Search

ABSTRACT The performance of a novel selective agar was evaluated against the performance of conventional mycobacterial cultures, i.e., a combination of the mycobacterial growth indicator tube (MGIT) with Löwenstein-Jensen (LJ), for the detection of nontuberculous mycobacteria (NTM) in sputum samples from people with cystic fibrosis (pwCF). Two hundred eighty-three sputum samples (231 fresh sputum and 52 spiked sputum) from 143 pwCF were collected. They were inoculated without prior decontamination on NTM Elite agar (30°C ± 2°C for 28 days) and inoculated on both MGIT and LJ (35°C–37°C for 6–8 weeks) after N-acetyl-L-cysteine-2% sodium hydroxide decontamination. NTM were identified by Matrix-Assisted Laser Desorption Ionization/Time of Flight Mass Spectrometry and/or PCR, and whole-genome sequencing. A total of 67 NTM were recovered overall by the combination of all culture media. NTM Elite agar allowed the recovery of 65 NTM (97%), compared to 22 for the conventional MGIT and LJ media combination (32.8%), including 22 NTM for MGIT (32.8%) and 3 NTM with the LJ medium (4.5%). For Mycobacterium abscessus complex, the sensitivity of NTM Elite agar was 95% compared with a sensitivity of 30% for the conventional MGIT and LJ media combination. Overall, 17.3% of cultures on NTM Elite agar were contaminated with other micro-organisms vs 46.3% on MGIT and 77% on LJ. This study shows that the novel selective agar (NTM Elite agar) significantly outperforms the conventional MGIT and LJ media combination in terms of sensitivity, selectivity, and ease of culture, without the requirement of an L3 laboratory.IMPORTANCENontuberculous mycobacteria (NTM) are significant pulmonary pathogens in patients with pre-existing structural lung conditions such as cystic fibrosis, bronchiectasis, or chronic obstructive pulmonary disease. Mycobacterium avium complex and Mycobacterium abscessus complex (MABSC) are the most frequently isolated organisms. Compared to the recommended culture method for NTM, which combines solid and liquid culture media, NTM Elite agar enables a faster/easier diagnosis and speeds up identification and susceptibility testing as the final reading is at 28 days instead of 6–8 weeks for the conventional mycobacterial cultures. In addition, for the NTM Elite agar, no decontamination stage before inoculation is necessary, unlike the conventional mycobacterial cultures. NTM Elite agar is derived from a formulation of medium adapted to rapidly growing mycobacteria (RGM). The medium enables the growth of RGM while suppressing other flora. It is supported with published clinical data showing the benefits of this medium.

Introduction: The family Mycobacteriaceae contains over 188 species, most of which are saprophytic non-tuberculous mycobacteria (NTM). In wildlife, a variety of different NTM can be found, with different reports about their pathogenic potential. A pathogenic member of NTM is Mycobacterium avium ssp. paratuberculosis (MAP), which can infect farmed and wild ruminants. It causes paratuberculosis which is an economically important chronic disease. Infected farm animals are considered to be the source of infection in wild animals. Wildlife, on the other hand, is thought to be a reservoir for certain members of the Mycobacterium tuberculosis complex (MTBC), such as M. caprae, which causes tuberculosis in cattle and red deer. Methods: Switzerland implemented a surveillance program for tuberculosis in wild animals in 2014. Here, we describe the results from the mycobacterial culture of lymph node samples collected from red deer, roe deer, chamois, ibex, and badgers collected within this surveillance program from 2020 to 2022. Overall, samples from 548 animals were checked macroscopically for tuberculosis-like lesions. Results: In total, 88 animals (16.1%), which either had lesions in their lymph nodes or were male and aged older than 5 years, were investigated using mycobacterial culture. In total, 25 animals (28.4%) were positive for NTM, while no MTBC was detected. The most often identified NTM was M. vaccae, followed by M. avium. Most animals positive for NTM did not show any macroscopic lesions. Furthermore, MAP was isolated from the head lymph nodes of two male red deer. Neither of the two MAP-positive animals had any macroscopic lesions in their head lymph nodes or any other signs of disease. Discussion: The shooting sites of the two MAP-positive animals were located in Alpine pastures used for grazing of cattle during summer, which confirms that species transmission can occur when contaminated pastures are used by different species. In agreement with other studies, the occurrence of MAP in red deer was quite low. However, so far, MAP was mostly isolated from feces and intestinal lymph nodes of wild animals. This is the first detection of MAP in the head lymph nodes of red deer in Switzerland. [ABSTRACT FROM AUTHOR]

Background: The microbial diagnosis of tuberculosis (TB) remains challenging and relies on multiple microbiological tests performed on different clinical specimens. Polymerase chain reactions (PCRs), introduced in the last decades has had a significant impact on the diagnosis of TB. However, questions remain about the use of PCRs in combination with conventional tests for TB, namely microscopy and culture. We aimed to determine the performance of microscopy, culture and PCR for the diagnosis of pulmonary tuberculosis according to the type of clinical specimen in order to improve the diagnostic yield and to avoid unnecessary, time and labor-intensive tests. Methods: We conducted a retrospective study (2008-2018) on analysis (34'429 specimens, 14'358 patients) performed in our diagnostic laboratory located in the Lausanne University Hospital to compare the performance ofmicrobiological tests on sputum, induced sputum, bronchial aspirate and bronchoalveolar lavage (BAL). We analysed the performance using a classical "per specimen" approach and a "per patient" approach for paired specimens collected from the same patient. Results: The overall sensitivities of microscopy, PCR and culture were 0.523 (0.489, 0.557), 0.798 (0.755, 0.836) and 0.988 (0.978, 0.994) and the specificity were 0.994 (0.993, 0.995), 1 (0.999, 1) and 1 (1, 1). Microscopy displayed no significant differences in sensitivity according to the type of sample. The sensitivities of PCR for sputum, induced sputum, bronchial aspirate and BAL were, 0.821 (0.762, 0.871), 0.643 (0.480, 0.784), 0.837 (0.748, 0.904) and 0.759 (0.624, 0.865) respectively and the sensitivity of culture were, 0.993 (0.981, 0.998), 0.980 (0.931, 0.998), 0.965 (0.919, 0.988), and 1 (0.961, 1) respectively. Pairwise comparison of specimens collected from the same patient reported a significantly higher sensitivity of PCR on bronchial aspirate over BAL (p < 0.001) and sputum (p < 0.05) and a significantly higher sensitivity of culture on bronchial aspirate over BAL (p < 0.0001). Conclusions: PCR displayed a higher sensitivity and specificity than microscopy for all respiratory specimens, a rational for a smear-independent PCR-based approach to initiate tuberculosis microbial diagnostic. The diagnosis yield of bronchial aspirate was higher than BAL. Therefore, PCR should be systematically performed also on bronchial aspirates when available. [ABSTRACT FROM AUTHOR]

