Rapid detection of Mycobacterium tuberculosis in respiratory samples by transcription-reverse transcription concerted reaction with an automated system

Lower dose of ethambutol may reduce ocular toxicity without radiological deterioration for Mycobacterium avium complex pulmonary disease

BACKGROUND

Ethambutol ocular toxicity is a major problem during combination chemotherapy for Mycobacterium avium complex (MAC) pulmonary disease (MAC-PD) due to years-long therapy for MAC.

OBJECTIVES

This study aimed to identify the lower dose of daily ethambutol that can reduce ocular toxicity.

METHODS

We retrospectively reviewed the medical records of 312 patients who visited The University of Tokyo Hospital between January 2007 and December 2017 for nontuberculous mycobacterial pulmonary disease. Seventy-six patients with MAC-PD who were treated with combination chemotherapy for the first time were analyzed in this study.

RESULTS

Ethambutol was discontinued because of visual symptoms in 13 patients (17%), 7 of whom were diagnosed with ethambutol ocular neuropathy. The dose per body weight was significantly higher in patients who developed ocular neuropathy than in those who did not (15.4 mg/kg/d vs. 12.5 mg/kg/d, respectively; p = 0.048). We assigned patients to higher or lower dose groups according to the median dose of 12.5 mg/kg/d. Although ocular neuropathy developed in 6 out of 38 patients in the higher dose group, ocular neuropathy developed in 1 out of 38 patients in the lower dose group (16% vs. 3%, respectively; p = 0.038). The failures of sputum culture conversion and radiological improvement were not significantly different between the two groups (p = 0.638 and 0.305, respectively). Macrolide resistance developed in one patient per group during follow-up (3% per group, p = 0.945).

CONCLUSIONS

A lower dose of ethambutol may reduce ocular toxicity without radiological deterioration for pulmonary MAC infection.

Functional expression of the reverse transcriptase αβ heterodimer from avian myeloblastosis virus in Escherichia coli

The α subunit of avian myeloblastosis virus reverse transcriptase (AMV-RT) is generated from the β-subunit by proteolysis, and the αβ heterodimer represents the active form. The codon-optimized gene was expressed in Escherichia coli, and an active αβ heterodimer was generated. The RNA amplification activity of the purified recombinant AMV-RT αβ heterodimer was similar to that of the native one.

Disseminated Tuberculosis with Cholecystitis in a Patient after Cord Blood Transplantation

The incidence of an active tuberculosis infection after allogeneic hematopoietic cell transplantation is high. We herein report the case of a patient with acute myeloid leukemia after cord blood transplantation (CBT). On day 36 after CBT, the patient developed fever, and a computed tomography scan on day 36 showed mild thickening of the wall of the gallbladder. Subsequently, a sputum specimen and a blood culture returned positive for the growth of Mycobacterium tuberculosis. After 2 months of administering combination therapy, both the symptoms and gallbladder findings improved. We therefore describe a case of disseminated tuberculosis with the gallbladder mimicking acute cholecystitis in a CBT recipient.

Clinical Features and Prognosis of Nontuberculous Mycobacterial Pleuritis

BACKGROUND

While nontuberculous mycobacterial (NTM) pleuritis rarely complicates pulmonary NTM infection, high mortality has been reported in case reports and small studies.

OBJECTIVES

The purpose of this study was to clarify the clinical features and treatment outcomes of pulmonary NTM infection cases accompanied by NTM pleuritis.

METHODS

Medical records of 1,044 patients with pulmonary NTM disease were retrospectively reviewed to select patients complicated by NTM-proven pleuritis. We investigated clinical characteristics, pathogens, pleural effusion examinations, radiographic findings, treatments, and clinical course of the NTM pleuritis patients.

RESULTS

Among 1,044 cases with pulmonary NTM, NTM pleuritis occurred in 15 cases (1.4%). The mean age was 69 years with a performance status of mostly 2 or better (80.0%), and 6 cases (40.0%) were complicated by pneumothorax. Subpleural cavities were radiologically detected in 11 cases (73.3%), and extrapulmonary air-fluid level was detected in 14 cases (93.3%). Eleven patients were treated with combinations of 2-4 antimycobacterial drugs, including clarithromycin, and 2 patients were treated with isoniazid, rifampicin, and ethambutol. Chest tube drainage was performed in 11 cases, and surgical approach was added in 6 cases. The pleural effusion of 2 patients treated with only antimycobacterial medications gradually deteriorated. Two patients died from NTM pleuritis, and 1 patient died from pneumonitis during a mean of 1.8 years of follow-up.

