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Objectives: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potent tool for detecting drug resistance in tuberculosis (TB); however, concerns about its reliability have been raised. In this study, we assessed the reliability of MassARRAY (Sequenom, Inc.), which is a MALDI-TOF MS-based method, by comparing it to the wellestablished GeneXpert assay (Cepheid) as a reference method. Methods: A retrospective study was conducted using laboratory data retrieved from Henan Chest Hospital (Zhengzhou, China). To ensure a rigorous evaluation, we adopted a comprehensive assessment approach by integrating multiple outcomes of the Xpert assay across various specimen types. Results: Among the 170 enrolled TB cases, MassARRAY demonstrated significantly higher sensitivity (85.88%, 146 of 170) compared to the Xpert assay (76.62%, 118 of 154) in TB diagnosis (p < 0.05). The concordance in detecting rifampicin resistance between MassARRAY and the combined outcomes of the Xpert assay was 90%, while it was 97.37% (37 of 38) among smear-positive cases and 89.06% (57 of 64) among culture-positive cases. When compared to the phenotypic susceptibility outcomes of the 12 included drugs, consistency rates of 81.8 to 93.9% were obtained, with 87.9% for multiple drug resistance (MDR) identification. Conclusion: MassARRAY demonstrates high reliability in detecting rifampicin resistance, and these findings may offer a reasonable basis for extrapolation to other drugs included in the test panel. [ABSTRACT FROM AUTHOR]

Background: In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using specimens collected by bronchoscopy in a tertiary care center. Methods: Bronchoscopy specimens received in the TB laboratory were processed by microscopy, Xpert MTB/RIF assay, LPA, and mycobacteria growth indicator tube (MGIT) culture. Results of MGIT culture are considered gold standard. Results: Of the 173 specimens tested, MTB was detected in 48 (27.74%) samples by any of the above methods. Positivity in bronchoalveolar lavage was 31.4% (44/140) and in bronchial wash was 12.1% (4/33). Detection by microscopy, Xpert assay, and culture was 20 (11.56%), 45 (26.01%), and 38 (21.96%), respectively. Culture detected MTB in three additional specimens compared to Xpert assay. Xpert assay detected MTB in 45 (26%) specimens which include 10 specimens which were negative by culture. LPA detected MTB in 18 (90%) out of 20 smear-positive specimens. RIF resistance was detected in 20 (41.7%) specimens by Xpert and/or MGIT culture drug susceptibility testing (DST). Isoniazid (INH) resistance was detected in 19 specimens by LPA and MGIT culture DST. Conclusion: Bronchoscopy can provide alternative respiratory specimens for diagnosing PTB in patients with difficulty to expectorate sputum. The utility of Xpert MTB/RIF as a rapid, sensitive, and specific test should always be supplemented with culture in difficult-to-obtain and precious respiratory specimens. LPA plays an important role in rapid detection of INH monoresistance.

Background: In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using specimens collected by bronchoscopy in a tertiary care center. Methods: Bronchoscopy specimens received in the TB laboratory were processed by microscopy, Xpert MTB/RIF assay, LPA, and mycobacteria growth indicator tube (MGIT) culture. Results of MGIT culture are considered gold standard. Results: Of the 173 specimens tested, MTB was detected in 48 (27.74%) samples by any of the above methods. Positivity in bronchoalveolar lavage was 31.4% (44/140) and in bronchial wash was 12.1% (4/33). Detection by microscopy, Xpert assay, and culture was 20 (11.56%), 45 (26.01%), and 38 (21.96%), respectively. Culture detected MTB in three additional specimens compared to Xpert assay. Xpert assay detected MTB in 45 (26%) specimens which include 10 specimens which were negative by culture. LPA detected MTB in 18 (90%) out of 20 smear-positive specimens. RIF resistance was detected in 20 (41.7%) specimens by Xpert and/or MGIT culture drug susceptibility testing (DST). Isoniazid (INH) resistance was detected in 19 specimens by LPA and MGIT culture DST. Conclusion: Bronchoscopy can provide alternative respiratory specimens for diagnosing PTB in patients with difficulty to expectorate sputum. The utility of Xpert MTB/RIF as a rapid, sensitive, and specific test should always be supplemented with culture in difficult-to-obtain and precious respiratory specimens. LPA plays an important role in rapid detection of INH monoresistance. [ABSTRACT FROM AUTHOR]

Objectives: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potent tool for detecting drug resistance in tuberculosis (TB); however, concerns about its reliability have been raised. In this study, we assessed the reliability of MassARRAY (Sequenom, Inc.), which is a MALDI-TOF MS-based method, by comparing it to the well-established GeneXpert assay (Cepheid) as a reference method., Methods: A retrospective study was conducted using laboratory data retrieved from Henan Chest Hospital (Zhengzhou, China). To ensure a rigorous evaluation, we adopted a comprehensive assessment approach by integrating multiple outcomes of the Xpert assay across various specimen types., Results: Among the 170 enrolled TB cases, MassARRAY demonstrated significantly higher sensitivity (85.88%, 146 of 170) compared to the Xpert assay (76.62%, 118 of 154) in TB diagnosis ( p  < 0.05). The concordance in detecting rifampicin resistance between MassARRAY and the combined outcomes of the Xpert assay was 90%, while it was 97.37% (37 of 38) among smear-positive cases and 89.06% (57 of 64) among culture-positive cases. When compared to the phenotypic susceptibility outcomes of the 12 included drugs, consistency rates of 81.8 to 93.9% were obtained, with 87.9% for multiple drug resistance (MDR) identification., Conclusion: MassARRAY demonstrates high reliability in detecting rifampicin resistance, and these findings may offer a reasonable basis for extrapolation to other drugs included in the test panel., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Liang, Li, Zhao, Qi, Bao, Wang, Duan and Huang.)

