• Tuberculosis and Respiratory Diseases
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• v.76 no.2
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• pp.59-65
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• 2014

Background: Variable-number tandem repeat (VNTR) typing is a promising method to discriminate the Mycobacterium tuberculosis isolates in molecular epidemiology. The purpose of this study is to determine the optimal VNTR combinations for discriminating isolated M. tuberculosis strains in Korea. Methods: A total of 317 clinical isolates collected throughout Korea were genotyped by using the IS6110 restriction fragment length polymorphism (RFLP), and then analysed for the number of VNTR copies from 32 VNTR loci. Results: The results of discriminatory power according to diverse combinations were as follows: 25 clusters in 83 strains were yielded from the internationally standardized 15 VNTR loci (Hunter-Gaston discriminatory index [HGDI], 0.9958), 25 clusters in 65 strains by using IS6110 RFLP (HGDI, 0.9977), 14 clusters in 32 strains in 12 hyper-variable VNTR loci (HGDI, 0.9995), 6 clusters in 13 strains in 32 VNTR loci (HDGI, 0.9998), and 7 clusters in 14 strains of both the 12 hyper-variable VNTR and IS6110 RFLP (HDGI, 0.9999). Conclusion: The combination of 12 hyper-variable VNTR typing can be an effective tool for genotyping Korean M. tuberculosis isolates where the Beijing strains are predominant.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.1
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• pp.49-53
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• 2015

MRA1997 is a 76-residue conserved hypothetical protein of Mycobacterium tuberculosis H37Ra, one of the most pathogenic bacterial species and the causative agent of tuberculosis. In this study, the sequence-specific backbone resonance assignment of MRA1997 was performed using NMR spectroscopy. Approximately 88.3% of the total resonances could be unambiguously assigned. By analyzing deviations of the $C{\alpha}$ and $C{\beta}$ chemical shift values, the secondary structure of MRA1997 was calculated. The result revealed that secondary structure of MRA 1997 consists of one ${\alpha}$-helix and five ${\beta}$-sheets. Our structural study will be a footstone towards the characterization of the three-dimensional structure of MRA1997.

• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.227-230
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• 2016

Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne's disease (JD) in ruminants. This is the first large scale report to estimate the herd-level prevalence of antibodies against MAP by using an ELISA to detect antibodies in bulk tank milk (BTM) samples. The samples were collected from January 2011 to November 2011, from 636 herds of the dairy farms in the Gyeonggi and Chungbuk areas of Korea. The overall apparent prevalence of MAP antibody-positive herds was 8.5%, and regional prevalence were 32/440 (7.3%) and 22/196 (11.2%) of dairy farms in the Gyeonggi and Chungbuk areas, respectively. The results did not differ significantly by region. While we have determined the prevalence rate of MAP in the Gyenoggi and Chungbuk areas in this study, there is a continuing need for well-designed studies to calculate the prevalence of MAP in dairy herds based on culture and molecular findings.

• Annals of Geriatric Medicine and Research
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• v.22 no.4
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• pp.204-207
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• 2018

Mycobacterium abscessus comprises rapidly growing mycobacteria, and the clinical manifestations of M. abscessus skin infection include papule, nodule, ulcer, scar and mixed form. The cutaneous infections have been reported due to minor trauma, cosmetic therapy, acupuncture and disseminated infection. A 75-year-old man presented with pruritic diffuse various sized erythematous papuloplaques and pustules on the neck and chest for 2 months. The cutaneous lesions were spread around the wound of the shaving on the neck. The histopathologic findings were consistent with abscess showing infiltrations of neutrophils and lymphocytes in the dermis and negative findings were observed on immunohistochemical stain including acid-fast bacilli stain. One month later, mycobacterial culture result showed positive findings, and the pathogen was identified by reversetranscriptase polymerase chain reaction with hybridization. The patient was treated with combination of clarithromycin and ethambutol for 5 months and there is no evidence of recurrence after 6 months of follow-up. Herein, we report a case of M. abscessus cutaneous infection through minor trauma caused by shaving in the elderly.

