• Journal of Microbiology
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• v.45 no.1
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• pp.69-74
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• 2007

Escherichia coli is a clonal species, and occurs as both commensal and pathogenic strains, which are normally classified on the basis of their O, H, and K antigens. The O-antigen (O-specific polysaccharide), which consists of a series of oligosaccharide (O-unit) repeats, contributes major antigenic variability to the cell surface. The O-antigen gene cluster of E. coli O66 was sequenced in this study. The genes putatively responsible for the biosynthesis of dTDP-6-deoxy-L-talose and GDP-mannose, as well as those responsible for the transfer of sugars and for O-unit processing were identified based on their homology. The function of the wzy gene was confirmed by the results of a mutation test. Genes specific for E. coli O66 were identified via PCR screening against representatives of 186 E. coli and Shigella O type strains. The comparison of intergenic sequences located between galF and the O-antigen gene cluster in a range of E. coli and Shigella showed that this region may perform an important function in the homologous recombination of the O-antigen gene clusters.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1599-1608
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• 2024

Yersinia enterocolitica is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of Y. enterocolitica, allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined. In addition to the O-antigen, several virulence factors are involved in infection and pathogenesis of Y. enterocolitica strains, and these are closely related to their biotypes, reflecting pathogenic properties. In this study, we identified the O-AGC of a Y. enterocolitica strain WL-21 of serotype O:10, and confirmed its functionality in O-antigen synthesis. Furthermore, we analyzed in silico the putative O-AGCs of uncommon serotypes, and found that the O-AGCs of Y. enterocolitica were divided into two genetic patterns: (1) O-AGC within the hemH-gsk locus, possibly synthesizing the O-antigen via the Wzx/Wzy dependent pathway, and (2) O-AGC within the dcuC-galU-galF locus, very likely assembling the O-antigen via the ABC transporter dependent pathway. By screening the virulence genes against genomes from GenBank, we discovered that strains representing different serotypes were grouped according to different virulence gene profiles, indicating strong links between serotypes and virulence markers and implying an interaction between them and the synergistic effect in pathogenicity. Our study provides a framework for further research on the origin and evolution of O-AGCs from Y. enterocolitica, as well as on differences in virulent mechanisms among distinct serotypes.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.416-419
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• 1998

Identification of escherchia coli K1 polysaccharide antigen isolated from urine specimens of urinary tract infections in children were performed from of 1992 to 1993 in Kyoto, Japan. The serotypes of E. coli were categorized that O1:H7, O2:H6, O2:H7, O16:H6, O18:H7, O18:H￣, and O135:H44 among 14 strains isolated from urine specimens of urinary tract infections in children by the serological test. And, one strain (O18:H￣, isolation rate: 7.1%) of E. coli K1 polysaccharide antigen among 14 strains were isolated from urine specimens of urinary tract infections in children by the bacteriophage test.

• The Journal of the Korean Society for Microbiology
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• v.22 no.4
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• pp.445-451
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• 1987

Coagglutination method is widely used for the diagnosis of Salmonella infection. This test, however, has a disadvantage of false positive reaction due to the coagglutination of staphylococci with non-specific immune complexes or anti-staphylococci antibody in serum. Salmonell O antigen was detected by enzyme immunoassay with protein A-bearing Staphylococcus aureus as in the solid phase. Horse radish peroxidase was labeled to IgG specific against Salmonella O antigen. This enzyme immunoassay was much more sensitive than conventional coagglutination method without false poitive agglutination. To improve the sensitivity for detection of Salmonella O antigen in samples, we tried to determine the optimal concentration of normal IgG that inhibits non-specific binding of horse radish peroxidase labeled IgG to staphylococci, and to establish the optimal condition of reaction between antigen-antibody complex and staphylococci. Non-specific binding of horse radish peroxidase labeled specific IgG to staphylococci was almost blocked when the enzyme labeled IgG was 500-fold diluted with phosphate buffered saline containing 2mg/ml of normal IgG. When staphylococci coated with antibody to Salmonella O antigen were mixed with antigen-antibody complex and then incubated for 1 hour at room temperature, the minimal detectable concentration of Salmonella O antigen was 1ng/ml. The sensitivity of enzyme immunoassay was 100-fold greater than a conventional coagglutination method. This enzyme immunoassay could be expected as an improved method for detection of other infectious agents.

