Final Exam: Gastrointestinal Infections

Question 1

Most common residents in the mouth

Answer 1

Streptococcus species

Question 2

Feces are rich in

Answer 2

Bacteriodes species

Question 3

live in the digestive tract

Answer 3

Fungi (e.g., Candida) and some protozoa
Though outnumbered by bacteria

Question 4

Normal gut microbiota have essential roles

Answer 4

Limit available surfaces for colonization
Compete for nutrients
Excrete antimicrobial products
Assist in digestion
Provide nutrients for the body, Escherichia coli produces vitamin K

Question 5

Diarrhea

Answer 5

frequent passing of loose or watery stool

Question 6

Enteritis

Answer 6

inflammation of the intestines

Question 7

Gastritis

Answer 7

inflammation of the stomach

Question 8

Gastroenteritis

Answer 8

inflammation of the stomach and intestines

Question 9

Dysentery

Answer 9

diarrhea accompanied by pain, blood, and/or mucus

Question 10

Hypovolemic shock

Answer 10

organ failure

Question 11

Milder signs and symptoms of GI tract infections

Answer 11

Abdominal pain
Diarrhea: loose or watery stools (may contain blood or mucus)
Fever and/or vomiting

Question 12

Diagnosis of GI tract infections

Answer 12

Collecting fecal samples for:
Culturing on selective and differential media (e.g., MacConkey agar)
Molecular diagnostic analysis
Microscopic examination to identify parasites or their eggs

Question 13

Common Human Pathogens: Viral

Answer 13

Rotavirus: attributed for children under 5 years
Norovirus: Attributed for adults in health facilities (Long term care)

Question 14

Common Human Pathogens: bacterial

Answer 14

E. coli (most important to know)
Campylobacter species
Shigella species
Salmonella
Listeria monocytogenes

Question 15

Norovirus: Etiological agent and characteristics

Answer 15

RNA virus

Leading cause of acute viral gastroenteritis in the U.S.

Question 16

Norovirus: Signs/symptoms and transmission

Answer 16

Infectious dose of 20 viral particles
Feces and vomit spread the virus via the fecal–oral route

Develop within 12–48 hours
Acute diarrhea and projectile vomiting(common) lasting 36–72 hours

Question 17

Norovirus: Treatment, complications and Diagnosis

Answer 17

Most healthy individuals recover without medical intervention
Some require fluid replacement treatment

Dehydration

Detection of norovirus RNA in patient stool samples

Question 18

Foodborne Infection versus Food Poisoning: Description

Answer 18

Infection: after ingestion, pathogen begins to infect
Poisoning: no infection, toxins cause illness

Question 19

Foodborne Infection versus Food Poisoning: Common bacterial agents

Answer 19

Infection: E. coli, Salmonella species, Listeria species, Shigella species, Campylobacter jejuni
Poisoning: Toxins from S. aureus, B. cereus, and Clostridium perfringens

Question 20

Foodborne Infection versus Food Poisoning: Symptoms onset

Answer 20

Infection: 1-5 days after exposure
Poisoning: 30 min - 6 hours after exposure

Question 21

Foodborne Infection versus Food Poisoning: Signs and symptoms

Answer 21

Infection: Fever, headache, muscle aches, nausea, Abdominal pain, diarrhea
Poisoning: Nausea, vomiting, and occasionally diarrhea and abdominal pain

Question 22

Foodborne Infection versus Food Poisoning: Recovery:

Answer 22

Infection: days
Poisoning: ~24 hours, several days sometimes

Question 23

Food poisoning

Answer 23

Bacteria don’t actively grow in the host
Symptoms are triggered by ingested enterotoxins (a type of exotoxin)
They may be emetic (trigger vomiting)
Causes inflammation of intestinal cells ->Prevents water absorption -> to diarrhea and abdominal pain

Question 24

Food poisoning is often associated with

Answer 24

Prepared foods that require a lot of handling
Leaving foods at room temperature for extended periods

Question 25

Will cooking food handle food poisoning toxins?

Answer 25

No, cooking or reheating may kill the bacteria, but won’t affect the enterotoxin

Question 26

S. aureus food poisoning

Answer 26

Linked to creamy salads (e.g., tuna, chicken), dairy-based foods, poultry and meat products Transmission is easy if hands are not washed before preparing food

Question 27

C. perfringens food poisoning

Answer 27

Spore-forming organism Commonly found in animal intestines and found on raw meat Most cases linked to gravy and meat products that are left too long at room temperature

Question 28

B. cereus food poisoning

Answer 28

Spore-forming organism Present in soil and can contaminate produce Cooking does not always kill its spores Food is left at room temperature: Allows spores to germinate, Bacteria actively grow, Produce toxin

Question 29

Botulism: Etiological agent and mechanism

Answer 29

Spore-forming Clostridium botulinum Exotoxin enters the blood and targets nerves

Question 30

Foodborne Infections: Prevention

Answer 30

Thoroughly cook meats/poultry Use safe food-handling practices: Handwashing, Minimal meat rinsing, Separate utensils Use a different cutting board for meat and vegetables Discard any questionable meat/poultry products Do not eat any questionable meat/products products