CONCLUSIONS

Comorbid NTM pleuritis was difficult to treat by medical therapy alone and resulted in a poor prognosis. In addition to antimycobacterial agents, chest tube drainage and surgical procedures in the early stages should be considered to treat NTM pleuritis.

Real time PCR quantification of viable Mycobacterium tuberculosis from sputum samples treated with propidium monoazide

Diagnostic methods of TB, nowadays, are prone to delay in diagnosis, increased false negative results and are not sensitive to many forms of paucibacillary disease. The aims of this study were to implement a quantitative nucleic acid-based diagnostic test for paucibacillary tuberculosis, enabling the identification and quantification of viable Mycobacterium tuberculosis bacilli by quantitative Real-Time PCR (qRT-PCR). The intergenic region of the single-copy inhA-mabA gene was chosen as the target region for design of primers and probes conjugated with fluorophores. The construction of synthetic DNA flanking the target region served as standards for absolute quantification of nucleic acids. Using the intercaling dye, propidium monoazide, we were able to discriminate between viable and dead cells of M. tuberculosis. The diagnosis method showed a broad sensitivity (96.1%) when only compared to samples of smear-positive sputum and ROC analyses shows that our approach performed well and yielded a specificity of 84.6% and a sensitivity of 84.6% when compared to M. tuberculosis colony-forming units counting.

Mycobacterium shinjukuense lung disease that was successfully treated with antituberculous drugs

An 80-year-old woman was referred to our hospital due to a persistent productive cough. Acid-fast staining and a commercial Mycobacterium tuberculosis identification kit with TRC (TRC kit) were positive. However, a false-positive result on the TRC kit was suspected because Mycobacterium tuberculosis was not detected in the sputum culture. Finally, Mycobacterium shinjukuense was detected in an analysis of the rpoB and hsp65 gene sequences. As the diagnostic criteria proposed by the American Thoracic Society were met, a diagnosis of Mycobacterium shinjukuense lung disease was made. Following treatment with isoniazid, rifampicin and ethambutol with drug susceptibility, the patient's acid-fast culture became negative, and the areas of opacity improved.

Rapid detection of the Mycobacterium tuberculosis complex by use of quenching probe PCR (geneCube)

Early detection of tuberculosis (TB) is essential for infection control. The geneCube (Toyobo) is a novel fully automated gene analyzer that can amplify target DNAs within 60 min. In this study, we evaluated the ability of the geneCube to directly detect Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium complex (MAC) in clinical specimens. The results were then compared with those obtained using conventional culture, microscopy, and the Cobas Amplicor assay (Roche). We examined a total of 516 frozen samples from 69 patients who showed culture-positive infection (73 samples; 39 MTBC, 32 MAC, and 2 mixed infections) and from 354 patients who were culture negative (443 samples). Assays using the geneCube had a sensitivity of 85.4% and a specificity of 99.8% for detection of MTBC and a sensitivity of 85.3% and a specificity of 99.8% for detection of MAC. These results are similar to those obtained using the Amplicor system but were obtained much more rapidly (1 h with the geneCube versus 5.5 h with the Amplicor system). The geneCube thus enables a significant shortening of the assay time with no loss of sensitivity or specificity.

Is real-time PCR better than conventional PCR for Mycobacterium tuberculosis complex detection in clinical samples?

Cobas Amplicor MTB and later Cobas TaqMan MTB were used to test a very large series of consecutive specimens received for tuberculosis diagnosis. Performance parameters were estimated and compared overall and for separate specimen categories. Both systems showed excellent specificity, and that of TaqMan was the higher. The sensitivities were similar but satisfactory only with respiratory specimens and smear-positive samples.

Mycobacterium tuberculosis and M. bovis infection in Feedlot Deer (Cervus unicolor swinhoei and C. nippon taiouanus) in Taiwan

BACKGROUND/PURPOSE

Mycobacterium bovis frequently infects wild and farm deer species with tuberculosis. This study investigated mycobacterial infection in two native deer species Cervus unicolor swinhoei (Formosan Sambar, Sambar) and C. nippon taiouanus (Formasan Sika, Sika).

