Clinical diagnostic value of simultaneous amplification and testing for the diagnosis of sputum-scarce pulmonary tuberculosis

Diagnostic value of SAT-TB in stool and urine samples for intestinal and urinary tuberculosis

BACKGROUND

The simultaneous amplification/testing for tuberculosis (SAT-TB) targets specific 16s rRNA for detecting Mycobacterium tuberculosis in real-time.

OBJECTIVE

To evaluate SAT-TB's performance in detecting intestinal and urinary TB using stool and urine samples.

METHODS

Stool (94) and urine samples (69) (From 2021 to 2022), were collected from pulmonary combined with suspected intestinal or urinary tuberculosis. Simultaneous detection of Mycobacterium tuberculosis was performed using the SAT-TB method, Xpert MTB/RIF assay, and MGIT960 culture.

RESULTS

For stool samples, the sensitivity, specificity, and area under the curve (AUC) were 53.33 %, 93.88 %, and 0.736 for SAT-TB; 60 %, 81.63 %, and 0.708 for Xpert; and 40 %, 95.92 %, and 0.680 for MGIT960. For urine samples, the sensitivity, specificity, and AUC for SAT-TB, Xpert, and MGIT960 were 27.27 %, 98.28 %, 0.628; 54.55 %, 96.35 %, 0.755; and 45.45 %, 100 %, 0.727, respectively.

CONCLUSION

ROC analysis indicated that SAT-TB had the highest diagnostic efficacy for stool samples when tested individually.

Diagnostic value of SAT-TB in smear-negative pulmonary tuberculosis: A diagnostic accuracy study

This study aimed to evaluate the diagnostic value of rapid simultaneous RNA amplification and testing for tuberculosis (SAT-TB) in smear-negative pulmonary tuberculosis (PTB). We performed a multicenter prospective analysis of 206 patients with smear-negative suspected PTB between December 2018 and March 2022. We collected sputum or bronchoalveolar lavage fluid (BALF) for simultaneous SAT-TB and Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assays. The efficiency of SAT-TB detection was also evaluated. The final analysis included 161 patients with smear-negative suspected PTB, of whom 114 provided sputum specimens and 47 provided BALF specimens. In sputum samples, the area under the curve, sensitivity, and specificity of SAT-TB for diagnosing PTB were 0.75, 50.7%, and 100.0%, respectively, and those of the Xpert MTB/RIF assay were 0.81, 62.3%, and 100.0%, respectively. The kappa coefficient k of the consistency between SAT-TB and Xpert MTB/RIF in sputum specimens was 0.686. In BALF specimens, the area under the curve, sensitivity, and specificity of SAT-TB for diagnosing PTB were 0.79, 57.1%, and 100.0%, respectively, and those of Xpert MTB/RIF were 0.86, 76.2%, and 96.2%, respectively. The kappa coefficient k of the consistency between SAT-TB and Xpert MTB/RIF in BALF specimens was 0.656. The SAT-TB and Xpert MTB/RIF assays were highly consistent in diagnosing smear-negative PTB. It is a valuable method for early detection, prevention, and managing smear-negative PTB suspects. Meanwhile, the detection efficiency and cost-effectiveness of SAT-TB are more suitable for the rapid diagnosis of smear-negative PTB in low- and middle-income countries.

Unlocking the potential of miRNAs in detecting pulmonary tuberculosis: prospects and pitfalls

Tuberculosis (TB) is one of the deadliest infectious diseases globally, ranking as 13th leading cause of mortality and morbidity. According to the Global Tuberculosis Report 2022, TB claimed the lives of 1.6 million people worldwide in 2021. Among the casualties, 1 870 000 individuals with HIV co-infections contributed to 6.7% of the total fatalities, accounting TB as the second most lethal infectious disease following COVID-19. In the quest to identify biomarkers for disease progression and anti-TB therapy, microRNAs (miRNAs) have gained attention due to their precise regulatory role in gene expression in disease stages and their ability to distinguish latent and active TB, enabling the development of early TB prognostic signatures. miRNAs are stable in biological fluids and therefore will be useful for non-invasive and broad sample collection. However, their inherent lack of specificity and experimental variations may lead to false-positive outcomes. These limitations can be overcome by integrating standard protocols with machine learning, presenting a novel tool for TB diagnostics and therapeutics. This review summarizes, discusses and highlights the potential of miRNAs as a biomarker, particularly their differential expression at disease stages. The review assesses the advantages and obstacles associated with miRNA-based diagnostic biomarkers in pulmonary TB and facilitates rapid, point-of-care testing.

