Bugs

Question 1

Candida

Answer 1

germ tube positive fungus (associated with HIV)

Question 2

Giardia

Answer 2

• small bowel inflammation and villous atrophy –> malabsorption
• tx: metronidazole (ADR w/alcohol, disulfram!)

Question 3

Entamoeba histolytica

Answer 3

• fecal-oral transmission, often via water, presents with bloody mucoid diarrhea
• amoeba with ingested RBC’s on microscopy
• liver abscesses (infiltrative enzyme tests: only elevated alk phos)
• tx: metronidazole (ADR with alcohol, disulfram!)

Question 4

Shigella

Answer 4

• bloody diarrhea, fever

- gram negative rods, do not ferment lactose, DOES produce hydrogen sulfide

Question 5

Salmonella

Answer 5

• gram negative rods, do not ferment lactose, motile

- can make it worse if treated with antibiotics

Question 6

E. coli 0157:H7

Answer 6

• bloody diarrhea, NO fever
• gram negative, oxidase negative
• **hemolytic uremic syndrome)
• undercooked hamburger
• can be made worse by Tx with antibiotics, supportive only
• shiga toxin, part A and B– B binds cell membrane, A inactivates ribosomes…cell death

Question 7

rotavirus

Answer 7

• most common cause worldwide of infantile diarrhea
• supportive Tx
• destroys brush border, can lead to transient lactose intolerance
• single stranded RNA, carries its own polymerase

Question 8

brucella melitensis

Answer 8

• comes from unpasteurized dairy, or direct contact with livestock
• undulating fever
• gram negative coccobaccili

Question 9

bartonella spp

Answer 9

cat scratch

Question 10

trichinella

Answer 10

bear, fox, cat

Question 11

C. difficile

Answer 11

• gram positive anaerobe

- Tx: metronidazole or IV vanco

Question 12

Corynebacterium diptheriea

Answer 12

• gram positive rod
• MOA: toxin inhibits protein synthesis by ADP ribosylation of elongation factor 2
• induces apoptosis

Question 13

Campylobacter jejuni

Answer 13

• gram negative, comma shaped, single polar flagellum
• vomitting, bloody diarrhea
• fecal-oral transmission
• associated with Guillen-Barré
• tx with erythromycin (inhibits 50s)

Question 14

Echinoccocus granulosus

Answer 14

• parasitic tapeworm found in feces of kangaroo, wallabies
• causes liver cysts
• tx: with albendazole - inhibits tubulin polymerization

Question 15

HAV (hepA)

Answer 15

-single stranded linear RNA

Question 16

actinomyces israeleii

Answer 16

• normal flora of GI tract, known for forming abcesses
• important characteristic is sulfur granules
• tx: with simple penicillin

Question 17

parvovirus b19

Answer 17

• fifth disease
• slapped cheek rash
• pruritic maculopapular rash, starts on extremities and spreads to trunk
• no prodromal symptomology

Question 18

borrelia burgdorferi

Answer 18

• intracellular, rod shaped, causes lyme disease

- tx: doxycycline

Question 19

francisella tularensis

Answer 19

• cause of tularemia
• carried in rabbits, transmitted by ticks
• ulcerated lesion with black base

Question 20

pastuerella multocida

Answer 20

• found in normal oral flora of dogs and cats
• creates abcesses
• gram negative rod

Question 21

yersinia pestis

Answer 21

• cause of the plague, prevalent in prairie dogs
• exquisitely tender lymph nodes, painful ulcerations on skin
• can lead to DIC

Question 22

bacillus anthracis

Answer 22

-cutaneous anthrax, painless ulcers with black scabs

Question 23

EBV

Answer 23

• linear dsDNA

- assoc. with Burkitt’s lymphoma

Question 24

Ehrlichia chaffeenis

Answer 24

• carried by common dog tick, in the order of rickettsia

- tx: with doxycycline

Question 25

shistosoma mansoni

Answer 25

- katayama fever - markedly enlarged spleen and liver, hugely elevated Eos - water supply in middle east, and africa - bugs mate in the body then lay tons of eggs (can form granulomas)

Question 26

rabies virus

Answer 26

- single stranded, enveloped RNA virus - rhabdovirus family - hydrophobia and hyper salivation - negri body inclusions on path

Question 27

naegleria fowleri

Answer 27

- swimming in freshwater lakes - rapid progressive meningoencephalopathy - amoeba in the CSF, amphoterrible might work, most times it doesn't

Question 28

toxoplasmosis gondii

Answer 28

-new onset Sz and focal neurological deficits in an HIV pt with CD4 below 100

Question 29

latose fermenters vs non-fermenters MacConkey agar

Answer 29

- lactose fermenters are pink | - non-fermenters are clear or brown

Question 30

calicivirus (structure... and name 2 common) (single or double strand, positive or negative, linear or circular, shape and envelop or no envelope)

Answer 30

- single stranded, positive sense, linear, nonsegmented RNA, icosahedral, no envelope - hepatitis E - norovirus

Question 31

paramyxovirus (structure, 4 common types) ((single or double strand, positive or negative, linear or circular, shape and envelop or no envelope))

Answer 31

- single stranded, negative sense, linear, nonsegmented RNA, helical, enveloped - parainfluenza (croup), RSV, measles and mumps - ***same exact structure but segmented...influenza virus***