• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.56-62
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• 2000

Pasteurella multocida is kind of commensal bacteria in the upper respiratory tract of pigs. It is classified toxigenic and nontoxigenic strains based on the production of dermonecrotic toxin. Toxigenic strain is most associated with atrophic rhinitis which brings great economical loss in swine industry. However, toxigenic and nontoxigenic strains do not differ by diagnostic biochemical reaction or morphology. One of recently developed techniques, PCR detects the toxigenic P multocida. Amplification of an 846-nucleotide fragment of toxA gene was developed. The fragment amplified by PCR was detected in P multocida type D not type A. The PCR amplification was as sensitive as it could detect 1 pg of P multocida DNA. We compared the result of the PCR with the enzyme linked immunosorbent assay (ELISA) in a test for 40 swine nasal swabs. All of these isolates were toxin negative based on the ELISA while 2 isolates were detected in the PCR technique. in addition to accuracy, as required for rapid detection from contaminated nasal swabs, toxigenic P multocida was recovered efficiently from contaminated culture without inhibition of the PCR. The results show that the PCR detection of toxigenic P multocida directly form nasal swabs are feasible.

• KSBB Journal
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• v.18 no.6
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• pp.522-528
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• 2003

The purpose of this study is to inquire into molecular epidemiological characteristics of Vibrio parahaemolyticus. For this study, 120 strains(120 strains of Vibrio parahaemolyticus sampled from diarrhea patients) were examined and analyzed for biochemical characteristics, TDH (thermostable direct hemolysin) antibiotics sensitivity and detection of toxR, gyrE, tdh, and tds gents. G-S PCR (Group Specific Polymerase), PFGE (Pulsed-field Gel Electrophoriesis) methods were performed on the materials from patients were results. 1 Vibrio parahaemolyticus didn't grow in 0% density of NaCl, but the fact was found that those grew in 8% density of NaCl. 2. O：K serotypes of Vibrio parahaemolyticus was turned up in domestic patients was 17 types. Among those O3：K6 was the most, it was 68.3%. 3. In 18 kinds of antibiotic tests resistant against Ampicillin, Ticacillin was comparatively high. the case of resistant against Ampicillin, Ticacillin, Vancomycin at the multiple resistant was 52.5%. 4. Toxin gene tdh had only 109 strains among 120 ones isolated from patients held the genes of 199bp size, and 11 strains was negativity 5. In the test of Kanagawa toxic productivity, 107 strains among strains isolated from patients appeared to be positivity reaction 6. The strain that held trh toxin was only 3, and those among test strains had the genes of 250bp size and that had tdh, trh genes at a time were 3 strains, and TDH toxic productivity of those were 16 times, and it was weak. 7. Group Specific-PCR appeared to be useful in the confirmation of O3:K6 serotype interrelations. 8. Three strains which showed difference of 7 DNA sequence even in the same serotype were detected by the result of analyzing the regular gene, toxRS DNA sequence. These strains are differ from general strains which carry infection easily. 9. These mutual dose epidemiological relations were classified into smaller-parts through PFGE method. As a result of such classify, 3 findings were found. V. parahaemolyticus sampled from diarrhea patients were classified into 3 types. And third, the result obtained through PFGE method can be used as a useful tool in a point of molecular-epidemiological view.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.386-395
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• 2007

A total of 27 strains of Vibrio parahaemolyticus (18 strains isolated from Korea and 9 strains from Japan) were serotyped and examined for biochemical characteristics, antimicrobial susceptibility patterns, cytotoxicity assay, thermostable direct hemolysin (TDH) production and molecular epidemiology. Using polymerase chain reaction (PCR) method and DNA probe hybridization method, the strains were tested for toxR, tdh, trh and ORF 8 genes. The V. parahaemolyticus isolated from patients were belonged to 8 different serotypes : O3:K6, O1:K38, O3:K57, O4:K9, O4:Kl2, O4:K68, O5:Kl5 and O6:K46. Urease-positive strain possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahemolyticus strains strongly correlates with the possession of the trh gene. Most strains showed multiple resistant to more than three antibiotics and the antibiogram could be classified into 6 group (I to VI). All of the O3:K6 strains isolated in South Korea and Japan producted TDH at high levels. The TDH titers ranged between 256 and 2.048, and the average titer was 1009. To distinguish the new and increasingly common V. parahaemolyticus strains from clinical isolates, ORF 8 is a useful genetic marker. After Southern hybridization, the HindIII restriction fragment patterns of the tdh gene were grouped one type, respectively. One type showed two bands one of which was 4.3kb and the other was 11.5kb in size. Variation between the O3:K6 serotype are minor when compared to the differences seen with the non O3:K6 strains. The migration patterns of Not I -digested of the total DNA of the O3:K6 strains were similar, and only slight variations were observed between the serotypes. By contrast, the O3:K6 strains and non O3:K6 had markedly different profiles. In conclusion, Random amplified polymorphic DNA (RAPD) profile using appropriate primers was an effective epidemiological marker.