BackgroundThe microbial diagnosis of tuberculosis (TB) remains challenging and relies on multiple microbiological tests performed on different clinical specimens. Polymerase chain reactions (PCRs), introduced in the last decades has had a significant impact on the diagnosis of TB. However, questions remain about the use of PCRs in combination with conventional tests for TB, namely microscopy and culture. We aimed to determine the performance of microscopy, culture and PCR for the diagnosis of pulmonary tuberculosis according to the type of clinical specimen in order to improve the diagnostic yield and to avoid unnecessary, time and labor-intensive tests.MethodsWe conducted a retrospective study (2008-2018) on analysis (34’429 specimens, 14’358 patients) performed in our diagnostic laboratory located in the Lausanne University Hospital to compare the performance of microbiological tests on sputum, induced sputum, bronchial aspirate and bronchoalveolar lavage (BAL). We analysed the performance using a classical “per specimen” approach and a “per patient” approach for paired specimens collected from the same patient.ResultsThe overall sensitivities of microscopy, PCR and culture were 0.523 (0.489, 0.557), 0.798 (0.755, 0.836) and 0.988 (0.978, 0.994) and the specificity were 0.994 (0.993, 0.995), 1 (0.999, 1) and 1 (1, 1). Microscopy displayed no significant differences in sensitivity according to the type of sample. The sensitivities of PCR for sputum, induced sputum, bronchial aspirate and BAL were, 0.821 (0.762, 0.871), 0.643 (0.480, 0.784), 0.837 (0.748, 0.904) and 0.759 (0.624, 0.865) respectively and the sensitivity of culture were, 0.993 (0.981, 0.998), 0.980 (0.931, 0.998), 0.965 (0.919, 0.988), and 1 (0.961, 1) respectively. Pairwise comparison of specimens collected from the same patient reported a significantly higher sensitivity of PCR on bronchial aspirate over BAL (p < 0.001) and sputum (p < 0.05) and a significantly higher sensitivity of culture on bronchial aspirate over BAL (p < 0.0001).ConclusionsPCR displayed a higher sensitivity and specificity than microscopy for all respiratory specimens, a rational for a smear-independent PCR-based approach to initiate tuberculosis microbial diagnostic. The diagnosis yield of bronchial aspirate was higher than BAL. Therefore, PCR should be systematically performed also on bronchial aspirates when available.

Background and Objectives: Tuberculous pleurisy is a common extrapulmonary TB that poses a health threat. However, diagnosis of TB pleurisy is challenging because of the low positivity rate of pleural effusion mycobacterial culture and difficulty in retrieval of optimal pleural tissue. This study aimed to investigate the efficacy of mycobacterial culture from pleural tissue, obtained by forceps biopsy through medical pleuroscopy, in the diagnosis of TB pleurisy. Materials and Methods: This study retrospectively enrolled 68 TB pleurisy patients. Among them, 46 patients received semi-rigid pleuroscopy from April 2016 to March 2021 in a tertiary hospital. We analyzed the mycobacterial culture from pleural tissue obtained by forceps biopsy. Results: The average age of the study participants was 62.8 years, and 64.7% of them were men. In the pleuroscopic group, the sensitivity of positive Mycobacterium tuberculosis (M. TB) cultures for sputum, pleural effusion, and pleural tissue were 35.7% (15/42), 34.8% (16/46), and 78.3% (18/23), respectively. High sensitivities of M. TB culture from pleural tissue were up to 94.4% and 91.7% when pleural characteristic patterns showed adhesion lesions and both adhesion lesions and presence of micronodules, respectively. Conclusions: M. TB culture from pleural tissue should be considered a routine test when facing unknown pleural effusion during pleuroscopic examination. [ABSTRACT FROM AUTHOR]

The performance of a novel selective agar was evaluated against the performance of conventional mycobacterial cultures, i.e., a combination of the mycobacterial growth indicator tube (MGIT) with Löwenstein-Jensen (LJ), for the detection of nontuberculous mycobacteria (NTM) in sputum samples from people with cystic fibrosis (pwCF). Two hundred eighty-three sputum samples (231 fresh sputum and 52 spiked sputum) from 143 pwCF were collected. They were inoculated without prior decontamination on NTM Elite agar (30°C ± 2°C for 28 days) and inoculated on both MGIT and LJ (35°C-37°C for 6-8 weeks) after N-acetyl-L-cysteine-2% sodium hydroxide decontamination. NTM were identified by Matrix-Assisted Laser Desorption Ionization/Time of Flight Mass Spectrometry and/or PCR, and whole-genome sequencing. A total of 67 NTM were recovered overall by the combination of all culture media. NTM Elite agar allowed the recovery of 65 NTM (97%), compared to 22 for the conventional MGIT and LJ media combination (32.8%), including 22 NTM for MGIT (32.8%) and 3 NTM with the LJ medium (4.5%). For Mycobacterium abscessus complex, the sensitivity of NTM Elite agar was 95% compared with a sensitivity of 30% for the conventional MGIT and LJ media combination. Overall, 17.3% of cultures on NTM Elite agar were contaminated with other micro-organisms vs 46.3% on MGIT and 77% on LJ. This study shows that the novel selective agar (NTM Elite agar) significantly outperforms the conventional MGIT and LJ media combination in terms of sensitivity, selectivity, and ease of culture, without the requirement of an L3 laboratory.IMPORTANCENontuberculous mycobacteria (NTM) are significant pulmonary pathogens in patients with pre-existing structural lung conditions such as cystic fibrosis, bronchiectasis, or chronic obstructive pulmonary disease. Mycobacterium avium complex and Mycobacterium abscessus complex (MABSC) are the most frequently isolated organisms. Compared to the recommended culture method for NTM, which combines solid and liquid culture media, NTM Elite agar enables a faster/easier diagnosis and speeds up identification and susceptibility testing as the final reading is at 28 days instead of 6-8 weeks for the conventional mycobacterial cultures. In addition, for the NTM Elite agar, no decontamination stage before inoculation is necessary, unlike the conventional mycobacterial cultures. NTM Elite agar is derived from a formulation of medium adapted to rapidly growing mycobacteria (RGM). The medium enables the growth of RGM while suppressing other flora. It is supported with published clinical data showing the benefits of this medium., Competing Interests: J.G. is an employee of bioMérieux. The Newcastle upon Tyne Hospitals, UK, represented by John Perry, receive ongoing funding from bioMérieux, France, for the development and evaluation of culture media. UZ Leuven and Munster University Hospital received funding from bioMérieux, France, for the evaluation of NTM culture media.

