• 대한임상검사과학회지
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• 제46권2호
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• pp.47-53
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• 2014

The purpose of this study was to evaluate the clinical utility of TB/NTM PCR by comparing the results of TB PCR to detect Mycobacterium tuberculous (MTB) and nontuberculous mycobacteria (NTM) from paraffin-embedded tissue specimens. A total of 60 cases were tested using TB PCR and TB/NTM PCR. The MTB and NTM rate of TB/NTM PCR was 84.2% (16/19), 10.5% (2/19) in TB positive of TB PCR. The NTM rate of TB/NTM PCR was 29.3% (12/41) in TB negative of TB PCR. Fourteen different species of NTM were identified, the common isolate was M. gordonae (21.4%), M. avium (14.3%), M. ulcerans (7.1%), M. interjectum (7.1%), M. gilvum (7.1%), M. fortuitum (7.1%), M. mucogenicum (7.1%). The rare species identified were M. farcinogenes (7.1%), M. tokaiense (7.1%). Therefore, TB/NTM PCR is useful to differentiate MTB and NTM from paraffin-embedded tissue specimens and it is more effective in detecting NTM with TB PCR.

• Tuberculosis and Respiratory Diseases
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• 제69권4호
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• pp.250-255
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• 2010

Background: The purpose of this study was to evaluate recently developed real-time polymerase chain reaction (PCR) assay kit to detect Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) in respiratory specimens. Methods: We assessed the positive rate of the real-time PCR assay to detect MTB and NTM in 87 culture-positive specimens (37 sputum, 50 bronchial washing), which were performed real-time PCR by using $Real-Q_{TM}$ MTB&NTM Kit from January 2009 to June 2009, at Gyeongsang University Hospital. To compare the efficacy with the TB-PCR assay, we evaluated 63 culture-positive specimens (19 sputum, 44 bronchial washing) for MTB or NTM, which were performed TB-PCR by using ABSOLUTETM MTB II PCR Kit from March 2008 to August 2008. Results: Among 87 specimens tested using real-time PCR, MTB and NTM were cultured in 58 and 29, respectively. The positive rate of real-time PCR assay to detect MTB was 71% (22/31) and 92.6% (25/27) in AFB stain-negative and stain-positive specimens. For NTM, the positive rate of real-time PCR was 11.1% (2/18) and 72.7% (8/11) in AFB stain-negative and stain-positive specimens. Among 63 specimens performed using TB-PCR, MTB and NTM were cultured in 46 and 17, respectively. The positive rate of TB-PCR was 61.7% (21/34) and 100% (12/12) in AFB stain-negative and stain-positive specimens. TB-PCR was negative in all NTM-cultured 17 specimens. Conclusion: TB/NTM real-time PCR assay is useful to differentiate MTB and NTM in AFB stain-positive respiratory specimens and it is as effective in detecting MTB with TB-PCR.

• Tuberculosis and Respiratory Diseases
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• 제57권6호
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• pp.528-534
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• 2004

