The Mycobacterium genus is comprised of approximately 200 species to date, which can be broadly separated into two major categories; tuberculosis (TB)-causing bacteria and non-tuberculous mycobacteria (NTM). The TB complex includes notable pathogenic species such as M. tuberculosis (the causative agent of TB), which is responsible for 10.6 million infections and 1.6 million deaths globally in 2021. NTM is predominantly comprised of >95% environmental saprophytes, in which important pathogenic species such as M. avium and M. abscessus are responsible for severe pulmonary and soft-tissue infections in immunocompetent and immunocompromised individuals. The current TB treatment regimen involves multiple antibiotics prescribed for at least 6 months, poses significant challenges in patient-compliance, which is associated with the development of drug-resistant TB cases. Similarly, there are no effective therapies available to cure NTM diseases. M. leprae is a non-culturable, obligate intracellular pathogen that causes a chronic granulomatous infection characterized predominantly by peripheral nerve damage and prominent skin lesions known as Leprosy or Hansen’s disease. Leprosy is endemic mostly to tropical underdeveloped and developing countries.

Furthermore, all mycobacteria possess intrinsic and acquired high level drug resistance to many important antimicrobial families, significantly limiting available treatment options. Therefore, new and improved therapeutic strategies are needed for better control of TB, leprosy and NTM diseases. Pathogenic mycobacteria are able to hijack host macrophages and exploit cellular machinery to create an intracellular niche capable of facilitating bacterial replication and protecting bacteria from immune detection. However, the host and pathogen determinants underpinning the progression of mycobacterial infection into active disease, versus containment of infection are not fully understood. Therefore, advanced molecular and cellular immunologic studies are needed for better understanding of host-pathogen interactions during mycobacterial infections.

At present, vaccination of young children with Bacillus Calmette-Guerin (BCG), developed more than a century ago, is the only TB preventive measure endorsed by the World Health Organization (WHO). However, the efficacy of BCG vaccination in preventing TB development among children is highly variable; it does not protect against TB in adults and is not recommended for individuals infected with human immunodeficiency virus (HIV). There is currently no vaccine, specific against M. leprae, which provides complete protection towards leprosy; however, administration of the BCG has been shown to provide some protective effects among those susceptible to infection by M. leprae. Although the BCG vaccine was originally intended for use against M. tuberculosis, the proposed mechanism for the protective properties of BCG against M. leprae involve cross-reactivity B cells and T cells against mycobacterial antigens that are shared between different mycobacterial species.
Thus, more efficacious vaccines are urgently needed to protect various human populations against all mycobacterial diseases, including TB and leprosy.

Together, it is imperative that there is an urgent and unmet need to further our understanding of mycobacterial pathogenesis, improve diagnostic tools for the identification of mycobacterial species, and explore novel drug and vaccine candidates for the treatment and prevention of mycobacterial infections and/or disease. As such, the goal of this research topic is to highlight the latest scientific research in the following areas, including:

• Host-pathogen interactions of mycobacterial spp.
• Mycobacterial pathogenesis (including co-infections)
• Mycobacterial drug resistance mechanisms (innate and acquired)
• Improved diagnostic testing for mycobacterial disease
• Novel therapies to treat mycobacterial infections
• Vaccine development for the prevention of mycobacterial diseases

We are particularly interested in receiving manuscripts in the format of original research articles, review articles (full and mini-reviews), and any other article types which prescribe to the overall goal of the Special Issue

Submit your idea

Impact

Frontiers in Microbiology

Participating Journals

Impact