Micro Final D2

Question 1

Pseudomonas aeruginosa

Answer 1

Gram-negative, opportunistic pathogen causing hospital-acquired infections (HAIs).

Question 2

Transmission of P. aeruginosa

Answer 2

Contact (medical devices/hands) or vehicle (water/respiratory equipment).

Question 3

Risk groups for P. aeruginosa

Answer 3

Immunocompromised, burn victims, cystic fibrosis patients, catheter/ventilator users.

Question 4

P. aeruginosa virulence factors

Answer 4

Exotoxin A, biofilm formation, Type III secretion system, pili/flagella.

Question 5

P. aeruginosa treatment

Answer 5

Antibiotics: Piperacillin-tazobactam, ceftazidime, meropenem (resistance common).

Question 6

Legionnaire’s disease

Answer 6

Scientifically known as Legionella pneumophila, is a gram-negative aerobic bacterium via airborne water aerosols.

Question 7

Legionella transmission

Answer 7

Inhalation of aerosols from cooling towers, showers, or fountains.

Question 8

Legionella risk groups

Answer 8

Elderly, smokers, immunocompromised (e.g., HIV/AIDS, chemotherapy).

Question 9

Legionella virulence factors

Answer 9

Dot/Icm secretion system, flagella, LPS (lipopolysaccharide).

Question 10

Legionella treatment

Answer 10

Macrolides (azithromycin) or fluoroquinolones (levofloxacin).

Question 11

Tuberculosis (TB)

Answer 11

Acid-fast, gram positive aerobic bacterium causing mycobacterium tuberculosis.

Question 12

TB transmission

Answer 12

Airborne droplets from coughing/sneezing of infected individuals.

Question 13

TB risk groups

Answer 13

HIV/AIDS patients, diabetics, smokers, healthcare workers, inmates.

Question 14

TB virulence factors

Answer 14

Mycolic acid (cell wall), granuloma formation, cord factor.

Question 15

TB treatment

Answer 15

Long-term antibiotics: Isoniazid, rifampin, pyrazinamide, ethambutol (6+ months).

Question 16

Klebsiella pneumoniae

Answer 16

Gram-negative, encapsulated bacterium causing pneumonia/UTIs.

Question 17

Klebsiella transmission

Answer 17

Contact (hands/devices) or vehicle (contaminated water/IV fluids).

Question 18

Klebsiella risk groups

Answer 18

Hospitalized patients, neonates, elderly, alcoholics.

Question 19

Klebsiella virulence factors

Answer 19

Capsule (antiphagocytic), biofilm formation, ESBL enzymes.

Question 20

Klebsiella treatment

Answer 20

Carbapenems (meropenem) for resistant strains; cephalosporins if susceptible.

Question 21

Exotoxin A (P. aeruginosa)

Answer 21

Inhibits host protein synthesis; key virulence factor.

Question 22

Biofilm (P. aeruginosa)

Answer 22

Protective extracellular matrix enhancing antibiotic resistance.

Question 23

Dot/Icm system (Legionella)

Answer 23

Secretion system injecting proteins to hijack host macrophages.

Question 24

Mycolic acid; part of which disease?

Answer 24

Waxy lipid in cell wall resisting macrophage digestion; TB

Question 25

Granuloma (TB)

Answer 25

Immune structure trapping bacteria but enabling latent infection.

Question 26

ESBL (Klebsiella)

Answer 26

Extended-spectrum beta-lactamase enzyme conferring antibiotic resistance.

Question 27

HAIs

Answer 27

Hospital-acquired infections; often caused by P. aeruginosa or Klebsiella.

Question 28

A-B toxin (e.g., cholera toxin)

Answer 28

Toxin with binding (B) and active (A) subunits; e.g., Shiga toxin in STEC.

Question 29

ID50

Answer 29

Median infectious dose; number of pathogens needed to infect 50% of hosts.

Question 30

LD50

Answer 30

Median lethal dose; number of pathogens needed to kill 50% of hosts.

Question 31

Koch’s Postulates

Answer 31

Criteria to link pathogens to diseases: isolate, culture, reinfect, reisolate.

Question 32

Adhesins

Answer 32

Pathogen surface molecules (e.g., pili) binding host cell receptors.

Question 33

Antigenic variation

Answer 33

Pathogen alters surface proteins (e.g., Neisseria gonorrhoeae pili) to evade immunity.

Question 34

Endotoxin (LPS)

Answer 34

Lipid A component of Gram-negative cell walls; triggers fever/shock.

Question 35

Pyrogenic response

Answer 35

Fever induced by endotoxins (e.g., LPS) via cytokine release.

Question 36

TORCH infections

Answer 36

Pathogens crossing placenta: Toxoplasma, Rubella, CMV, Herpes, Syphilis.

Question 37

Fomites

Answer 37

Inanimate objects (e.g., doorknobs) transmitting pathogens indirectly.

Question 38

Biological vector and ex.s of diseases

Answer 38

Diseases transmitted from animals to humans; Lyme disease, rabies, leprosy).

Question 39

Nosocomial infections

Answer 39

Infections acquired in healthcare settings (e.g., P. aeruginosa, Klebsiella).