MIDTERM 07 - Mycobacteria and Atypical Pneumonia Flashcards by Juan Carlos Cornelio

Are rod-shaped, obligate aerobic bacteria; is an acid-fast bacteria that cannot be classified as gram-positive or gram-negative

Mycobacteria

How well did you know this?

Not at all

Perfectly

Bacteria that resist decolorization by acid or alcohol

Acid fast bacteria

How well did you know this?

Not at all

Perfectly

Cultured using inspissated egg media (ex. Lowenstein-Jensen); causes primary complex, latent TB, and reactivation/secondary TB (Mycobacterium species)

Mycobacterium tuberculosis/Koch’s bacillus

How well did you know this?

Not at all

Perfectly

Media that contains salts, glycerol, and complex organic substances; used to culture Mycobacterium tuberculosis

Inspissated egg media (Ex. Lowenstein-Jensen)

How well did you know this?

Not at all

Perfectly

Responsible for acid fastness (Mycobacterium tuberculosis virulence factors)

Lipids

How well did you know this?

Not at all

Perfectly

Can cause granuloma formation; resists drying (Mycobacterium tuberculosis virulence factors)

Mycolic acid

How well did you know this?

Not at all

Perfectly

Inhibits migration of leukocytes; causes chronic granulomas (Mycobacterium tuberculosis virulence factors)

Cord factor

How well did you know this?

Not at all

Perfectly

Induces caseous necrosis (Mycobacterium tuberculosis virulence factors)

Phosphatides

How well did you know this?

Not at all

Perfectly

Elicit tuberculin reaction and antibody production (Mycobacterium tuberculosis virulence factors)

Proteins

How well did you know this?

Not at all

Perfectly

Characterized by granuloma (tubercle) formation due to migration of macrophages (Clinical findings of Mycobacterium tuberculosis)

Primary complex

How well did you know this?

Not at all

Perfectly

Characterized by dormancy of bacilli in the granuloma (Clinical findings of Mycobacterium tuberculosis)

Latent TB

How well did you know this?

Not at all

Perfectly

Characterized by reactivation of dormant bacilli due to depressed cell-mediated immunity or reinfection (Clinical findings of Mycobacterium tuberculosis)

Reactivation/Secondary TB

How well did you know this?

Not at all

Perfectly

Refers to the spread of Mycobacterium tuberculosis through regional lymph nodes

Lymphatic spread

How well did you know this?

Not at all

Perfectly

Refers to the spread of Mycobacterium tuberculosis to all organs (Miliary distribution)

Hematogenous spread

How well did you know this?

Not at all

Perfectly

Occurs usually in childhood; usually involves the base of the lungs (Clinical findings of Mycobacterium tuberculosis)

Primary complex

How well did you know this?

Not at all

Perfectly

Has no clinical manifestations; host is noninfectious (Clinical findings of Mycobacterium tuberculosis)

Latent TB

How well did you know this?

Not at all

Perfectly

May be due to tubercle bacilli that have survived the primary lesion; usually involves the apex of the lung, where O2 tension is the highest (Clinical findings of Mycobacterium tuberculosis)

Reactivation/Secondary TB

How well did you know this?

Not at all

Perfectly

Due to dormant bacilli in the primary lesion; more common (Causes of Reactivation/Secondary TB)

Endogenous

How well did you know this?

Not at all

Perfectly

Due to reinfection (Causes of Reactivation/Secondary TB)

Exogenous

How well did you know this?

Not at all

Perfectly

Characterized by fatigue, weakness, weight loss, fever, and night sweats (Clinical findings of Mycobacterium tuberculosis)

Tuberculosis (Koch’s disease)

How well did you know this?

Not at all

Perfectly

Characterized by chronic cough and hemoptysis (Types of tuberculosis)

Pulmonary TB

How well did you know this?

Not at all

Perfectly

Involves ≥2 adjacent vertebral bodies (Types of tuberculosis)

Spinal TB (Pott’s disease)

How well did you know this?