Application of Mycobacterium tuberculosis RNA for the Rapid Diagnosis of Lymph Node Tuberculosis Using Different Specimens

Purpose

To evaluate the accuracy of Mycobacterium tuberculosis (MTB)-RNA in the rapid diagnosis of lymph node tuberculosis (LNTB). Moreover, the difference in the diagnostic accuracy of MTB-RNA using different specimens was determined.

Methods

We included patients with suspected LNTB who met the inclusion criteria and retrospectively analyzed their clinical data. The sensitivity, specificity, positive-predictive value (PPV), negative-predictive value (NPV), and area under the curve (AUC) of MTB-RNA and culture were calculated and its diagnostic accuracy for LNTB was evaluated in comparison with the final clinical diagnosis.

Results

Overall, 285 patients were included in the study. The overall sensitivity, specificity, PPV, NPV, and AUC of MTB-RNA were 40.6%, 100.0%, 100.0%, 17.0%, and 0.70, respectively. These values were 30.8%, 100.0%, 100.0%, 16.0%, and 0.65, respectively, for tissue specimens; 34.2%, 100.0%, 100.0%, 24.6%, and 0.67, respectively, for puncture specimens; and 57.14%, 100.0%, 100.0%, 5.3%, and 0.79, respectively, for pus specimens. These values of culture were 24.4%, 100.0%, 100.0%, 13.9%, and 0.62, respectively, for all specimens; 17.6%, 100.0%, 100.0%, 13.8%, and 0.59, respectively, for tissue specimens; 25.3%, 100.0%, 100.0%, 22.4%, and 0.63, respectively, for puncture specimens; and 31.0%, 100.0%, 100.0%, 3.3%, and 0.65, respectively, for pus specimens.

Conclusion

The diagnostic efficacy of MTB-RNA for the rapid diagnosis of LNTB was moderate, but its sensitivity was low. The lymph node pus specimens were the most sensitive for MTB-RNA testing, followed by puncture specimens; tissues were the least sensitive. Pus specimens should be preferably obtained in case only this test is to be used for diagnosis.

The Usefulness of Bronchoscopy in the Diagnosis of Mycobacterium tuberculosis Complex Species Infection

BACKGROUND: Pulmonary tuberculosis is an active chronic infection of the lungs. It is still a public health problem globally caused by the Mycobacterium tuberculosis Complex (MTBC). These species are difficult to determine only by conventional tests. The clinical manifestations are almost similar between the strains and cause diagnosis delays. Prolonged and intolerable MTBC therapy inhibits infection control. AIM: This study aims to evaluate the usefulness of bronchoscopy in diagnosing the MTBC species infection. METHODS: This study recruited patients with difficulty expectorating sputum. Pulmonary tuberculosis was diagnosed with the Xpert MTB/RIF assay. This study assessed sputum Acid Fast Bacilli (AFB) staining, chest X-rays with active pulmonary tuberculosis, characteristics of Bronchoalveolar lavage (BAL), and bronchoscopic findings based on the Chung classification. The BAL of polymerase chain reaction analysis using RD9 and TbD1 primers to determine MTBC species. RESULTS: Out of the 30 cases, M. tuberculosis and Mycobacterium bovis 24 (80.0%) and 6 (20.0%) were identified in BAL fluid. There were 12 cases (40.0%) with AFB sputum test, and 25 (83.3%) of the Xpert MTB/RIF detected tuberculosis cases. All chest X-rays showed infiltrated and 22 (73.3%) pulmonary ectasis. There was a significant difference in MTBC species between sputum and BAL fluid (p < 0.05). The ulcerative type of bronchoscopy findings was significantly different in MTBC species (p < 0.05) and there was no macroscopic BAL fluid difference (p > 0.05). CONCLUSIONS: Bronchoscopy is a specimen collection technique that is beneficial in determining the diagnosis of MTBC. Analysis of BAL with molecular methods contributes to identifying MTBC species quickly and accurately.