METHODS

Based on different sampling sources of 19 intradermal tuberculin test (ITT) Sambar, mycobacterial infection and/or species were detected by acid-fast stain, duplex polymerase chain reaction (PCR) and multiplex nested PCR (mnPCR) methods, traditional mycobacterial culture and gross lesion. Blood samples of 167 Sambar deer and 147 Sika deer were then tested by duplex PCR and mnPCR methods to investigate the prevalence of mycobacterial infection. Sequence variations of these mycobacterial species were analyzed as well.

RESULTS

Duplex PCR and mnPCR assays could differentiate between MTBC (M. bovis and M. tuberculosis) and M. avium, as well as between M. bovis and M. tuberculosis, respectively. These PCR methods showed a higher detection rate than traditional culture and matched the gross lesions examined in 19 ITT-examined Sambar. Therefore, the mycobacterial infection in blood samples of 314 deer samples was detected using these PCR methods. Duplex PCR and mnPCR showed an identical prevalence of 16.1% in Sambar and 8.2% in Sika and a significant difference in prevalence between these two deer species. M. bovis and M. tuberculosis were the species detected in feedlot Sambar and Sika. M. tuberculosis was found only and first in Sambar fed in central Taiwan. Sequence analysis revealed diverse genetic variations in M. bovis and M. tuberculosis associated with deer subspecies.

CONCLUSION

Multiplex PCR methods were established, and M. bovis and M. tuberculosis were identified in feedlot deer in Taiwan. Sequence variations indicated diverse sources of both mycobacterial species.

Development of a transcription-reverse transcription concerted reaction method for specific detection of human enterovirus 71 from clinical specimens

A transcription-reverse transcription (RT) concerted reaction (TRCR) method was developed for rapid and specific detection of EV71 from clinical specimens. This method was validated with EV71 strains from all of the known genotypes (genotypes A, B1 to B5, and C1 to C5), with detection limits of 10 to 10(3) copies, and was useful for identification of EV71 from throat swabs of patients with hand, foot, and mouth disease (HFMD).

Comprehensive multicenter evaluation of a new line probe assay kit for identification of Mycobacterium species and detection of drug-resistant Mycobacterium tuberculosis

We evaluated a new line probe assay (LiPA) kit to identify Mycobacterium species and to detect mutations related to drug resistance in Mycobacterium tuberculosis. A total of 554 clinical isolates of Mycobacterium tuberculosis (n = 316), Mycobacterium avium (n = 71), Mycobacterium intracellulare (n = 51), Mycobacterium kansasii (n = 54), and other Mycobacterium species (n = 62) were tested with the LiPA kit in six hospitals. The LiPA kit was also used to directly test 163 sputum specimens. The results of LiPA identification of Mycobacterium species in clinical isolates were almost identical to those of conventional methods. Compared with standard drug susceptibility testing results for the clinical isolates, LiPA showed a sensitivity and specificity of 98.9% and 97.3%, respectively, for detecting rifampin (RIF)-resistant clinical isolates; 90.6% and 100%, respectively, for isoniazid (INH) resistance; 89.7% and 96.0%, respectively, for pyrazinamide (PZA) resistance; and 93.0% and 100%, respectively, for levofloxacin (LVX) resistance. The LiPA kit could detect target species directly in sputum specimens, with a sensitivity of 85.6%. Its sensitivity and specificity for detecting RIF-, PZA-, and LVX-resistant isolates in the sputum specimens were both 100%, and those for detecting INH-resistant isolates were 75.0% and 92.9%, respectively. The kit was able to identify mycobacterial bacilli at the species level, as well as drug-resistant phenotypes, with a high sensitivity and specificity.

Clinical evaluation of TRCRapid M.TB for detection of Mycobacterium tuberculosis complex in respiratory and nonrespiratory specimens

The rapid and accurate diagnosis of tuberculosis is crucial to providing optimal treatment and reducing the spread of infection. We evaluated respiratory and nonrespiratory clinical specimens using a new automated Mycobacterium tuberculosis complex (MTBC) rRNA detection kit (TRCRapid M.TB; Tosoh Bioscience, Tokyo, Japan), which is based on the transcription-reverse transcription concerted reaction (TRC). TRC enables the rapid and completely homogeneous real-time monitoring of isothermal RNA sequence amplification without any postamplification procedures. The results were compared with those obtained by M. tuberculosis culture. A total of 1,155 respiratory specimens and 420 nonrespiratory specimens collected from 1,282 patients were investigated. Of the 45 specimens culture positive for MTBC, 42 were TRC positive, and of the 1,530 specimens culture negative for MTBC, 1,523 were TRC negative. Compared to the results of culture, the overall sensitivity and specificity of TRC were 96.6% and 99.9%, respectively, for respiratory specimens and 87.5% and 98.5%, respectively, for nonrespiratory specimens. The sensitivities of TRC were 100% for smear-positive respiratory and nonrespiratory specimens, 88.9% for smear-negative respiratory specimens, and 80% for smear-negative nonrespiratory specimens. No significant differences in test performance between respiratory and nonrespiratory specimens were observed. The TRC method proved to be clinically useful for the rapid identification of MTBC in respiratory and nonrespiratory specimens and in both smear-positive and smear-negative samples.