배 경 : 객담 항산균 도말 검사는 저렴하고 간편한 검사이며, 검사 결과를 빨리 얻을 수 있다는 장점이 있지만, 결핵균과 NTM을 구별하지 못한다는 제한점이 있다. 외국에서는 도말 양성 환자에서 폐결핵과 NTM 폐질환을 구별하기 위하여 TB-PCR 검사가 권장되고 있다. 본 연구는 국내에서도 객담 도말 양성 환자에서 객담 또는 기관지 세척액의 TB-PCR 검사가 폐결핵과 NTM 감염의 감별 진단에 유용한가를 알아보고자 하였다. 대상 및 방법 : 2003년 1월 1일부터 2003년 12월 31일까지 1년간 진단검사의학과 임상미생물검사실로 항산균 도말 및 배양검사가 의뢰된 객담 검체 중 도말과 배양이 모두 양성인 826건의 객담 검체를 연구대상으로 하였고, 이 검체가 분리된 환자 299명의 의무기록과 방사선학적 소견을 후향적으로 조사하였다. 결 과 : 결핵균이 분리된 객담은 606건(73.4%)이었고 NTM이 분리된 객담은 220건(26.6%)이었다. 299명의 환자 중 결핵균이 분리된 폐결핵 환자는 229명(76.6%)이었고, NTM이 분리된 환자는 70명(23.4%)이었으며 모두 임상적 의의가 있는 NTM 폐질환 환자였으며, 원인균은 M. avium complex 38명(54.3%), M. abscessus 26명(37.1%), 기타 6명 등이었다. 폐결핵 환자 229명 중 112명(48.9%)와 NTM 폐질환 환자 70명 중 51명 (72.9%)에서 객담 또는 기관지 세척액을 이용한 TB-PCR 검사가 시행되었다. 검사를 시행한 폐결핵 환자 112명 중 99명(88.4%)에서 TB-PCR 검사가 양성을 보였고, NTM 폐질환 환자는 모두 음성을 보였다 (p<0.001). 객담 도말 양성 환자에서 객담 또는 기관지 세척액의 TB-PCR 검사 양성 반응이 폐결핵을 예측하는 민감도와 특이도는 각각 88.4%(99/112)와 100%(51/51)였고, 양성 예측치는 100%(99/99) 그리고 음성 예측치는 79.7%(51/64)였다. 결 론 : 객담 항산균 도말 양성을 보이는 환자에서 객담 또는 기관지 세척액 TB-PCR 검사는 국내에서도 폐결핵과 NTM 폐질환을 구별하는데 임상적 유용성이 있을 것으로 사료된다.

• 대한의생명과학회지
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• 제26권3호
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• pp.170-178
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• 2020

Mycobacterium tuberculosis (MTB) continues to be one of the main causative agents of tuberculosis (TB); moreover, the incidence of nontuberculous mycobacteria (NTM) infections has been rising gradually in both immunocompromised and immunocompetent patients. Precise and rapid detection and identification of MTB and NTM in respiratory specimens are thus important for MTB infection control. Molecular diagnostic methods based on the nucleic acid amplification test (NAAT) are known to be rapid, sensitive, and specific compared to the conventional acid-fast bacilli (AFB) smear and mycobacterial culture methods. In the present study, the clinical performances of three commercial molecular diagnostic assays, namely TB/NTM PCR (Biocore), MolecuTech Real MTB-ID^® (YD Diagnostics), and REBA Myco-ID^® (YD Diagnostics), were evaluated with a total of 92 respiratory specimens (22 AFB smear positives and 67 AFB smear negatives). The sensitivity and specificity of TB/NTM PCR were 100% and 75.81%, respectively. The corresponding values of MolecuTech Real MTB-ID^® and REBA Myco-ID^® were 56.52% and 90.32%, and 56.52% and 82.26%, respectively. TB/NTM PCR showed the highest sensitivity; however, the concordant rate was 10% compared with sequence analysis. Although MolecuTech Real MTB-ID^® showed lower sensitivity, its specificity was the highest among the three methods. REBA Myco-ID^® allowed accurate classification of NTM species; therefore, it was the most specific diagnostic method. Of the three PCR-based methods, MolecuTech Real MTB-ID^® showed the best performance. This method is expected to enable rapid and accurate identification of MTB and NTM.

• Tuberculosis and Respiratory Diseases
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• 제71권4호
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• pp.249-253
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• 2011

Background: Mycobacterial infection is a problem throughout the world along with the increase of immunocompromised patients. For this reason, there have been many methods for faster and more accurate diagnosis. In this study, we evaluated several laboratory methods for mycobacterial infection. Methods: From January to December 2009, 635 specimens were cultured with mycobacteria growth indicator tube (MGIT) and Ogawa media. Polymerase chain reaction (PCR) was performed with the AdvanSure tuberculosis (TB)/non-tuberculosis mycobacterium (NTM) real-time PCR Kit (LG Life Sciences, Seoul, Korea). The 69 samples showing positive culture results were identified with the AdvanSure Mycobacteria Genotyping Chip Kit (LG Life Science, Seoul, Korea). Results: Sixty-nine (10.9%) out of 635 samples showed positive results for mycobacterial culture. Among the 635 samples, 64 were positive in MGIT, but only 42 were positive in Ogawa media. Of the 635 samples, 607 (95.6%) showed the same results between MGIT and Ogawa and the results of 579 (95.4%) were also consistent with the TB/NTM real-time PCR results. However, in the case of NTM, only one (1/24, 4.2%) was positive in PCR. In the Mycobacteria genotyping chip analysis, the most frequently identified NTM species in descending order were M. avium, M. intracellulare, M. chelonae and M. abscessus. Conclusion: Culturing with a combination of MGIT and Ogawa is recommended to increase the recovery rate of mycobacteria. Although PCR missed a reasonable number of NTM, it is faster and usually gives results that concur with those from the culture. The appropriate combination of diagnostic methods with clinical correlation are necessary.

