• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.513-522
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• 2002

Antigenic ompC genes of S. gallinarum, S. pullorum and S. dublin were characterized among Salmonella spp. isolated from chickens and other animals to identify genetic variation. Salmonella ompC gene fragment (1,027 bp) was amplified by PCR and the amplicons were cloned for comparison of nucleotide sequences. The identity of the sequences between S. gallinarum and S. pullorum, S. gallinarum and S. dublin, S. pullorum and S. dublin was 99.8%, 97.6% and 97.8%, respectively. Also, we found that ompC has some diversity between S. gallinarum and S. pullorum, and other Salmonella spp. which may be useful to type the organisms. Similar to diagnosis in other organisms, the TaqMan PCR method can be applied to rapid and accurate diagnosis of salmonellosis in chickens and other animals. We designed PCR primers and TaqMan probe for flagellin gene (fliC) for detection of Salmonella spp. by TaqMan PCR. The TaqMan PCR method was 10,000 times more sensitive than conventional PCR.

• Biomedical Science Letters
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• v.10 no.2
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• pp.153-161
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• 2004

Antibiotic resistance is often associated with the production of inner membrane proteins (for example, AcrAB/TolC efflux pump) that are capable to extrude antibiotics, detergents, dyes and organic solvents. In order to evaluate the unknown MarB function of Escherichia coli, especially focused on the function of OmpF porin, several mutants were construted by T4GT7 transduction. MarA plays a major roles in mar (multiple antibiotic resistance) phenotype with AcrAB/TolC efflux pump in E. coli K-12. Futhermore, MarA decreases OmpF porin expression via micF antisense RNA. Expression of acrAB is increased in strains containing mutation in marR, and in those carrying multicopy plasmid expressing marA. MarB protein of E. coli K-12 showed its activity at OmpF porin & TolC protein as target molecule. Some paper reported MarB positively regulates OmpF function. MarA shows mar phenotype, and MarB along with MarA show decreased MIC through OmpF function. By this experiment, MarB could decrease MIC through the OmpF porin & TolC protein as target.

• Journal of Life Science
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• v.31 no.1
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• pp.28-36
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• 2021

Edwardsiella piscicida is a significant cause of hemorrhagic septicemia in fish and gastrointestinal infections in humans. Survival bacteria require specialized mechanisms to adapt to environmental fluctuations. Hence, to understand the mechanism through which E. piscicida senses and responds to environmental osmolarity changes, we determined the protein expression profile and physiological properties under various salinity conditions in this study. The OmpR protein is a part of the Env-ZOmpR two-component system that has been implicated in sensing salt stress in bacteria. However, the physiological role played by this protein in E. piscicida remains to be elucidated. Therefore, in this work, the function of the OmpR protein in response to salt stress was investigated. Phenotypic analysis revealed that, in the mutant, three of the biochemical phenotypes were different from the wild type, including, citrate utilization, hydrogen sulfide, and indole production. Introduction of the plasmid containing the entire ompR gene to the mutant strain returned it to its parental phenotype. The retarded growth rate also partially recovered. Furthermore, in our studies, OmpR was not found to be related to cell motility. Taken together, our results from the mutational analysis, the growth assay, MALDI-TOF MS, qRT-PCR, and the phenotype studies suggest that the OmpR of E. piscicida is implicated in osmoregulation, growth, expression of porins (ETAE_1826), virulence-related genes (EseC, EseD and EvpC), and certain genes of unknown function (ETAE_1540 and ETAE_2706).

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1196-1202
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• 2005

Omeprazole (OMP) is a proton pump inhibitor used as an oral treatment for acid-related gastrointestinal disorders. In the liver, it is primarily metabolized by cytochrome P-450 (CYP450) isoenzymes such as CYP2C19 and CYP3A4. 5-Hyroxyomeprazole (5-OHOMP) and omeprazole sulfone (OMP-SFN) are the two major metabolites of OMP in human. Cimetidine (CMT) inhibits the breakdown of drugs metabolized by CYP450 and reduces, the clearance of coad-ministered drug resulted from both the CMT binding to CYP450 and the decreased hepatic blood flow due to CMT. Phenobarbital (PB) induces drug metabolism in laboratory animals and human. PB induction mainly involves mammalian CYP forms in gene families 2B and 3A. PB has been widely used as a prototype inducer for biochemical investigations of drug metabolism and the enzymes catalyzing this metabolism, as well as for genetic, pharmacological, and toxicological investigations. In order to investigate the influence of CMT and PB on the metabolite kinetics of OMP, we intravenously administered OMP (30 mg/kg) to rats intraperitoneally pretreated with normal saline (5 mL/kg), CMT (100 mg/kg) or PB (75 mg/kg) once a day for four days, and compared the pharmacokinetic parameters of OMP. The systemic clearance ($CL_{t}$) of OMP was significantly (p<0.05) decreased in CMT-pretreated rats and significantly (p<0.05) increased in PB-pretreated rats. These results indicate that CMT inhibits the OMP metabolism due to both decreased hepatic blood flow and inhibited enzyme activity of CYP2C19 and 3A4 and that PB increases the OMP metabolism due to stimulation of the liver blood flow and/or bile flow, due not to induction of the enzyme activity of CYP3A4.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1508-1521
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• 2015

