atypical bacterial pneumonia

Question 1

legionella characteristics

Answer 1

poorly staining gram (-) rods. facultative intracellular parasite. normally found living in amoeba.

Question 2

which form of legionella is contagious

Answer 2

the free-living motile form with the flagella.

Question 3

which form is the replicative of legionella

Answer 3

intracellular, nonmotile form.

Question 4

natural atmosphere for legionella

Answer 4

forms biofilms in stagnant freshwater, parasite protozoan, full life cycle.

Question 5

unnatural atmosphere for legionella

Answer 5

form biofilms on HVAC systems, enters human lungs, parasitizes alveolar macrophages. dead end

Question 6

is legionella contagious?

Answer 6

NO.

Question 7

How can legionella form outbreaks?

Answer 7

from the same water supply. water has to be aspirated

Question 8

what diseases occur when legionella infects?

Answer 8

there are three infections likely: asymptomatic seroconversion, pontiac fever, legionnaires disease

Question 9

pontiac fever

Answer 9

flulike illness. all symptoms are immunogenic as the immune system kills the bacteria. patient is previously healthy

Question 10

legionnaires disease

Answer 10

pneumonia with kidney involvement and diarrhea. symptoms from infection and killing of alveolar macro. renal failure. can be fatal.

Question 11

who gets legionnaires?

Answer 11

patient is previously ill such as elderly, immunocompromised, diabetic, heart or lung disorder, smoker, kidney disease, alcohol at time of exposure.

Question 12

incubation period for legionnaires disease

Answer 12

2-10 days.

Question 13

pontiac fever incubation?

Answer 13

2 days.

Question 14

legionella common history

Answer 14

male, elderly, smoker, pre-existing malfunction of swallowing/immunity/respiratory system. recent travel with alcohol.

Question 15

exam for legionella

Answer 15

altered mental status HA, fever, chills. pneumonia/cough/chest pain, acute renal failure. pancreatitis., diarrhea. geriatric community acquired pneumonia with renal failure and diarrhea is suggestive but not diagnostic.

Question 16

labs for legionella

Answer 16

urine antigen test quickly detects LP1 strain of legionella 90% of cases. does not detect the others. culturing. for optimal diagnosis do both. biopsy is not necessary but will show silver stain. gram will fail.

Question 17

culturing legionella

Answer 17

fastidious, requiring special nutrients. slow, takes a week. technically demanding.

Question 18

treatment of pontiac fever

Answer 18

generally resolves without

Question 19

LD treatment

Answer 19

admit. fluoroquinolones or doxy, azithromycin, macrocodes with rifampin. supportive care for recoverees it takes time!

Question 20

coxiella burnettii characteristics

Answer 20

protobacteria similar to legionella. zoonosis of asymptomatic infection of ruminants. extremely infectious

Question 21

how is coxiella burnettii transmitted

Answer 21

by inhalation of aerosols of infected urine, feces or borhting products

Question 22

where is coxiella burnettii common

Answer 22

netherlands, france, spain, iraq.

Question 23

what is the life cycle of coxiella burnettii

Answer 23

it multiplies intracellularly in alveolar macrophages. encodes acid phosphatase that allows it survive endosomal fusion. infected macros carry to the liver, spleen and bone marrow.

Question 24

exam for coxiella burnettii

Answer 24

pneumonia with hepatitis, fever, chills, sweats, severe HA dry cough.

Question 25

labs for coxiella burnettii

Answer 25

IF, IHC, ELISA all available.

Question 26

treatment for coxiella burnettii

Answer 26

doxy or fluoroquinolones.

Question 27

prevention of coxiella burnettii

Answer 27

vaccine available for farm personnel stationed in middle east.

Question 28

mycoplasma pneumoniae characteristics

Answer 28

smallest free-living organism. strictly aerobic. no cell wall little gram stain. cell wall contains cholesterol. requires special nutrients to grow. only one serotype but the immunity is incomplete

Question 29

why are penicillin and cephalosporins ineffective for mycoplasma

Answer 29

because they have no cell wall

Question 30

what do the mycoplasma pneumoniae colonies look liek

Answer 30

fried egg appearance

Question 31

what does mycoplasma pneumoniae cause?

Answer 31

tracheobronchitis, bronchiolitis, atypical pneumonia

Question 32

what is another name for atypical pneumonia?

Answer 32

walking pneumonia

Question 33

how is mycoplasma pneumoniae transmitted?

Answer 33

respiratory droplets.

Question 34

what happens when mycoplasma pneumoniae gets into the lung?

Answer 34

it changes shape to a rod, due to attachment at the tip. inhibits ciliary motion causing irritation and nonproductive cough. causes epithelial necrosis and tissue damage from toxic metabolites.

Question 35

what does the mycoplasma pneumoniae infection due to the immune system?

Answer 35

it causes autoantibodies against red cells, brain, lung, liver.

Question 36

what is the course of mycoplasma pneumoniae

Answer 36

10-14 days very low mortality even without treatment.

Question 37

when is mycoplasma pneumoniae more prevalent

Answer 37

in the winter.

Question 38

who is more at risk for mycoplasma pneumoniae

Answer 38

young adults are more common. can form outbreaks.

Question 39

symptoms of mycoplasma pneumoniae

Answer 39

slow onset, nonproductive cough, sore throat, earache, small amounts of whitish sputum, fever, HA, malaise, myalgias, chest sounds are unremarkable.

Question 40

what does the CXR show for mycoplasma pneumoniae

Answer 40

prominent infiltrates.

Question 41

labs for mycoplasma pneumoniae

Answer 41

not usually necessary

Question 42

treatment of mycoplasma pneumoniae

Answer 42

antibiotics can reduce duration but disease will resolve spontaneously. first choice is macrolides or tetracyclines. alt are fluoroquinolones. need extended course of 10-14 days. because of the slow growth and intracellular penetrations.