Colony morphotype governs innate and adaptive pulmonary immune responses to Mycobacterium abscessus infection in C3HeB/FeJ mice.

Mycobacterium abscessus is an emerging pathogen that causes chronic pulmonary infection. Treatment is challenging owing in part to our incomplete understanding of M. abscessus virulence mechanisms that enable pathogen persistence, such as the differing pathogenicity of M. abscessus smooth (S) and rough (R) colony morphotype. While R M. abscessus is associated with chronic infection and worse patient outcomes, it is unknown how immune responses to S and R M. abscessus differ in an acute pulmonary infection setting. In this study, immunological outcomes of M. abscessus infection with S and R morphotypes were examined in an immune-competent C3HeB/FeJ murine model. R M. abscessus infection was associated with the rapid production of inflammatory chemokines and recruitment of activated, MHC-II+ Ly6C+ macrophages to lungs and mediastinal LN (mLN). While both S and R M. abscessus increased T helper 1 (Th1) phenotype T cells in the lung, this was markedly delayed in mice infected with S M. abscessus. However, histopathological involvement and bacterial clearance were similar regardless of colony morphotype. These results demonstrate the importance of M. abscessus colony morphotype in shaping the development of pulmonary immune responses to M. abscessus, which further informs our understanding of M. abscessus host-pathogen interactions.

Pharmacological validation of dihydrofolate reductase as a drug target in Mycobacterium abscessus.

The Mycobacterium abscessus drug development pipeline is poorly populated, with particularly few validated target-lead couples to initiate de novo drug discovery. Trimethoprim, an inhibitor of dihydrofolate reductase (DHFR) used for the treatment of a range of bacterial infections, is not active against M. abscessus. Thus, evidence that M. abscessus DHFR is vulnerable to pharmacological intervention with a small molecule inhibitor is lacking. Here, we show that the pyrrolo-quinazoline PQD-1, previously identified as a DHFR inhibitor active against Mycobacterium tuberculosis, exerts whole cell activity against M. abscessus. Enzyme inhibition studies showed that PQD-1, in contrast to trimethoprim, is a potent inhibitor of M. abscessus DHFR and over-expression of DHFR causes resistance to PQD-1, providing biochemical and genetic evidence that DHFR is a vulnerable target and mediates PQD-1's growth inhibitory activity in M. abscessus. As observed in M. tuberculosis, PQD-1 resistant mutations mapped to the folate pathway enzyme thymidylate synthase (TYMS) ThyA. Like trimethoprim in other bacteria, PQD-1 synergizes with the dihydropteroate synthase (DHPS) inhibitor sulfamethoxazole (SMX), offering an opportunity to exploit the successful dual inhibition of the folate pathway and develop similarly potent combinations against M. abscessus. PQD-1 is active against subspecies of M. abscessus and a panel of clinical isolates, providing epidemiological validation of the target-lead couple. Leveraging a series of PQD-1 analogs, we have demonstrated a dynamic structure-activity relationship (SAR). Collectively, the results identify M. abscessus DHFR as an attractive target and PQD-1 as a chemical starting point for the discovery of novel drugs and drug combinations that target the folate pathway in M. abscessus.

Mavintramycin A is a promising antibiotic for treating Mycobacterium avium complex infectious disease.

Mycobacterium avium complex (MAC) is a serious disease that is mainly caused by infection with the non-tuberculous mycobacteria (NTM), Mycobacterium avium and Mycobacterium intracellulare. Seven new compounds, designated mavintramycins A-G (1-7), were isolated along with structurally related compounds, including amicetin (9) and plicacetin (10), from the culture broth of Streptomyces sp. OPMA40551 as anti-MAC compounds that were active against M. avium and M. intracellulare. Among them, mavintramycin A showed the most potent and selective inhibition of M. avium and M. intracellulare. Furthermore, mavintramycin A was active against more than 40 clinically isolated M. avium, including multidrug-resistant strains, and inhibited the growth of M. avium in a persistent infection cell model using THP-1 macrophages. Mavintramycin A also exhibited in vivo efficacy in silkworm and mouse infection assays with NTM. An experiment to elucidate its mechanism of action revealed that mavintramycin A inhibits protein synthesis by binding to 23S ribosomal RNA in NTM. Mavintramycin A, with a different chemical structure from those of clinically used agents, is a promising drug candidate for the treatment of MAC infectious disease.

