Bacterial Pneumonia 2

Question 1

what type of pathogen is legionella? what is the infection outcome?

Answer 1

it is opportunistic and facultative intracellular

variable infection outcome

Question 2

how is one exposed to legionella?

Answer 2

from aspiration or inhalation of contaminated water. outbreaks often traced to contaminated locations. it is not contagious

Question 3

how does legionella live in the human body?

Answer 3

it is endocytosed by macrophages and alters the endosomes so that they don’t fuse with lysosomes. they replicate there then escape.

Question 4

what are the old and new living environments for legionella?

Answer 4

old: biofilms on natural water sources
new: biofilms on cooling towers and whirlpool spas

Question 5

what is the prognosis of legionnaires disease?

Answer 5

it may be fatal even when treated by antibiotics

Question 6

what is the optimal way to diagnose legionnaires disease?

Answer 6

with both the urine antigen test and culture of respiratory secretions with special media (grows slow)

Question 7

what is the order of diagnosis and treatment for legionnaires disease in the elderly?

Answer 7

take samples for culture/ELISA and start treatment with levofloxacin before labs come back

Question 8

what is one common location for legionella outbreaks?

Answer 8

in healthcare buildings: vulnerable individuals exposed to bad plumbing.

Question 9

what is the infectious source of C burnetii?

Answer 9

aerosols of urine, feces or birthing matter of ruminants. highly infectious and long lived in the environment

Question 10

where does C burnetii grow in a human host?

Answer 10

grows in alveolar macrophages by surviving endolysosomal fusion

Question 11

what disease does C burnetti cause?

Answer 11

Q fever: pneumonia/hepatitis

Question 12

how is C burnetii diagnosed? treated?

Answer 12

diagnosed with immunohistochemistry and treated with tetracyclines or fluoroquinolones

Question 13

describe the morphology of mycoplasma

Answer 13

very small organisms lacking a cell wall and including cholesterol in their cell membranes

Question 14

describe the pneumonia caused by mycoplasma

Answer 14

walking pneumonia: mild and self limited

Question 15

what is the major virulence factor of mycoplasma? what does it cause?

Answer 15

CARDS exotoxin causes ciliostasis (loss of bronchiolar cilia), local inflammation and tissue destruction

Question 16

what is one immunogenic effect of mycoplasma infection?

Answer 16

produces cold agglutinins that target red blood cells and may cause anemia

Question 17

what makes mycoplasma difficult to treat?

Answer 17

slow growth and intracellular hiding

Question 18

how is mycoplasma cleared from the body?

Answer 18

it is either self limited or treated with tetracyclines or macrolides

Question 19

where do other mycobacteria infect?

Answer 19

reproductive and urinary tracts