• Journal of Microbiology
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• v.43 no.spc1
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• pp.110-117
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• 2005

Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. A critical virulence determinant of Salmonella is the ability to invade mammalian cells. The expression of genes required for invasion is tightly regulated by environmental conditions and a variety of regulatory genes. The hilA regulator encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. Work from several laboratories has highlighted that regulation of hilA expression is a key point for controlling expression of the invasive phenotype. A number of positive regulators of hilA expression have been identified including csrAB, sirA/barA, pstS, hilC/sirC/sprA, fis, and hilD. HilD, an AraC/XylS type transcriptional regulator, is of particular importance as a mutation in hilD results in a 14-fold decrease in chromosomal hilA::Tn5lacZY-080 expression and a 53-fold decrease in invasion of HEp-2 cells. It is believed that HilD directly regulates hilA expression as it has been shown to bind to hilA promoter sequences. In addition, our research group, and others, have identified genes (hilE, hha, pag, and lon) that negatively affect hilA transcription. HilE appears to be an important Salmonella-specific regulator that plays a critical role in inactivating hilA expression. Recent work in our lab has been directed at understanding how environmental signals that affect hilA expression may be processed through a hilE pathway to modulate expression of hilA and the invasive phenotype. The current understanding of this complex regulatory system is reviewed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.254-284
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• 2015

Objectives: There is a requirement to select target materials for mutagenicity(Genotoxicity) testing, so we determined to set the test priorities of them by searching the related database. Methods and Results: We searched a number of databases to find information on mutagenicity tests with chemicals under the Occupational Safety and Health Act(OSH Act), such as KOSHANET, National Toxicology Program(NTP), European Chemicals Agency(ECHA), US National Library of Medicine(NLM), and Genetic Toxicology Data Bank(GENE-TOX), as well as ChemIDplus webpage, and presented the information. Also we anticipated their hazards with ACToR sites to confirm the 58 mutagenicity(Genotoxicity) tests we will perform. Conclusions: We presented target materials for mutagenicity testing with specific GLP tests consisting of reverse mutation(Ames), chromosomal aberration and micronucleus test.

• BMB Reports
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• v.39 no.5
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• pp.642-647
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• 2006

Botulinum neurotoxin A (BoNT/A) has been used therapeutically to treat muscular hypercontractions and sudomotor hyperactivity and it has been reported that BoNT/A might have analgesic properties in headache. PEP-1 peptide is a known carrier peptide that delivers fulll-ength native proteins in vitro and in vivo. In this study, a BoNT/A gene were fused with PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame PEP-1-BoNT/A fusion protein. The expressed and purified PEP-1-BoNT/A fusion proteins were efficiently transduced into cells in a time- and dose-dependent manner when added exogenously in a culture medium. In addition, immuno-histochemical analysis revealed that PEP-1-BoNT/A fusion protein efficiently penetrated into the epidermis as well as the dermis of the subcutaneous layer, when sprayed on mice skin. These results suggest that PEP-1-BoNT/A fusion protein provide an efficient strategy for therapeutic delivery in various human diseases related to this protein.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.355-360
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• 2010

Vibrio parahaemolyticus (V. parahaemolyticus), which is commonly found in raw seafood, causes gastroenteritis in humans. Rapid and effective methods have been developed as culture methods require up to 5-7 days. In this study, real-time PCR was compared with the standard culture method for detecting V. parahaemolyticus in seafood and radish sprout samples. Five hundred grams of the samples were artificially contaminated with V. parahaemolyticus then divided into 20 samples. The samples were incubated in alkaline peptone water and then streaked onto thiosulfate-citrate-bile saltssucrose agar. Biochemical tests for suspicious colonies were performed using the API 20NE strip. In parallel, real-time PCR was performed targeting the toxR gene using the enrichment broth. The real-time PCR was sensitive in discriminating V. parahaemolyticus from other foodborne pathogens. The detection limit of the real-time PCR was $10^3\;CFU/mL$ in phosphate-buffered saline. Although the real-time PCR detected more positive samples (76 out of 180, 42%) than the culture method (66 out of 180, 37%), there was no significant statistical difference (p>0.05) between the two methods. In conclusion, real-time PCR assays could be an alternative to the standard culture method for detecting V. parahaemolyticus in seafood and radish sprouts, which has many advantages in terms of detection time, labor, and sensitivity.