Week 11 - Topic 1: GI Tract Disease & Bacterial Infection

Question 1

What is an outbreak?

Answer 1

When the number of cases exceeds what has been defined as “normal” in an area/season

Question 2

What are the 6 type of GI infections?

Answer 2

1) Colitis
2) Diarrhea
3) Dysentery
4) Enteritis
5) Gastritis
6) Gastroenteritis

Question 3

What is colitis?

Answer 3

Inflammation of large intestine

Question 4

What is dysentery?

Answer 4

> 20-30 watery stools per day that may contain blood, mucus or pus

Question 5

What is gastroenteritis?

Answer 5

Inflammation of the mucosal lining of stomach and intestines

Question 6

What is diarrhea?

Answer 6

Frequent discharge of liquid fecal matter (takes the shape of a container)

Question 7

What is enteritis?

Answer 7

Inflammation of the small intestine

Question 8

What is gastritis?

Answer 8

Inflammation of the mucosal lining of the stomach

Question 9

How does the stomach protects itself against microorganisms?

Answer 9

Has a pH < 1 very acidic

Question 10

How does the small intestine protects itself against microorganisms?

Answer 10

• Bicarbonate-buffered pancreatic juices (pH = 9)
• Enzymes (lysozymes, proteases, lipases) inhibit growth
• Peristalsis dislodges bacteria

Question 11

Where in the GI tract do we find the most flora?

Answer 11

Large intestine

A lot of gram -

Question 12

What normal flora do we find in the stomach?

Answer 12

Aerobic organisms: lactobacilli and streptococci

Question 13

What normal flora do we find in the small intestine?

Answer 13

Lactobacilli
E coli
Enterococcus faecalis

Question 14

What normal flora do we find in the large intestine?

Answer 14

Anaerobic organisms: lactic acid bacteria, bacteroids, bifidobacterium bifidum

Question 15

What are the 6 major causes of diarrhea?

Answer 15

1) Rx (iron, Abx)
2) Psychological stress
3) Allergies
4) Disease (Chron’s)
5) Procedures (gall bladder or stomach surgery)
6) Pathogens –> contagious

Question 16

What prevents flora from overgrowing and how?

Answer 16

Neutrophiles

Keep the flora in the gut lumen contained (esp in large intestine) by being recruited when the flora secrete chemotaxins

Question 17

What can reduce the # of neutrophiles in our body and affect GI bacteria?

Answer 17

Bone marrow fails
Over growth of pathogens
Chemo
Radiation

Question 18

What happens when there are not enough neutrophiles to contain flora in GI tract?

Answer 18

Gut flora translocate to the bloodstream = secondary bacteremia

Question 19

Name some GI infection sx that is not diarrhea

Answer 19

Nausea
Vomiting
Abdominal pain
Cramping
Bloody stool
Liquid stool
Loss of appetite
Weight loss
Bloating
Increased gas
Fatigue
Body aches, headache, fever, and other flu-like symptoms

Question 20

What must you document with regards to bowel patterns?

Answer 20

Frequency of stool passage over 24h
Color
Consistency
Associated Sx
Odour
Bristol stool chart

–> compare with normal pattern of pt

Question 21

True or False: When you send out a sample for GI infection diagnosing, the lab will find all the pathogens.

Answer 21

False, you must specify which pathogens you are looking so they can perform specific tests that vary in sensitivity and specificity

Question 22

True or False: A rectal swab is used to culture for GI pathogens.

Answer 22

False, used to screen for MDROs.

Stool cultures are used to diagnose GI pathogens

Question 23

What is more infectious: liquid or formed stool

Answer 23

Liquid

But formed stool may also carry pathogens

Question 24

Why should you not send out urine/water mixed stool?

Answer 24

The test might not be sensitive enough for that diluted sample

Question 25

What are some MO that cause food poisonings?

Answer 25

``` Campylobacter jejuni Clostridium botulinum Clostridium perfringens Cronobacter Cyclospora E. coli O157:H7 Hepatitis A and E Listeria monocytogenes Marine Toxins in Bivalve Shellfish Norovirus Salmonella Scombroid Poisoning Shigella Vibrio ```

Question 26

What fish can cause scombroid poisoning?

Answer 26

Fish used in sushi (tuna, mackerel, swordfish, marlin, mahi-mahi, sardines) that was not properly stored on ice

Question 27

What will you notice on the skin of those with scombroid poisining?

Answer 27

Red rash

Question 28

What predisposes (6) someone to having a GI infection?

Answer 28

1) Diminished secretion of gastric acid 2) Abx (decr. levels of stomach acid) 3) Alcoholism or liver disease (decr. phagocytic and chemotaxis capacity) 4) Lack of long term immunity for viral infections (norovirus) 5) Diminished levels of basic hygiene and increased contact with others 6) Asymptomatic shedders (typhoid)

Question 29

What can cause diminished secretion of gastric acid?

Answer 29

- Extremes of ages (newborns, elderly) - Illnesses (pernicious anemia) - Infections (H pylori) - Gastric resection, diversion, or removal of vagus nerve - Anti-ulcer drugs that inhibit gastric acids by blocking H2

Question 30

What infections do people with diminished gastric acid commonly have?

Answer 30

Salmonella | Virbo cholerae

Question 31

What are the 7 F routes of transmission for GI?

Answer 31

Fecal oral: -Feces / Foods / Fluids Intermediary vehicles: -Fingers / Flies / Fomites / Fornication

Question 32

What are complications of GI infections?

Answer 32

- Dehydration **** - Weight loss - Acute renal failure (E coli 0157) - Secondary bacterial infections (Shigella, salmonella, typhoid) - Miscarriage, fetal death - Septic shock - Death

Question 33

What bacteria commonly causes gastritis and ulcers?

Answer 33

Helicobacter pylori (reservoir is humans only!)

Question 34

How does H pylori cause gastritis and ulcers?

Answer 34

They compete with other bacteria on the gastric epithelium. They have an advantage because of a flagella (swim up the mucosal layer), can adhere to cells and release enzymes (urease) that neutralizes stomach acid to inhibit phagocytosis and cause ulcers.

Question 35

What bacteria commonly causes enteritis?

Answer 35

Campylobacter jejuni (reservoir is animals)

Question 36

What bacteria commonly causes diarrhea?

Answer 36

- Vibrio cholera (reservoirs is feces and water) | - Vibrio vulnificus (mollusks, oysters, clams)

Question 37

What bacteria commonly causes gastroentiritis?

Answer 37

Salmonella sp

Question 38

What bacteria commonly causes enteric/typhoid fever?

Answer 38

Salmonella typhi (hosts are human only!!!)

Question 39

What bacteria commonly causes dysentery?

Answer 39

Shigella sp

Question 40

What bacteria commonly causes hemorrhagic diarrhea or hemolytic uremic syndrome?

Answer 40

E coli 0157:H7 (reservoir cattle --> undercooked hamburgers!)

Question 41

What complications (5) does E coli 0157:H7 tend to cause?

Answer 41

1) Bloody diarrhea 2) Thrombocytopenia 3) Hemolytic Anemia 4) Acute Renal Failure 5) Hemolytic-uremic syndrome

Question 42

What causes traveler's diarrhea?

Answer 42

Enterotoxigenic E coli (produces toxins)

Question 43

How many types of E coli exist?

Answer 43

5

Question 44

What abnormal flora do you find in the esophagus?

Answer 44

Candida and herpes