The value of fiberoptic bronchoscopy in culture-positive pulmonary tuberculosis patients whose pre-bronchoscopic sputum specimens were negative both for smear and PCR analyses

OBJECTIVE

This study assessed the diagnostic rate of pulmonary tuberculosis (PTB) using fiberoptic bronchoscopy (FBS) in patients with suspected PTB, and negative pre-bronchoscopy smear and polymerase-chain reaction (PCR) in sputum.

PATIENTS AND METHODS

We retrospectively reviewed 201 culture-positive PTB patients that underwent FBS because both smear and PCR results in sputum were negative. The positive rates of smear for acid fast bacilli, PCR for Mycobacterium tuberculosis, the presence of granuloma in transbronchial biopsy (TBB), and culture of M. tuberculosis were analyzed. In addition, the radiographic features, contribution of FBS to rapid and/or definitive diagnosis of PTB, and drug susceptibility results of M. tuberculosis were also reviewed.

RESULTS

There were 136 males and 102 patients under the age of 40 years; non-cavitary (156 cases) and minimal disease (119 cases) on radiographs predominated. The positive rates of FBS were: 44% (smear), 62% (PCR), 61% (TBB), and 87% (culture). These rates increased in smear and PCR examinations when taken from wider spread shadows on radiographs. The combination of the various bronchoscopy samples increased the diagnostic rate to 92% when all examinations were combined. Positive culture results depended on FBS procedures in 80 cases. Twenty-one cases showed resistance to at least one of the major anti-tuberculous agents.

CONCLUSION

This analysis revealed high positive rates of PTB from bronchoscopy samples, providing rapid and definitive ability for PTB diagnosis, and details of drug susceptibility. Therefore, FBS is an important diagnostic procedure in patients with suspected PTB whose sputum specimens were negative both for smear and PCR analyses.

Multicenter evaluation of a transcription-reverse transcription concerted assay for rapid detection of mycobacterium tuberculosis complex in clinical specimens

A European multicenter study was performed to evaluate the performance of a new method, based on the transcription-reverse transcription concerted reaction (TRC-2), which enabled one-step amplification and real-time detection of the Mycobacterium tuberculosis 16S rRNA target directly in clinical specimens. A total of 633 respiratory and nonrespiratory specimens were tested, and the results were compared with those from smears and cultures. A total of 129 patients (Paris center) were followed up in order to evaluate the clinical performance of TRC-2. By using M. tuberculosis complex strains to inoculate sterile sputa, the detection limit of TRC-2 was found to be 30 to 50 CFU/ml. A total of 548 respiratory specimens and 59 extrapulmonary specimens were assessable. For pulmonary specimens, the sensitivities of TRC-2 and acid-fast smear were 86.8% and 50.4%, respectively (P = 0.002). The specificities were 97.5% and 100%, respectively. For extrapulmonary specimens, the sensitivities of TRC-2 and acid-fast smear were 83.3% and 8.3% (P < 0.0001), and the specificities were 95.8% and 100%, respectively. Fifteen of 129 patients were diagnosed with pulmonary tuberculosis (TB). The sensitivities of culture and TRC-2 were 80% (12/15) and 86.7% (13/15) (P = 0.16), and the specificities were 100% and 93.9%, respectively. Based on an 11.6% incidence of TB in our population, the positive predictive values of TRC-2 and culture were 81.3% and 100%, respectively, and the negative predictive values were 98.2% and 97.4%, respectively. These results demonstrated that detection of M. tuberculosis complex in clinical specimens by TRC-2 with ready-to-use reagents was an efficient and rapid method for the diagnosis of pulmonary and extrapulmonary TB.

