Dysentery

Question 1

Stool features in dysentery

Answer 1

Scant volume with blood, mucus, WBC, and tissue invasion

Question 2

Site affected in dysentery

Answer 2

Large intestine

Question 3

Causal organisms of dysentery

Answer 3

Shigella
Entamoeba histolytica
EIEC

Question 4

Non-motile gram negative rod enterobacteriaceae, non-lactose fermenter, and resistant to acid

Answer 4

Shigella

Question 5

Shigella species most frequently seen in US

Answer 5

S sonnei

Question 6

Shigella species most frequently seen in developing countries

Answer 6

S flexneri

Question 7

Infective dose of Shigella

Answer 7

10-100 organisms
Very low –> highly infective

Question 8

Transmission of Shigella

Answer 8

Feco-oral, humans are only host

Question 9

4 virulence factors of Shigella

Answer 9

LPS endotoxin
Shiga-toxin/verotoxin-1
Plasmid encoded type III secretion system
Hemolysin

Question 10

Shigella virulence factor that induces membrane ruffling on target cell and engulfment of bacteria

Answer 10

Plasmid encoded type III secretion system (Ipa A-D)

Question 11

Cell targeted in mucosal invasion of Shigella

Answer 11

M cell

Question 12

Pt complains of fever, abdominal cramps, tenesmus, and diarrhea that was initially bloody, but has became bloody. MacConkey agar shows NLF colonies and salmonella-shigella agar has transparent colonies with no black center.

Answer 12

Shigellosis

Question 13

Incubation period of Shigella

Answer 13

1-4 days

Question 14

Complications of shigellosis

Answer 14

Reiter’s syndrome
Hemolytic uremic syndrome

Question 15

Stool microscopy findings in shigellosis

Answer 15

Plenty of inflammatory cells with RBCs and mucus

Question 16

Antibiotics used in treating shigellosis

Answer 16

Trimethoprim-sulfamethoxazole
Ciprofloxacin

Question 17

Protozoans that cause dysentery

Answer 17

Entamoeba histolytica
Balantidium coli

Question 18

Histologic finding in non-diarrheal stools in entamoeba histolytica infection

Answer 18

4 nuclei cysts

Question 19

Histologic findings in lesions and diarrheal stools in entamoeba histolytica

Answer 19

Motile trophozoites with single nucleus

Question 20

Protozoan causing dysentery with virulence factors specific lectin GAL/GalINAc, amoebapores, cysteine proteinases

Answer 20

Entamoeba histolytica

Question 21

Gradual onset of bloody diarrhea, abdominal pain, and tenderness that lasts for several weeks that may be accompanied by RUQ pain because of liver involvement

Answer 21

Amebic colitis

Question 22

Complications of entamoeba histolytica infection

Answer 22

Amebic liver abscess
Cerebral amebiasis
Pleuropulmonary amebiasis

Question 23

Where amebulae accumulate in liver abscess in entamoeba histolytic

Answer 23

Edge of abscess

Question 24

Treatment of asymptomatic amebiasis

Answer 24

Luminal agent –> lodoquinol, paromomycin, or diloxanide furoate

Question 25

Treatment for symptomatic amebiasis

Answer 25

Metronidazole first, followed by luminal agent

Question 26

Treatments for Balantidium coli

Answer 26

Metronidazole Lodoquinol Tetracycline Nitazoxanide