Pathologically increased vascular permeability is an important dysfunction in the pathomechanism of life-threatening conditions, such as sepsis, ischemia/reperfusion, or hereditary angioedema (HAE), diseases accompanied by uncontrolled activation of the complement system. HAE for example is caused by the deficiency of C1-inhibitor (the main regulator of early complement activation), which leads to edematous attacks threatening with circulatory collapse. We have previously reported that endothelial cells become activated during HAE attacks. A natural target of C1-inhibitor is mannan-binding lectin-associated serine protease-1 (MASP-1), a multifunctional serine protease, which plays a key role in the activation of complement lectin pathway. We have previously shown that MASP-1 induces the pro-inflammatory activation of endothelial cells and in this study we investigated whether MASP-1 can directly affect endothelial permeability. All experiments were performed on human umbilical vein endothelial cells (HUVECs). Real-time micro electric sensing revealed that MASP-1 decreases the impedance of HUVEC monolayers and in a recently developed permeability test (XperT), MASP-1 dose-dependently increased endothelial paracellular transport. We show that protease activated receptor-1 mediated intracellular Ca2+-mobilization, Rho-kinase activation dependent myosin light chain (MLC) phosphorylation, cytoskeletal actin rearrangement, and disruption of interendothelial junctions are underlying this phenomenon. Furthermore, in a whole-transcriptome microarray analysis MASP-1 significantly changed the expression of 25 permeability-related genes in HUVECs—for example it up-regulated bradykinin B2 receptor expression. According to our results, MASP-1 has potent permeability increasing effects. During infections or injuries MASP-1 may help eliminate the microbes and/or tissue debris by enhancing the extravasation of soluble and cellular components of the immune system, however, it may also play a role in the pathomechanism of diseases, where edema formation and complement lectin pathway activation are simultaneously present. Our findings also raise the possibility that MASP-1 may be a promising target of anti-edema drug development. [ABSTRACT FROM AUTHOR]

Management of Norovirus and Clostridium difficile gastroenteritis is challenging for rehabilitation and long-term care facilities. We evaluated the contribution of a 2-step laboratory-based strategy, including a new ready-to-use Norovirus polymerase chain reaction assay to promote isolation precautions. C difficile and Norovirus were successively identified from 17% and 23% of 52 episodes of diarrhea, respectively, during the winter season, leading to 100% adequate isolation measures. In patient populations with numerous risk factors for diarrhea, a combined laboratory-based approach could improve infection control. [ABSTRACT FROM AUTHOR]

Introduction: The presence of Mycobacterium tuberculosis in a respiratory specimen is diagnostic in patients with pleural effusion. It is difficult to obtain sputum even after induction in these patients. An alternative method of acquiring respiratory specimens is via bronchial lavage. This study was undertaken to evaluate the diagnostic yield of acid-fast bacilli (AFB) smear, AFB culture, and Xpert assay of bronchial lavage fluid in the workup of pleural tuberculosis patients., Material and Methods: All patients who met the inclusion criteria of the study underwent thoracentesis, pleural biopsy, and bronchial lavage. Specimens of pleural fluid, pleural biopsy, and bronchial lavage fluid were sent for acid fast bacilli smear, culture, and Xpert assay., Result: Bronchial lavage AFB smear, culture, and Xpert assay was positive in 9.5%, 17.9%, and 26.2% of patients, respectively. It gave an immediate diagnosis in 22 (26.2%) patients., Conclusion: Bronchial lavage, though not a surrogate to pleural biopsy, offers an additional approach to the early diagnosis of pleural tuberculosis in patients not producing sputum. Besides being diagnostic, this method also has epidemiologic significance in containing the tuberculosis epidemic because detecting Mycobacterium in bronchial lavage confirms that the patient is infectious.

Setting: Department of Microbiology., Objective: To determine the common mutations responsible for rifampicin resistance in TB cases detected by Xpert MTB/RIF assay., Design: Results of Xpert MTB/RIF assay performed from 2013 to 2017 were analysed for missing probes in different types of specimens containing rifampicin resistant MTB., Results: Successful results were obtained in14872 of the total 15129 specimens processed by Xpert MTB/RIF assay, of which 9458 (63.6%) were sputum and 5414 (36.4%) were extrapulmonary specimens. MTB was detected in 1624 (17.17%) sputum and 1121 (20.70%) extrapulmonary specimens of which 409 (25.18%) and 277 (24.71%) were rifampicin resistant respectively. Probe E (83.82%) was the commonest probe responsible for rifampicin resistance followed by D (3.93%) and B (3.79%). Mutation in probe C (0.29%) was very rare. Combination of missing probes like AB (0.73%), DE (1.16%) and ADE (0.14%) was observed. 22 (3.2%) specimens showed presence of all five probes., Conclusion: Xpert MTB/RIF assay uses various combinations of probe to detect MTB along with rifampicin resistance and is a valuable diagnostic tool. It can become a useful epidemiological tool to identify dynamics of transmission of TB by addition of few more probes to identify mutations at specific codons., (Copyright © 2018 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.)