Background: The diagnosis of Tuberculosis (TB) has been a challenge till the advent of rapid molecular diagnostic tests. The traditional diagnostic tests have its own limitations with regard to its performance or the turnaround time. Truenat MTB Plus assay, a battery-operated molecular assay developed in India has been introduced for its use in pulmonary TB (PTB). However, the diagnostic accuracy of the assay is not well studied in comparison with Mycobacterial culture, especially for extrapulmonary TB (EPTB)., Aim: We aimed at evaluating the diagnostic accuracy of Truenat MTB Plus assay for both PTB and EPTB comparing with culture for adult population., Methods: The specimens from presumptive PTB and EPTB patients were processed for Truenat MTB Plus assay, solid or liquid culture and AFB staining. The electronic data of all the specimen reports collected retrospectively were analysed for the sensitivity and specificity., Results: Out of the 736 samples which had valid culture reports, 364 (49.4 %) were respiratory and 372 (50.6 %) were extrapulmonary specimens. The test positivity rate for smear microscopy, Truenat MTB Plus assay and culture was 3.7 % (27), 8.2 % (60), 7.1 % (52) respectively. Of the 60 Truenat MTB Plus positive patients with TB, 33 (55 %) were PTB and 27 (45 %) were EPTB. We estimated overall sensitivity and specificity of Truenat MTB Plus as 90 % (95 % CI: 73.4-97.8) and 98. 2 (95 % CI:96-99.3) respectively for the detection of PTB. The overall sensitivity and specificity for EPTB was 81.8 % (95 % CI: 59.7-94.8) and 97.4 % (95 % CI: 95.1-98.8) respectively., Conclusions: Truenat MTB Plus assay has comparable diagnostic accuracy with other molecular assays. The Truenat MTB Plus assay can be used for the diagnosis of PTB and EPTB, especially in resource limited settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Indian Association of Medical Microbiologists. Published by Elsevier B.V. All rights reserved.)

Background: Microbiological confirmation of pulmonary tuberculosis (PTB) in children is a well-documented challenge. This study evaluated Xpert Mycobacterium Tuberculosis (MTB)/Rifampicin (RIF) Ultra (Ultra) and mycobacterial cultures in routine clinical care at a tertiary paediatric hospital. Methods: Children treated for PTB and who had at least one respiratory specimen investigated by Ultra and mycobacterial culture before tuberculosis (TB) treatment was commenced were included. The findings of this retrospective study were summarised using descriptive and inferential statistics. Results: A total of 174 children were included. The median age was 2.5 years. Microcytic anaemia, airway compression, cavitary disease and miliary TB were significantly observed in children with microbiologically confirmed TB (cTB). Tuberculosis was microbiologically confirmed in 93 (53.4%) children. The positive yield from testing the first respiratory specimens was 68/174 (39.1%) on Ultra and 82/174 (47.1%) on combined Ultra and mycobacterial culture. In the subset of children (n = 70) tested with Ultra on two sequential respiratory specimens, the incremental yield from the second specimen was 30.3%. In the subset of children (n = 16) tested with Ultra on three sequential respiratory specimens, the incremental yield from the second and third specimens was 16.7% and 0.0%, respectively. When Ultra and mycobacterial culture results were combined, the incremental yield in children who had two sequential respiratory specimens tested was 24.4% and 3.1% on Ultra and mycobacterial culture, respectively. Conclusion: Ultra and mycobacterial culture on a single respiratory specimen resulted in a high microbiological yield. Ultra-testing on a second respiratory specimen increased the yield of microbiologically cTB. Additional diagnostic testing may require further study.

Background: Female genital tuberculosis (FGTB) is an underobserved clinical entity owing to diagnostic challenges stemming from difficulty of obtaining diagnostic specimens and paucibacillary nature of the disease. Yet, FGTB is a cause of infertility, pelvic pain, or menstrual irregularities in high-burden countries. To assess laboratory and microbiology diagnostic utilization for FGTB in Pakistan, we have collected data from 2007 to 2016 to inform the need for improved laboratory diagnostics. The objectives of this study were to determine the proportion of FGTB as culture-confirmed extrapulmonary tuberculosis (EPTB) and to describe the characteristics of women with culture-confirmed FGTB in a nationwide laboratory network in Pakistan. Method: A retrospective database was established by accessing laboratory archives and analyzed by sex and source to determine extrapulmonary cases among women. Data were checked for quality, and after removing patient identifiers and duplicate samples, frequencies were calculated in MS Excel. Clinical characteristics of patients were derived from a linked hospital database for those patients who were diagnosed and managed at the affiliated university hospital in Karachi, Pakistan. Results: Over 10 years, 410,748 mycobacterial cultures were received from multiple geographic sites throughout Pakistan and processed at the study laboratory. The overall mean culture positivity rate was 5.9% ± 3.5%, while the mean culture positivity rate among females was 2.8% ± 0.8%. Among female culture-confirmed tuberculosis cases, the pulmonary-to-EPTB ratio of infection was 5. Over 10 years, a total of 32 FGTB cases were reported on the basis of positive cultures for Mycobacterium tuberculosis; 3 (9.4%) were rifampin resistant. Conclusions: FGTB currently constitutes a small but significant proportion of culture-confirmed EPTB. A fewer number of laboratory requisitions suggest the need to increase awareness and testing. The advent of high-sensitivity molecular testing on extrapulmonary specimens has the potential to improve diagnostic accuracy and improved detection of FGTB cases in high-burden regions.