Improved detection of mycobacteria in CF and tissue samples grown in mycobacteria growth indicator tube incubated at 30°C compared to conventional growth conditions of liquid and solid media.

This study evaluates the growth of mycobacteria in samples from cystic fibrosis (CF) patients and tissue samples using the mycobacteria growth indicator tube (MGIT) incubated at 30°C in comparison to conventional MGIT cultures incubated at 37°C in a BACTEC MGIT 960 device and solid media incubated at 36°C and 30°C. A total of 1,549 samples were analyzed, of which 202 mycobacterial isolates were cultured from 197 positive specimens, including five mixed cultures. The highest detection rate was achieved from MGIT at 30°C, with 84.2% of mycobacterial isolates (170 of 202), which was significantly higher than any other culture condition (P < 0.0001 for any condition). MGIT at 37°C yielded 61.4% (124 of 202) of the recovered isolates, whereas Löwenstein Jensen (LJ) and Stonebrink at 36°C, and LJ and Stonebrink at 30°C retrieved 47.0% (95), 49.5% (100), 50.0% (101), and 53.0% (107) of the isolates, respectively. Of the 53 isolates that were grown exclusively under one culture condition, the highest number of isolates (36) was recovered from MGIT incubated at 30°C. MGIT at 37°C recovered eight of the 53 isolates, whereas LJ incubated at 30°C and Stonebrink incubated at 30°C and 36°C recovered five, three, and one isolate, respectively. No isolates were grown exclusively from LJ incubated at 36°C. In CF patients and tissue samples, MGIT cultivated at 30°C for 8 weeks increases the performance of mycobacterial culture. IMPORTANCE: Our study shows that the addition of mycobacteria growth indicator tube (MGIT) liquid culture incubated at 30°C improves the detection of mycobacteria from CF and tissue samples. MGIT incubated at 30°C recovered significantly more mycobacterial isolates than MGIT incubated at 37°C and significantly more isolates than either Lowenstein Jensen or Stonebrink solid media incubated at either 36°C or 30°C. Of 202 mycobacterial isolates recovered from 1,549 specimens, 170 were recovered from MGIT incubated at 30°C, followed by MGIT incubated at 37°C with 124 isolates and solid media culture conditions that recovered between 95 and 107 mycobacterial isolates. All conventional culture conditions combined without MGIT incubated at 30°C recovered 166 isolates. MGIT incubated at 30°C recovered the highest number of isolates detected exclusively by a single culture condition and recovered mycobacterial isolates of highly relevant mycobacterial species, including Mycobacterium abscessus and Mycobacterium tuberculosis.

Profile of non-tuberculous mycobacteria amongst tuberculosis presumptive people in Cameroon.