Comparing Mycobacterium tuberculosis RNA Accuracy in Various Respiratory Specimens for the Rapid Diagnosis of Pulmonary Tuberculosis

Objective

To evaluate the rapid diagnostic accuracy of Mycobacterium tuberculosis RNA (TB-RNA) for pulmonary tuberculosis (PTB) in a large patient sample and to evaluate the difference in TB-RNA diagnostic accuracy in various respiratory specimens.

Methods

Patient medical records were retrospectively reviewed to determine the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of the acid-fast bacillus (AFB) smear and TB-RNA to evaluate their diagnostic accuracy against final clinical diagnosis.

Results

Of the 2336 patients ultimately included, 1123 provided 1 sputum specimen each and 1213 provided 1 bronchoalveolar lavage fluid (BALF) specimen each. The overall sensitivity, specificity, PPV, NPV, and AUC of the AFB smear were 36.2%, 86.4%, 90.6%, 27.3%, and 0.61, respectively. The overall sensitivity, specificity, PPV, NPV, and AUC of TB-RNA for the rapid detection of PTB were 57.4%, 99.4%, 99.7%, 39.3%, and 0.78, respectively. When sputum and BALF specimens were used for AFB smear testing, the sensitivity, specificity, PPV, NPV, and AUC of the AFB smear were 44.5%, 81.5%, 87.5%, 33.5%, and 0.63; and 29.2%, 92.7%, 94.8%, 22.5%, and 0.61, respectively. The sensitivity, specificity, PPV, NPV, and AUC of TB-RNA for the rapid detection of PTB using sputum were 49.6%, 99.3%, 99.5%, 40.4%, and 0.74, respectively; whereas those of TB-RNA determined using BALF were 63.9%, 99.5%, 99.8%, 38.0%, and 0.82, respectively.

Conclusion

The diagnostic accuracy of TB-RNA for PTB was moderate and considerably better than that of the AFB smear. The diagnostic accuracy of TB-RNA for various respiratory specimens differed; the diagnostic accuracy of TB-RNA for BALF specimens was substantially better than that for sputum samples, and BALF specimens were more suitable for TB-RNA.

The Diagnostic Value of the Thermostatic Amplification of Ribonucleic Acid in Bronchoalveolar Lavage Fluid in Smear-Negative Pulmonary Tuberculosis

Objective

This study aimed to determine the value of the simultaneous amplification and testing for Mycobacterium tuberculosis in bronchoalveolar lavage fluid (BALF) in the diagnosis of smear-negative pulmonary tuberculosis (PTB).

Methods

A total of 316 patients were selected, of which 197 had smear-negative PTB (observation group), and 119 did not have TB (control group). Bronchoscopy was performed in both groups, and BALF samples were collected for acid-fast bacilli smears, simultaneous amplification/testing for TB (SAT-TB), and BACTEC MGIT 960 cultures. The sensitivity, specificity, positive predictive, and negative predictive values of SAT-TB in BALF for the diagnosis of negative TB were calculated.

Results

The sensitivity of SAT-TB detection was 45.18%, which was significantly higher than smears and slightly lower than cultures. The specificity of SAT-TB was 99.16%, which differed slightly from the other two methods. The positive predictive value was 98.89%, which was not significantly different from the other two methods. The negative predictive value of SAT-TB was 58.91%, which was higher than smears and slightly lower than cultures.

Conclusion

The very high specificity and negative prediction of SAT-TB in BALF means that the method has great application value for the rapid diagnosis of smear-negative PTB.

PCR-reverse blot hybridization assay in respiratory specimens for rapid detection and differentiation of mycobacteria in HIV-negative population

Background

Rapid identification of pathogenic Mycobacterium species is critical for a successful treatment. However, traditional method is time-consuming and cannot discriminate isolated non-tuberculosis mycobacteria (NTM) at species level. In the retrospective study, we evaluated the clinical applicability of PCR-reverse blot hybridization assay (PCR-REBA Myco-ID) with clinical specimens for rapid detection and differentiation of mycobacterial species.

Methods

A total of 334 sputum and 362 bronchial alveolar lavage fluids (BALF) from 696 patients with mycobacterium pulmonary disease (MPD) and 210 patients with non-mycobacterium pulmonary disease used as controls were analyzed. Sputum or BALF were obtained for MGIT 960-TBc ID test and PCR-REBA Myco-ID assay. High resolution melt analysis (HRM) was used to resolve inconsistent results of MGIT 960-TBc ID test and PCR-REBA Myco-ID assay.

