• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1336-1340
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• 2000

Overall prevalence of Y. enterocolitica in frozen foods was 5.6% (35 cases of 624 samples). Seasonal variation of contamination was observed. Isolation rate of Y. enterocolitica from samples collected in the second half of the year was six times higher than those of the first half of the year. Serotype of the isolated Y. enterocolitica was mainly serotype O:5 (9 cases). However, 25 cases of 35 isolates could not be serotyped with antiserum used in this study. The biotype test showed that all isolates were non-pathogenic type 1A. The polymerase chain reaction test with ail gene specific primers also confirmed that pathogenic strains were not found in frozen food isolates.

• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.181-194
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• 1992

Two hundred and eighty nine strains of Yersinia enterocolitica isolated from healthy pigs were tested for the presence of 40~50 Megadalton virulence-associated plasmids and plasmidmediated in vitro virulence-associated properties, i.e., congo red uptake, calcium dependency, autoagglutination, CRMOX reaction, crystal violet binding and pyrazinamidase reaction. The correlationships between in vitro virulence-associated properties and the presence of 220 Kdalton outer membrane protein(OMP) were examined in strains with or without virulence-associated plasmids. The correlationships between the presence of plasmids on the production of the OMP and the expression of in vitro virulence-associated properties were studied with $CRMOX^+$ strains and acridine orangecured $CRMOX^-$ mutants. The results were as follows : 1. Of the in vitro virulence-associated tests with 289 strains of Y enterocolitica, 275 strains (95.2%) were positive for pyrazinamidase test, and followed by in order of crystal violet binding test, 226 (79.2% ) ; CRMOX test, 190 (65.7%) ; autoagglutination test, 1.85(64.0%) : calcium dependency test, 86 (29.8%) and congo red uptake test, 47(16.3%). 2. The correlationship between autoagglutination and CRMOX test(r=0.90) was highly significant (p<0.01). 3. In 190 strains(65.7%) bearing the virulence-associated plasmids(MW 40~50 Mdalton), the correlation between the presence of plasmids and their in vitro virulence-associated properties were highest with CRMOX test(r=0.93) and followed by in orders of AAG test(0.81), CV test(0.46), PYZ test(0.37) and CD test(0.18), but no correlationship between the presence of plasmids and CR test(-0.11). 4. The $CRMOX^+$ strains produced the 220 Kdalton OMP when they were cultured at $37^{\circ}C$, but not at $26^{\circ}C$. The presence of 220 Kdalton OMP was correlated significantly with in vitro virulence properties and the presence of virulence-associated plasmid, respectively. 5. In the isogenic $CRMOX^-$ mutant strains, of which plasmid were cured by treatment with acridine orange not only in vitro virulence-associated properties(CR 100%, CD 100%, AAG 82.6%, CV 58.3%) disappeared but also 220 Kdalton OMP(100%) was not produced. These results indicate that the positive CRMOX reaction is plasmid-mediated and the CRMOX test is potential as an in vitro virulence tests with Y enterocolitica.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.486-491
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• 2001

The pathogenicity for one hundred strains of domestic and foreign Y. enterocolitica was tested with HEp-2 cell invasion method as a reference. The serotyping, biotyping, PCR and esculin hydrolyis, salicin fermentation, pyrazinamidase activity, indole production, xylose fermentation, CRMOX and autoagglutination were compared to determine the possibility of pathogenic detection method. According to the test results, serotyping was limited to verify pathogenicity, however, biotyping was quite related to pathogenicity up to 99%. The biotype 1A strains were non-pathogenic, while all strains of biotype $1B{\sim}4$ showed pathogenicity with the exception of one strain belonged to type 1B. The esculin and salicin test results were completely close and correlated to pathogenicity up to 99%. The HEp-2 cell invasion and pyrazinamidase test were related to pathogenicity by 95%. Biochemical tests such as D-xylose fermentation, CRMOX agar test and autoagglutination in broth were effective as a support test. It is strongly recommended that sequencial esculin test and PCR test could be done to verify pathogenicity of Y. enterocolitica as the easiest and accurate procedure.