BACKGROUND: Cameroon is a tuberculosis (TB) burden country with a 12% positivity among TB presumptive cases. Of the presumptive cases with a negative TB test, some are infected with Non-tuberculous Mycobacteria (NTM). However, the diagnosis of NTM infections remains difficult due to the lack of tools in many laboratories, particularly in resource limited laboratories and remote setting. The present study was undertaken to determine NTM profile and associated comorbidities among TB presumptive people. METHODS: A retrospective study was conducted from December 2018 to December 2019 in the Tuberculosis-National Reference Laboratory (TB-NRL) for Bacteriological analysis of samples and Jamot Hospital of Yaounde (JHY) for clinical evaluation of confirmed NTM patients. We included in this study data of 5267 TB presumptive people previously diagnosed using three consecutive samples and having culture and SD Bioline results with or without Microscopy and reverse hybridization-based Line Probe Assay(LPA) results. The data on co-morbidities or history of people infected with NTM were then collected from the three participants with available clinical data. RESULTS: We collected data of 5267 presumptive TB people. Among them, 3436 (65.24%), have a positive culture with 3200 (60.75%) isolates belong to Mycobacterium tuberculosis Complex (MBTC) and 236 (4.48%) to NTM. Our results showed that, 123 (52.11%) NTM were isolated from people with negative microscopy and 113 (47.88%) from people with positive microscopy. Among the 236 NTM, 108 (45.8%) isolates were identified using LPA. M. fortuitum was the most represented species (32.41%) followed by M. intracellulare (19.44%). Sputum had the highest proportion of NTM (56%), followed by bronchial aspirations (31%). The extra-pulmonary samples presented lower proportions of isolates compared to pulmonary samples. Some patients affected with NTM presented comorbidities as HIV infection, Pulmonary tuberculosis, Type 2 diabetes, Chronic bronchitis and Alveolar pneumonia. CONCLUSIONS: Our study showed the presence of NTM strains among presumptive TB people with a predominance of M. fortuitum and M. intracellulare. It is important to implement a surveillance system of NTM in TB burden country and also to develop a point-of-care test for NTM identification in limited-resource settings.

Susceptibility to mycobacterial infection in VEXAS syndrome.

OBJECTIVES: VEXAS is a recently described acquired auto-inflammatory and hematologic syndrome caused by somatic mutations in UBA1. To date, VEXAS is not a recognized cause of acquired immunodeficiency. PATIENTS AND METHODS: Two of our 10 VEXAS patients developed a disseminated Mycobacterium avium infection. To shed light on this observation, we retrospectively studied all patients with disseminated non-tuberculous mycobacterial infections (NTMi) seen at our institution over 13 years. Inclusion criteria were a positive blood/bone marrow culture, or 2 positive cultures from distinct sites, or one positive culture with 2 involved sites. RESULTS: patient 1 presented with fever, rash, orbital cellulitis and lung infiltrates. Patient 2 presented with fever and purpura. In both cases, Mycobacterium avium was identified on bone marrow culture. Twenty cases of disseminated NTMi were reviewed. Among 11 HIV-negative patients, three had chronic immune-mediated disease; three had untreated myeloid neoplasm; two had VEXAS; one had undergone kidney transplantation; one had GATA-2 deficiency; and one had no identified aetiology. None had lymphoid neoplasia or had undergone bone marrow transplantation. HIV-negative cases had higher CD4 counts than HIV-positive patients (median CD4: 515/mm3  vs 38/mm3, p< 0.001). Monocytopenia was present in seven cases. At 2 years, six patients had died, including both VEXAS patients. DISCUSSION: VEXAS patients have an intrinsic susceptibility to disseminated NTMi, which may result from monocytic dysfunction. NTMi can mimic VEXAS flare. Clinicians should maintain a high suspicion for opportunistic infections before escalating immunosuppressive therapy. Further studies are needed to confirm and better decipher the herein reported observations.

The additional value of 18F-FDG PET/CT imaging in guiding the treatment strategy of non-tuberculous mycobacterial patients.

