Bacte mycobacteria

• What type of organisms are mycobacteria?

  Non-motile, non-spore forming rods
• Why do mycobacterial cells resist staining with basic aniline dyes?

  They have extremely high lipid content in cell wall
• How can mycobacteria be stained effectively?

  By increasing staining time or applying heat
• What is the term for the characteristic of mycobacteria that allows them to resist decolorization?

  Acid fastness
• What enhances the growth of some mycobacterial species?

  Increased carbon dioxide (CO2)
• Which species are included in the Mycobacterium tuberculosis complex?

  1. tuberculosis, M. bovis, M. africanum
• What is the primary disease caused by Mycobacterium tuberculosis?

  Tuberculosis (TB)
• How is TB primarily acquired?

  From persons with active disease excreting bacilli
• What forms in response to TB infection?

  A hard tubercle or granuloma
• What is the composition of a granuloma in TB?

  Lymphocytes, macrophages, fibroblasts, and capillaries
• What happens with granuloma formation in TB?

  Healing occurs with fibrosis and calcification
• What is a clinical diagnosis indicator of primary TB?

  Positive PPD skin test
• How is TB diagnosis confirmed?

  By stained smear and culture of specimens
• What does miliary TB refer to?

  Seeding of many organs with AFB
• Which organ can be infected by M. tuberculosis?

  Almost any organ of the body
• What is Pott disease?

  Skeletal TB of the spine
• What does CSF examination reveal in TB meningitis?

  Elevated protein, decreased glucose, lymphocytes
• How do colonies of M. tuberculosis typically appear?

  Raised, dry, rough appearance
• What color are the colonies of M. tuberculosis described as?

  Buff-colored
• What is the significance of cord factor in mycobacteria?

  It can result in characteristic cord formation
• What is the optimal growth temperature for mycobacteria?

  35° C to 37° C
• What is a positive test for niacin accumulation indicative of?

  Mycobacterium tuberculosis
• What does reduction of nitrate to nitrite indicate?

  Presence of certain mycobacteria
• What is the significance of catalase production in mycobacteria?

  It indicates metabolic activity
• What does growth on thiophene-2-carboxylic acid hydrazide (T2H) indicate?

  Specific mycobacterial species identification
• What animals can Mycobacterium bovis infect?

  Cattle, dogs, cats, swine, parrots
• How long is the incubation period for Mycobacterium bovis?

  21 days at 37° C
• What is a characteristic of non-tuberculous mycobacteria?

  Found in the environment, non-transmissible
• What is the Mycobacterium avium complex (MAC)?

  Includes M. avium and M. intracellulare
• What is the growth environment for M. avium?

  Soil, water, house dust
• What disease does Mycobacterium avium subsp. paratuberculosis cause?

  Johne disease
• What is the growth rate of Mycobacterium avium subsp. paratuberculosis?

  Very slow, 3 to 4 months
• What is a unique requirement for Mycobacterium haemophilum growth?

  Requires hemoglobin or hemin
• What are the clinical manifestations of Mycobacterium haemophilum?

  Submandibular lymphadenitis and ulcers
• What is the optimal growth temperature for Mycobacterium haemophilum?

  28° C to 32° C
• What is the appearance of Mycobacterium kansasii colonies?

  Smooth to rough with wavy edges
• What is the susceptibility profile of Mycobacterium kansasii?

  Sensitive to rifampin and ethambutol
• What is the characteristic of Mycobacterium malmoense?

  Causes chronic pulmonary disease
• What is the growth appearance of Mycobacterium scrofulaceum?

  Cervical lymphadenitis in children
• What is the growth rate of Mycobacterium simiae?

  Slow, 4 to 6 weeks