ch 20 objectives Flashcards
List the natural defenses present in the gastrointestinal tract
- Layer of mucus
- Secretory IgA
- Action of peristalsis
- Saliva contains lysozyme and lactoferrin
- Stomach fluid: antimicrobial due to its high acidity
- Bile; also antimicrobiaL
List the types of normal biota presently known to occupy the oral cavity, gastrointestinal tract and stomach
oral: bacteria, fungi, protozoa
GI tract: bacteria, fungi, protozoa/archaea
stomach: bacillus, clostridium, staphylococcus, streptococcus
dental caries
causative agents: cariogenic bacteria (streptococcus mutans group
characteristics: plague is biofil, caused by plaque building
prevention: dietary restriction of sucrose, regular brushing and flossing
periodontitis
causative agents: oral bacteria
characteristics: begins as gingivitis, loosened or lost teeth, degradation of periodontal ligaments
prevention: good oral hygiene
mumps
causative agent: mumps virus
signs: asymptomatic, swollen salivary glands
prevention/treatment: mmr vaccine
gastritis/gastric ulcers
causative agent: heliobacter pylori
signs: gastritis:burning pain in abdomen; gastric ulcers: lesions in mucosa of stomach
prevention/treatment: antibiotics augmented by acid suppressors
Discuss the discovery of Helicobacter pylori gastric ulcer infections
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
Name the enzyme that is tested in the breath test and a biopsy to detect presence of Helicobacter pylori
urease
staphy aur
transmission: food contamination
characterisitics: sudden onset and duration depends on toxin recovery, no fever
prevention: proper food handling
clostridium perfringens
transmission: food contamination
characterisitics: heat labile toxin detected in stool
prevention: proper food handling
bacillus cerus
transmission: contaminated food
characterisitics: heat-stable toxin, can either be emetic or diarrheal
prevention: proper food handling
ehec
transmission: vehicle (food/beverage), fecal-oral
characterisitics: severity relation to amount of toxins products, diarrhea is bloody
prevention: avoid live e. coli
etec
transmission: vehicle, fecal-oral
characterisitics: produces 1-2 toxins, watery diarrhea
prevention: food hygiene and personal hygiene
salmonella species
transmission: vehicle, fecal-oral
characterisitics: zoonosis
prevention: food hygiene and personal hygiene
shigella species
transmission: fecal-oral, direct contact
characterisitics: shiga toxin production triggers gastroenteritis
prevention: food hygiene and personal hygiene
campylobacter species
transmission: Vehicle (food, water), fecal-oral
characterisitics: diarrhea and cramping
prevention: food hygiene and personal hygiene
clostridioides diffcile
transmission: fecal-oral
characterisitics: mild to moderate diarrhea to fulminant and sometimes fatal pseudomembranous colitis
prevention: improve microbial use, effective handwashing
Differentiate intoxications from infection
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
health care acquired diarrhea
common cause: clostridiodes difficile infection
prevention: hand hygiene,
forms of treatment: antibiotics, supportive care
hepatitis A, b c
virulence factors
prevention/treatment:
hepatitis a, b ,c transmission and vaccine availability
A: fecal-oral, vehicle Hep. A vaccine
B: parenteral (blood contact), direct contact (sexual), vertical HBV recombinant vaccine
C: parenteral (blood contact), vertical
rotavirus
transmission: fecal oral
virulence factors
prevention/treatment: two rota virus vaccines are licensed for infants
noroviruses
transmission: fecal oral (contaminated food and water
virulence factors
prevention/treatment: rehydration no vaccine
Describe the white blood cell count that is elevated in helminthic infections.
Eosinophils
Name the 3 categories of helminths
Nematodes (roundworms, cestodes (tapeworms), trematodes (flukes)
giardiasis
causative agent: giardia lamblia
transmission: food or water contaminated with sewage
treatment: tinidazole or nitazoxanide
cysticercosis
causative agent: larval stage of pork tapeworm
transmission: eating animal flesh with worms or eggs
treatment: worms die in weeks without treatment
taneiasis
causative agent: adult stage of pork tapeworm
transmission: eating animal flesh with worms or eggs
treatment: worms die in weeks without treatment
pinworm
causative agent: Enterobius vermicularis
transmission:food/ water
treatment:mebendazole
ascariasis
causative agent:Ascaris lumbricoides
transmission: contaminated food/ water
treatment: albendazole