배경: 항산균 검사를 위한 호흡기 검체는 점액과 상재균 제거를 위해 N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH)로 전처리한 후, 인산완충용액으로 세척과 중화를 거치게 된다. 본 연구에서는 인산완충용액대신에 증류수 사용에 대한 유용성을 평가하고자 하였다.방법: 2016년 10월부터 2018년 9월까지 2년 동안 광주 소재 종합 병원에서 진행된 항산균검사를 분석했다. 호흡기검체의 전처리 세척제로 인산완충용액과 증류수를 각각 1년씩 사용하여 검사하였다.결과: 배양 양성률은 인산완충용액 사용시기에 12.7% (1,843/14,532), 증류수 사용시기에 14.7% (2,095/14,291)였다. MGIT의 양성률과 MTBC와 NTM의 분리비는 변화가 없었다. 그러나 2% Ogawa media에서는 NTM의 배양이 47.4% (399/841)에서 56.1% (630/1,122)로 증가함에 따라 양성률이 45.6% (841/1,843)에서 53.6% (1,121/2,095)로 증가하였다. MGIT 오염률은 6.5%에서 4.1% 로 감소하였다결론: NALC-NaOH 세척제로 증류수를 사용하는 것은 MGIT의 오염률은 감소시키면서 Ogawa media의 양성률을 증가시켰다. 따라서, 항산균 배양 검사에서 전처리 세척제로 인산완충용액대신 증류수 사용도 유용할 것으로 사료된다.

Objectives: To characterise and describe the diagnostic utility of Endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) in intrathoracic tuberculosis in a cohort of patients with mediastinal lymphadenopathy of unknown aetiology.Methods: Consecutive patients with intrathoracic lymphadenopathy undergoing EBUS-TBNA between 2012 and 2016 were identified. Demographic data, biopsy cytopathology and mycobacteriology results, HIV and vitamin D status, susceptibility results and final diagnoses were recorded. Pre- and post-procedure probability scores were assigned to each case to reflect the probability of tuberculosis.Results: 315 cases were identified; 54 (17.1%) had tuberculosis and 261 (82.9%) had a non-tuberculosis diagnosis. amongst TB cases, the sensitivity of EBUS-TBNA was 59.3% (95% CI 45.06-72.14), specificity 100% (95% CI 98.19-100) and the negative predictive value (NPV) was 92.23% (95% CI 88.31-94.95). 19/54 (35%) TB cases were confirmed by EBUS mycobacterial culture and 13/54 (24.1%) by cytopathology.  33 (61.1%) of the TB cases, had a low to medium pre-test probability score assigned prior to EBUS-TBNA. Amongst EBUS culture-confirmed cases, we found a resistance rate of 10.5% to one or more first line TB drugs, with one case of multi-drug resistant TB.Conclusions: We confirmed the utility of EBUS-TBNA in the diagnosis of intrathoracic tuberculosis in an undifferentiated cohort of patients with mediastinal lymphadenopathy of unknown aetiology and advocate sending samples for mycobacterial culture in all cases in high tuberculosis incidence areas. [ABSTRACT FROM AUTHOR]

Background: Microbiological confirmation of pulmonary tuberculosis (PTB) in children is a well-documented challenge. This study evaluated Xpert Mycobacterium Tuberculosis (MTB)/Rifampicin (RIF) Ultra (Ultra) and mycobacterial cultures in routine clinical care at a tertiary paediatric hospital. Methods: Children treated for PTB and who had at least one respiratory specimen investigated by Ultra and mycobacterial culture before tuberculosis (TB) treatment was commenced were included. The findings of this retrospective study were summarised using descriptive and inferential statistics. Results: A total of 174 children were included. The median age was 2.5 years. Microcytic anaemia, airway compression, cavitary disease and miliary TB were significantly observed in children with microbiologically confirmed TB (cTB). Tuberculosis was microbiologically confirmed in 93 (53.4%) children. The positive yield from testing the first respiratory specimens was 68/174 (39.1%) on Ultra and 82/174 (47.1%) on combined Ultra and mycobacterial culture. In the subset of children (n = 70) tested with Ultra on two sequential respiratory specimens, the incremental yield from the second specimen was 30.3%. In the subset of children (n = 16) tested with Ultra on three sequential respiratory specimens, the incremental yield from the second and third specimens was 16.7% and 0.0%, respectively. When Ultra and mycobacterial culture results were combined, the incremental yield in children who had two sequential respiratory specimens tested was 24.4% and 3.1% on Ultra and mycobacterial culture, respectively. Conclusion: Ultra and mycobacterial culture on a single respiratory specimen resulted in a high microbiological yield. Ultra-testing on a second respiratory specimen increased the yield of microbiologically cTB. Additional diagnostic testing may require further study. [ABSTRACT FROM AUTHOR]

Objectives: Mycobacterium xenopi is a nontuberculous mycobacterium (NTM) whose clinical diagnosis and drug susceptibility studies are frequently hampered by poor in vitro growth. Extending the culture incubation time from 42 days (common-standard) to 56 days could improve the likelihood of diagnosis and provide strains for phenotypic drug susceptibility profiling of this poorly studied but clinically relevant mycobacterium. Methods: Time-to-positivity of mycobacterial cultures incubated for 56 days were analysed and compared. Clinical mycobacteriosis was defined by ATS/IDSA criteria. In vitro susceptibility of M. xenopi isolates was tested by broth microdilution. Results: Of 3852 mycobacteria-positive cultures (26 different mycobacterial species),M. xenopi required by far the longest growth time in culture, exceeding the 42 days commonly used in routine diagnostics in 41.2% of cases versus 4.7% for other NTM and 2.0% for Mycobacterium tuberculosis complex (P

Tuberculosis remains a significant global health issue, with spinal tuberculosis being a severe form of extrapulmonary tuberculosis. Despite the high morbidity associated with spinal tuberculosis, effective and rapid diagnostic methods are limited. The aim of this study was to evaluate the diagnostic accuracy of the GeneXpert compared to other microbiological methods in diagnosing spinal tuberculosis. A systematic review and meta-analysis were conducted following the PRISMA guidelines. Six databases (PubMed, Scopus, EBSCO, EMBASE, ScienceDirect, and Cochrane Central) were searched for relevant studies as of August 31, 2023. Studies were selected based on predefined inclusion criteria, focusing on patients diagnosed with spinal tuberculosis and comparing GeneXpert to microbiological culture, acid-fast bacilli (AFB) staining, and polymerase chain reaction (PCR). Two authors independently performed data extraction and quality assessment, and the meta-analysis was conducted using Meta-DiSc 2.0. Fourteen studies comprising retrospective cohort, prospective cohort, and cross-sectional designs were included. GeneXpert demonstrated a pooled sensitivity of 92% (85-96%) and specificity of 71% (51-86%) compared to culture. AFB smear had the highest specificity at 80% (70- 88%) but the lowest sensitivity at 27% (20-35%). The PCR had sensitivity and specificity of 83% (67-92%) and 58% (31-81%), respectively. Substantial heterogeneity was noted across the studies. This study highlighted that GeneXpert had high sensitivity and moderate specificity in diagnosing spinal tuberculosis, making it an alternative to conventional methods. However, further validation through larger, interventional studies is necessary to standardize its use in clinical practice., Competing Interests: All the authors declare that there are no conflicts of interest., (© 2024 The Author(s).)