• The Journal of the Korean Society for Microbiology
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• v.15 no.1
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• pp.3-8
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• 1980

Yersinia enterocolitica has been known to be an important enteric pathogen especially in Scandinavian countries and Canada. In Korea, the authors reported the first case of Y. pseudotuberculosis septicemia in 1979. In 1980, three isolates of Y enterocolitica were obtained from 3 adult patients with enteritis, besides the already reported one in a 5-month-old child, during March to June 1980. Difficulty in the isolation was experienced; ie., the organism was isolated only from the SS primary isolation plate in one case and in the other two cases only from the SS plates inoculated with overnight culture of selenite broth. The isolates showed typical cultural and biochemical characteristics except for the nonmotility even at room temperature. Two isolates were indole negative possibly belonging to Wauter's biotype 3 and the other one was indole positive belonging to biotype 2. One patient was tested for the serum agglutinin titer on the 8th hospital day and it was found to be 1:128. All of the isolates were susceptible to chloramphenicol, colistin, gentamicin, kanamycin, tetracyclne, and tobramycin by the Kirby-Bauer disc diffusion method. All of the infections were controled by ampicillin, amoxicillin, amikacin, or gentamicin treatment. It is considered urgent to broaden our knowledge on yersiniosis in Korea not only by isolating, serotyping and biotyping of the organism, but also by surveying serum agglutinin titer of enteritis patients and normal individuals.

• Journal of Life Science
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• v.20 no.5
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• pp.697-702
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• 2010

Ten farrow-finish farms participated in this seromonitoring that was conducted to investigate the porcine brucellosis situation in Korea. In total, eight (80.0%) of the 10 farms and 139 (24.0%) of 578 pigs tested showed a positive response in the Rose Bengal test (RBT). Seroprevalence levels were determined using RBT according to age; 35 (14.6%) of 239 piglets, 36 (31.3%) of 115 growing pigs, and 68 (30.4%) of 224 finishing pigs and sows were positive, respectively. All positive samples in RBT were tested with the tube agglutination test (TAT) and competitive ELISA (C-ELISA), simultaneously. Although 48 samples came up positive in the TAT, all samples tested with C-ELISA were negative. Among 26 rectal swab samples from the TAT positive-pigs, Yersinia enterocolitica O:9 was isolated from seven samples (26.9%). Therefore, we speculated that the positive reaction of RBT and TAT in this study might be induced by the serologically cross-reacting bacteria with Brucella abortus.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.303-303
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• 1999

No Abstract, See Full Text

• Journal of Environmental Health Sciences
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• v.24 no.1
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• pp.141-150
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• 1998

This study was performed to investigate the distribution of Yersiniae and correlation between Yersiniae and indicator organism by time and area in spring water located in northern part of Seoul. Samples collected from 46 spring waters located in four mountains(Dobong, Bukhan, Surak, Bulam) were inspected to detect Yersiniae and indicator organisms. And also there were examined bioserological characteristics and resistance of ahtibiotics of the isolated Yersiniae.The result were as follows. 1. The isolation rate of Yersiniae was 22% in February and 20% in April. The isolated species were 6 strains of Y. enterocolitica, 6 strains of Y. aldova, 4 strains of Y. intermedia and 43 strains of Y. pseudotuberculosis. The serotype of Y. pseudotuberculosis isolated from was all O:5 and biotype of Y. enterocolitica isolated from was all O:3. 2. The Geometric mean of standard plate count, coliform, and psychrotrophilic bacteria were 3.4 CFU/ml, 1.2 MPN/100 ml and 33.0 CFU/ml in February and 3.1 CFU/ml, 1.5 MPN/100 ml and 20.5 CFU/ml in April respectively. There was no significant difference by time and area but the indicator organisms were correlated significantly with each other (p<0.05). 3. Because detection of Yersiniae was not statistically associated with indicator organism, Yersiniae can be detected in the spring water approved microbiologically (p<0.05). 4. The Yersiniae isolated were resistant to Ampicillin, Colistin, Carbenicillin and Coilstin. All isolaed Y. enterocolitica were resistant to Ampicillin (100%). In the case of Y. pseudotuberculosis, only 1 of 3 isolated was resistant to Colistin but susceptible to other antibiotics.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.42-45
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• 2005

