BACKGROUND AND OBJECTIVE

Nontuberculous mycobacteria (NTM) lung disease appears like tuberculosis infection but is resistant to primary anti-tuberculosis drugs. Hence, patients whose sputum sample tests positive for acid-fast bacilli (AFB) and bacterial culture for several times should be assessed for colonization or infection with NTM in a damaged lung secondary to TB. In such cases, though drug-resistant TB may be adequately treated, treatment may need to be directed towards the NTM as well. In NTM therapy, the duration and choice of treatment agent is based upon the specific organism and disease extent. This study used one-step multiplex PCR (mPCR) assay for rapid differentiation of solid cultures in Ogawa medium as Mycobacterium tuberculosis (MTB) and/or NTM.

A total of 80 stocked isolates obtained from the Lung Center of the Philippines from January to December 2018 were screened for NTM in terms of growth in Ogawa medium, acid fastness, and MPT64 TB antigen test result. These were from sputum specimens of multidrug-resistant tuberculosis (MDR-TB) patients. DNA was extracted from cultures (n=55) grown in Ogawa medium and one-step mPCR was performed to identify NTM to the species level.

Out of 80 samples screened, a total of 55 isolates were identified as NTM. One-step mPCR identified 12.73% (7/55) as M. abscessus, 34.55% (19/55) as M. massiliense, 1.82% (1/55) as M. kansasii, and 50.91% (28/55) were identified only up to genus Mycobacteria spp. Neither M. avium complex nor M. intracellulare was identified among the samples tested.

One-step mPCR was able to identify isolates as MTB or NTM coinciding with the initial screening using MPT64 TB antigen test. Multiplex PCR has given a more specific identificati on to the species level. The use of mPCR in identifying MTB and clinically significant NTM’s is suitable for the adequate treatment of mycobacterial infection.

Early secreted antigenic target of 6 kDa protein (ESAT-6) is the major virulence factor of Mycobacterium tuberculosis (MTB), which can resist the clearance of MTB in bodies by inhibiting macrophage phagocytosis and autophagy reaction, thus impeding the immune defense function of the body against MTB infection. In addition, ESAT-6-induced apoptosis of macrophage and massive necrosis of innate immune cells can foster MTB proliferation and colonization, leading to systemic MTB infection. Moreover, ESAT-6 hampers the protective immune response of Th1 cells, reducing the secretion of pro-inflammatory cytokines and contributing to immune dysfunction, thus accelerating the course of MTB infection. During the process, the high immunogenicity of ESAT-6 can be leveraged as a dominant antigen in the development of new TB vaccines, making it a promising candidate with broad prospects for further development.
Humans ; Mycobacterium tuberculosis ; Vaccines ; Cytokines ; Apoptosis ; Autophagy ; Sepsis

Humans ; Child ; Nontuberculous Mycobacteria ; Lung Diseases

A molecular diagnostic assay which could be stored at room temperature was developed to rapidly detect Mycobacterium tuberculosis (MTB) based on loop-mediated isothermal amplification (LAMP) technology and dry-reagent process. LAMP uses 4 or 6 primers and Bst DNA polymerase to amplify DNA at a constant temperature. The results showed that the LAMP assay could detect the amplification of IS6110 target gene within 20 min using real-time fluorescence signal detection. The sensitive of LAMP assay was similar to the PCR technology while the precision of PCR was better than LAMP (coefficient of variation, LAMP 18.9%, PCR 3.4%), meaning LAMP was more suitable for qualitative detection. The LAMP assay did not amplify DNA of other 10 types of pathogens, including Neisseria meningitidis, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Rubivirus, mumps virus, adenovirus (type 3), adenovirus (type 7), respiratory syncytial virus B and parainfluenza virus type 2, indicating a good specificity. Furthermore, a dry-reagent assay was developed using air-drying and freeze-drying process. The performance of dried reagents did not change after 10 days storage at 50 ℃, meaning the dried reagents could be stored at room temperature (25 ℃) for more than six months. The dry-reagent LAMP assay also successfully amplified MTB DNA from several clinical samples within 20 min. In conclusion, the developed LAMP assay together with isothermal amplifier could rapidly detection MTB.
Humans ; Mycobacterium tuberculosis/genetics* ; Indicators and Reagents ; Sensitivity and Specificity ; Nucleic Acid Amplification Techniques/methods* ; DNA

Humans ; Retrospective Studies ; Bronchiectasis ; Mycobacterium avium Complex ; Syndrome ; Nocardia Infections/drug therapy* ; Nocardia ; Mycobacterium avium-intracellulare Infection

Humans ; Isoniazid/pharmacology* ; Mycobacterium tuberculosis/genetics* ; Rifampin/pharmacology* ; Antitubercular Agents/pharmacology* ; Mutation ; Microbial Sensitivity Tests ; Tuberculosis, Multidrug-Resistant/microbiology* ; Drug Resistance, Multiple, Bacterial/genetics* ; Bacterial Proteins/genetics*