• 대한임상검사과학회지
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• 제53권3호
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• pp.225-232
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• 2021

본 연구는 인천지역에 위치한 단일기관의 비결핵항산균의 분포 및 항균제 내성률과 동반 세균 빈도를 조사한 것으로, 2015년부터 2020년까지 TB/NTM real-time PCR 검사가 의뢰된 8,258건의 환자 데이터를 후향적으로 검토하였다. 총 296건의 검체가 NTM 양성이었고, 발생률은 2015년 2.5% (30/1,209)에서 2020년 3.8% (66/1,740)로 증가하였다. NTM으로 확인된 296건 중, 54.7% (162/296)는 M. avium complex (MAC)에 속하는 균종으로 확인되었고, 그다음으로 M. abscessus complex (MABC) 20.9% (62/296), M. fortuitum 6.4%(19/296) 및 M. flavescens 3.4% (10/296) 순이었다. NTM 양성 검체 중, 약제내성검사가 의뢰된 검체는 76.7% (227/296)였다. 다제내성 NTM은 40.1% (91/227)였고, 광범위 내성 NTM은 59.9% (136/227)였다. NTM과 동시 감염은 43.4% (63/145)이었고 가장 흔한 균종은 Klebsiella pneumonia (23.8%, 15/63)였다. 본 연구는 인천지역의 NTM 분포 및 항균제 내성률과 동반 세균 빈도에 관한 최초 보고이다. NTM 감염의 비율은 점차적으로 증가하는 추세이며 효과적인 관리를 위해 적극적인 진료와 철저한 감염관리가 필요할 것이다.

• Tuberculosis and Respiratory Diseases
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• 제63권4호
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• pp.331-336
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• 2007

연구배경: 결핵은 호흡기를 통한 전염성 질환이지만 말초혈액에서 결핵균 PCR이 양성이거나 결핵균이 배양된 보고가 일부 있었다. 이는 결핵의 진단에 있어서의 유용성과 헌혈을 통한 결핵의 전염 가능성의 두 가지 문제를 제기하게 되었고, 저자들은 상기 문제들에 대한 향후 연구방향의 기초자료로 사용하고자 연구를 시행하여 보았다. 방법: 속립성 결핵이 아닌 폐결핵, 비결핵항산균 폐질환, 폐암 및 폐렴 환자 69명을 대상으로 말초혈액에서 결핵균 PCR을 시행하였고, 결핵균이 많을 것으로 추정되는 10명의 폐결핵 환자의 말초혈액을 대상으로 결핵균 배양을 시행하였다. 결핵균 PCR은 nested PCR을 이용한 TB-taq (M&D, Korea)을 이용하였고 혈액배양에는 BACTEC Myco/F Lytic 혈액배양병(Becton Dickinson, Sparks, Md)을 사용하였다. 결과: 결핵균 PCR을 시행한 환자는 69명으로 각각 폐결핵 35명, 비결핵항산균 폐질환 6명, 폐암 20명, 폐렴 8명이었다. 폐렴이나 폐암 환자 28명 모두에서 PCR은 음성이었고, 비결핵항산균 폐질환 6명 중 1명(16.7%), 폐결핵 35명 중 8명(22.8%)에서 양성이었다. 혈액 배양은 폐결핵 10명 모두에서 음성이었다. 결론: 미만성 결핵이 동반되지 않은 폐결핵 환자의 말초혈액에서 결핵균의 DNA가 검출됨을 확인할 수 있었으나 균배양이 되지 않는 것으로 보아 살아있는 균이 존재하기 보다는 균의 일부 성분만 존재할 가능성을 제시하였다.