Results

A total of 334 sputum and 362 BALF specimens from 696 MPD patients (292 MTB and 404 NTM) were eventually analyzed. In total, 292 MTBC and 436 NTM isolates (mixed infection of two species in 32 specimens) across 10 Mycobacterium species were identified. The most frequently isolated NTM species were M. intracellulare (n = 236, 54.1%), followed by M. abscessus (n = 106, 24.3%), M. kansasii (n = 46, 10.6%), M. avium (n = 36, 8.3%). Twenty-two cases had M. intracellulare and M. abscessus mixed infection and ten cases had M. avium and M. abscessus mixed infection. A high level of agreement (n = 696; 94.5%) was found between MGIT 960-TBc ID and PCR-REBA Myco-ID (k = 0.845, P = 0.000). PCR-REBA Myco-ID assay had higher AUC for both MTBC and NTM than MGIT 960-TBc ID test.

Conclusion

PCR-REBA Myco-ID has the advantages of rapid, comparatively easy to perform, relatively low cost and superior accuracy in mycobacterial species identification compared with MGIT 960-TBc ID. We recommend it into workflow of mycobacterial laboratories especially in source-limited countries.

Strategies for advanced personalized tuberculosis diagnosis: Current technologies and clinical approaches

Diagnosis of tuberculosis can be difficult as advances in molecular diagnosis approaches (especially nanoparticles combined with high-throughput mass spectrometry for detecting mycobacteria peptide) and personalized medicine result in many changes to the diagnostic framework. This review will address issues concerning novel technologies from bench to bed and new strategies for personalized tuberculosis diagnosis.

Highly electrically conductive two-dimensional Ti3C2 Mxenes-based 16S rDNA electrochemical sensor for detecting Mycobacterium tuberculosis

Tuberculosis is one of the life-threatening infectious diseases caused by the obligate pathogenic bacterium Mycobacterium tuberculosis (M. tuberculosis). The current M. tuberculosis detection approaches cannot satisfy the requirement for early clinical diagnosis because of long detection time as well as low specificity. In our study, an electrochemical M. tuberculosis sensor was constructed by using specific fragment of 16S rDNA of M. tuberculosis H37Ra as target biomarker, peptide nucleic acid (PNA) as capture probe and highly conductive two-dimensional Ti₃C₂ MXenes as the signal amplified transduction material. After the hybridization between PNA and the specific fragment of 16S rDNA on the substrate of PNA-AuNPs nanogap network electrode, the target fragments were directly linked with conductive Ti₃C₂ MXenes by strong interactions between zirconium-cross-linked Ti₃C₂ MXenes and phosphate groups of the target fragments. The linking of Ti₃C₂ MXenes to the hybridized target fragments would bridge the gaps of the interrupted AuNPs in the nanogap network electrode and forming the conductive connection to cause the change in conductance between the electrodes. This conductance change could be used for M. tuberculosis detection. The limit of detection (LOD) of proposed method was 20 CFU mL^-1, and detection time was 2 h. Proposed method would find potential application in rapid detection of M. tuberculosis.

Application of real-time simultaneous amplification and testing method to accurately and rapidly detect extra-pulmonary tuberculosis

BACKGROUND

This study aimed to establish and evaluate a simultaneous amplification and testing method for detection of extra-pulmonary tuberculosis (EPTB).

METHODS

From January 2016 and December 2017 the pus or surgical excision from the lesions of inpatients admitted from Chongqing Public Health Treatment Center were collected. According to the clinical diagnosis, the samples were divided into two groups including EPTB (Group A) and other diseases excluded from tuberculosis diseases (Group B). Simultaneous detection of Mycobacterium tuberculosis (MTB) used Roche culture method, liquid culture method and simultaneous amplification and testing (SAT) method. The sensitivity and specificity of the SAT method were compared with culture methods and clinical diagnosis of EPTB.

RESULTS

For 433 EPTB specimens and 49 non-TB specimens, the simultaneous amplification and testing tuberculosis (SAT-TB) results correlated with 80.5% (388/482 specimens) of the culture assay results. The sensitivity, specificity, and positive and negative predictive values of the SAT-TB test for the diagnosis of EPTB were 83.6, 79.4, 59.4, and 93.0%, respectively, compared to culture methods. Compared with the clinical diagnosis of patients, the sensitivity and specificity of the SAT-TB test were 41.6 and 100%, respectively, the cultures test were 29.3 and 98.0%.