Not at all

Perfectly

Characterized by bloodstream dissemination and infection of many organs (Types of tuberculosis)

Miliary TB

How well did you know this?

Not at all

Perfectly

Used to test for tuberculosis; patient is examined within 48-72 hours after injection; a positive result is an induration/wheal formation

Tuberculin skin test (TST)/Mantoux test

How well did you know this?

Not at all

Perfectly

Derivative that is obtained by chemical fractionation of old tuberculin (A concentrated filtrate of broth in which tubercle bacilli have grown for 6 weeks); injected on the inner surface of the forearm

Purified protein derivative (PPD)

Diagnosis for tuberculosis with a low sensitivity (40-60%); 2 sputum specimens are collected early in the morning

Acid fast smear/AFB microscopy/Ziehl-Neelsen method

Diagnosis for tuberculosis that has a high sensitivity but poor specificity; for diagnosis of PTB in children who cannot expectorate (<5 y/o)

Chest X-ray

Used for rapid diagnosis of TB with high specificity and sensitivity

Gene Xpert MTB/RIF

An intradermal, attenuated vaccine derived from Mycobacterium bovis that is given at birth and is used for Mycobacterium tuberculosis prevention

Bacillus Calmette-Guérin (BCG) vaccine

Meaning of DOTS (Mycobacterium tuberculosis treatment)

Directly Observed Treatment, Short Course

4 drugs that are 1st line agents used for treatment of Mycobacterium tuberculosis (RIPE/HRZE)

Rifampicin, Isoniazid, Pyrazinamide, Ethambutol

Tuberculosis that is resistant to one 1st line agent (Types of resistant tuberculosis)

Monoresistant TB

Tuberculosis that is resistant to rifampicin (Types of resistant tuberculosis)

Rifampicin resistant (RR) tuberculosis

Tuberculosis that is resistant to >1 1st line agent other than isoniazid and rifampicin combined (Types of resistant tuberculosis)

Poly-drug resistant tuberculosis

Tuberculosis that is resistant to at least both isoniazid and rifampicin (Types of resistant tuberculosis)

Multi-drug resistant tuberculosis

Often found within the endothelial cells of blood vessels or in mononuclear cells; transmitted through respiratory droplets and requires prolonged and close contact (Mycobacterium species)

Mycobacterium leprae

Characterized by insidious onset, skin lesions, and neurologic disturbance (Clinical findings of Mycobacterium leprae)

Leprosy (Hansen's disease)

Is progressive and malignant; characterized by nodular skin lesions with abundant acid-fast bacilli (Types of leprosy)

Lepromatous leprosy

Is benign and nonprogressive; characterized by a small number of macular skin lesions with few bacilli (Types of leprosy)

Tuberculoid leprosy

Uses scrapings from skin or nasal mucosa or biopsy of earlobe skin; used for diagnosing Mycobacterium leprae

AFB smear/Ziehl-Neelsen method

Drug of choice for Mycobacterium leprae

Dapsone

Treatment for lepromatous leprosy (DRC)

Dapsone + Rifampin + Clofazimine

Treatment for tuberculoid leprosy (DR)

Dapsone + Rifampin

Infrequently causes disease in immunocompetent humans; one of the most common infections of bacterial origin in patients with AIDS and cystic fibrosis (Mycobacterium species)

Mycobacterium avium complex (M. avium intracellulare)

Causes TB-like disease; is the source of Bacillus Calmette-Guérin (BCG) vaccine (Mycobacterium species)

Mycobacterium bovis

Clinical and laboratory findings are limited to the lungs; responds to β-lactam antibiotics (Types of pneumonia)

Typical pneumonia

Systemic findings with pulmonary competent; does not respond to β-lactam antibiotics (Types of pneumonia)

Atypical pneumonia

3 bacteria that causes atypical pneumonia (LMC)

Legionella pneumophila, Mycoplasma pneumoniae, Chlamydophyla pneumoniae

A fastidious, aerobic gram-negative bacteria that caused an outbreak of pneumonia in persons attending an American Legion convention in Philadelphia in 1976 (Types of bacteria that causes atypical pneumonia)

