• Korean Journal of Clinical Laboratory Science
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• v.40 no.1
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• pp.1-5
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• 2008

Thirty two of bathroom water samples from public bathroom in Seoul areas were examined using acid-fast staining, Lowenstein-Jensen (L-J) medium culture and PCR-restriction fragment length polymorphism (PCR-RFLP). In 6.25% (2/32) bathroom water samples, acid-fast bacilli were detected by AFB stain, and in 21.9% (7/32) bathroom water samples, acid fast bacilli grew on L-J media. Of them, six acid-fast bacilli were identified as Mycobacterium avium, and the other AFB as Mycobacterium szulgai by PCR-RFLP. These results are suggested that accidental nontuberculosis mycobacterial infection to a weakness person will be possible in public area.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.191-198
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• 2009

Phlegm smear testing for acid-fast bacilli (AFB) requires careful examination of tubercle bacilli under a microscope to distinguish between positive and negative findings. The biggest weakness of this method is the visual limitations of the examiners. It is also time-consuming, and mistakes may easily occur. This paper proposes a method of identifying tubercle bacilli that uses a computer instead of a human. To address the challenges of AFB testing, this study designs and investigates image systems that can be used to identify tubercle bacilli. The proposed system uses an electronic microscope to capture digital images that are then processed through feature extraction, image segmentation, image recognition, and neural networks to analyze tubercle bacilli. The proposed system can detect the amount of tubercle bacilli and find their locations. This paper analyzes 184 tubercle bacilli images. Fifty images are used to train the artificial neural network, and the rest are used for testing. The proposed system has a 95.6% successful identification rate, and only takes 0.8 seconds to identify an image.

• Biomedical Science Letters
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• v.6 no.1
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• pp.55-63
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• 2000

This study has been carried out to investigate the sensitivity of polymerase chain reaction (PCR) method over conventional acid-fast bacilli (AFB) staining and/culture methods for the detection of Mycobacterium tuberculosis from trace body fluid and paraffin-embedded tissues (PET) specimens. A total of 65 cases were employed for the AFB staining and culture test, and a total of 50 cases were subjected to PCR and histopathological analysis. Among the specimen showing negative reaction to AFB staining, 12.1% were positive to PCR and 3.7% of the specimen representing negative result to culture test showed positive reaction to PCR. In addition, 20.0% of the specimen with AFB negative showed positive reaction to PCR. From these results, it could be concluded that PCR method overwhelms AFB staining and culture tests in sensitivity and specificity to M tuberculosis detection.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.408-411
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• 2021

Tuberculosis (TB)-infected giant bullae are rare. A 55-year-old man was referred when an infected bulla did not respond to empirical treatment. Computed tomography showed a giant bulla in the right upper lobe with an air-fluid level and surrounding infiltrate. Sputum culture, acid-fast bacilli (AFB) stain, and polymerase chain reaction (PCR) for TB were negative. Percutaneous drainage of the bullous fluid was performed. AFB stain and PCR were positive in the drained fluid. The patient was given anti-TB drugs and later underwent obliteration of the pulmonary cavity using talc. To summarize, we report a patient with a TB-infected giant bulla that was treated successfully with anti-TB drugs and obliteration of the pulmonary cavity using talc.

• Tuberculosis and Respiratory Diseases
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• v.74 no.5
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• pp.215-221
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• 2013

Background: Nontuberculous mycobacteria (NTM) are considered opportunistic pathogens, and several species of NTM are associated with human diseases that typically involve the pulmonary, skin/soft tissue, or lymphatic systems; such infection may also cause disseminated diseases. Recent studies have reported increasing rates of NTM-induced disease worldwide. Methods: Respiratory samples are being analyzed for acid-fast bacilli (AFB) culture and NTM identification at Dankook University Hospital in Cheonan, Korea, from September 2005 to September 2011. Identification is performed by using polymerase chain reaction-restriction fragment length polymorphism analysis targeting a novel region of the rpoB gene. Results: A total of 25,133 specimens were received for AFB culture, of which 1,014 (4.0%) were NTM-positive. A total of 267 samples from 186 patients were tested for NTM identifications, and 232 samples from 157 patients were positive for NTM species. Among the patients who tested positive for NTM, 65.6% were men and the average age was 63.3 years. Mycobacterium avium complex, the most commonly detected NTM pathogen, was found in 65.9% of the 232 samples. The annual average percentage of NTM isolates from AFB culture-positive specimens was 31.3%: the highest rate was seen in 2011 (44.3%), followed by 2009 (37.4%) and 2010 (37.2%). An upward trend in NTM incidence was found during the study period. Conclusion: The prevalence of pulmonary NTM isolates continues to increase in Cheonan, suggesting that pulmonary NTM disease is becoming increasingly common.