OBJECTIVES: Non-tuberculous mycobacteria (NTM) infection is an increasing health problem due to delaying an effective treatment. However, there are few data on 18F-FDG PET/CT for evaluating the status of NTM patients. The aim of this study was to investigate the potential value of 18F-FDG PET/CT in guiding the treatment strategy of NTM patients. METHODS: We retrospectively analyzed the cases of 23 NTM patients who underwent 18F-FDG PET/CT. The clinical data, including immune status and severity of NTM pulmonary disease (NTM-PD), were reviewed. The metabolic parameters of 18F-FDG included maximum standardized uptake value (SUVmax), SUVmax of the most FDG-avid lesion (SUVTop), SUVTop/SUVmax of the liver (SURLiver), SUVTop/SUVmax of the blood (SURBlood), metabolic lesion volume (MLV), and total lesion glycolysis (TLG). The optimal cut-off values of these parameters were determined using receiver operating characteristic curves. RESULTS: There were 6 patients (26.09%) with localized pulmonary diseases and 17 patients (73.91%) with disseminated diseases. The NTM lesions had high or moderate 18F-FDG uptake (median SUVTop: 8.2 ± 5.7). As for immune status, the median SUVTop in immunocompromised and immunocompetent patients were 5.2 ± 2.5 and 10.0 ± 6.4, respectively, with a significant difference (P = 0.038). As for extent of lesion involvement, SURLiver and SURBlood in localized pulmonary and disseminated diseases were 1.9 ± 1.1 vs. 3.8 ± 1.6, and 2.7 ± 1.8 vs. 5.5 ± 2.6, respectively, with a significant difference (P = 0.016 and 0.026). Moreover, for disease severity, SUVmax of the lung lesion (SUVI-lung) and SUVmax of the marrow (SUVMarrow) in the severe group were 7.7 ± 4.3 and 4.4 ± 2.7, respectively, significantly higher than those in the non-severe group (4.4 ± 2.0 and 2.4 ± 0.8, respectively) (P = 0.027 and 0.036). The ROC curves showed that SUVTop, SURLiver, SURBlood, SUVI-lung, and SUVMarrow had a high sensitivity and specificity for the identification of immune status, lesion extent, and severity of disease in NTM patients. CONCLUSION: 18F-FDG PET/CT is a useful tool in the diagnosis, evaluation of disease activity, immune status, and extent of lesion involvement in NTM patients, and can contribute to planning the appropriate treatment for NTM.

Cutaneous infection due to Mycobacterium marinum: A series of four cases from Kerala, India.

Mycobacterium marinum is a non-tuberculous mycobacterium which can be found in naturally occurring, non-chlorinated water sources and is a known pathogen that affects fish. In humans, M. marinum typically results in cutaneous lesions, it can occasionally lead to more invasive disorders. We discuss four cases of M. marinum-related cutaneous infections examined in a tertiary care facility. We want to draw attention to the challenges of accurately diagnosing this infection, stress the significance of having a high level of clinical suspicion in order to identify it, and discuss the available treatment choices.

Mycolicibacterium cyprinidarum sp. nov., a rapidly growing species isolated from diseased koi carp, Cyprinus carpio.

A rapidly growing nontuberculous mycobacterium was isolated from diseased koi carp in Niigata, Japan, which was identified as representing a novel Mycolicibacterium species through whole genome sequence analysis. The bacterial isolates (NGTWS0302, NGTWS1803T and NGTWSNA01) were found to belong to the genus Mycolicibacterium through phylogenetic analysis using whole genome sequences of mycobacteria species. The bacterial colony was smooth, moist and non-chromogenic on 1% Ogawa medium at 30 °C. In biochemical characteristic tests, the bacterial isolates showed positive reactions for catalase activity, Tween 80 hydrolysis and tellurite reduction. The isolates were sensitive to 2-4 µg ml-1 ampicillin, kanamycin and rifampicin. Based on these results, we propose a novel Mycolicibacterium species, Mycolicibacterium cyprinidarum sp. nov. The type strain is NGTWS1803T (=JCM 35117T=ATCC TSD-289T).

Bigger problems from smaller colonies: emergence of antibiotic-tolerant small colony variants of Mycobacterium avium complex in MAC-pulmonary disease patients.

BACKGROUND: Mycobacterium avium complex (MAC) is a group of slow-growing mycobacteria that includes Mycobacterium avium and Mycobacterium intracellulare. MAC pulmonary disease (MAC-PD) poses a threat to immunocompromised individuals and those with structural pulmonary diseases worldwide. The standard treatment regimen for MAC-PD includes a macrolide in combination with rifampicin and ethambutol. However, the treatment failure and disease recurrence rates after successful treatment remain high. RESULTS: In the present study, we investigated the unique characteristics of small colony variants (SCVs) isolated from patients with MAC-PD. Furthermore, revertant (RVT) phenotype, emerged from the SCVs after prolonged incubation on 7H10 agar. We observed that SCVs exhibited slower growth rates than wild-type (WT) strains but had higher minimum inhibitory concentrations (MICs) against multiple antibiotics. However, some antibiotics showed low MICs for the WT, SCVs, and RVT phenotypes. Additionally, the genotypes were identical among SCVs, WT, and RVT. Based on the MIC data, we conducted time-kill kinetic experiments using various antibiotic combinations. The response to antibiotics varied among the phenotypes, with RVT being the most susceptible, WT showing intermediate susceptibility, and SCVs displaying the lowest susceptibility. CONCLUSIONS: In conclusion, the emergence of the SCVs phenotype represents a survival strategy adopted by MAC to adapt to hostile environments and persist during infection within the host. Additionally, combining the current drugs in the treatment regimen with additional drugs that promote the conversion of SCVs to RVT may offer a promising strategy to improve the clinical outcomes of patients with refractory MAC-PD.