CONCLUSIONS

SAT test is a simple and rapid test with high specificity which may enhance the detection of EPTB. SAT-TB is a higher clinical diagnosis value for EPTB in clinical microbiology laboratories.

The construction of Mycobacterium tuberculosis 16S rDNA MSPQC sensor based on Exonuclease III-assisted cyclic signal amplification

Tuberculosis caused by Mycobacterium tuberculosis (M. tuberculosis) remains one of the most serious infectious diseases all over the world. The key to reduce the spread and mortality rate of tuberculosis is to develop faster and more sensitive approaches for detection of M. tuberculosis. However, current detection methods can not meet the requirements of rapid clinical M. tuberculosis detection in terms of detection time. Herein, a new 16S rDNA multichannel series piezoelectric quartz crystal (MSPQC) sensor based on Exonuclease III (Exo III)-aided target recycling has been developed for rapid detection of M. tuberculosis. The specific 16S rDNA fragment of M. tuberculosis was used as biomarker, DNA capture probes complementary to the biomarker were designed and modified on the surface of AuNPs. The Exo III which could recognise hybrid duplexes and selectively digest DNA capture probe was used to assist digestion cycle by digesting DNA capture probe and releasing the intact target fragment. After all DNA probes loading on the surface of AuNPs were removed, the surface of AuNPs was exposed and conductive connection was formed between the nanogap network electrode by self-catalytic growth of exposed AuNPs in the glucose and HAuCl₄ solution. This resulted in sensitive response of M. tuberculosis sensor and M. tuberculosis was detected by recording this response. The limit of detection (LOD) of the method was 20 CFU/mL and the detection time was less than 3 h. It was expected to be widely used in detection methods of M. tuberculosis.

Simultaneous amplification and testing method forMycobacterium tuberculosisrRNA to differentiate sputum-negative tuberculosis from sarcoidosis

We use the simultaneous application and testing method to detect Mycobacterium tuberculosis rRNA (SAT-TB) with the endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy specimens to differentiate sputum-negative tuberculosis from sarcoidosis. In the first part, we validated the SAT-TB on the bronchial or EBUS-TBNA biopsy specimens from sputum smear-positive pulmonary tuberculosis. In the second part, all EBUS-TBNA specimens for sputum smear-negative intrathoracic tuberculous lymphadenopathies or sarcoidosis were tested with the SAT-TB, acid-fast bacilli smear, and culture. In the 16 sputum-positive tuberculosis cases, 5 showed negative SAT (2 nontuberculous mycobacteria and 3 had anti-tuberculosis therapies previously); the remaining 11 were positive. Of the 41 sputum-negative tuberculosis cases in the second part, five other diseases were negative. In the remaining 36 cases, 27 sarcoidosis cases were negative; 7 in 9 with sputum-negative tuberculosis were positive (77.78%). In these 36 patients, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the SAT method were 77.78, 100, 100, 93.10, and 94.44%, respectively. The SAT distinguished sputum-negative tuberculosis from sarcoidosis significantly ( P < 0.0001) and identified cases with active M. tuberculosis as accurately as the conventional methods (κ = 0.912, P < 0.0001). We conclude that the SAT-TB may be an effective method for using biopsy specimens to differentiate sputum-negative tuberculosis from sarcoidosis.

