MIDTERM LEC 2: PNEUMOCYSTIS SPP.

Question 1

New/current name of Pneumocystis carnii

Answer 1

Pneumocystis jirovecii

Question 2

Primary host of P. wakefieldiae/P. carinii

Answer 2

rats (rodents)

Question 3

Primary host of P. jirovecii

Answer 3

humans

Question 4

P. carinii was originally classified with what protozoa?

Answer 4

trypanosome

Question 5

How was P. carinii reclassified from protozoa to fungi?

Answer 5

Through nucleic acid
sequencing (showed it is a fungus)

Question 6

Pneumocystis spp. most often recovered from humans

Answer 6

P. jirovecii

Question 7

T/F: P. jirovecii is an opportunistic, atypical fungus that
infects immunocompromised hosts

Answer 7

true

Question 8

P. jirovecii mostly manifests as what disease?

Answer 8

Pneumocystic Pneumonia (PCP) / Pneumocystis jirovecii pneumonia (PJP)

Question 9

At what age do most children gain antibodies against pneumocystic pneumonia?

Answer 9

2-4 years old

Question 10

Pneumocystis infection is (asymptomatic/symptomatic?) in immunocompetent patients

Answer 10

asymptomatic

Question 11

Hallmark of PJP/PCP

Answer 11

interstitial pneumonitis

Question 12

The hallmark of PJP, interstitial pneumonitis, is accompanied with

Answer 12

a mononuclear infiltrate composed predominantly of plasma cells

Question 13

Pneumocystis spp. is initially identified as the
causative agent of?

Answer 13

interstitial plasma cell pneumonia

Question 14

In which patients is interstitial plasma cell pneumonia commonly seen?

Answer 14

malnourished or premature infants

Question 15

Which specialized cells does interstitial plasma cell pneumonia target?

Answer 15

type I pneumocytes (for gas exchange)

Question 16

Pneumocystis remained one of the
primary opportunistic infections found in
patients with what type of disease?

Answer 16

AIDS

Question 17

Since what year has Pneumocystis been the primary opportunistic infection of patients with AIDS?

Answer 17

since the early 1980s

Question 18

What are the symptoms of PJP/PCP?

Answer 18

• nonproductive cough (cough with no mucus)
• difficulty breathing
• low-grade fever

Question 19

Range of temperature of low-grade fever

Answer 19

37.5°C - 38.3°C

Question 20

What findings might a chest radiograph of a patient with PJP show?

Answer 20

normal or a diffuse interstitial infiltrate

Question 21

What causes normal or diffuse interstitial infiltrate findings on a chest radiograph?

Answer 21

Due to the organism’s immunological response after
it binds to and destroys alveolar cells.

Question 22

Environmental sources or reservoirs of Pneumocystis jirovecii

Answer 22

• soil
• water
• airborne particles
• animal reserviors

Question 23

Mode of transmission of P. jirovecii

Answer 23

Inhalation of airborne particles

Question 24

Invasive stage of P. jirovecii

Answer 24

trophic form

Question 25

Infective stage of P. jirovecii

Answer 25

mature cyst

Question 26

State the developmental stages of Pneumocystis jirovecii from the invasive stage to the infective stage.

Answer 26

trophozoite (trophic form) - precyst - cyst

Question 27

How do trophic forms ASEXUALLY multiply on the surface of the epithelial cells (pneumocytes) lining the lungs?

Answer 27

through binary fission

Question 28

By producing what, do trophic forms SEXUALLY multiply?

Answer 28

producing precyst and then cyst containing spores/intracystic bodies

Question 29

What procedure is used to find cysts and trophozoites in tissue for the laboratory diagnosis of PJP?

Answer 29

open lung biopsy

Question 30

T/F: Pneumocystis spp. can be cultured outside the lungs

Answer 30

false (it cannot be cultured outside the lungs, thus open lung biopsy is needed for diagnosis)

Question 31

Clinical standard specimen for the laboratory diagnosis of PJP

Answer 31

bronchoalveolar lavage (BAL) fluid

Question 32

Least productive specimen

Answer 32

sputum

Question 33

Lavage and sputum specimens are often prepared using what machine

Answer 33

cytocentrifuge

Question 34

Why is cytocentrifuge needed for preparing lavage and sputum specimens?

Answer 34

to decrease bacterial contamination

Question 35

Othe specimens for the laboratory diagnosis of PJP

Answer 35

- transbronchial biopsy - tracheal aspirate - pleural fluid - induced sputum

Question 36

What stain is utilized if cyst wall of Pneumocystis spp. is BARELY VISIBLE

Answer 36

giemsa stain

Question 37

In giemsa stain, what is the color of nuclei?

Answer 37

pink

Question 38

Identify the stain used: Intracystic bodies are seen around the interior of the organism

Answer 38

giemsa stain

Question 39

Identify the stain: Cyst wall stains black

Answer 39

gomori methenamine silver stain

Question 40

What stain detects chitin in the cell wall?

Answer 40

calcoflour white

Question 41

What stain demonstrates punched-out pingpong ball appearance of cyst?

Answer 41

gomori methenamine silver stain

Question 42

Commercially available and widely used stain for Pneumocystis spp.

Answer 42

immunofluorescent monoclonal antibody stain

Question 43

What stain fluoresce with a blue-white color?

Answer 43

calcofluor white

Question 44

Treatment of choice for PJP/PCP

Answer 44

Trimethoprim-sulfamethoxazole (TMP-SMX)

Question 45

Trimethoprim-sulfamethoxazole is also known as?

Answer 45

co-trimoxazole

Question 46

How is TMP-SMX administered to patients?

Answer 46

through a vein or by mouth for 3 weeks

Question 47

Possible side effects after taking TMP-SMX

Answer 47

rash and fever

Question 48

For first line treatment, dapsone is combined with?

Answer 48

pyrimethamine

Question 49

First line of treatment

Answer 49

- Pentamidine isethionate - Dapsone (combined with pyrimethamine) - Aerosolized pentamidine

Question 50

For what purpose do patients with AIDS use aerosolized pentamidine?

Answer 50

for prophylactic treatment