of pine needle(PNW), 70% ethanol extract of pine needle(PNE), water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activty. Tryptic soy broth(TSB) containing 0∼2%(w/v) of pine needle and green tea extracts were inoculated with 10$\^$5/∼10$\^$6/ cells/ml of each bacterium and incubated at 35$\^{C}$ for 24 hours. The standard plate count method was used to measure the inhibitory effect of the extracts. Minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) were derived from the survival curves of pathogenic bacteria. Antibacterial activities of the pine needle and green tea extracts were compared with that of sodium benzoate, a preservative, by clear zone test. L. monocytogenes, S. aureus and A. hydrophila were completely inhibited at 0.4∼1.6% level while E. coli and S. typhimurium were very resistant to the pine needle extracts. Green tea extracts completely inhibited all strains tested at 0.2∼1.0% level and bactercidal to all strains except L. monocytogenes at 0.5∼2.0% level. Antibacterial activities of pine needle and green tea extracts were stronger than that of sodium benzoate. The order of antibacterial activities of pine needle and green tea extracts to the pathogenic bacteria was GTE > GTW > PNE > PNW. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.