• Korean Journal of Microbiology
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• v.55 no.1
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• pp.74-76
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• 2019

Gram-positive anaerobic bacilli Actinomyces spp. commonly reside on mucosal surfaces of the oropharynx, gastrointestinal tract, and urogenital tract. Here, we first report the draft genome sequence of Actinomyces georgiae KHUD_A1, isolated from dental plaque of a Korean elderly woman. The genome is 2,652,059 bp in length and has a GC content of 68.06%. The genome includes 2,242 protein-coding genes, 9 rRNAs, and 64 tRNA. We identified 157 KHUD_A1 strain-specific genes, including genes encoding CPBP family intramembrane metalloprotease, bile acid: sodium symporter family protein, Txe/YoeB family addiction module toxin and Phd/YefM family antitoxin. The sequence information of A. georgiae KHUD_A1 will help understand the general characteristics of the bacterial species and the genome diversity of the genus Actinomyces.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.343-349
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• 2019

Gul jeotgals (GJs) were prepared using solar salt aged for 3 years. One sample was fermented using starters, such as Bacillus subtilis JS2 and Tetragenococcus halophilus BS2-36 (each $10^6CFU/g$), and another sample was fermented without starters for 49 days at $10^{\circ}C$. Initial counts of bacilli and lactic acid bacteria (LAB) in non-starter GJ were found to be $3.20{\times}10^2$ and $7.67{\times}10^1CFU/g$ on day 0, and increased to $1.37{\times}10^3$ and $1.64{\times}10^6CFU/g$ on day 49. Those of starter GJ were found to be $2.10{\times}10^5$ and $3.30{\times}10^7CFU/g$ on day 49, indicating the growth of starters. The pH values of GJ were $5.93{\pm}0.01$ (non-starter) and $5.92{\pm}0.01$ (starter) on day 0 and decreased to $5.78{\pm}0.01$ (non-starter) and $5.75{\pm}0.01$ (starter) on day 49. Amino-type nitrogen (ANN) production increased continuously during fermentation, and $407.19{\pm}15.85$ (non-starter) and $398.04{\pm}13.73$ (starter) mg% on day 49. Clone libraries of 16S rRNA genes were constructed from total DNA extracted from non-starter GJ on days 7, 21, and 42. Nucleotide sequences of Escherichia coli transformants harboring recombinant pGEM-T easy plasmid containing 16S rRNA gene inserts from different bacterial species were analyzed using BLAST. Uncultured bacterium was the most dominant group and Gram - bacteria such as Acidovorax sp., Afipia sp., and Variovorax sp. were the second dominant group. Bacillus amyloliquefaciens (day 7), Bacillus velezensis (day 21 and 42), and Bacillus subtilis (day 42) were observed, but no lactic acid bacteria were detected. Acidovorax and Variovorax species might play some role in GJ fermentation. Further studies on these bacteria are necessary.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.171-176
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• 2019

A comparative study between commercially available mycobacteria growth indicator tubes (MGIT) in the BACTEC MGIT 960 System and the conventional Ogawa media was carried out to assess the effectiveness of the re-decontaminating process for the recovery of mycobacteria. Processed specimens with 5% sodium hydroxide and 0.5% N-acetyl-L-cysteine were inoculated into MGIT and Ogawa media. The acid fast bacilli (AFB) recovered from the cultures were identified using a mycobacterium tuberculosis (TB) antigen kit. If contaminants were observed in the MGIT tubes within five days, a decontaminating process was repeated. A total of 1,190 out of 4,790 (24.8%) specimens showed positive results using the BACTEC MGIT 960 system. Among them, 278 specimens were reprocessed. When the MGIT and Ogawa results were compared, it showed discordant results (weighted kappa value: 0.283). One TB and 10 nontuberculous mycobacteria (NTM) were newly detected in MGIT only. The likely benefit of the re-decontaminating process is the detection of additional mycobacteria that could not be detected without a re-decontaminating process despite being small in number. In addition to the combination of MGIT and Ogawa, the re-decontaminating process is recommended in the case of contaminations to recover mycobacteria.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.155-163
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• 2019

