Term
|
Definition
| obligate aerobes and poorly gram staining |
|
|
Term
| Why are mycobacterium acid fast staining? |
|
Definition
because of the components in their cell wall
-waxy and hydrophobic lipid laden
-lipid layer holds "fast" to the red carbofuschin stain in the acid fast stain and resists decolorization and the addition of methylene blue coloration |
|
|
Term
| What is one acid-fast staining method used for Mycobacterium tuberculosis? |
|
Definition
|
|
Term
| Explain the Ziehl-Neelsen staining method. |
|
Definition
1. Smear is fixed and stained with carbofuschin (pink dye).
2. Decolorized with acid-alcohol.
3. Counterstained with methylene blue (or certain other dyes). |
|
|
Term
| What do acid fast bacilli look like using the Ziehl-Neelsen method of staining? |
|
Definition
| pink against a contrasting background |
|
|
Term
| transmission of Mycobacterium tuberculosis |
|
Definition
respiratory spread
crowded conditions with untreated pts (homeless population) |
|
|
Term
| Where is the virulence factor found in Mycobacterium tuberculosis? |
|
Definition
|
|
Term
| What does the virulence factor in the cell envelope of Mycobacterium tuberculosis do? |
|
Definition
prevents destruction of phagocytosed organisms
(type IV cell-mediated immunity) |
|
|
Term
| What bacteria is responsible for causing granulomas with central caseating necrosis, Langhan giant cells, and numberous mononuclear cells in the lungs? |
|
Definition
| Mycobacterium tuberculosis |
|
|
Term
| What does mycobacteria need that is in the special media? |
|
Definition
|
|
Term
| What is Lowenstein-Jensen media used for? |
|
Definition
|
|
Term
| What bacteria causes leprosy? |
|
Definition
|
|
Term
| What acid fast bacteria causes an opportunistic infection in patients who are immunocompromised, especially AIDS patients? |
|
Definition
| Mycobacterium avium-intracellullare (MAI) |
|
|
Term
After phagocytosis of tubercle bacilli, macrophages secrete _________ that attract __________.
Interaction with lymphocytes stimulates macrophages to produce ___________ and ______, thereby activating ______________.
These lymphocytes produce ___________, _____, and ____, which activate macrophages and other lymphocytes. |
|
Definition
chemokines; leukocytes
IFN-gamma and TNF; CD4 + T lymphocytes
cytokines, IL-2, and IFN-gamma |
|
|
Term
|
Definition
| cough, night sweats, weight loss |
|
|
Term
| Where does primary TB usually develop? |
|
Definition
| lower middle lobe or upper lower lobe |
|
|
Term
| Where does reactivation TB usually occur? |
|
Definition
| upper lobe (apex), where oxygen tension is higher |
|
|
Term
|
Definition
-associated with primary TB
-ipsilateral lymphadenopathy because the infected lymph is drained along the interstitium to the hilar and mediastinal lymph nodes |
|
|
Term
| How does primary TB become milliary TB? |
|
Definition
venous drainage from the lungs allows hematogenous dissemination of the infection
spreads to bone marrow, kidneys, etc. |
|
|
Term
|
Definition
primary
progressive-primary
postprimary |
|
|
Term
| What does a postprimary TB infection mean? |
|
Definition
| either reactivation of a latent primary infection or a repeat infection of a previously sensitized host (less common) |
|
|
Term
| What do you look for the distinguish primary TB? |
|
Definition
|
|
Term
| What do you look for to distinguish progressive-primary TB? |
|
Definition
|
|
Term
| What population is more susceptible to a progressive-primary TB infection? |
|
Definition
|
|
Term
| Why could a PPD test be negative in someone with progressive-primary TB? |
|
Definition
| unable to mount T cell mediated defense |
|
|
Term
| Why does a TB infection in an immunocompetent patient usually resolve without further spread of the infection? |
|
Definition
| macrophages are successful in containing the bacilli (even though the bacilli may remain viable within the macrophages) |
|
|
Term
| What is another term for postprimary TB? |
|
Definition
|
|
Term
| Postprimary TB means the primary infection has resolved, but the bacteria are _________, or _________. |
|
Definition
|
|
Term
| When would a postprimary TB infection occur? |
|
Definition
| when conditions become favorable (a lowered immunity) |
|
|
Term
| What is the less common postprimary TB infection? |
|
Definition
| repeat infection of a previously sensitized host |
|
|
Term
| What is an important radiographic feature of postprimary TB and indicates active and transmissible disease? |
|
Definition
|
|
Term
| Why does Mycobacterium prefer the area of the lung with the highest oxygen tension? |
|
Definition
|
|
Term
| What type of immune reaction causes the clinical manifestations of TB? |
|
Definition
| type IV cell mediated hypersensitivity reaction |
|
|
Term
| Explain the immune reaction involved in a TB infection. |
|
Definition
1. interaction of CD4+ and CD8+ T cells
2. antigen is non-degradable and a granuloma with macrophages forms
3. accumulation of mononuclear cells (primarily CD4+ T cells) |
|
|
Term
|
Definition
| committee of epithelioid macrophages |
|
|
Term
| What properties of Mycobacterium tuberculosis are associated with the high concentration of lipids in the cell wall? |
|
Definition
-impermeability to stains and dyes
-resistance to many antibiotics
-resistance to killing by acidic and alkaline compounds
-resistance to osmotic lysis via complement deposition
-resistance to lethal oxidations and survival inside of macrophages |
|
|
Term
| What inhibits phagosome-lysosome fusion in TB? |
|
Definition
|
|
Term
| TB can be diagnosed by skin testing for ________ ___________ with _________. |
|
Definition
| delayed hypersensitivity; tuberculin (PPD) |
|
|
Term
| What is important to remember about the PPD test? |
|
Definition
| A person who is extremely debilitated may not show a positive PPD when a M. tuberculosis infection if present. |
|
|
Term
| What is important to remember about the elderly and/or debilitated when assessing symptoms of TB? |
|
Definition
| may not show a fever in the face of overwhelming infection |
|
|
Term
| What is different about the acid fast stain results of a M. tuberculosis infection compared to a M. avium-intracellulare infection? |
|
Definition
| M. avium-intracellulare infection shows a tremendous number of acid-fast bacilli whereas a M. tuberculosis infection will only show very few |
|
|
