Mycobacterial Infections

• Mycobacterium leprae causes bone erosion and can take up to 20 years to grow
• Mycobacterium leprae can be tuberculoid, where it is paucibacillary, so not many bacteria are present as they can be easily removed
• Mycobacterium leprae can be lepromatous, where it is multibacillary, so many bacteria are present and the humoral response can't damage them due to living within self cells
• Mycobacteria leprae affect peripheral Schwann cells and reverse them into stem cell progenitors to enter body tissues like muscle and macrophages
• Bacterial dissemination is the spread of a bacterium around the body via the immune or cell distribution system
• Scrofula is caused by mycobacterium tuberculosis and mycobacterium scrofulaceum cause a tubercular infection of the lymph nodes
• Mycobacteria tuberculosis are obligate aerobes which affect the upper lobes of the lung and spinal vertebrae
• Mycobacteria tuberculosis enter lung alveoli by droplets and survive phagocytosis, they enter lymph node granulomas of B and T cells and are released later in life as the immune system degrades
• Pulmonary tuberculosis causes caseous tissue necrosis in the upper lung and can be seen on x ray
• MGIT is where you look for evidence of bacterial metabolism instead of the bacteria when it is slow growing like mycobacterium leprae and mycobacterium tuberculosis
• Multiple drug therapy of antibiotics and chemotherapy is necessary to treat mycobacterium, as it may be resistant to a single antibiotic
• Mycobacterium tuberculosis can be detected in the MTB/Rif system machine in approximately 2 hours
• The mycolic acid layer prevents a stain like ziehl neelsen from penetrating, so it must be boiled in and can't be removed with acid
• Auramine rhodamine is a fluorescent stain used instead of ziehl neelsen as it is easier to view
• Streptomycin is an effective antibiotic in combination with chemotherapy for mycobacterium