General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus

Abstract

Nontuberculous mycobacteria (NTM) are emerging human pathogens, causing a wide range of clinical diseases affecting individuals who are immunocompromised and who have underlying health conditions. NTM are ubiquitous in the environment, with certain species causing opportunistic infection in humans, including Mycobacterium avium and Mycobacterium abscessus. The incidence and prevalence of NTM infections are rising globally, especially in developed countries with declining incidence rates of M. tuberculosis infection. Mycobacterium avium, a slow-growing mycobacterium, is associated with Mycobacterium avium complex (MAC) infections that can cause chronic pulmonary disease, disseminated disease, as well as lymphadenitis. M. abscessus infections are considered one of the most antibiotic-resistant mycobacteria and are associated with pulmonary disease, especially cystic fibrosis, as well as contaminated traumatic skin wounds, postsurgical soft tissue infections, and healthcare-associated infections (HAI). Clinical manifestations of diseases depend on the interaction of the host’s immune response and the specific mycobacterial species. This review will give a general overview of the general characteristics, vulnerable populations most at risk, pathogenesis, treatment, and prevention for infections caused by Mycobacterium avium, in the context of MAC, and M. abscessus.

Does Mycobacterium tuberculosis var. bovis Survival in the Environment Confound Bovine Tuberculosis Control and Eradication? A Literature Review

“…The slow-growing species tend to be more associated with an intracellular lifestyle and pathogenicity: rapid-growing species tend to be mostly environmental saprophytes and include only a limited number of opportunistic pathogens [ 22 , 23 ]. Modern genomics suggests that slow-growing, pathogenic species likely evolved from rapid-growing, environmental saprophytes [ 24 ].…”

Antimicrobial Resistance in Common Respiratory Pathogens of Chronic Bronchiectasis Patients: A Literature Review

“…Another group of pathogens found in NCFB patients is NTM. Members of this family, most frequently found in NCFB, are Mycobacterium avium complex and Mycobacterium abscessus [ 57 ]. Aspergillus [ 58 ], and Candida [ 59 ] are fungi commonly identified in the respiratory secretions of NCFB patients [ 59 , 60 ].…”

The double‐edged sword of Tregs in M tuberculosis, M avium, and M. abscessus infection

“…83 However, unlike Mtb, the ubiquitous nature of Mycobacterium avium complex organisms in the environment, relatively few infected people develop disease. 85 The fact that M avium is killed by effector immunity in most healthy individuals highlights the requirement of some degree of susceptibility due to either underlying lung disease or immunosuppression to develop a progressive M avium disease.…”