Distinctive clinical features of radiological pleuroparenchymal fibroelastosis with nontuberculous mycobacterial pulmonary disease: A multicenter retrospective cohort study

Targeting Autophagy as a Strategy for Developing New Host-Directed Therapeutics Against Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTMs) are increasingly being recognized as opportunistic pathogens in clinical practice because of their innate resistance to antimicrobial treatment and the widespread increase in multidrug-resistant strains on a global scale. NTMs pose a tremendous infection management challenge, especially in individuals with pre-existing lung conditions, as well as those who are immunocompromised. NTMs' capability to evade or suppress the immune responses of their host is a key feature that makes them a cause of persistent chronic infection. Autophagy, an essential cellular defense mechanism that delivers and breaks down intracellular materials in lysosomes, protects the host from mycobacterial infection. Initial studies have revealed encouraging therapeutic strategies that augment endogenous autophagic mechanisms or block harmful host responses, thus having the potential to decrease intracellular mycobacterial infection, including that caused by multidrug-resistant strains. This review discusses how NTMs can evade autophagic mechanisms and considers the possibilities of using autophagy-inducing agents to develop novel therapeutic strategies to combat NTM infection.

Analysis of non-tuberculous mycobacteria types in high tuberculosis endemic areas

BACKGROUND

The incidence of non-tuberculous mycobacteria (NTM) has been rising globally, posing significant challenges for diagnosis and treatment, particularly in regions with high tuberculosis (TB) incidence. This study aims to investigate the epidemiological, demographic, and clinical characteristics of non-tuberculous mycobacterial lung disease (NTM-PD) in areas with a high incidence of TB.

METHOD

This study was conducted at the Affiliated Hospital of Zunyi Medical University from January 2017 to December 2021. A total of 6259 culture-positive specimens were analyzed. Screening was based on acid-fast staining, colony morphology, and p-nitrobenzoic acid detection, which identified 107 suspected NTM strains. Gene sequencing confirmed 51 NTM-positive cases.

RESULTS

The predominant species identified were Mycobacterium abscessus (33.33%) and Mycobacterium intracellulare (27.45%). Several risk factors were associated with higher susceptibility to NTM-PD suspect, including bronchiectasis, low serum albumin levels (< 3.5 g/L), and male gender. The study found that although the isolation rate of NTM remained stable over the five-year period, drug resistance rates for the dominant species were notably high.

CONCLUSIONS

The findings highlight the need for clinicians in TB-endemic areas to carefully distinguish NTM infections from TB. The stable isolation rates of NTM, coupled with the high drug resistance of key species, underscore the importance of accurate diagnosis and tailored treatment strategies to manage NTM-PD effectively.