Vibrio harveyi is a pathogenic marine bacterium causing systemic symptoms resulting in mass mortalities in fishes and shrimps in aquaculture. Outer membrane proteins(OMPs) are related to the pathogenicity and thus good targets for diagnosis and vaccination for Gram negative bacteria. Recently vaccination strategies using the OMPs have been suggested to control vibriosis in several fish species. In this study, we have isolated V. harveyi from diseased marine fishes from different regions of Korea and investigated genetic variations of four OMP genes including OmpK, OmpU, OmpV and OmpW. Consequently, OmpK and U genes could be divided into 3 subgroups of type I, II, III and type A, B, C, respectively, without any correlation with geographical regions and species while OmpV and W were highly homologous. OmpW gene of V. harveyi FP4138 was fully sequenced and predicted the deduced amino acid sequence to form ${\beta}-barrel$ with hydrophobic channel. Indeed, the immunogenicity of recombinant OmpW produced in Escherichia coli was assessed by vaccinating flounder. As a result, the high antibody response with antibody titer of $4.2{\pm}0.7$ and protection with relative percent survival of 60% against artificial infection of V. harveyi were demonstrated. This result indicates that OmpW is a virulence related factor and it can be a vaccine candidate to prevent a high mortality caused by V. harveyi infection in olive flounder, Paralichthys olivaceus.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.6-14
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• 2022

Brucella spp. are facultative intracellular pathogens that invade, survive and proliferate in numerous phagocytic and non-phagocytic cell types, thereby leading to human and animal brucellosis. Outer membrane proteins (Omps) are major immunogenic and protective antigens that are implicated in Brucella virulence. A strain deleted of the omp16 gene has not been obtained which suggests that the Omp16 protein is vital for Brucella survival. Nevertheless, we previously constructed an omp16 conditional deletion strain of Brucella, ∆Omp16. Here, the virulence and immune response elicted by this strain were assessed in a mouse model of infection. Splenomegaly was significantly reduced at two weeks post-infection in ∆Omp16-infected mice compared to infection with the parental strain. The bacterial load in the spleen also was significantly decreased at this post-infection time point in ∆Omp16-infected mice. Histopathological changes in the spleen were observed via hematoxylin-eosin staining and microscopic examination which showed that infection with the ∆Omp16 strain alleviated spleen histopathological alterations compared to mice infected with the parental strain. Moreover, the levels of humoral and cellular immunity were similar in both ∆Omp16-infected mice and parental strain-infected mice. The results overall show that the virulence of ∆Omp16 is attenuated markedly, but that the immune responses mediated by the deletion and parental strains in mice are indistinguishable. The data provide important insights that illuminate the pathogenic strategies adopted by Brucella.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.610-616
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• 2013

Loop-mediated isothermal amplification (LAMP) is an emerging detection technology for the amplification of DNA under isothermal conditions. The aim of this study was to develop a rapid and reliable LAMP technique for the detection of Cronobacter sakazakii in milk powder. In order to enhance the sensitivity and specificity, LAMP primers targeting outer membrane protein A (ompA) gene of C. sakazakii were designed using Explorer V4 software. Thirty seven C. sakazakii strains and 13 pathogenic microorganisms were used for comparative detection of C. sakazakii using polymerase chain reaction (PCR), real-time PCR, and LAMP. LAMP developed in this study could specifically detect C. sakazakii strains without cross-reactivity with other foodborne pathogens. LAMP products amplified from ompA gene of C. sakazakii were digested with with HhaI and NruI enzyme. The specificity of LAMP was confirmed by restriction fragment length polymorphism (RFLP) analysis. LAMP could detect C. sakazakii within 1 h without bacterial culture and its detection limit was as low as 1 CFU/mL C. sakazakii in milk. In the comparison of the sensitivity, LAMP showed 10,000- and 100-times higher detection limit than PCR or real-time PCR, respectively. Therefore, this study can conclude that LAMP is a rapid and reliable detection technique for C. sakazakii contaminated in powdered milk.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.553-559
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• 1998

cDNA of human thrombopoietin (hTPO) amplified by polymerase chain reaction from a cDNA library of human fetal liver was cloned. EPO-like domains ($hTPO_{153} \;or\; hTPO_{l63})\; of\; hTPO(hTPO_{332}$) were expressed in Escherichin coli using several kinds of expression systems, such as ompA secretion, thioredoxin fusion, and the $P_L$ and T7 expression systems. To obtain $hTPO_{153}$ in soluble form, $hTPO_{153}$ cDNA was fused in-frame behind the gene encoding ompA signal sequence and thioredoxin protein. When fused with either of the genes, $hTPO_{153}$ was not expressed to the detectable level. However, a high level expression of the EPO-like domain of hTPO was obtained using the PL and T7 expression system. $hTPO_{153} \;or\; hTPO_{l63} cDNA were subcloned into the pLex and pET-28a(＋) vectors under the control of the inducible$ P_L\;T_7$ promoter, respectively. Proteins expressed using pl.ex vector and pET-28a(＋) detected in insoluble forms with an expression level of about 14% and 9% of total cellular proteins, respectively, and the level of expression was rapidly diminished in 2 h after the maximum level of expression was reached.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1271-1279
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• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.368-377
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• 2020

Enterotoxigenic Bacteroides fragilis (ETBF) is the main pathogen causing severe inflammatory diseases and colorectal cancer. Its biofilm plays a key role in the development of colorectal cancer. The objective of this study was to determine the antagonistic effects of cell-free supernatants (CFS) derived from Clostridium butyricum against the growth and biofilm of ETBF. Our data showed that C. butyricum CFS inhibited the growth of B. fragilis in planktonic culture. In addition, C. butyricum CFS exhibited an antibiofilm effect by inhibiting biofilm development, disassembling preformed biofilms and reducing the metabolic activity of cells in biofilms. Using confocal laser scanning microscopy, we found that C. butyricum CFS significantly suppressed the proteins and extracellular nucleic acids among the basic biofilm components. Furthermore, C. butyricum CFS significantly downregulated the expression of virulence- and efflux pump-related genes including ompA and bmeB3 in B. fragilis. Our findings suggest that C. butyricum can be used as biotherapeutic agent by inhibiting the growth and biofilm of ETBF.