Background and Objectives: Tuberculous pleurisy is a common extrapulmonary TB that poses a health threat. However, diagnosis of TB pleurisy is challenging because of the low positivity rate of pleural effusion mycobacterial culture and difficulty in retrieval of optimal pleural tissue. This study aimed to investigate the efficacy of mycobacterial culture from pleural tissue, obtained by forceps biopsy through medical pleuroscopy, in the diagnosis of TB pleurisy. Materials and Methods: This study retrospectively enrolled 68 TB pleurisy patients. Among them, 46 patients received semi-rigid pleuroscopy from April 2016 to March 2021 in a tertiary hospital. We analyzed the mycobacterial culture from pleural tissue obtained by forceps biopsy. Results: The average age of the study participants was 62.8 years, and 64.7% of them were men. In the pleuroscopic group, the sensitivity of positive Mycobacterium tuberculosis (M. TB) cultures for sputum, pleural effusion, and pleural tissue were 35.7% (15/42), 34.8% (16/46), and 78.3% (18/23), respectively. High sensitivities of M. TB culture from pleural tissue were up to 94.4% and 91.7% when pleural characteristic patterns showed adhesion lesions and both adhesion lesions and presence of micronodules, respectively. Conclusions: M. TB culture from pleural tissue should be considered a routine test when facing unknown pleural effusion during pleuroscopic examination.

Background We describe the performance of GeneXpert MTB/RIF (Xpert) for diagnosing tuberculosis (TB) among symptomatic household contacts (HHCs) of rifampicin-resistant and drug-sensitive index cases. Methods We conducted a cross-sectional study among HHCs of recently diagnosed (<2 weeks) smear-positive and Xpert-positive index cases in the Bojanala District, South Africa. The HHCs were screened for TB symptoms; persons with ≥1 TB symptom provided 1 sputum for smear microscopy, Xpert, and mycobacterial growth indicator tube (MGIT) culture. Diagnostic test performance of Xpert was determined using MGIT as the reference standard. Results From August 2013 to July 2015, 619 HHCs from 216 index cases were enrolled: 60.6% were female, median age was 22 years (interquartile range, 9–40), and 126 (20.4%) self-reported/tested human immunodeficiency virus positive. A total of 54.3% (336 of 619) of contacts had ≥1 TB symptom (cough, fever, night sweats, weight loss), 297 of 336 (88.4%) of which provided a sputum; 289 (97.3%) had complete testing and 271 were included in the analysis. In total, 42 (6.8%) of 619 HHCs had microbiologically confirmed TB. The MGIT identified 33 HHCs as positive for Mycobacterium tuberculosis ; of these, 7 were positive on Xpert resulting in a sensitivity of 21.2% (95% confidence interval [CI], 9.0–38.9), specificity of 98.3% (95% CI, 95.6–99.5), positive predictive value of 63.6% (95% CI, 30.8–89.1), and negative predictive value of 90.0 (95% CI, 85.7–93.4). Conclusions Among symptomatic HHCs investigated for TB, Xpert performed suboptimally compared with MGIT culture. The poor performance of Xpert for diagnosing TB suggests that a more sensitive test, such a Xpert Ultra or culture, may be needed to improve yield of contact investigation, where feasible. [ABSTRACT FROM AUTHOR]

Background: Female genital tuberculosis (FGTB) is an underobserved clinical entity owing to diagnostic challenges stemming from difficulty of obtaining diagnostic specimens and paucibacillary nature of the disease. Yet, FGTB is a cause of infertility, pelvic pain, or menstrual irregularities in high-burden countries. To assess laboratory and microbiology diagnostic utilization for FGTB in Pakistan, we have collected data from 2007 to 2016 to inform the need for improved laboratory diagnostics. The objectives of this study were to determine the proportion of FGTB as culture-confirmed extrapulmonary tuberculosis (EPTB) and to describe the characteristics of women with culture-confirmed FGTB in a nationwide laboratory network in Pakistan. Method: A retrospective database was established by accessing laboratory archives and analyzed by sex and source to determine extrapulmonary cases among women. Data were checked for quality, and after removing patient identifiers and duplicate samples, frequencies were calculated in MS Excel. Clinical characteristics of patients were derived from a linked hospital database for those patients who were diagnosed and managed at the affiliated university hospital in Karachi, Pakistan. Results: Over 10 years, 410,748 mycobacterial cultures were received from multiple geographic sites throughout Pakistan and processed at the study laboratory. The overall mean culture positivity rate was 5.9% ± 3.5%, while the mean culture positivity rate among females was 2.8% ± 0.8%. Among female culture-confirmed tuberculosis cases, the pulmonary-to-EPTB ratio of infection was 5. Over 10 years, a total of 32 FGTB cases were reported on the basis of positive cultures for Mycobacterium tuberculosis; 3 (9.4%) were rifampin resistant. Conclusions: FGTB currently constitutes a small but significant proportion of culture-confirmed EPTB. A fewer number of laboratory requisitions suggest the need to increase awareness and testing. The advent of high-sensitivity molecular testing on extrapulmonary specimens has the potential to improve diagnostic accuracy and improved detection of FGTB cases in high-burden regions. [ABSTRACT FROM AUTHOR]

We discuss a case of a 60-year-old man with no known comorbidities who presented with sudden onset severe haemoptysis and chest pain. Sputum and pleural fluid smears for acid fast bacillus and Gene-Xpert were repeatedly negative. Pleural fluid cytology demonstrated presence of fungal organisms with hyphae and serum IgE was elevated. The patient developed a haemorrhagic pericardial effusion and cardiac tamponade. Sputum mycobacterial culture after 7 weeks was positive for Mycobacterium tuberculosi. This case highlights the difficulties that may be associated with diagnosis of PTB in the acute clinical setting and the importance of mycobacterial culture, particularly in the presence of negative initial investigations and superadded non-tuberculous infections. Furthermore, it demonstrates the potential clinical course of MTB infection, including development of severe extra-pulmonary complications. Finally, it highlights the importance of the multidisciplinary team in assessing the need to presumptively start anti-TB medication in selected cases.