Mycolic acids (MAs), i.e. 2-alkyl, 3-hydroxy long-chain fatty acids, are the hallmark of the cell envelope of Mycobacterium tuberculosis and are related with antibiotic resistance and host immune escape. Nowadays, they've become hot target of new anti-tuberculosis drugs. There are two main methods to detect MAs, ¹⁴C metabolic labeling thin-layer chromatography (TLC) and liquid chromatograph mass spectrometer (LC-MS). However, the user qualification of ¹⁴C or the lack of standards for LC-MS hampered the easy use of this method. TLC is a common way to analyze chemical substance and can be used to analyze MAs. In this study, we used tetrabutylammonium hydroxide and methyl iodide to hydrolyze and formylate MAs from mycobacterium cell wall. Subsequently, we used diethyl ether to extract methyl mycolate. By this method, we can easily extract and analyze MA in regular biological labs. The results demonstrated that this method could be used to compare MAs of different mycobacterium in different growth phases, MAs of mycobacteria treated by anti-tuberculosis drugs or MAs of mycobacterium mutants. Therefore, we can use this method as an initial validation for the changes of MAs in researches such as new drug screening without using radioisotope or when the standards are not available.
Mycolic Acids/metabolism* ; Chromatography, Thin Layer ; Mycobacterium tuberculosis ; Fatty Acids ; Antitubercular Agents/pharmacology*

To prepare a lipid nanoparticle (LNP)-based subunit vaccine of Mycobacterium tuberculosis (Mtb) antigen EsxV and study its immunological characteristics, the LNP containing EsxV and c-di-AMP (EsxV: C: L) was prepared by thin film dispersion method, and its encapsulation rate, LNP morphology, particle size, surface charge and polyphase dispersion index were measured. BALB/c mice were immunized with EsxV: C: L by nasal drops. The levels of serum and mucosal antibodies, transcription and secretion of cytokines in lung and spleen, and the proportion of T cell subsets were detected after immunization. EsxV: C: L LNPs were obtained with uniform size and they were spherical and negatively charged. Compared with EsxV: C immunization, EsxV: C: L mucosal inoculation induced increased sIgA level in respiratory tract mucosa. Levels of IL-2 secreted from spleen and ratios of memory T cells and tissue-resident T cells in mice were also elevated. In conclusion, EsxV: C: L could induce stronger mucosal immunity and memory T cell immune responses, which may provide better protection against Mtb infection.
Animals ; Mice ; Mycobacterium tuberculosis ; Antigens, Bacterial ; Immunization ; Nanoparticles ; Vaccines, Subunit ; Mice, Inbred BALB C

Mycobacterium neoaurum has the ability to produce steroidal intermediates known as 22-hydroxy-23, 24-bisnorchol-4-en-3-one (BA) upon the knockout of the genes for either the hydroxyacyl-CoA dehydrogenase (Hsd4A) or acyl-CoA thiolase (FadA5). In a previous study, we discovered a novel metabolite in the fermentation products when the fadA5 gene was deleted. This research aims to elucidate the metabolic pathway of this metabolite through structural identification, homologous sequence analysis of the fadA5 gene, phylogenetic tree analysis of M. neoaurum HGMS2, and gene knockout. Our findings revealed that the metabolite is a C23 metabolic intermediate, named 24-norchol-4-ene-3, 22-dione (designated as 3-OPD). It is formed when a thioesterase (TE) catalyzes the formation of a β-ketonic acid by removing CoA from the side chain of 3, 22-dioxo-25, 26-bisnorchol-4-ene-24-oyl CoA (22-O-BNC-CoA), followed by spontaneously undergoing decarboxylation. These results have the potential to contribute to the development of novel steroid intermediates.
Mycobacterium/metabolism* ; Phylogeny ; Steroids/metabolism* ; Metabolic Networks and Pathways ; Sterols/metabolism*

Objective: To explore the influencing factors of the adverse outcome of pulmonary tuberculosis (PTB) among adolescents in Hangzhou City between 2005 and 2020. Methods: A retrospective cohort study was used to collect the information of adolescent PTB patients with the onset of PTB occurring from January 1, 2005 to December 31 in 12 designated tuberculosis hospitals in Hangzhou, mainly including demographic, epidemiological, clinical manifestations, bacteriological characteristics and other data, through the China Management Information System for Infectious Disease Surveillance and Reporting and the follow-up survey. All patients were followed up and the end time was December 31, 2021. Multivariate Cox regression model was used to analyze the factors affecting the adverse outcome of these patients. Results: The mean age of 4 921 adolescent PTB patients was (18.9±3.6) years old, and the number of male and female patients were 3 074 and 1 847 respectively. The adverse outcome accounted for 14.7% (725) of all patients. Multivariate Cox regression model showed that eight risk factors, including management model from patients themselves or family members (HR=5.87, 95%CI: 4.55-7.64), molecular biology examination positive for PTB (HR=4.62, 95%CI: 2.98-7.19), the number of sputum smears-positive≥1 (HR=3.72, 95%CI: 2.87-4.83), non-standardized therapy regimens of PTB (HR=3.69, 95%CI: 2.95-4.64), history of retreated PTB (HR=2.22, 95%CI: 1.46-3.36), migrant adolescents (HR=1.89, 95%CI: 1.54-2.34), the number of chest X-ray scan (HR=1.83, 95%CI: 1.65-2.04), and severe PTB (HR=1.38, 95%CI: 1.02-2.05), were associated with the adverse outcome of adolescent PTB patients. Age (HR=0.94, 95%CI: 0.92-0.96), as the only protective factor, was associated with the adverse outcome of these patients. Conclusion: The management mode, molecular biological examination, chemotherapy program, history of tuberculosis, sputum smear examination, severity of tuberculosis, household residence, chest X-ray examination and age are associated with the adverse outcomes of adolescent PTB patients in Hangzhou.
Humans ; Male ; Adolescent ; Female ; Young Adult ; Adult ; Retrospective Studies ; Tuberculosis, Pulmonary/drug therapy* ; Risk Factors ; Proportional Hazards Models ; Sputum ; Mycobacterium tuberculosis