Fungal and parasitic CNS infections

Question 1

Which agent has terminal, “tennis racket” like spores?

Answer 1

Clostridium Tetani

Question 2

What population is at the largest risk for C. tetani, esp in underdeveloped countries?

Answer 2

newborns and IV drug users

Question 3

What is the key VF in C. Tetani?

Answer 3

Tetanospasmin, a potent exotoxin

Question 4

What does tetanospasmin toxin activity result in?

Answer 4

disruption of CNS control, autonomic dysfunction, and NM junction dysfunction

Question 5

What are the signs of tetanus?

Answer 5

Trismus, risus sardonicus, opisthotonos, and flexion of the arms and extension of the lower extremities, pneumonia, hypo/hypertension, tachycardia (death due to resp/cardiac failure)

Question 6

What is used to neutralize the tetanus exotoxin and for passive immunization?

Answer 6

Human Tetanus Immune Globulin (HTIG)

Question 7

What is the DOC for Tetanus?

Answer 7

PCN plus antitoxin (HTIG)

Question 8

What agent produces the most potent toxin known, has subterminal spores, and is greatly heat resistant?

Answer 8

Clostridium botulinum

Question 9

What is the reason for GI distrubance in food poisoning with c. botulinum? Infant botulism?

Answer 9

Neurotoxin; spores and neurotoxin

Question 10

What antibiotic should be used with C. botulinum?

Answer 10

NONE! Use antitoxin only

Question 11

Cryptococcus neoformans is to ___ as cryptococcus gattii is to___

Answer 11

Immunocompromised; immunocompetent (fatal)

Question 12

What does cryptococcus neoformans result in in immunocompromised hosts?

Answer 12

meningoencephalitis, all cases are fatal

Question 13

Thick capsule that produces creamy, mucoid colonies

Answer 13

Cryptococcus neoformans

Question 14

What medium does cryptococcus neoformans grow on?

Answer 14

Saboroud’s dextrose agar or potato dextrose agar

Question 15

What two serotypes are found in c. neoformans? c. gattii?

Answer 15

A/D; B and C

Question 16

What is the CP of cryptococcosis?

Answer 16

Fever, HA, stiff neck, change in mental status, LOW GLUCOSE

Question 17

What stain is used if you suspect C. Neoformans?

Answer 17

India Ink

Question 18

How do you differentiate between C. neoformans and C. gattii?

Answer 18

C. neoformans will grow on CGB medium

Question 19

What is the DOC for crypto neoformans?

Answer 19

ampho B + flucytosine, fluconazole following acute tx in AIDS pts.

Question 20

What does toxoplasma gondii cause?

Answer 20

the third leading cause of death in the US due to FBI, most are asymptomatic in immunocompetent hosts

Question 21

Where do we see severe complications of toxoplasma gondii?

Answer 21

in immunocompromised hosts and women NEWLY infected in PGN

Question 22

What is the name of the tissue cyst that contains bradyzoites in toxoplasmosis?

Answer 22

zoitocyst

Question 23

What is the triad of sx that suggest congenital toxoplasmosis?

Answer 23

Chorioretinitis, hydrocephalus, intracranial calcifications

Question 24

What is the CP of postnatal toxoplasmosis?

Answer 24

Fever, myalgia, blurred vision

Question 25

How does transmission of toxoplasma gondii usually occur?

Answer 25

foodborne (usually zoitocysts), zoonotic (oocysts), and rarely through blood transfusion and organ transplantation

Question 26

What is the test of choice for diagnosing toxoplasmosis?

Answer 26

PCR to evaluate DNA or ELISA to evaluate IgG or IgM in amniotic fluid, DIFFICULT TO OBTAIN CSF SAMPLE

Question 27

What is the treatment for toxoplasmosis?

Answer 27

pyrimethamine and sulfadiazine (parasite still stays in tissues)

Question 28

What is considered the business end of the naegleria fowleri?

Answer 28

amoeboid

Question 29

What is the causitive agent that results in primary acute meningoencephalitis in HEALTHY individuals? How many days post exposure?

Answer 29

Naegleria Fowleri, 1-14 days post exposure, death occurs in two days of becoming symptomatic!

Question 30

Why is Naegleria caught so late?

Answer 30

Because we treated them for bacterial and fungal meningitis first!

Question 31

Summer months, southern states, freshwater, cannot be contracted from drinking contaminated water, and by using tap water in Neti pots

Answer 31

Naegleria fowleri

Question 32

What is the combination therapy for naegleria fowleri?

Answer 32

Amphotericin B, rifampin, and miconazole

Question 33

Which protozoan possesses spiked pseudopodia?

Answer 33

acanthamoeba

Question 34

Which agent causes pain and blurred vision following trauma to the eye that can resemble corneal herpes?

Answer 34

acanthamoeba

Question 35

How can you control infection of acanthamoeba?

Answer 35

wear gloves while gardening, properly clean lesions

Question 36

What is the treatment of choice for keratitis?

Answer 36

oral itraconazole, topical miconazole + corticosteroid