Background: Mozambique is among the highest tuberculosis, tuberculosis–HIV and multidrug-resistant-tuberculosis burden countries. Although molecular technologies are available in-country, mycobacterial isolation through culture remains an important tool for tuberculosis diagnostics and drug susceptibility testing. Objective: We evaluated the use of the Ogawa-Kudoh (OK) mycobacterial culture, a simple technique, to isolate Mycobacterium tuberculosis in two health units, in Maputo City, Mozambique. Methods: From May to December 2014, 122 patient samples were collected in Chamanculo General Hospital and Polana Caniço General Hospital. The specimens were first tested in the health units using the OK method and afterwards shipped to the National Tuberculosis Reference Laboratory for mycobacterial culture using the NALC-NaOH-Citrate (NALC) decontamination method followed by inoculation in Lowenstein Jensen (LJ) solid media as the reference standard. Results: Among 107 samples with valid results, 98 (91.6%) had concordant results in both methods; 9 (8.4%) had discordant results. The contamination rate was 4.1% (5/122) for the OK and 9.0% (11/122) for the NALC/LJ methods. The sensitivity of OK was 80% (95% confident interval [CI]: 51.4–94.7) and the specificity was 94% (95% CI: 85.8–97.3). The degree of agreement between both methods was moderate (Kappa: 0.68; 95% CI: 0.48–0.89). Conclusion: The OK method showed satisfactory sensitivity and specificity. The method also had a lower contamination rate when compared to the NALC/LJ. Similar to other studies in resource-limited settings, our findings showed that the OK method can effectively be implemented in settings with limited laboratory capacity to isolate tuberculosis bacteria by culture for further testing.

The GENEDIA MTB/NTM Detection Kit (GENEDIA MTB/NTM; Green Cross Medical Science Corp., Chungbuk, Korea) is a multiplex real-time PCR assay used for differential identification of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM). While the importance of differential identification of MTB/NTM is recognized, there is limited data on the performance of GENEDIA MTB/NTM assay to date. A total of 687 consecutive sputum specimens were cultured and analyzed with the GENEDIA MTB/NTM and GENEDIA MTB assays. Nineteen specimens (2.8%) were MTBC-positive, and 69 (10.0%) were NTM-positive based on mycobacterial culture. All specimens showed concordant results for MTBC using both assays, with a kappa value of 1.00, overall sensitivity of 63.2% (12/19), and specificity of 100% (668/668). The overall NTM sensitivity and specificity were 23.2% (16/69) and 99.7% (616/618) for GENEDIA MTB/NTM. The association between NTM-positivity using GENEDIA MTB/NTM and the diagnosis of NTM pulmonary disease was not statistically significant. In conclusion, the two real-time PCR assays showed similar diagnostic performance for MTBC detection. However, the sensitivity for NTM detection was lower than that for MTBC detection. [ABSTRACT FROM AUTHOR]

Background: Mozambique is among the highest tuberculosis, tuberculosis–HIV and multidrug-resistant-tuberculosis burden countries. Although molecular technologies are available in-country, mycobacterial isolation through culture remains an important tool for tuberculosis diagnostics and drug susceptibility testing. Objective: We evaluated the use of the Ogawa-Kudoh (OK) mycobacterial culture, a simple technique, to isolate Mycobacterium tuberculosis in two health units, in Maputo City, Mozambique. Methods: From May to December 2014, 122 patient samples were collected in Chamanculo General Hospital and Polana Caniço General Hospital. The specimens were first tested in the health units using the OK method and afterwards shipped to the National Tuberculosis Reference Laboratory for mycobacterial culture using the NALC-NaOH-Citrate (NALC) decontamination method followed by inoculation in Lowenstein Jensen (LJ) solid media as the reference standard. Results: Among 107 samples with valid results, 98 (91.6%) had concordant results in both methods; 9 (8.4%) had discordant results. The contamination rate was 4.1% (5/122) for the OK and 9.0% (11/122) for the NALC/LJ methods. The sensitivity of OK was 80% (95% confident interval [CI]: 51.4–94.7) and the specificity was 94% (95% CI: 85.8–97.3). The degree of agreement between both methods was moderate (Kappa: 0.68; 95% CI: 0.48–0.89). Conclusion: The OK method showed satisfactory sensitivity and specificity. The method also had a lower contamination rate when compared to the NALC/LJ. Similar to other studies in resource-limited settings, our findings showed that the OK method can effectively be implemented in settings with limited laboratory capacity to isolate tuberculosis bacteria by culture for further testing. [ABSTRACT FROM AUTHOR]

This single center study assessed the performance of a novel solid rapidly-growing mycobacteria (RGM) medium for the recovery of nontuberculous mycobacteria (NTM), especially Mycobacterium abscessus complex, in patients with underlying bronchiectasis. A total of 297 mycobacterial sputa from 116 patients were plated directly on RGM medium and, following decontamination, onto an agar biplate [Middlebrook 7H11 and Mitchison (selective) agar] and into broth media (VersaTrek). The recovery of M. abscessus complex was increased by approximately 12% by implementation of the RGM medium. Contamination was reduced to 2% from 48% and 95% on routine solid media and broth cultures respectively. Our study corroborated previous studies in that recovery of M. abscessus complex was enhanced and contamination was virtually eliminated without the need for specimen decontamination when utilizing RGM medium.

Mycobacterial culture remains the gold standard for detection of Mycobacterium tuberculosis (MTB) in clinical samples. However, no external quality assessment (EQA) tools exist to validate results obtained using this sophisticated method. Therefore, we developed EQA panels to assess the quality of mycobacterial culture results produced by designated TB hospitals in China. Artificial sputum containing methylcellulose was used to supplement quantified mycobacterial solutions to simulate culture-negative and culture-positive clinical sputum samples of low or high mycobacterial concentration, respectively. After storage of the quantified simulated EQA panels for 4 weeks at 4 °C, experimental bacterial quantification of the panels was again conducted, with no impact of artificial sputum on mycobacterial culture results observed. Next, 47 tuberculosis (TB) hospitals were recruited for evaluation of the EQA panels. Overall, 29 hospitals (61.7%) produced mycobacterial culture test results matching expected results for the EQA panels, while the remaining 18 (38.3%) hospitals did not. False-negative results for the low mycobacterial concentration panel sample accounted for 33 (73.3%) diagnostic errors. Compared with hospitals using solid culture methods as a control group, hospitals using the liquid culture method were less likely to produce uncertified results (aOR 0.064, 95% CI 0.005–0.770). In conclusion, we first developed then evaluated EQA panels for validation of mycobacterial culture testing in China. Our data demonstrate that approximately one-third of TB hospitals failed to produce results that met criteria for classification as certified mycobacterial culture testing providers, emphasizing the importance of quality control and quality assurance in TB diagnostics. [ABSTRACT FROM AUTHOR]