Rapid lateral flow test for Mycobacterium tuberculosis complex and non-tuberculous mycobacteria differentiation.

The diagnosis of mycobacterial infections, including both the Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM), poses a significant global medical challenge. This study proposes a novel approach using immunochromatographic (IC) strip tests for the simultaneous detection of MTBC and NTM. Traditional methods for identifying mycobacteria, such as culture techniques, are hindered by delays in distinguishing between MTBC and NTM, which can affect patient care and disease control. Molecular methods, while sensitive, are resource-intensive and unable to differentiate between live and dead bacteria. In this research, we developed unique monoclonal antibodies (mAbs) against Ag85B, a mycobacterial secretory protein, and successfully implemented IC strip tests named 8B and 9B. These strips demonstrated high concordance rates with conventional methods for detecting MTBC, with positivity rates of 93.9% and 85.9%, respectively. For NTM detection, the IC strip tests achieved a 63.2% detection rate compared to culture methods, considering variations in growth rates among different NTM species. Furthermore, this study highlights a significant finding regarding the potential of MPT64 and Ag85B proteins as markers for MTBC detection. In conclusion, our breakthrough method enables rapid and accurate detection of both MTBC and NTM bacteria within the BACTEC MGIT system. This approach represents a valuable tool in clinical settings for distinguishing between MTBC and NTM infections, thereby enhancing the management and control of mycobacterial diseases. KEY POINTS: • Panel of mAbs for differentiating MTB versus NTM • IC strips for diagnosing MTBC and NTM after the BACTEC MGIT • Combined detection of MTP64 and Ag85B enhances diagnostic accuracy.

Drug repositioning identifies histone deacetylase inhibitors that promote innate immunity in non-tuberculous mycobacterial infection.

Non-tuberculosis infections in immunocompromised patients represent a cause for concern, given the increased risks of infection, and limited treatments available. Herein, we report that molecules for binding to the catalytic site of histone deacetylase (HDAC) inhibit its activity, thus increasing the innate immune response against environmental mycobacteria. The action of HDAC inhibitors (iHDACs) was explored in a model of type II pneumocytes and macrophages infection by Mycobacterium aurum. The results show that the use of 1,3-diphenylurea increases the expression of the TLR-4 in M. aurum infected MDMs, as well as the production of defb4, IL-1ß, IL-12, and IL-6. Moreover, we observed that aminoacetanilide upregulates the expression of TLR-4 together with TLR-9, defb4, CAMP, RNase 6, RNase 7, IL-1ß, IL-12, and IL-6 in T2P. Results conclude that the tested iHDACs selectively modulate the expression of cytokines and antimicrobial peptides that are associated with reduction of non-tuberculous mycobacteria infection.

Distinct clinical parameters were associated with shorter spontaneous resolution in children with non-tuberculous mycobacterial lymphadenitis.

