ch 20 objectives

Question 1

List the natural defenses present in the gastrointestinal tract

Answer 1

• Layer of mucus
• Secretory IgA
• Action of peristalsis
• Saliva contains lysozyme and lactoferrin
• Stomach fluid: antimicrobial due to its high acidity
• Bile; also antimicrobiaL

Question 2

List the types of normal biota presently known to occupy the oral cavity, gastrointestinal tract and stomach

Answer 2

oral: bacteria, fungi, protozoa
GI tract: bacteria, fungi, protozoa/archaea
stomach: bacillus, clostridium, staphylococcus, streptococcus

Question 3

dental caries

Answer 3

causative agents: cariogenic bacteria (streptococcus mutans group
characteristics: plague is biofil, caused by plaque building
prevention: dietary restriction of sucrose, regular brushing and flossing

Question 4

periodontitis

Answer 4

causative agents: oral bacteria
characteristics: begins as gingivitis, loosened or lost teeth, degradation of periodontal ligaments
prevention: good oral hygiene

Question 5

mumps

Answer 5

causative agent: mumps virus
signs: asymptomatic, swollen salivary glands
prevention/treatment: mmr vaccine

Question 6

gastritis/gastric ulcers

Answer 6

causative agent: heliobacter pylori
signs: gastritis:burning pain in abdomen; gastric ulcers: lesions in mucosa of stomach
prevention/treatment: antibiotics augmented by acid suppressors

Question 7

Discuss the discovery of Helicobacter pylori gastric ulcer infections

Answer 7

Helicobacter pylori gastric ulcer infections were first detected by J. Robin Warren in 1979 in stomach biopsies from ulcer patients.
–>Proved that the microbe would cause gastric ulcers by swallowing a large inoculum of the organism

Question 8

Name the enzyme that is tested in the breath test and a biopsy to detect presence of Helicobacter pylori

Answer 8

urease

Question 9

staphy aur

Answer 9

transmission: food contamination
characterisitics: sudden onset and duration depends on toxin recovery, no fever
prevention: proper food handling

Question 10

clostridium perfringens

Answer 10

transmission: food contamination
characterisitics: heat labile toxin detected in stool
prevention: proper food handling

Question 11

bacillus cerus

Answer 11

transmission: contaminated food
characterisitics: heat-stable toxin, can either be emetic or diarrheal
prevention: proper food handling

Question 12

ehec

Answer 12

transmission: vehicle (food/beverage), fecal-oral
characterisitics: severity relation to amount of toxins products, diarrhea is bloody
prevention: avoid live e. coli

Question 13

etec

Answer 13

transmission: vehicle, fecal-oral
characterisitics: produces 1-2 toxins, watery diarrhea
prevention: food hygiene and personal hygiene

Question 14

salmonella species

Answer 14

transmission: vehicle, fecal-oral
characterisitics: zoonosis
prevention: food hygiene and personal hygiene

Question 15

shigella species

Answer 15

transmission: fecal-oral, direct contact
characterisitics: shiga toxin production triggers gastroenteritis
prevention: food hygiene and personal hygiene

Question 16

campylobacter species

Answer 16

transmission: Vehicle (food, water), fecal-oral
characterisitics: diarrhea and cramping
prevention: food hygiene and personal hygiene

Question 17

clostridioides diffcile

Answer 17

transmission: fecal-oral
characterisitics: mild to moderate diarrhea to fulminant and sometimes fatal pseudomembranous colitis
prevention: improve microbial use, effective handwashing

Question 18

Differentiate intoxications from infection

Answer 18

intoxication: illness in which bacterial toxins are ingested with food and water
infections: illnesses in which live bacterial pathogens are ingested and grow in the body

Question 19

health care acquired diarrhea

Answer 19

common cause: clostridiodes difficile infection
prevention: hand hygiene,
forms of treatment: antibiotics, supportive care

Question 20

hepatitis A, b c

Answer 20

virulence factors
prevention/treatment:

Question 21

hepatitis a, b ,c transmission and vaccine availability

Answer 21

A: fecal-oral, vehicle Hep. A vaccine
B: parenteral (blood contact), direct contact (sexual), vertical HBV recombinant vaccine
C: parenteral (blood contact), vertical

Question 22

rotavirus

Answer 22

transmission: fecal oral
virulence factors
prevention/treatment: two rota virus vaccines are licensed for infants

Question 23

noroviruses

Answer 23

transmission: fecal oral (contaminated food and water
virulence factors
prevention/treatment: rehydration no vaccine

Question 24

Describe the white blood cell count that is elevated in helminthic infections.

Answer 24

Eosinophils

Question 25

Name the 3 categories of helminths

Answer 25

Nematodes (roundworms, cestodes (tapeworms), trematodes (flukes)

Question 26

giardiasis

Answer 26

causative agent: giardia lamblia
transmission: food or water contaminated with sewage
treatment: tinidazole or nitazoxanide

Question 27

cysticercosis

Answer 27

causative agent: larval stage of pork tapeworm
transmission: eating animal flesh with worms or eggs
treatment: worms die in weeks without treatment

Question 28

taneiasis

Answer 28

causative agent: adult stage of pork tapeworm
transmission: eating animal flesh with worms or eggs
treatment: worms die in weeks without treatment

Question 29

pinworm

Answer 29

causative agent: Enterobius vermicularis
transmission:food/ water
treatment:mebendazole

Question 30

ascariasis

Answer 30

causative agent:Ascaris lumbricoides
transmission: contaminated food/ water
treatment: albendazole