The diagnosis of mycobacterial infections has been dramatically improved by the introduction of molecular methods aimed to reduce the time to diagnosis as compared with culture. The broad range pan-mycobacterial PCR can detect all the mycobacterial species directly from clinical specimens. We aimed to evaluate its usefulness and its clinical added value for the diagnosis of nontuberculous mycobacterial (NTM) infections. We performed a retrospective study (2003–2013) including 952 samples taken from 639 patients with clinical suspicion of NTM infection. The performance of smear microscopy, PCR and culture was established using clinical data to investigate discrepant results. We also compared the time to microbial diagnosis between the direct PCR and culture. The sensitivity, specificity, positive and negative predictive values of the PCR were 61.6% (53.5–69.1), 99.1% (98.2–99.6), 92.8% (85.8–96.5) and 93.4% (91.6–94.9), respectively, when considering all specimens. When considering smear-positive specimens and smear-negative specimens, the sensitivity was 81.6% and 40%, respectively. The sensitivity for pulmonary and extra-pulmonary smear-positive specimens was 85.2% versus 72.7%. The median time to identification at species level was 35 days (SD, 17.67) for culture and 6 days (SD, 2.67) for the PCR (when positive), which represents a 29-day shorter time to results (p < 0.0001). The 16S rRNA gene pan-mycobacterial PCR displays a substantial benefit in terms of time to diagnose NTM infections when compared with culture. Despite an excellent specificity, its sensitivity is yet limited in particular for smear-negative specimens, which might be improved by relying onto real-time PCRs. [ABSTRACT FROM AUTHOR]

This study describes clinical and histopathological features, treatment, and outcome of cats diagnosed with ocular mycobacteriosis. Cases diagnosed from 2012 to 2017 were reviewed for (a) histopathological evidence of ocular (pyo)granulomatous inflammation containing acid-fast bacilli with mycobacterial morphology, (b) positive mycobacterial culture and/or mycobacterial DNA identified by polymerase chain reaction of ocular tissue, or (c) presumed mycobacteriosis based on ophthalmic examination and positive interferon-gamma release assay. Twenty-five cats (31 eyes) were included; 14 cats (17/31 eyes, 55%) were blind at presentation (unilateral: n = 12 cats; bilateral: n = 2 cats); one unilaterally affected cat later became bilaterally blind. Another 5 cats (7/31 eyes, 23%) became blind after initially being bilaterally visual (unilateral: n = 3 cats; bilateral: n = 2 cats). The commonest ocular finding was uveitis (87%). The main histopathological features were granulomatous to pyogranulomatous chorioretinitis with retinal detachment, anterior uveitis, optic neuritis, episcleritis, scleritis, and/or retrobulbar cellulitis. Nineteen cats (76%) had systemic signs, with disseminated disease being diagnosed in 9, defined by interstitial pulmonary disease, generalized lymphadenopathy, and/or nonocular infection. Nine cats were diagnosed with Mycobacterium bovis, 2 with Mycobacterium microti, 1 with Mycobacterium tuberculosis complex, and 1 with Mycobacterium avium-intracellulare complex. The infecting species was unknown in the remaining cats. Combined surgery (enucleation: n = 5 cats; biopsy: n = 3 cats) and systemic treatment with 2 or 3 appropriate antibiotics for 2 to 7 months resulted in remission in 8 of the 10 cats treated; however, the cat treated with dual therapy relapsed after 8 months. A total of 16 cats (64%) were euthanized; 2 were lost to follow-up. [ABSTRACT FROM AUTHOR]

The diagnosis of childhood tuberculosis is a challenge due to the pauci-bacillary nature of infection and the difficulty in obtaining appropriate sample. In the past 2-3 decades, many new tests were introduced for the diagnosis of tuberculosis (TB) and some of them have been evaluated for their application in pediatric tuberculosis as well. There is an attempt to improve smear microscopy by introducing light-emitting diode (LED) fluorescence microscopy and there are also some automated digital microscopy platforms under evaluation. Introduction of automated liquid culture platform along with rapid molecular based identification methods have considerably reduced the time delay in mycobacterial culture. Recent addition of many nucleic acid amplification platforms like Amplicor PCR, Genprobe, Xpert MTB/Rif, line probe assays, loop mediated isothermal amplification etc are also been found to be useful. Latest techniques like microarray and gene sequencing are also being used in clinical laboratories with variable results. Indirect methods of TB diagnosis like T cell based assays including tuberculin skin test and interferon-gamma release assays have their role primarily in the diagnosis of latent TB. Biomarkers are the latest addition in the battery of TB diagnostic tests facilitating diagnosis using easily accessible samples like urine, blood and breath of patients. Many biomarkers are still under evaluation and some of them are found to have a potential role as promising diagnostic tests of future. [ABSTRACT FROM AUTHOR]

Background Mycobacterial culture is the gold standard test for diagnosing tuberculosis (TB), but it is time-consuming. Polymerase chain reaction (PCR) is a highly sensitive and specific method that can reduce the time required for diagnosis. The diagnostic efficacy of PCR differs, so this study determined the actual sensitivity of TB-PCR in tissue specimens. Methods We retrospectively reviewed 574 cases. The results of the nested PCR of the IS6110 gene, mycobacterial culture, TB-specific antigen-induced interferon-γ release assay (IGRA), acid-fast bacilli (AFB) staining, and histological findings were evaluated. Results The positivity rates were 17.6% for PCR, 3.3% for the AFB stain, 22.2% for mycobacterial culture, and 55.4% for IGRA. PCR had a low sensitivity (51.1%) and a high specificity (86.3%) based on the culture results of other studies. The sensitivity was higher (65.5%) in cases with necrotizing granuloma but showed the highest sensitivity (66.7%) in those with necrosis only. The concordance rate between the methods indicated that PCR was the best method compared to mycobacterial culture, and the concordance rate increased for the methods using positive result for PCR or histologic features. Conclusions PCR of tissue specimens is a good alternative to detect tuberculosis, but it may not be as sensitive as previously suggested. Its reliability may also be influenced by some histological features. Our data showed a higher sensitivity when specimens contained necrosis, which indicated that only specimens with necrosis should be used for PCR to detect tuberculosis.