AIM: Non-tuberculous mycobacteria (NTM) lymphadenitis typically resolves spontaneously, yet factors influencing the duration remain explored. We aimed to identify clinical parameters associated with shorter spontaneous resolution. METHODS: This cohort study included children with NTM lymphadenitis from 1 January 2015 to 1 March 2021 at Copenhagen University Hospital. Time-to-event analysis assessed clinical parameters associated with the duration of NTM lymphadenitis. RESULTS: Sixty children (57% boys) with a median age of 24 months (range 11-84) were included; 13 (22%) received primary surgery, 13 (22%) underwent surgery after a wait-and-see period and 34 (57%) received no intervention. In children without intervention, the median duration was 10 months (range 2-25). Faster resolution was associated with parental-reported lymph node enlargement within 2 weeks (HR 2.3, 95% CI 1.0-5.0; p = 0.044), abscess on ultrasound examination (HR 3.3, 95% CI 1.5-7.3; p = 0.003) and skin discoloration and/or perforation within 3 months of onset (HR 4.3, 95% CI 1.3-14.4; p = 0.017 and HR 3.7, 95% CI 1.5-9.1; p = 0.005). CONCLUSION: Knowledge of predictors for shorter spontaneous resolution of NTM lymphadenitis, such as rapid initial lymph node enlargement, abscess on ultrasound examination, and skin discoloration and/or perforation within 3 months of disease onset, may guide clinical management decisions concerning surgery versus a conservative approach.

Antibiotic resistance and genomic characterization of Mycobacterium abscessus complex isolates from patients with pulmonary tuberculosis in Iran: A multi-center study (2010-2021).

One hundred and eighteen sputum specimens suspected of Mycobacterium abscessus infection were collected. Species level identification of M. abscessus was performed by rpoB sequencing. Clonality analysis was done by multilocus sequence typing (MLST) for M. abscessus. Antibiotic susceptibility testing was performed for clarithromycin, amikacin, ciprofloxacin and moxifloxacin. Altogether 128 isolates were obtained and were subjected to rpoB gene sequencing for definite identification. Among them 59 were identified as M. abscessus, and these included 22 (37.28%) isolates of M. abscessus subsp. abscessus, 22 (37.28%) isolates of M. abscessus subsp. massiliense, and 15 (25.42%) isolates of M. abscessus subsp. bolletii. All 59 M. abscessus complex isolates were analyzed by MLST in this study. Certain sequence types (STs) were identified among the 59 isolates and were specific for each subspecies. Two STs (ST40 and ST33) were specific to M. abscessus subsp. abscessus, one ST (ST20) was specific to M. abscessus subsp. bolletii, and one ST (ST15) was specific to M. abscessus subsp. massiliense. In antibiotic resistance, clarithromycin susceptibility testing of 22 M. abscessus subsp. abscessus strains detected 15 (68.18%) resistant strains, while among 22 M. abscessus subsp. massiliense strains 5 (22.72%) exhibited resistance, and among 15 M. abscessus subsp. bolletii 8 (53.33%) were resistant. Our study revealed a significant level of antibiotic resistance in isolates of the M. abscessus complex.

ADP-ribosylation-resistant rifabutin analogs show improved bactericidal activity against drug-tolerant M. abscessus in caseum surrogate.

Necrotic lesions and cavities filled with caseum are a hallmark of mycobacterial pulmonary disease. Bronchocavitary Mycobacterium abscessus disease is associated with poor treatment outcomes. In caseum surrogate, M. abscessus entered an extended stationary phase showing tolerance to killing by most current antibiotics, suggesting that caseum persisters contribute to the poor performance of available treatments. Novel ADP-ribosylation-resistant rifabutin analogs exhibited bactericidal activity against these M. abscessus persisters at concentrations achievable by rifamycins in caseum.

Prevalence and Characteristics of Non-tuberculous Mycobacteria (NTM) Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation: a Systematic Review and Meta-analysis.

