23 Microbial Diseases of the Digestive System

Question 1

List the species that typically inhabit the large intestine as a part of normal microbiota.

Answer 1

Streptococcus, lactobacillus, escherichia, proteus, and candida

Question 2

Which genus and species of bacteria is typically the causative agent of dental caries?

Answer 2

streptococcus mutans

Question 3

peptic ulcer disease list or describe:
a. causative agent
b. risk factors

Answer 3

a. heliobacter pylori
b. smoking, thin layer of mucus in stomach, use of NSAIDS

Question 4

cholera list or describe:
a. the causative agent
b. signs and symptoms
c. risk factors

Answer 4

a. vibrio cholerae
b. rice water stool, vomitting, blood thickens
c. contaminated seafood or water

Question 5

shigellosis (bacillary dysentary) list or describe:
a. the pathogenesis
b. causative agents
c. incubation time
d. signs and symptoms
e. treatment

Answer 5

a. attaches to intestinal epithelial cells and multiples and then invades neighbor cells
b. shigella dysenteriae or shigella sonnei
c. 12hrs-2 weeks
d. severe diarrhea with blood and mucus in stool, cramps, and fever
e. fluids and antibiotics

Question 6

Escherichia coli gastroenteritis list or describe:
a. the bacterial group
b. the different mechanisms of pathogenicity for enterotoxigenic and enterohemorrhagic strains
c. special name for the toxin present for enterohemorrhagic strains

Answer 6

a. gram negative rod
b. enterotox: not invasive to mucosa, a toxin is produced
enterohem: inflammation and bleeding of the colon, invasive
c. Shiga-toxin

Question 7

salmonellosis list or describe:
a. the causative agent
b. incubation time, pathogenesis
c. how long can infected individuals shed the organism in their feces
d. transmission

Answer 7

a. salmonella enterica
b. 12-36 hours, bacteria reproduces in intestinal epithelial cells
c. 6 months
d. poultry products and pet reptiles

Question 8

typhoid fever list or describe:
a. the causative agent
b. four ways in which it is different from salmonellosis
c. signs and symptoms
d. how long can infected individuals shed the organism in their feces

Answer 8

a. salmonella typhi
b. humans are only reservoir, incubation time is 1-2 weeks, high fever and headache, most cases are foreign travel
c. high fever and headache
d. possibly entire lives

Question 9

Campylobacteriosis:
a. transmission
b. causative agent
c. signs and symptoms
d. a complication that can result

Answer 9

a. food vehicle, poultry
b.camplobacter jejuni
c. diarrhea and blood in stools
d. guillain-barre syndrome

Question 10

C. diff (antimicrobial-associated) diarrhea:
a. causative agent
b. signs and symptoms
c. events that precede this type of diarrhea
d. prevention and treatment options

Answer 10

a. clostridium difficile
b. watery diarrhea, fever, abdominal pain (pseudomembranous colitis)
c. antimicrobial therapy
d. limiting long term antimicrobials, probiotics, and fecal transplants

Question 11

Describe the usual sequence of events for staphylococcal entertoxicosis.

Answer 11

1. food becomes contaminated during prep
2. food sits at room temp, staph grows and produces toxin
3. even if food is cooked, toxin is not destroyed
4. toxin is ingested with the food resulting in vomiting, diarrhea, and abdominal cramps

Question 12

What organ does the mumps virus infect?

Answer 12

parotid gland

Question 13

List some common causative agents of viral gastroenteritis.

Answer 13

rotavirus and norovirus

Question 14

Hep A

Answer 14

-food vehicle (fecal-oral)
-nausea, diarrhea, jaundice
- yes vax

Question 15

Hep B

Answer 15

-STD, needles, contact with body fluids
-50% are asymptomatic, some have flu-like episodes and chronic liver problems
-yes vax

Question 16

Hep C

Answer 16

-STD/needles
-same symptoms as hep B
-no vax

Question 17

Describe the transmission and symptoms of giardiasis.

Answer 17

H20 transmission, cyst resists boiling and chlorine
diarrhea, nausea, cramps, and painful gas

Question 18

amebiasis list or describe:
a. causative agent
b. transmission
c. signs and symptoms

Answer 18

a. entamoeba histolytica
b. fecal-oral through food and H20
c. often no symptoms, diarrhea or cramps

Question 19

List the two main causes of tapeworm infestations.

Answer 19

taenia saginata- beef tapeworm
taenia solium- pork tapeworm

Question 20

pinworm infestations list or describe:
a. causative agent
b. signs and symptoms
c. life cycle
d. diagnosis

Answer 20

a. enterobius vermicularis
b. anal itching and diarrhea
c. fecal-oral, inhabits small and large intestines, females lay eggs at the anus
d. scotch tape to the butthole