Development of an in-house loop-mediated isothermal amplification (LAMP) assay for detection of Mycobacterium tuberculosis and evaluation in sputum samples of Nepalese patients

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal amplification (LAMP) is an NAA possessing superior isothermal reaction characteristics. In the present study, a set of six specific primers targeting the Mycobacterium tuberculosis 16S rRNA gene with high sensitivity was selected and a LAMP system (MTB-LAMP) was developed. Using this system, a total of 200 sputum samples from Nepalese patients were investigated. The sensitivity of MTB-LAMP in culture-positive samples was 100 % (96/96), and the specificity in culture-negative samples was 94.2 % (98/104, 95 % confidence interval 90.5-97.9 %). The positive and negative predictive values of MTB-LAMP were 94.1 and 100 %, respectively. These results indicate that this MTB-LAMP method may prove to be a powerful tool for the early diagnosis of TB.

Establishment of a new method, transcription-reverse transcription concerted reaction, for detection of plasma hnRNP B1 mRNA, a biomarker of lung cancer

PURPOSE

Development of an early detection marker is one of the most important strategies for improving overall prognosis in lung cancer patients. We previously reported that hnRNP B1--an RNA binding protein--is overexpressed in lung cancer tissue from the early stage of cancer, and found that hnRNP B1 mRNA is detectable in the plasma of lung cancer patients using real-time RT-PCR. The purpose of this study was to establish a quick and simple method for detecting plasma hnRNP B1mRNA for use in screening for lung cancer.

METHODS

TRC, a homogenous method for fluorescence real-time monitoring of isothermal RNA amplification using intercalation activating fluorescence DNA probe, was used to detect plasma hnRNP B1 mRNA.

RESULTS

The detection limit of hnRNP B1 mRNA by TRC using synthetic control RNA or total RNA derived from a lung cancer cell line was 25 or 8.65 x 10(2) copies, respectively. Using total RNA extracted from 600 mul of plasma, we detected hnRNP B1 mRNA in 39.1% (9/23) of lung cancer patients, with levels ranging from 1.9 to 19,045.5 copies/100 ng RNA, and in 5.2% (5/97) of healthy volunteers. Copy numbers were not associated with age, gender, smoking status, or histological type of cancer. TRC could detect 10(3) copies of hnRNP B1 mRNA in 10 min.

CONCLUSION

Detection of plasma hnRNP B1 mRNA by TRC is a quick, easy, and non-invasive method suitable for lung cancer screening.

Commercial nucleic-acid amplification tests for diagnosis of pulmonary tuberculosis in respiratory specimens: meta-analysis and meta-regression

Background

Hundreds of studies have evaluated the diagnostic accuracy of nucleic-acid amplification tests (NAATs) for tuberculosis (TB). Commercial tests have been shown to give more consistent results than in-house assays. Previous meta-analyses have found high specificity but low and highly variable estimates of sensitivity. However, reasons for variability in study results have not been adequately explored. We performed a meta-analysis on the accuracy of commercial NAATs to diagnose pulmonary TB and meta-regression to identify factors that are associated with higher accuracy.

Methodology/Principal Findings

We identified 2948 citations from searching the literature. We found 402 articles that met our eligibility criteria. In the final analysis, 125 separate studies from 105 articles that reported NAAT results from respiratory specimens were included. The pooled sensitivity was 0.85 (range 0.36–1.00) and the pooled specificity was 0.97 (range 0.54–1.00). However, both measures were significantly heterogeneous (p<.001). We performed subgroup and meta-regression analyses to identify sources of heterogeneity. Even after stratifying by type of commercial test, we could not account for the variability. In the meta-regression, the threshold effect was significant (p = .01) and the use of other respiratory specimens besides sputum was associated with higher accuracy.

Conclusions/Significance

The sensitivity and specificity estimates for commercial NAATs in respiratory specimens were highly variable, with sensitivity lower and more inconsistent than specificity. Thus, summary measures of diagnostic accuracy are not clinically meaningful. The use of different cut-off values and the use of specimens other than sputum could explain some of the observed heterogeneity. Based on these observations, commercial NAATs alone cannot be recommended to replace conventional tests for diagnosing pulmonary TB. Improvements in diagnostic accuracy, particularly sensitivity, need to be made in order for this expensive technology to be worthwhile and beneficial in low-resource countries.