During the time period from 2010 to 2017, out of 162,551 blood specimens, 11,233 (6.9%) specimens were positive for culture and 11,865 strains were cultured. Among the isolates, 47.8% were Gram positive cocci, 38.8% were Gram negative rods, 4.2% were Gram positive bacilli, 6.8% were fungi and 2.3% were anaerobes. When the culture results were compared according to gender, 55.0% (2,732/4,969) of the isolates were found in males and 45.0% (2,237/4,969) were isolated in females. In addition, when categorized according to age group, people in their 70s were the most separated by 28.7% (1,426/4,969) and this showed a great difference from 1.2% (62/4,969) of people in their teens. MRSA decreased significantly from 66.7% in 2016 to 46.8% in 2017. The vancomycin resistance rate of E. faecium was 35.0% (48/137). The ESBL positive rate of E. coli in intestinal bacteria was increased from 17.2% in 2010 to 28.8% in 2017, but the positive rate decreased for K. pneumoniae. 11.8% (14/119) of multidrug-resistant P. aeruginosa (MDRPA) of P. aeruginosa and 64.3% (161/252) of MDRAB of A. baumannii showed high resistance. Because the microbial susceptibility and antimicrobial susceptibility patterns of the blood specimens isolated from all the blood specimens differ according to the time period, region and patients, periodic analyses of different pathogens and understanding the changes in the degree of susceptibility to antimicrobial susceptibility have been conducted in hospitals.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.335-341
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• 2020

This study investigates the association of the AFB stain with the cycle threshold (Ct) value of the Cobas TaqMan MTB test (CTM test, Roche Diagnostics, Basel, Switzerland), and it establishes the base data for semi-quantitative identification of M. tuberculosis by the Ct value. CTM test were simultaneously conducted on 8,389 specimens submitted to the Samsung Medical Center from January 2015 to December 2015, and the results were analyzed and compared retrospectively investigates the association of the AFB stain with the Ct value of the CTM test, and it establishes the base data for semi-quantitative identification of M. tuberculosis by the Ct value. The Ct values for 135 positive specimens of the CTM were inversely correlated with the AFB stain (rs=-0.545, P<0.01). When the Ct value of the CTM test and the time to positivity (TTP) of the mycobacteria cultures were verified based on the AFB stain, they were found to have a positive correlation (rs=0.136, P<0.01). The negative correlation between the CTM test and the AFB stain grade was demonstrated. The clinical significance was verified by applying these criteria to the clinical results. The semi-quantitative criteria of this study can be used to facilitate the rapid isolation of patients with active tuberculosis and infection control in the hospital.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• Tuberculosis and Respiratory Diseases
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• v.62 no.3
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• pp.184-191
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• 2007

Background: For the diagnosis of pleural tuberculosis, polymerase chain reaction (PCR) of pleural effusion specimens has shown very low sensitivity, which might be due to the small number of bacilli in the samples. The purpose of this investigation is to determine whether the sensitivity of PCR testing can be improved when increasing the amount of pleural effusion specimens. Methods: We prospectively analyzed pleural effusion specimens obtained from 53 patients for whom the exclusion of the possibility of tuberculous pleural effusion was necessary. We performed Mycobacterium tuberculosis PCR testing using the Cobas Amplicor MTB test (Roche Diagnostic Systems) with three different amounts (10ml, 25ml, and 50ml) of pleural effusion specimen in each patient. Pleural tuberculosis was defined as having one of the following: culture-positive pleural fluid sample, histopathologic finding consistent with tuberculosis on pleural biopsy, culture-positive sputum specimen, and/or positive response to anti-tuberculous medication without other possible causes of pleural effusion. Results: Of the 53 patients, 26 received the diagnosis of pleural tuberculosis. The sensitivities of AFB smearing, Mycobacterium tuberculosis culture of pleural effusion specimen, pleural biopsy, and measurement of ADA were 3.8%, 15.4%, 84.6%, and 88.5%, respectively. The results of PCR testing were positive for 3 (11.5%), 4 (15.4%), and 3 (11.5%) of the 26 patients when using 10ml, 25ml, and 50ml of pleural effusion specimens, respectively. These results did not show a statistically significant difference in the sensitivity of PCR testing when increasing the amount of pleural effusion samples (p>0.05, symmetry exact test). Conclusion: For specimens such as pleural effusion, in which the bacillary load is very low, the clinical utility of PCR testing seems highly limited with the kits designed for the diagnosis of pulmonary tuberculosis. An increased amount of pleural effusion sample does not improve the sensitivity of PCR testing.

• Tuberculosis and Respiratory Diseases
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• v.63 no.4
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• pp.331-336
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• 2007

Background: Although pulmonary tuberculosis (TB) is a respiratory disease, the presence of Mycobacterium tuberculosis (Mtb) DNA or Mtb itself has been reported in the peripheral blood (PB) of several patients with pulmonary TB. Additionally, it was recently announced that active pulmonary TB patients donated PB, and that this blood was then transfused to other individuals in Korea. Methods: Sixty-nine patients with bacteriologically-confirmed pulmonary TB (35), non-tuberculous mycobacterial (NTM) lung disease (6), and other lung diseases (28) were enrolled in this study, which was conducted to determine if Mtb DNA could be detected in the PB by PCR. In addition, 10 pulmonary TB patients with high-burden bacilli were also enrolled in this study for the culture of Mtb in PB. Results: PCR detected the presence of Mtb in 22.8% (8/35) of the pulmonary TB patients, in 16.7% (1/6) of the patients with NTM lung disease, and in none of the patients with other diseases (0%). In addition, no Mtb was cultured from the PB of the 10 pulmonary TB patients. Conclusion: Although Mtb DNA was detected in the PB of some patients with pulmonary TB, viable Mtb was not isolated from the PB of those patients, which indicates that patients that viable Mth may not be transmitted via trasfusion of blood of pulmonary TB patients.

• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.17-26
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• 2002

Background : The detection and early elimination of the causes for acute respiratory distress syndrome(ARDS) at the initial stage can result in a more favorable prognosis. Miliary tuberculosis as a cause of the ARDS is quite rare. A diagnosis of miliary tuberculosis is difficult due to the diversity of radiological patterns and non-specific clinical finfings, and low sensitivity of sputum examinations for acid-fast bacilli(AFBs). An analysis of the clinical data is the first step in diagnosing these unusual, rare cases. Materials and Methods : In this study the clinical features, laboratory data, radiological findings and diagnostic methods were analyzed in 9 cases with an initial presentation of ARDS due to miliary tuberculosis. The ARDS was defined by the definition of the American-Europian consensus conference 1992. Results : The mean age of the patients was $67{\pm}18$ years (F:M=7:2). The chief complaints were dyspnea(5/9), coughing (3/9) and fever(5/9). On a physical examination, fine or coarse crackles were noted(6/9). The ARDS developed on average 6.7 days after the initial respiratory symptoms. The mean $PaO_2/FiO_2$ of the patients was $133.5{\pm}53.4$, the number of cases with a WBC<5000/$mm^3$ was 4 out of 9 cases. A platelet count<70,000/$mm^3$ was observed in 2 out of 9 cases, and the serum albumin level was $2.6{\pm}0.6$ g/dL. The initial simple chest PA showed ground glass appearances and consolidation in all cases, However, the miliary nodular densities were observed in only 4 out of the 9 cases. HRCT revealed alveolar densities and a consolidation in 5 out of 6 cases, and miliary nodules in 5 out of 6 cases, The diagnosis of tuberculosis was made by a liver biopsy (4/4, 100% sensitivity), a bone marrow biopsy (1/2, 50% sensitivity), and an open lung biopsy (1/1), the sputum AFB was positive in only 2 out of 9 cases. The patient was treated with INH, RFP, EMB, PZA, and steroids. The survival rate was 55.5%. Conclusion : Miliary tuberculosis should be considered as one of the causes for ARDS in areas where there is a high prevalence of tuberculosis. The chief complaints of the patients on admission are dyspnea, fever and coughing without any specific riskfactors. A liver biopsy is particularly useful in ARDS patients with mechanical ventilation to determine the causes of the ARDS if miliary tuberculosis is suspected as being the underlying disease.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.485-494
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• 2004

Background : To assess the effects of mDOT implementation on sputum smear conversion for AFB (Acid fast bacilli) positive pulmonary tuberculosis patients, modified Directly Observed Treatment (mDOT) was started on October $8^{th}$ 2001 at a health center in Seoul. mDOT was defined through weekly interviewing and supervising of a patient by a supervisor (doctor, nurse, or lay health worker). The sputum smear conversion of a mDOT group was compared with that of a self-medication (self) group. Methods : This study included 52 AFB positive pulmonary tuberculosis patients registered at a health center in Seoul between October $8^{th}$ 2001 and April $23^{rd}$ 2002. 24 and 28 patients were enrolled in the mDOT and self medication groups, respectively. Paired (1:1) individual matching, by gender, extent of disease, relapse and age-matching variables, was performed between the two groups, resulting in 20 paired matches. This prospective study was planned as an unblinded, non-randomized quasiexperimental pilot project. Outcomes were identified from results of sputum smear examinations for AFB in both groups at 2 weeks, and 1 and 2 months. The paired matching data were analyzed using the SAS program version 8.1 by McNemar test. Results : At the end of 2 weeks of treatment, the sputum smear conversion of the mDOT group was somewhat higher than that of the self medication group (78.57 vs. 50%, p-value=0.289), and after 1 month of treatment no statistically significant difference was shown between the two groups (83.33 vs. 50, p-value=0.125). At the end of 2 months of treatment (initial intensive phase), the sputum smear conversions of the mDOT and self groups were 95 and 75%, respectively (p-value=0.219). Conclusions : The implementation of mDOT did not result in clinically significant increases in the sputum smear conversion at 2 weeks, and 1 and 2 months compared with that of the self medication group. However, the increases experienced might contribute to diminishing the infectious period of AFB positive patients, and this approach may act as a guide for a specific group of patients. In this study, mDOT was performed for one hundred percent of the intensive treatment phase. It can also be an effective treatment for pulmonary tuberculosis patients, and may be useful for some high risk tuberculosis patients.