• Korean Journal of Veterinary Service
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• v.41 no.4
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• pp.239-244
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• 2018

Mycobacterium tuberculosis (M. tuberculosis) complex is the causative agent of tuberculosis (TB) in humans and bovine TB in mammalian hosts and grows very slowly. Selenium is a central molecule in nitrogen metabolism and an essential ingredient for all living cells and glutamic acid. The effects of selenium on the growth of M. tuberculosis, a representative slow-growing Mycobacterium species, were investigated and measured using the BacT Alert 3D System (MB/BacT System). Sodium selenate, at a final concentration of $10{\mu}g/mL$, reduced the average time-to detection (TTD) to 197.2 hours (95% confidence interval (CI), 179.6~214.8) from 225.1 hours (95% CI, 218~232.0) in the control culture media (P<0.05). The TTD did not increase with $\text\tiny{L}$-glutamate concentrations up to $10{\mu}g/mL$, but a significant reduction in the TTD was observed in the presence of $20{\mu}g/mL$ ${\text\tiny{L}}$-glutamate in culture media (P<0.05). In conclusion, selenate and ${\text\tiny{L}}$-glutamate enhance the growth of M. tuberculosis.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1221-1229
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• 2019

Mycobacterium tuberculosis, a causative pathogen of tuberculosis (TB), still threatens human health worldwide. To find a novel drug to eradicate this pathogen, we tested taurine-5-bromosalicylaldehyde Schiff base (TBSSB) as an innovative anti-mycobacterial drug using Mycobacterium smegmatis as a surrogate model for M. tuberculosis. We investigated the antimicrobial activity of TBSSB against M. smegmatis by plotting growth curves, examined the effect of TBSSB on biofilm formation, observed morphological changes by scanning electron microscopy and transmission electron microscopy, and detected differentially expressed proteins using two-dimensional gel electrophoresis coupled with mass spectrometry. TBSSB inhibited mycobacterial growth and biofilm formation, altered cell ultrastructure and intracellular content, and inhibited cell division. Furthermore, M. smegmatis adapted itself to TBSSB inhibition by regulating the metabolic pathways and enzymatic activities of the identified proteins. NDMA-dependent methanol dehydrogenase, NAD(P)H nitroreductase, and amidohydrolase AmiB1 appear to be pivotal factors to regulate the M. smegmatis survival under TBSSB. Our dataset reinforced the idea that Schiff base-taurine compounds have the potential to be developed as novel anti-mycobacterial drugs.

• Korean Journal of Veterinary Service
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• v.44 no.2
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• pp.119-124
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• 2021

The report describes an avian mycobacteriosis in a captive wild bird. A 7-year-old female Indian peafowl (Pavo cristatus) maintained in a zoo of Korea presented a gradual cachexia and eventually was found dead. At necropsy, severely atrophied pectoral muscles exposing the keel bone were noticed. Yellowish thick nodules in varying sizes were scattered in all lobes of lungs, liver and spleen, suggesting mycobacteriosis. Histopathologically, multifocal to coalescing granulomas surrounded by multinucleated giant cells were observed. Numbers of acid-fast bacilli were revealed in granulomas. Then, a series of molecular diagnostic techniques were followed: a nested PCR, DNA sequencing and bioinformatics analysis. It resulted as Mycobacterium genavense. The identification of M. genavense as an etiological agent suggested that it might serve as a risk factor for other captive wild animals, and for a potential zoonotic risk since M. genavense have been a definite cause of disseminated mycobacterial infection in immunocompromised people. To the authors' knowledge, this is the first report of avian mycobacteriosis with M. genavense in a captive Indian peafowl.