• Journal of Powder Materials
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• v.16 no.3
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• pp.180-184
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• 2009

In this paper, the electrochemical non-enzyme immunosensor has been developed for the determination of salmonella antigen, using inverse voltammetry. For the estimation of salmonella antigen concentration, the $Fe_3O_4$ nanoparticles synthesized by microemulsion method were conjugated with salmonella antigen. Then, the immunocomplex between antibody immobilized on the transducer surface and antigen containing a magnetic nanoparticles was formed. From the linear relationship between the reduction peak current of Fe(III) and salmonella antigen concentration, it is suggested that the electrochemical non-enzyme biosensor is applicable to detect salmonella antigen in the concentration range of $10^1-10^5$ CFU/ml.

• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.79-89
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• 1985

It is important to discriminate between tuberculosis and tuberculosis-like disease by Mycobacteria other than tuberculosis in the serodiagnosis of tuberculosis. But because common antigens share among Mycobacteria, their antigenicities to human are similar. Therefore degree of cross-reactivity of antibody in the sera of patients with tuberculosis between M. tuberculosis and Mycobacteria other than tuberculosis should be checked to increase the specificity in the serodiagnosis of tuberculosis. The activity levels of IgG antibody in the sera of 106 patients confirmed as active pulmonary tuberculosis and 30 normal healthy control person to the pressate extract antigen (TE, BE, AE, and FE antigen) from M. tuberculosis, M. bovis, M. avium, and M. fortuitum were measured by enzyme-linked immunosorbent assay and the crossreactivity of IgG antibody with mycobacterial species was analysed. The results were as follows; 1. The activity level(O.D. at 492nm) of IgG to TE antigen in sera of patients with pulmonary tuberculosis was $0.228{\pm}0.167$ in minimal tuberculosis; moderately advanced, $0.556{\pm}0.616$; far advanced, $1.116{\pm}0.651$ and $0.315{\pm}0.245$ in miliary tuberculosis. 2. The activity level (O.D. at 492nm) of IgG to BE antigen in sera of patients with pulmonary tuberculosis was $0.190{\pm}0.162$ in minimal tuberculosis; moderately advanced, $0.337{\pm}0.361$; far advanced, $0.713[\pm}0.460$ and $0.204{\pm}0.162$ in miliary tuberculosis. 3. The activity level (O.D. at 492nm) of IgG to AE antigen in sera of patients with pulmonary tuberculosis was $0.165{\pm}0.114$ in minimal tuberculosis; moderately advanced, $0.392{\pm}0.494$; far advenced, $0.751{\pm}0.512$ and $0.233{\pm}0.191$ in miliary tuberculosis. 4. The activity level (O.D. at 492nm) of IgG to FE antigen in sera of patients with pulmonary tuberculosis was $0.280{\pm}0.227$ in minimal tuberculosis; moderately advanced, $0.460{\pm}0.564$ ; far advanced, $0.845{\pm}0.573$ and $0.257{\pm}0.103$ in miliary tuberculosis. 5. The activity level (O.D. at 492nm) of IgG in sera of healthy control person was $0.126{\pm}0.084$ to TE antigen. $0.105{\pm}0.041$ to BE antigen, $0.103{\pm}0.052$ to AE antigen, and $0.095{\pm}0.061$ to FE antigen. 6. Degree of correlation(r) in activity level of IgG between TE antigen and BE antigen was 0.905 ; between TE antigen and AE antigen, 0.760; between TE antigen and FE antigen, 0.790, and between AE antigen and FE antigen, 0.945. 7. As O.D. above 0.200 was determined positive for the serodiagnosis of pulmonary tuberculosis, the sensitivity and specificity in ELISA using TE antigen were 80% and 87% respectively, whereas in the case of using BE antigen, 66% and 100%; in the case of using AE antigen, 62% and 100%, and in the case of using FE antigen, 72% and 93%, respecitively.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.520-528
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• 2021

Plesiomonas shigelloides, a member of the family Vibrionaceae, is a gram-negative, rod-shaped, facultative anaerobic bacterium with flagella. P. shigelloides has been isolated from such sources as freshwater, surface water, and many wild and domestic animals. P. shigelloides contains 102 O-antigens and 51 H-antigens. The diversity of O-antigen gene clusters is relatively poorly understood. In addition to O1 and O17 reported by other laboratories, and the 12 O serogroups (O2, O10, O12, O23, O25, O26, O32, O33, O34, O66, O75, and O76) reported previously by us, in the present study, nine new P. shigelloides serogroups (O8, O17, O18, O37, O38, O39, O44, O45, and O61) were sequenced and annotated. The genes for the O-antigens of these nine groups are clustered together in the chromosome between rep and aqpZ. Only O38 possesses the wzm and wzt genes for the synthesis and translocation of O-antigens via the ATP-binding cassette (ABC) transporter pathway; the other eight use the Wzx/Wzy pathway. Phylogenetic analysis using wzx and wzy showed that both genes are diversified. Among the nine new P. shigelloides serogroups, eight use wzx/wzy genes as targets. In addition, we developed an O-antigen-specific PCR assay to detect these nine distinct serogroups with no cross reactions among them.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2447-2451
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• 2013