Legionella pneumophila

Legionella pneumophila is cultured using __________ agar

Buffered charcoal yeast extract (BCYE) agar

Is an atypical pneumonia characterized by lobal, segmental, or patchy pulmonary infiltration (Clinical findings of Legionella pneumophila)

Legionnaires disease

Named after the clinical syndrome that occurred in an outbreak in Michigan; characterized by fever and chills, myalgia, malaise, and headache (Clinical findings of Legionella pneumophila)

Pontiac fever

The smallest organisms that are free living in nature and self-replicating on laboratory media; has no cell wall and requires sterol in the plasma membrane (Types of bacteria that causes atypical pneumonia)

Mycoplasma sp.

Mycoplasma sp. is cultured using ____________, which has a "fried-egg" apperance

Horse serum and yeast extract

Is a mild disease; characterized by malaise, fever, headache, sore throat, and cough, and there may be blood-streaked sputum and chest pain (Clinical findings of Mycoplasma pneumoniae)

Walking pneumonia

Causes postpartum fever and uterine tube infections (Examples of cell-wall defective bacteria)

Mycoplasma hominis

Causes nongonococcal and nonchlamydial urethritis in men (Examples of cell-wall defective bacteria)

Ureaplasma urealyticum

Causes chronic nongonococcal urethritis, cervicitis, endometritis, salpingitis, and infertility (Examples of cell-wall defective bacteria)

Mycoplasma genitalium

Is a long chain of fatty acids that is 78-90 carbons long; a virulence factor of Mycobacterium tuberculosis

Mycolic acid

Mycolic acid is a long chain of fatty acids that is __________ to __________ carbons long

78-90 carbons

Complex characterized by Ghon lesion/focus and regional lymphadenopathy present in primary complex

Ghon complex

Process of leukocytes migrating from the blood circulation to specific sites

Diapedesis

Lesion that is a calcified granuloma visible under x-ray

Ghon lesion/focus

Other name for Anti-TB drugs

Anti-Koch's drugs

Tuberculin skin test (TST) is examined __________ to __________ hours after injection

48-72 hours

The body's reaction to tuberculin skin test (TST) is due to __________

Type IV hypersensitivity

Tuberculin skin test (TST) is an indicator of __________ and __________ (LP)

Latent TB, Past infection

Tuberculin skin test (TST) may be negative upon __________ treatment

Isoniazid

__________ is the first-line diagnostic test of active TB recommended by WHO

Gene Xpert MTB/RIF

The immunity conferred by the BCG vaccine decreases after __________ to __________ years

15-20 years

Term used to describe abundant acid-fast bacilli

Multibacillary

Term used to describe few bacilli

Paucibacillary

Leprosy that has a negative lepromin skin test result

Lepromatous leprosy

Leprosy that has a positive lepromin skin test result

Tuberculoid leprosy

Other name for Mycobacterium avium complex

Mycobacterium avium intracellulare

Other name for isoniazid

Isonicotinic acid hydrazide

Inhibits mycolic acid synthesis; side effects include peripheral neuropathy, hepatotoxicity, and seizures (1st line agents for TB)

Isoniazid

Antidote for isoniazid overdose

Vitamin B6/Pyridoxine

Inhibits DNA-dependent RNA polymerase; side effects include red-orange discoloration of body fluid, and hepatotoxicity (1st line agents for TB)

Rifampicin

Its mechanism of action is unknown; is most dominant side effect is hepatotoxicity (1st line agents for TB)

Pyrazinamide

Inhibits arabinogalactan synthesis; its side effect includes dose-dependent retrobulbar neuritis, which leads to red-color blindness (1st line agents for TB)

Ethambutol

The gold standard for Mycobacterium tuberculosis diagnosis

Lowenstein-Jensen medium

Culture medium used for Legionella pneumophila that contains a-ketoglutarate, L-cysteine, and iron

Buffered charcoal yeast extract (BCYE) agar

Culture medium for Mycoplasma sp. that has a fried-egg appearance

Horse serum and yeast extract