• Biomedical Science Letters
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• v.22 no.1
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• pp.24-28
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• 2016

Tuberculosis (TB) remains an unsolved community health problem since identification of its causing microorganism called Mycobacterium tuberculosis (MTB) by Robert Koch in 1882. Annually, eight million TB cases are newly reported and 2~3 million patients die from TB. Pulmonary TB is highly infectious and untreated pulmonary TB patients are believed to infect >10 people in a year. The conventional methods for diagnosis of TB are chest X-ray and isolation of the causing microorganisms from patient specimens. Screening of TB is conducted with smeared sputum in slides, and TB is confirmed by identification of MTB in cultured specimens. One of the fatal pitfalls of screening detection for smeared sputum is that it is impossible to distinguish MTB and other acid-fast bacilli (AFB) because they are stained equally with Ziehl-Neelsen (ZN) stain. Culture of MTB is the most reliable method for diagnosis of TB but it takes 4~8 weeks. In this report, we suggest a fast and highly-reliable MTB detection method that distinguishes AFB in sputum samples. Purified DNA from the AFB stained slide samples offered by The Korean Institute of Tuberculosis were used to detect infected MTB in patients. PCR, real-time PCR and reverse blot hybridization assay (REBA) methods were applied to purified DNA. Conclusively, the real-time PCR method was confirmed to produce high sensitivity and we were able to further detect drug-resistant MTB with REBA.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.385-391
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• 2005

Background : The incidence of nontuberculous mycobacterium (NTM) infections in Korea is increasing. This retrospective study was performed to examine the recovery rate of NTM from respiratory specimens as well as the isolated NTM colony characteristics, and to assess the clinical significance of a NTM isolation. Methods : The results of the respiratory specimens requested for an acid-fast bacilli (AFB) examination during 2002 at Asan Medical Center, along with the patients clinical characteristics were analyzed. Results : A total 26,820 respiratory specimens were requested for the acid-fast bacilli (AFB) smear and culture during the study period. The proportion of M. tuberculosis and NTM isolation was 5.7% and 2.2%, respectively. Among the AFB smear and culture positive specimens, 12.2% were found to be NTM. The scotochromogen showing a low colony count < 20, which appeared to be contaminants, were isolated in 31.8% of the 584 NTM isolates. Excluding the low-colony scotochromogens, the M. avium-intracellulare complex was the most common NTM isolates (42.1%), and was also the most common causative organism for NTM pulmonary diseases. 8.4% (23/275) and 17.8% (49/275) of patients with NTM isolates met the American and British Thoracic Society diagnostic criteria for NTM pulmonary disease, respectively. Conclusion : In case of a positive AFB-smear or culture result, the possibility of NTM being a causative organism should always be considered, even in Korea, which has an intermediate incidence of tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.79 no.3
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• pp.153-157
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• 2016

Background: Vitamin D is known to have diverse effects on various systems in the body. There is evidence to suggest that a link exists between the serum vitamin D status and tuberculosis. The present study was designed to assess the alterations in serum 25-hydroxyvitamin D levels in newly diagnosed sputum acid fast bacilli (AFB) positive pulmonary tuberculosis patients and to study the association, if any, between serum vitamin D levels and different levels of sputum smear positivity. Methods: Serum 25-hydroxyvitamin D levels were estimated in 65 sputum AFB positive pulmonary tuberculosis patients and 65 age and gender-matched healthy controls. Results: The levels of serum 25 hydroxy-vitamin D in tuberculosis patients were not statistically different from the levels of serum 25 hydroxy-vitamin D in healthy controls. However, among patients with pulmonary tuberculosis, there was a significant negative correlation between the levels of serum 25 hydroxy-vitamin D and levels of sputum positivity. Conclusion: Serum vitamin D levels negatively correlates with bacterial load in patients with active pulmonary tuberculosis.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.83-89
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• 2015

Although Mycobacterium tuberculosis complex strains remain responsible for the majority of diseases caused by mycobacterial infections worldwide, the increase in HIV (human immuno deficiency virus) infections has allowed for the emergence of other non-tuberculous mycobacteria as clinically significant pathogens. M. tuberculosis was detected by two-tube nested polymerase chain reaction (PCR) and non-tuberculous mycobacteria was detected by PCR-restriction fragment length polymorphism (RFLP) with Msp I. Result of niacin test is equal to result of two-tube nested PCR after culture for M. tuberculosis. In this study, acid fast bacilli stain (AFB. stain) >2+ case, Detection of Mycobacteria is similar to result before culture and after culture. AFB. stain <1+ case, result of mycobacteria is distinguished. Conclusionly, these results suggest that identification of mycobacteria must go side by side both culture and PCR for more fast and accuracy.

• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.181-188
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• 1992

The incidence of the cutaneous tuberculosis has shown a steady decline over the past decades. This parallels the decreasing incidence of pulmonary tuberculosis. We experienced 5 cases of cutaneous tuberculosis from January 1990 to February 1991. We present herin 4 cases of cutaneous tuberculosis. They were 3 cases of vulgaris and 1 case of tuberculosis verrucosa cutis. Mantoux tests were done except one case and were reactive in all cases. Culture for Mycobactelium tuberculosis were done but Mycobacterium tuberculosis were not cultivated in the all cases. Histopathological findings showed tuberculoid granulomas in the dermis except one case and no acid fast bacilli were demonstrated on AFB stains.