PURPOSE: Non-tuberculous mycobacteria (NTM) infections in hematopoietic stem cell transplantation (HSCT) recipients represent a diagnostic and therapeutic challenge. Here, we aimed to review and analyze current literature on incidence, clinical presentation, and outcome of NTM infection after allogeneic HSCT. METHODS: We performed a systematic review and meta-analysis of available literature regarding NTM infection in children and adults receiving allogeneic HSCT. RESULTS: We identified 56 articles eligible for the analysis. Among 15 studies, describing 15,798 allogeneic HSCT, we estimated a prevalence of 1.26% (95% CI 0.72, 1.93) of NTM after transplant. Analysis of 175 patients with NTM infection showed a median time of diagnosis of 318 days after HSCT, an increased prevalence in adults (82.9%), and a most frequent pulmonary involvement (44%). Comparison between children and adults revealed an earlier post-transplant disease onset (median 130 days vs 287 days) and most frequent non-pulmonary presentation in children. A vast heterogeneity of therapeutic approach reflected the lack of universal recommendations regarding drug combination and duration of therapy. Overall, NTM-related mortality accounted for 33% in this systematic review. CONCLUSION: Although rare, NTM infections can complicate post-transplant course with a high mortality rate in children and adults. The lack of prospective studies and guidelines prevents identification of risk factors and therapeutic recommendations.

Cryo-EM structure of the Mycobacterium abscessus F1-ATPase.

The cases of lung disease caused by non-tuberculous mycobacterium Mycobacterium abscessus (Mab) are increasing and not reliably curable. Repurposing of anti-tuberculosis inhibitors brought the oxidative phosphorylation pathway with its final product ATP, formed by the essential F1FO-ATP synthase (subunits α3:ß3:γ:δ:ε:a:b:b':c9), into focus as an attractive inhibitor target against Mab. Because of the pharmacological attractiveness of this enzyme, we generated and purified a recombinant and enzymatically active Mab F1-ATPase complex, including subunits α3:ß3:γ:δ:ε (MabF1-αßγδε) to achieve mechanistic, regulatory, and structural insights. The high purity of the complex enabled the first cryo-electron microscopy structure determination of the Mab F1-ATPase complex to 7.3 Å resolution. The enzyme showed low ATP hydrolysis activity, which was stimulated by trypsin treatment. No effect was observed in the presence of the detergent lauryldimethylamine oxide.

Non-tuberculous mycobacteriosis of the liver responsive to empiric therapy.

This case demonstrates that clinical and pathological suspicion of NTM could be sufficient to start an empiric treatment even when microbiological isolation is unavailable. Moreover, disseminated mycobacteriosis may underlie an occult aggressive neoplasm.

Meningoencephalitis due to Mycobacterium lentiflavum in an immunocompromised patient: Case report.

The first case of meningoencephalitis due to Mycobacterium lentiflavum in an immunocompromised patient is reported. Clinical and radiological characteristics are described, as well as the treatment and prognosis of the patient.

Necroptosis-related subtypes are associated with bronchiectasis in pulmonary non-tuberculous mycobacteria-infected patients: a perspective based on transcriptomic analysis.

The aim of this study was to explore the potential mechanisms responsible for the different manifestations of bronchiectasis in patients with pulmonary non-tuberculous mycobacteria (pNTM) infection. We found that the necroptosis level increased significantly after NTM infection. Further, the 31 pNTM-infected patients were classified into two subtypes based on necroptosis-related genes (NRGs) by unsupervised cluster analysis. After that, we compared the differences in clinical parameters, immune cell infiltration, and gene expression between the two subtypes. We observed that the high-necroptosis subtype possessed higher CT scores for bronchiectasis extent (P = 0.008) and severity (P = 0.023). And, more neutrophil infiltration in the high-necroptosis subtype was demonstrated both by the CIBERSORT algorithm and by blood neutrophil count (P = 0.001). Next, 688 differentially expressed genes (DEGs) between two subtypes were identified. To explore the portion in DEGs that might contribute to bronchiectasis, we intersected the DEGs with two gene modules. These two gene modules were identified as the most associated with CT scores for bronchiectasis extent and severity by weighted gene co-expression network analysis (WGCNA). Ninety-three intersection genes were obtained. Finally, 7 hub genes including ACSL1, ANXA3, DYSF, HK3, SLC11A1, STX11, and TLR4 were further screened out by machine learning algorithms and protein-protein interaction network analysis. These results suggested that the differential levels of necroptosis in pNTM patients might lead to differential extent and severity of bronchiectasis on radiographic imaging. This process might be associated with neutrophil infiltration and the involvement of seven hub genes.