Nontuberculous mycobacteria

[3] Mycobacteria are a family of small, rod-shaped bacilli that can be classified into three main groups for diagnosis and treatment: In 1959, botanist Ernest Runyon put these human disease-associated bacteria into four groups (Runyon classification):[4] The number of identified and cataloged NTM species has been increasing rapidly, from about 50 in 1997 to over 125 by January 2007.

[citation needed] Pulmonary NTM is estimated by some experts in the field to be at least ten times more common than TB in the U.S., with at least 150,000 cases per year.

Most NTM disease cases involve the species known as Mycobacterium avium complex or MAC for short, M. abscessus, M. fortuitum and M. kansasii.

[10] Mayo Clinic researchers found a three-fold increased incidence of cutaneous NTM infection between 1980 and 2009 in a population-based study of residents of Olmsted County, Minnesota.

It is not uncommon for alpha 1-antitrypsin deficiency, Marfan syndrome, and primary ciliary dyskinesia patients to have pulmonary NTM colonization and/or infection.

[17] Disseminated mycobacterial disease was common in US and European AIDS patients in the 1980s and early 1990s, though the incidence has declined in developed nations since the introduction of highly active antiretroviral therapy.

[15] Diagnosis of opportunistic mycobacteria is made by repeated isolation and identification of the pathogen with compatible clinical and radiological features.

[15] Many reference centres now use a nucleic acid-based method such as sequence differences detection in the gene coding for 16S ribosomal RNA to identify the species.