30 Questions
What is the first step in the pathogenesis of pulmonary tuberculosis?
Tubercle bacilli reach the alveoli
What is the term used to describe an infection that affects multiple organs at the same time?
Systemic infection
What is the difference between latent TB and active TB?
Latent TB is when the person has the infection but no disease, while active TB is when the TB bacilli overcome the defense mechanisms and multiply with tissue destruction
What is the purpose of the tuberculin skin test (Mantoux test)?
To test for delayed hypersensitivity to TB antigens
What is the purpose of including a known positive smear as a positive control in microscopy for tuberculosis diagnosis?
To ensure the staining procedure is working correctly
How is the result of the tuberculin skin test (Mantoux test) interpreted?
By measuring the diameter of the induration (thickening) in millimeters and considering a reading of greater than 10 mm as positive
What does MOTT stand for in the text?
Mycobacteria Other Than Tuberculosis
Which group of species is known to cause a variety of diseases, especially in children and the immune-suppressed?
Mycobacteria Avium Intracellulare group
Infections by Mycobacterium tuberculosis can occur in different organs due to what factor?
Lack of cell mediated immunity
What percentage of TB cases are HIV-coinfected according to the text?
14-30%
Why is tuberculosis considered particularly severe in AIDs patients?
Infections are caused by multiple resistant species
How do tuberculosis infections initially start, according to the text?
As respiratory infections
What is the purpose of using selective enrichment media for the culture of Mycobacteria?
To provide a suitable environment for the slow-growing and fastidious Mycobacteria to grow
What is the purpose of decontaminating specimens before culture?
To kill the commensals before inoculating the specimen onto the media
What is the typical appearance of M.tuberculosis colonies on Lowenstein-Jensen agar?
Irregular raised pale yellow colonies with a hard texture, usually described as Rough, Tough, and Buff
Which of the following is a manual method used for the culture of Mycobacteria?
Lowenstein-Jensen agar slopes
What is the purpose of using Kirschner's Broth for the isolation of M.tuberculosis?
To make the culture process easier for the microbe to utilize in liquid media
What is the importance of a well-prepared and examined smear in the diagnosis of Mycobacterial infections?
It is the most important step in the diagnosis of Mycobacterial infections
What is the purpose of using fluorescent detection in automated culture methods?
To reduce the time required for culture methods
Which characteristic is used to categorize Mycobacteria into slow growers and fast growers?
Rate of growth
What is an example of a biochemical test used for identifying Mycobacterium species?
Niacin, Nitrate, Heat resistant catalase, Urease
What method can differentiate between M. tuberculosis (MTB) and other Mycobacteria?
NAP test
What happens to the BACTEC reading when Mycobacterium tuberculosis (MTB) fails to grow in the presence of NAP in the NAP test?
The growth reading falls
Why are specialized antibiotics needed for treating Mycobacterial infections?
Because Mycobacteria require a combination of antibiotics for treatment
Which stain is used as the primary stain in the Ziehl-Neelsen staining technique?
Carbol fuchsin
What is the purpose of the decolorizing step in the Ziehl-Neelsen staining technique?
To remove the primary stain from cells without a waxy lipid layer
Which stain is used as the counter-stain in the Auramine staining technique?
Potassium permanganate
Which disease is caused by the Mycobacterium tuberculosis complex?
Tuberculosis
Which group of mycobacteria is associated with opportunistic infections and low-grade infections?
Atypical mycobacteria/Non-tuberculous mycobacteria/MOTT
Which mycobacterial species causes leprosy (Hansen's disease)?
Mycobacterium leprae
Learn about the staining technique used in microbiology where Carbol fuchsin is applied to the slide, followed by acid decolorization and a counter stain such as Methylene blue or Malachite green. Understand why sputum is a suitable specimen to check for mycobacteria.
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