Mycobacterial culture provides definitive diagnosis of tuberculosis (TB), but commercially readyto-use culture media for Mycobacterium bovis are rarely available. The aims of this study were todevelop and to evaluate the ability of M. Bovis to grow in Modified Ogawa Agar (MOA) in comparisonwith the available culture media, such as Löwenstein Jensen (LJ) and Modified Ogawa (MO). Eachmedia were inculation with 0.1 ml suspension of 105 CFU/mL M. bovis and M. phlei in PhosphateBuffer Saline (PBS) and each media was replicated in five tubes. Mycobacterium phlei grew in everymedium since day 4. M. bovis grew in media LJ and MO since day 17, but failed to grow in mediumMOA. The recovery rate of M. phlei in LJ and MOA were significantly different. The ability of MOA tocultivate M. phlei was different from LJ. Colonies of M. phlei in MOA were easier to be harvested, muchsimpler to prepare, and more feasible than medium LJ. The recovery rate of M. bovis in media LJ andMO were not significantly different, but medium MO were much simpler to prepare and more feasiblethan medium LJ. Media MOA were able to cultivate M. phlei, but proven unable to cultivate M. bovisin this research.

Chronic respiratory tract infection by Pseudomonas aeruginosa is the hallmark of established lung disease in patients with cystic fibrosis (CF). Antibiotic therapy can usually only suppress but not eradicate infection. In recent years, pulmonary infection with non-tuberculous Mycobacteria (NTM) species has also been increasing. These patients are often colonised with multiple isolates and determination of clinical significance of each isolate is difficult. The clinical value of frequent routine susceptibility testing of individual isolates is unproven, particularly since a delay in susceptibility testing is inevitable when purification of multiple cultured isolates is required to test each isolate separately. From August 2019 until December 2020 we ceased routine susceptibility testing on P. aeruginosa respiratory tract isolates from patients with CF if a previous isolate from the patient had susceptibility testing performed. We found that the proportion of P. aeruginosa isolates that had susceptibility testing performed dropped from 97% to 11% as a result of this change in laboratory process. During this time, we also ceased routine culture for acid-fast bacilli if this had been performed within the previous 6 months. We present the cost and resource savings for these changes in laboratory process and assess for clinical impact measured as hospital admissions, length of stay in hospital and mortality., (Copyright © 2023 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Abstract Objectives The primary objective was to determine the association between histopathological and microbiological findings in patients clinically suspected to have tuberculous lymphadenitis. A secondary objective was to assess the diagnostic utility of GeneXpert in lymph node specimens. Method This was a single-centre prospective cohort study, performed in the Infectious Disease Clinic at The Indus Hospital. Three hundred and forty-one adult patients with chronically enlarged, accessible lymph nodes were enrolled after obtaining verbal consent, between February 2013 and April 2016. Tissue specimens were processed for histopathology, acid-fast bacillus (AFB) microscopy, AFB culture, and GeneXpert. Based on these results, anti-tuberculosis therapy (ATT) was prescribed. Clinical characteristics and treatment outcomes were recorded. Results There were 297 evaluable patients; 74.4% were diagnosed with tuberculous lymphadenitis (TBLA), 6.7% with a malignancy, and 12.8% with reactive nodes. TBLA was diagnosed on suggestive histopathology in 89.6% of cases, followed by GeneXpert (32.6%), mycobacterial culture (26.6%), and AFB smear positivity (12.5%). The sensitivity of GeneXpert was 65.7% when assessed against AFB culture. Drug resistance was displayed by 8.2% of GeneXpert-positive cases and 11.7% of culture-positive cases. The majority of TBLA patients (88.7%) responded favorably to ATT. Conclusions In light of laboratory evidence, a quarter of patients suspected of TBLA had an alternative diagnosis, highlighting its importance in avoiding over-treatment and diagnostic delays in malignancy. Although sensitivity is poor, the demonstration of drug resistance by both GeneXpert and AFB culture represents a useful tool to guide treatment. [ABSTRACT FROM AUTHOR]

Non Tuberculous Mycobacteria (NTM) are a group of rapidly growing mycobacteria and are generally considered to be of low virulence. Of late, there has been an increase in incidence of infections due to these organisms. Among them, Mycobacterium fortuitum, M. chelonae and M. abscessus are the common species which have been identified. Though they are occasionally implicated in pulmonary infections, NTM are very commonly associated with cutaneous infections, especially surgical site infections. Identification of NTM infection at such sites should be suspected when there is delayed healing of the wound. Histopathological Examination (HPE) of the wound site may reveal a classical picture of granulomas, epithelioid cells and giant cells which may lead to a suspicion of tuberculosis. It is important to perform mycobacterial culture and sensitivity testing of the wound tissue as this helps to differentiate tuberculous and non tuberculous infections. Here, we present a case of a patient who underwent mesh hernioplasty for umbilical hernia and was diagnosed with M. fortuitum infection at the site of umbilical hernioplasty.

Objective The influence of anti-tuberculosis (TB) treatment history on tuberculous lymphadenitis (TBLN) diagnosis is unclear. Therefore, this study aims to evaluate the diagnostic methods, including histology, microbiology, and molecular tests, used for TBLN. Methods In this study, suspected patients with TBLN and having different anti-TB treatment background were enrolled. All the samples were tested simultaneously by histology, Ziehl-Neelsen (ZN) staining, mycobacterial culture (culture), Xpert MTB/RIF (xpert), real-time PCR, and high-resolution melting curve PCR (HRM). Thereafter, the performance of these methods on samples with different anti-TB treatment background was assessed. Results In our study, 89 patients were prospectively included 82 patients with TBLN and 7 with other diseases. The overall sensitivities of Xpert, real-time PCR, histology, ZN staining, and culture were 86.6%, 69.5%, 58.5%, 43.9%, and 22.0%, respectively. The anti-TB treatment history revealed dramatic influences on the sensitivity of culture ( P < 0.0001). In fact, the treatment that lasted over 3 months also influenced the sensitivity of Xpert ( P < 0.05). However, the treatment history did not affect the performance of remaining tests ( P > 0.05). For rifampicin drug susceptibility test (DST), the anti-TB treatment showed only significant influence on the success rate of culture DST ( P = 0.001), but not on those of Xpert and HRM tests ( P > 0.05). Conclusion Other tests as well as culture should be considered for patients with TBLN having retreatment history or over 1-month treatment to avoid false negative results. [ABSTRACT FROM AUTHOR]