Nontuberculosis Mycobacterium

Acid-fast, lipid-rich cell walls. Free-living in soil and water. Biofilms allows them to persist in the environment. – For example, some species use biofilms to cling to water pipes. When they break free from the biofilm, they can contaminate drinking and bath water. Microbes are ingested or inhaled; in some cases, they gain access to the host via puncture wounds. Rapidly growing species grow within 7 days; these typically have low virulence. Slow-growing species Pigmented produce yellow carotenoids that lend their colonies a yellow or golden color. – The photochromogenic species, such as Mycobacterium kansaii, require exposure to light for pigment production to occur. – The scotochromogenic species do not require light exposure for pigment production. Non-pigmented slow growers include members of the Mycobacterium Avium Complex. Mycobacterium kansaii Found in tap water. Pulmonary disease resembles tuberculosis. – Lung cavitation with chest pain, cough with blood in the sputum (hemoptysis), and, in some patients, fever. Treatment varies, but can include rifampicin and ethambutol for at least 12 months. Mycobacterium Avium Complex (MAC) Comprises 2 key species and 4 subspecies (in addition to several uncommon pathogenic species).

• Mycobacterium avium subspecies hominissuis
• Mycobacterium intracellulare

Associated with Mycobacterium avium. Cervicofacial lymph nodes of young children. Associated with Mycobacterium avium. Associated with HIV infection, other immunocompromised conditions. High bacillary load. Widespread organ damage. Symptoms are nonspecific, and include fever, night sweats, diarrhea and weight loss. Mycobacterium avium complex Risk: Immunocompetent Symptoms include cough, weakness, fatigue, and chest pain. WITH underlying pulmonary disease – Upper lobe infiltrates and cavitation; severe destruction can lead to respiratory failure. – Men who smoke, heavy alcohol drinkers, and adolescents with cystic fibrosis are particularly susceptible to this form of pulmonary disease. WITHOUT underlying pulmonary disease – Nodules and bronchiectasis; bronchiectasis is characterized by chronically dilated and scarred bronchial tubes, which allows infiltrates to accumulate. – The bronchial tubes of the right middle lobe and left lingula are most often affected, possibly because of their relative narrowness and length. – Tends to affect nonsmoking women over the age of 50. – Associated with thinness, mitral valve prolapse, and skeletal abnormalities, such as concave chest cavity (pectus excavatum). It has been suggested that this form of pulmonary disease results from chronic voluntary cough suppression, hence the nickname Lady Windmere's syndrome; however, the association between voluntary cough suppression and pulmonary disease has not been rigorously studied. Mycobacterium Abscessus, Mycobacterium fortuitum, Mycobacterium chelonae RGM species tend to cause post-surgery infections in immunosuppressed patients. Mycobacterium Abscessus comprises 3 subspecies that respond differently to medications; thus, subspecies determination may be necessary for successful treatment. Mycobacterium Abscessus is resistant to many antibiotics and disinfectants. Most cases are attributed to Mycobacterium Abscessus. Patients with underlying pulmonary disease, particularly cystic fibrosis, tuberculosis, and bronchiectasis, are most susceptible to infection. Post-surgical skin and soft tissue infections are associated with contaminated surgical equipment or solutions; lesions tend to be red, painful, and can form nodules or ulcers. Uncommon; occur in immunocompromised patients. Possible, but rare.