A new DNA sensor system for specific and quantitative detection of mycobacteria

In the current study, we describe a novel DNA sensor system for specific and quantitative detection of mycobacteria, which is the causative agent of tuberculosis. Detection is achieved by using the enzymatic activity of the mycobacterial encoded enzyme topoisomerase IA (TOP1A) as a biomarker. The presented work is the first to describe how the catalytic activities of a member of the type IA family of topoisomerases can be exploited for specific detection of bacteria. The principle for detection relies on a solid support anchored DNA substrate with dual functions namely: (1) the ability to isolate mycobacterial TOP1A from crude samples and (2) the ability to be converted into a closed DNA circle upon reaction with the isolated enzyme. The DNA circle can act as a template for rolling circle amplification generating a tandem repeat product that can be visualized at the single molecule level by fluorescent labelling. This reaction scheme ensures specific, sensitive, and quantitative detection of the mycobacteria TOP1A biomarker as demonstrated by the use of purified mycobacterial TOP1A and extracts from an array of non-mycobacteria and mycobacteria species. When combined with mycobacteriophage induced lysis as a novel way of effective yet gentle extraction of the cellular content from the model Mycobacterium smegmatis, the DNA sensor system allowed detection of mycobacteria in small volumes of cell suspensions. Moreover, it was possible to detect M. smegmatis added to human saliva. Depending on the composition of the sample, we were able to detect 0.6 or 0.9 million colony forming units (CFU) per mL of mycobacteria, which is within the range of clinically relevant infection numbers. We, therefore, believe that the presented assay, which relies on techniques that can be adapted to limited resource settings, may be the first step towards the development of a new point-of-care diagnostic test for tuberculosis.

Using simultaneous amplification and testing method for evaluating the treatment outcome of pulmonary tuberculosis

Background

To evaluate the utility of Simultaneous Amplification and Testing (SAT-TB) Method for monitoring anti-TB treatment response.

Methods

Serial morning sputum specimens were obtained from 377 active pulmonary tuberculosis (PTB) cases at baseline, weeks 2, months 2, 5 and 6 (newly diagnosed patients) or 8 (previously treated patients) for AmpSure assay, smear fluorescence microscopy (FM) and BACTEC MGIT 960 culture assay.

Results

After treatment of 2 weeks, sputum culture was positive in 280 patients (74.27%). Among whom, 219 patients tested positive for SAT-TB assay and 143 patients smear FM positive. The detection rate of SAT-TB (78.21%) was significantly higher than sputum FM (51.07%, χ2 = 45.128, P < 0.001). At the end of the second month of treatment, 157 patients (41.64%) were still culture-positive, 115 patients of them SAT-TB positive and 79 smear FM positive. The difference of detection rate between SAT-TB (73.25%) and sputum FM (50.32%) was significant (χ2 = 17.480, P < 0.001). When patients underwent five months of treatment, 65 patients (17.24%) with sputum culture positive was defined as treatment failure. Among whom, 60 patients (92.31%) were SAT-TB positive and 38 patients (58.46%) were smear FM positive. The detection rate of SAT-TB assay was significantly higher than sputum FM (χ2 = 17.333, P < 0.001).

Conclusion

Results of AmpSure assays for monitoring treatment responses can be obtained without waiting for the results of BACTEC MGIT 960 assays and most patients with treatment failures could be detected after 5 months.

Parallel Tests Using Culture, Xpert MTB/RIF, and SAT-TB in Sputum Plus Bronchial Alveolar Lavage Fluid Significantly Increase Diagnostic Performance of Smear-Negative Pulmonary Tuberculosis

At present, tuberculosis remains a serious threat to human health. The diagnosis of pulmonary tuberculosis (PTB) is still difficult, and the prominent challenge for diagnosis is the lack of a highly sensitive and specific method. In order to explore the diagnostic value of parallel tests, this study prospectively enrolled 258 patients with smear-negative PTB from May 2, 2015 to December 31, 2016. The sputum specimens and bronchial alveolar lavage fluid (BALF) samples from all patients were assessed for MTB detection by culture, Xpert MTB/RIF, and simultaneous amplification and testing method for TB (SAT-TB). Overall, the sensitivity of any single test using culture, Xpert MTB/RIF, or SAT-TB was lower than that for parallel tests (p < 0.05), and the sensitivity rates for MTB detection in BALF were significantly higher than those in sputum samples. There were lower agreements in the detection results between sputum samples and BALF for all tests (p < 0.05). The parallel tests models of using culture plus Xpert MTB/RIF plus SAT-TB, culture plus Xpert, or culture plus SAT-TB achieved higher sensitivities compared with all three single test models (p < 0.05). Additionally, joint detection using sputum and BALF samples achieved a high sensitivity (0.8566, 95% CI: 0.8086-0.8941). In conclusion, the parallel tests model using culture, Xpert MTB/RIF, and SAT-TB in sputum plus BALF significantly increases the diagnostic performance of smear-negative PTB; thus, this method should be applied clinically when PTB is suspected but smear results are negative.