• Tuberculosis and Respiratory Diseases
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• 제85권1호
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• pp.89-95
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• 2022

Background: With the introduction of Xpert MTB/RIF assay (Xpert), its incorporation into tuberculosis (TB) diagnostic algorithm has become an important issue. The aim of this study was to evaluate the performance of the Xpert assay in comparison with a commercial polymerase chain reaction (PCR) assay. Methods: Medical records of patients having results of both Xpert and AdvanSure TB/NTM real-time PCR (AdvanSure) assays using the same bronchial washing specimens were retrospectively reviewed. Results: Of the 1,297 patients included in this study, 205 (15.8%) were diagnosed with pulmonary TB. Using mycobacterial culture as the reference method, sensitivity of the Xpert assay using smear-positive specimens was 97.5%, which was comparable to that of the AdvanSure assay (96.3%, p=0.193). However, the sensitivity of the Xpert assay using smear-negative specimens was 70.6%, which was significantly higher than that of the AdvanSure assay (52.9%, p=0.018). Usng phenotypic drug susceptibility testing as the reference method, sensitivity and specificity for detecting rifampicin resistance were 100% and 99.1%, respectively. Moreover, a median turnaround time of the Xpert assay was 1 day, which was significantly shorter than 3 days of the AdvanSure assay (p<0.001). Conclusion: In comparison with the AdvanSure assay, the Xpert assay had a higher sensitivity using smear-negative specimens, a shorter turnaround time, and could reliably predict rifampin resistance. Therefore, the Xpert assay might be preferentially recommended over TB-PCR in Korean TB diagnostic algorithm.

• Tuberculosis and Respiratory Diseases
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• 제72권1호
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• pp.82-87
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• 2012

In 2005, a group of mycolic acid-containing bacteria was characterized as belonging to a novel genus, Segniliparus with species Segniliparus rugosus and S. rotundus. We report a case of the S. rugosus isolated from a 54-year-old woman with radiologic features mimicking that of non-tuberculous mycobacteriosis (NTM). When the patient first visited our hospital, an acid-fast bacteria (AFB) smear tested positive and Mycobacterium tuberculosis polymerase chain reaction (TB PCR) was negative in the bronchoalveolar lavage sample. After 2 months, the growing colonies were reported as NTM, but could not be identified because they had died. One year after the initial visit, induced sputum samples showed the same results, positive AFB smear and negative TB PCR. At this point, the growing colonies were identified as S. rugosus. Therefore, we should consider Segniliparus genus as a differential diagnosis for AFB in respiratory specimens in addition to the genus Mycobacterium.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.745-752
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• 2015

Tuberculosis (TB) is the most common mycobacterial infection in developing countries, requiring a rapid, accurate, and well-differentiated detection/diagnosis. For the rapid detection and discrimination of Mycobacterium tuberculosis complex (MTC) from non-tuberculous mycobacteria (NTM), a novel, simple, and primer-combined single-step multiplex PCR using three primer pairs (6110F-6110R, 1081F-1081R, and 23SF-23SR; annealing on each of IS6110, IS1081, and 23S rDNA targets), hereafter referred to as a triplex PCR, has been developed and evaluated. The expected product for IS6110 is 416 bp, for IS1081 is 300 bp, and for 23S rDNA is 206 bp by single PCR, which was used to verify the specificity of primers and the identity of MTC using DNA extracted from the M. tuberculosis H37Rv reference strain (ATCC, USA) and other mycobacteria other than tuberculosis (MOTT) templates. The triplex PCR assay showed 100% specificity and 96% sensitivity; the limit of detection for mycobacteria was ~100 fg; and it failed to amplify any target from DNA of MOTT (50 samples tested). Of 307 blinded clinical samples, overall 205 positive M. tuberculosis samples were detected by single PCR, 142 by conventional culture, and 90 by AFB smear methods. Remarkably, the triplex PCR could subsequently detect 55 positive M. tuberculosis from 165 culture-negative and 115 from 217 AFB smear-negative samples. The triplex PCR, targeting three regions in the M. tuberculosis genome, has proved to be an efficient tool for increasing positive detection/discrimination of this bacterium from clinical samples.