Comparison of the thermal stabilities of reverse transcriptases from avian myeloblastosis virus and Moloney murine leukaemia virus

Reverse transcriptases (RTs) from avian myeloblastosis virus (AMV) and Moloney murine leukaemia virus (MMLV) have been most extensively used as a tool for conversion of RNA to DNA. In this study, we compared the thermal stabilities of AMV RT and MMLV RT by observing their irreversible thermal inactivation. The temperatures reducing initial activity by 50% in 10-min incubation, T(50), of AMV RT were 47 degrees C without the template-primer (T/P), poly(rA)-p(dT)(12-18), and 52 degrees C with the T/P (28 microM). T(50) of MMLV RT were 44 degrees C without the T/P and 47 degrees C with the T/P (28 microM). Unexpectedly, AMV RT was considerably activated when incubated with the T/P at 45 and 48 degrees C. Such activation was not observed in MMLV RT. These results suggest that AMV RT and MMLV RT are different in the following: (i) The intrinsic thermal stability of AMV RT is higher than that of MMLV RT; (ii) AMV RT is activated by thermal treatment with the T/P at 45-48 degrees C; and (iii) AMV RT is stabilized by the T/P more potently than MMLV RT. Thermodynamic analysis indicates that thermal inactivation of AMV RT and MMLV RT is due to the large entropy change of activation for thermal inactivation.

Transcription-reverse transcription concerted reaction and minimal residual disease in axillary sentinel nodes of breast cancer

AIMS

To investigate the use of transcription-reverse transcription concerted reaction (TRC) to detect axillary lymph node metastases.

METHODS

Metastases in 423 lymph nodes obtained from 50 breast cancer patients were investigated by routine pathological hematoxylin and eosin (H and E) staining and quantitative analysis of carcinoembryonic antigen (CEA) mRNA by TRC. Enhanced pathological studies, serial sectioning and immunohistochemistry were conducted for cases which were negative by routine pathology, but positive by TRC.

RESULTS

Pathological examination identified metastatic disease in 67 lymph nodes. TRC CEA mRNA results were concordant with 89.8% of these cases at a threshold of 100 copies. TRC identified 30 false negative nodes, which was reduced to 15 by excluding node biopsies yielding less than 40 microg total RNA. Twelve nodes were histologically negative for cancer, but positive according to TRC. Serial sectioning and immunohistochemical analysis of these nodes revealed macrometastatic lesions in three, micrometastasis in one, and isolated tumor cells in two.

CONCLUSION

TRC for the detection of CEA mRNA may complement routine pathological examination by sentinel lymph node biopsy (SNB) in early breast cancer. We have started an enhanced pathological examination with serial sectioning on all excised sentinel nodes to set the best threshold for the TRC method.

Abcès tuberculeux de la marge anale

Gastrointestinal tuberculosis represents 1% of extrapulmonary tuberculoses and only sporadic cases of anal tuberculosis have been reported in the literature. We report two cases of tuberculous anal abscess and a review of the literature for diagnosis and treatment.

[Automated RNA amplification for the rapid identification of Mycobacterium tuberculosis complex in respiratory specimens]

Rapid and sensitive detection of Mycobacterium tuberculosis complex (MTB) directly on clinical respiratory specimens is essential for a correct management of patients suspected of tuberculosis. For this purpose PCR-based kits are available to detect MTB in respiratory specimen but most of them need at least 4 hours to be completed. New methods, based on TRC method (TRC: Transcription Reverse transcription Concerted--TRCRapid M. Tuberculosis--Tosoh Bioscience, Tokyo, Japon) and dedicated monitor have been developed. A new kit (TRC Rapid M. tuberculosis and Real-time monitor TRCRapid-160, Tosoh Corporation, Japan) enabling one step amplification and real-time detection of MTB 16S rRNA by a combination of intercalative dye oxazole yellow-linked DNA probe and isothermal RNA amplification directly on respiratory specimens has been tested in our laboratory. 319 respiratory specimens were tested in this preliminary study and results were compared to smear and culture. Fourteen had a positive culture for MTB. Among theses samples, smear was positive in 11 cases (78.6%) and TRC process was positive in 8 cases (57.1%). Overall sensitivity of TRC compared to smear positive samples is 73%. Theses first results demonstrated that a rapid identification of MTB was possible (less than 2 processing hours for 14 specimens and about 1 hour for 1 specimen) in most cases of smear positive samples using ready to use reagents for real time detection of MTB rRNA in clinical samples. New pretreatment and extraction reagents kits to increase the stability of the sputum RNA and the extraction efficiency are now tested in our laboratory.