The present study was carried out to envisage the aerobic growth of Listeria monocytogenes and Yersinia enterocolitica on pork, which is one of the major meat sources in Korea. The results were compared with the previously developed predictive model systems for the verification of microbial growth in a real situation during pork processing. Pork loin samples (8.0 g, 5 mm thick) were aseptically prepared and inoculated with each pathogen by immersing into the respective inoculums for one min. Each of the samples were then wrapped with PE film and stored at 5, 10, and $15^{\circ}C$ up to 36 days to measure the growth profile of the respective pathogens. The growth parameters were calculated by using Gompertz equation and were compared with the previously reported data. The predicted generation time (GT) of L. monocytogenes at 5, 10 and $15^{\circ}C$ was 28.74, 7.85 and 4.02 hr, respectively, and for Y. enterocolitica was 10.29, 4.74 and 2.50 hr, at the same temperatures respectively. In this study, the GT values predicted on pork were slightly higher than the values predicted in other studies using liquid model systems. Unlike previous reports, both the pathogens were found to grow at $5^{\circ}C$ on pork. This finding recommends the necessity of controlling the growth of both the pathogens during the slaughtering process and distribution.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.584-587
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• 2000

The invasion genes from Salmonella typhimurium were identified by the construction of a cosmid library and subcloning genes into a plasmid vector, pGEM-7Z. The 4.65 kb fragment of the invasion-conferring genomic region of the subclone, pSV6235 was sequenced in both direction. The three open reading frames, which were located at downstream of a promoter region, were designated as sir (Salmonella invasion region)A coding for the 36 amino acids, sirB coding for the 132 amino acids and sirC for the 82 amino acids, respectively. Interesingly, the genomic region of pSV6235 was highly homologous to Yersinia enterocolitica genomic DNA for a high pathogenicity island and Salmonella enteritidis insertion element IS1351 and IS200 DNA. These results show that there could be a significant relationship between S. typhimurium, Y. enterocolitica and S. enteritidis with respect to horizontal evolution process and acquisition of virulence determinants by means of transposon, plasmid or bacteriophage.

• Food Science and Preservation
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• v.12 no.5
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• pp.470-475
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• 2005

Antimicrobial activities of pyroligneous liquor were investigated by determining Minimal Inhibitory Concentration (MIC). The solvent extracts of pyroligneous liquor, which were extracted by using solvents with different polarities such as hexane, ethylacetate, or butanol. The activities were examined by disc diffusion method using MIC against 7 food poisoning microbe type strains. Antimicrobial activities were shown in hexane, ethylacetate, butanol, and aqueous fractions of pyroligneous liquor. Among the four fractions, ethylacetate fraction showed the highest inhibitory effect on the microorganism such as Shigella sonnei, and Yersinia enterocolitica at the concentration of 2.0 mg/disc. The purified P-1 and P-2 fractions isolated by silica gel column chromatography from ethylacetate fraction of pyroligneous liquor had the highest antimicrobial activity. The total phenolic compounds content in ethylacetate, hexane, butanol, and aqueous fraction was 488.3 mg/g, 403.8 mg/g, 83.6mg/g, and 74.5 mg/g, respectively. Taken together, these results suggest that the ethyl acetate fraction could be suitable for the development of isolation and identification of antimicrobial compound from pyroligneous liquor, resulting from the above antimicrobial activity.