Objective: To study changes of tumor associated carbohydrate antigen (TACAs) expression and mRNA levels for tumor associated glycosyltransferases, and assess subcellular localizations of N-acetyl galactosyltransferases (GalNAc-Ts) in the K562 leukemia cell line after imatinib treatment. Methods: RT-PCR was performed to analyze the expression of glycosyltransferases which synthesize O-glycan in tumor-associated carbohydrate antigens (TCTAs). The expression of Tn antigen, T antigen and sialyl T antigen on K562 cell membranes was measured by flow cytometry after treatment with different concentrations of imatinib. Co-localization of GalNAc-Ts and ER (endoplasmic reticulum) was determined by confocal laser scanning microcopy. Results: Transcript expression levels of several glycosyltransferases related to TCTAs were decreased after imatinib ($0-0.3{\mu}M$) treatment. Expression of Tn antigen and T antigen was increased while that of sialyl T antigen was decreased. Co-localization of GalNAc-Ts and ER was reduced by $0.2{\mu}M$ of imatinib. Conclusion: Imatinib inhibited the expression of O-glycan related TACAs and several related glycosyltransferases, while decreasing the co-localization of GalNAc-Ts and ER and normalizing O-glycosylation in the K562 human leukemia cell.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1191-1199
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• 2021

Enteropathogenic Escherichia coli (EPEC), which belongs to the attaching and effacing diarrheagenic E. coli strains, is a major causative agent of life-threatening diarrhea in infants in developing countries. Most EPEC isolates correspond to certain O serotypes; however, many strains are non-typeable. Two EPEC strains, EPEC001 and EPEC080, which could not be serotyped during routine detection, were isolated. In this study, we conducted an in-depth characterization of their putative O-antigen gene clusters (O-AGCs) and also performed constructed mutagenesis of the O-AGCs for functional analysis of O-antigen (OAg) synthesis. Sequence analysis revealed that the occurrence of O-AGCs in EPEC001 and E. coli O132 may be mediated by recombination between them, and EPEC080 and E. coli O2/O50 might acquire each O-AGC from uncommon ancestors. We also indicated that OAg-knockout bacteria were highly adhesive in vitro, except for the EPEC001 wzy derivative, whose adherent capability was less than that of its wild-type strain, providing direct evidence that OAg plays a key role in EPEC pathogenesis. Together, we identified two EPEC O serotypes in silico and experimentally, and we also studied the adherent capabilities of their OAgs, which highlighted the fundamental and pathogenic role of OAg in EPEC.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.130-137
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• 2000

In order to diagnose canine heartworm infection by antigen capture ELISA, the crude somatic(S), partial somatic(below 45kDa) and excretory/secretory(E/S) antigen of adult heartworm were identified and the antigenicity was examined by silver stain, immunoblot and ELISA. Then, production of monoclonal antibody to specific antigen carried out in this experiment. The bands to S antigen and E/S antigen were recognized between 10 and 200kDa and common bands were recognized strongly 14, 18, 28, 43kDa by silver stain. By western blot analysis, fractions to S antigen were recognized 14, 16, 18, 20, 24, 28, 32, 43, 50, 55kDa, etc. and only a 14kDa to E/S antigen in positive sera which were positive in modified Knott's test and necropsy. In ELISA, the positive sera reacted to antigens(SA, $SA_{45}$, E/S) were significantly different from negative sera by Student's t-test(p<0.05). Four hybridoma cell lines(14, 16, 17, 32kDa) than produce specific monoclonal antibodies for these antigens were obtained by immunizing BALB/c mice with a partially purified somatic antigen (below 45kDa) preparation, by fusing spleen cells with SP2/O cell myeloma cells, and by screening cell culture supernatants for antibody. In these results, it was confirmed that partial somatic antigen(below 45kDa) or E/S antigen can be used for serologic diagnosis of heartworm infection and monoclonal antibody reacting with specific antigen(14kDa) can be used for antigen capture ELISA in prepatent period of canine heartworm infection.