• Journal of Life Science
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• v.28 no.3
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• pp.351-356
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• 2018

L-Serine dehydratase (LSD) is an iron-sulfur containing enzyme that catalyzes the conversion of L-serine to pyruvate and ammonia. Among the bacterial amino acid dehydratases, it appears that only the L-serine specific enzymes utilize an iron-sulfur cluster at their catalytic site. Moreover, bacterial LSDs are classified into four types based on structural characteristics and domain arrangement. To date, only the LSD enzymes from a few bacterial strains have been studied, but more detailed investigations are required to understand the catalytic mechanism of various bacterial LSDs. In this study, LSD type II from Mycobacterium tuberculosis (MtLSD) H37Rv was expressed and purified to elucidate the biochemical and catalytic properties using the enzyme kinetic method. The L-serine saturation curve of MtLSD exhibited a typically sigmoid character, indicating an allosteric cooperativity. The values of $K_m$ and $k_{cat}$ were estimated to be $59.35{\pm}1.23mM$ and $18.12{\pm}0.20s^{-1}$, respectively. Moreover, the plot of initial velocity versus D-serine concentration at fixed L-serine concentrations showed a non-linear hyperbola decay shape and exhibited a competitive inhibition for D-serine with an apparent $K_i$ value of $30.46{\pm}5.93mM$ and with no change in the $k_{cat}$ value. These results provide insightful biochemical information regarding the catalytic properties and the substrate specificity of MtLSD.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.283-289
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• 1989

In order to measure in vitro cell mediated immunity in the guinea pigs sensitized with the killed bacilli of Mycobacterium bovis ($AN_5$), M avium (serotype 2), M tuberculosis and M intracellulare (serotype 8), leukocyte adherence inhibition (LAI) test was established using the antigens of purified protein derivatives (PPD) tuberculin. By using LAI test, specificity of cell-mediated immune responses of the guinea pigs inoculated with various Mycobacterium spp was investigated, and comparison between values of LAI and skin test was also made to evaluate the specificity of the newly designed test. The results obtained throughout the experiments were summarized as follows; 1. The optimal concentration of PPD antigens for LAI test was 1 to 2mg per ml of medium. 2. When the leukocytes of guinea pigs sensitized with both M bovis($AN_5$) and M avium (serotype 2) for 2 to 8 weeks were incubated with homologous or heterologous PPD antigens, mean values of LAI test were $61.2{\pm}11.2$ and $65.6{\pm}5.1%$ in homologous PPD antigens respectively, while $30.0{\pm}3.7$ and $32.8{\pm}5.7%$ in heteNlogous PPD antigens, showing the prominently high value of LAI in the homologous syst,em (p<0.01). 3. When the leukocytes of guinea pigs sensitized with both M tuberculosis and M intracellulare (serotype 8) for 2 to 8 weeks were incubated with homologous and heterologous PPD antigens, mean values of LAI test were $67.9{\pm}2.9$ and $66.9{\pm}5.0%$ in homologous PPD antigens, while $27.4{\pm}7.4$ and $24.4{\pm}7.1%$ in heterologous PPD antigens, showing the prominently high value of LAI in the homologous system (p<0.01). 4. Comparing with the specificity of LAI and skin tests on the basis of the value obtained from the homologous system, deviation of reaction was revealed to be 49.5 to 100.2 in LAI test, and -15.9 to 52.0 in skin test.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.219-223
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• 2015

Mycobacterium avium subsp. paratuberculosis (MAP) causes paratuberculosis or Johne's disease, an intestinal granulomatous infection in domestic and wild animals. The study aimed to develop and evaluate a panel of multiplex quantitative real-time polymerase chain reaction (mqPCR) assay for simultaneous detection of three MAP-specific genes (IS900, F57 and ISMAP02 genes). The analytic sensitivity (i.e., limit of detection, expressed as cells per 1 ml) was 150 for IS900, 1500 for F57, and 50 for ISMAP02. The specificity of the method was determined by testing 152 bovine fecal samples. Based on the test, it showed that the assay simultaneously detected the target genes in short period of time and at lower cost compared to laboratory routine tests. The test agreement between the assay and routine test was 94%. The discrepancy in the results was due to samples that were tested positive by the panel but negative by the routine tests, suggesting that the assay has higher sensitivity than the routine tests. In conclusion, the mqPCR assay could be a rapid and accurate testing tool for investigating paratuberculosis or Johne's disease cases in domestic and wild animals.