Chapter 25 - Microbial Diseases of the Digestive System Flashcards
What is dental plaque?
an accumulation of microorganisms that are involved in tooth decay
What is dental caries?
tooth decay
What directly attacks tooth enamel?
lactic acid that was created by sucrose that bacteria broke down
What bacteria causes tooth decay?
Streptococcus mutans
Streptococcus Mutans
-gram-positive
-cocci
-tolerates high level of acidity
-capsule
How does S. mutans attach?
capsuke
Dextran
a gummy polysaccharide synthesized by S. mutans to form plaque
Stage 1 of Periodontal Disease
-S. mutins attaches via capsule
-builds up plaque by breaking down dextran and fermenting sugar into lactic acid
-results in tooth decay
What is lysozyme?
-produced by saliva to protect exposed enamel
Periodontal Disease
-a number of conditions characterized by inflammation and degeneration of teeth structures
Stage 2 of Periodontal Disease: Gingivitis
-inflammation of the gums
-bleeding gums
What bacteria cause gingivitis?
-S. mutins
-Bacteriodetes
-Fusobacteria
What can gingivitis progress into?
Periodontitis
Stage 3 Periodontal Disease: Periodontitis
-chronic condition
-gum-line recedes
-periodontal pockets fill with pus
-bone and tissue destruction
What fills the pus of periodontitis?
exotoxins
What are porphyromonas species?
-bacteria that cause periodontitis
What are the general gastroenteritis symptoms?
-fever
-nausea
-vomiting
-diarrhea, dysentery (blood), or constipation
-possible shock
Infection vs. Intoxication
-infection involved incubation of an organism
-intoxication involves ingesting toxins
How are infection and intoxication treated?
-ORT
-antibiotics
Oral Rehydration Therapy (ORT)
-ingestion of electrolytes, soup, easy foods
What pathogen causes staphylococcal food poisioning?
Staphylococcus aureus
S. aureus food poisoning is an infection/intoxication (pick one)
intoxication; it involves an enterotoxin
Staphylococcal food poisoning is caused by ingesting…
contaminated high protein foods (ie. cured ham)
What are the symptoms of staphylococcal food poisioning?
nausea, vomiting, diarrhea
How does a staphylococcal food poisoning outbreak occur?
-food is contaminated during handling
-food is improperly stored, incubation occurs
-toxins released
-food is eaten
How long does staphylococcal intoxication take to occur?
1-6 hours (pretty quick)
Will reheating the food get rid of the toxin?
no
What is another term for shigellosis?
bacillary dysentery
Shigellosis in an i_______ and has a longer incubation period of ___ hour to ___ weeks
infection; 12 hours to 2 weeks
What pathogen causes shigellosis?
shigella dystenteriae
Shigella
-gram-negative
-rods
-facultative anaerobes
Does shigella use animals as a reservoir?
no, only person to person
What toxin is produced by S. dysenteriae?
Shiga toxin
What are the symptoms of shigellosis?
-tissue damage
-dysentery
What does shigella do to cells in the large intestine?
blocks protein synthesis and leads to cell death
Shigellosis cause cause up to ___ bowel movements in one day.
20
Shigellosis is spread by what route?
fecal-oral
Shigellosis is common in _____ _____ centres
day care
What toxins are used by S. dystenteriae?
-endotoxin (symptoms)
-shiga exotoxin
How is shigellosis diagnosed?
isolation of bacteria
How is shigellosis treated?
-ORT
-quinolones
What bacteria causes salmonellosis?
Salmonella enterica
Salmonella enterica
-gram-negative
-facultative anaerobe
-rods
Salmonellosis is always a _____ borne infection.
food borne infection
What are some possible food sources of salmonellosis?
beef, poultry, eggs, veggies, pets
Salmonellosis symptoms
nausea and diarrhea
Is salmonellosis an infection or intoxication?
infection via an endotoxin
How is salmonellosis treated?
ORT
What is the pathogen that causes typhoid fever?
Salmonella typhi
What are the symptoms of typhoid fever?
-high fever
-vomiting
-severe diarrhea or constipation
-high mortality
-rose spots (abdominal rash)
-hemorrhaging
Is typhoid fever spread by a food source?
no, only human source
S. typhi carriers are _____ long
lifelong
Where is S. typhi stored in lifelong carriers?
gallbladder
What is used to treat typhoid fever?
-quinolones
-cephalosporins
Is S. typhi an infection or intoxication?
infection via endotoxin
S. typhi is spread how?
fecal-oral transmission
What pathogen causes cholera?
Vibrio cholerae
Vibrio cholerae
-gram-negative
-curved rod
-single polar flagellum
Does cholera produce an exotoxin?
yes, cholera toxin
What does cholera toxin do?
causes cells to secrete water and electrolytes
What are the symptoms of cholera?
-rice water stool
-severe dehydration
How is cholera treated?
ORT then tetracycline
If untreated, cholera can lead to…
shock and multiple organ failure
E. coli gastroenteritis attaches to _______ cells
intestinal
Does E. coli gastroenteritis produce toxins?
yes
How many forms of E. coli gastroenteritis are there?
5
Enterotoxigenic E. Coli (ETEC)
-secretes enterotoxins that cause diarrhea
-responsible for 60-65% of travellers diarrhea cases
ETEC is often fatal for children under age ___
5
Are ETEC bacteria invasive?
no, they remain in the intestinal lumen
What is the most common E. coli form?
ETEC
Enteroaggregative E. Coli (EAEC)
-found only in humans
-create a brick wall configuration when grown
-cause 35-40% of travellers diarrhea
IS EAEC invasive?
no
Does EAEC produce an enterotoxin?
yes, causes watery diarrhea
Enterohemorrhagic E. Coli (EHEC)
-has a shiga-like toxin
-Hemolytic Uremic Syndrome that affects kidneys and blood clotting
Enteroinvasive E. Coli (EIEC)
-synonymous with shigella
-causes dysentery
-affects Large intestin
Is EIEC invasive?
yes
Enteropathogenic E. Coli (EPEC)
-major cause of diarrhea in infants
What pathogen causes campylobacter gastroenteritis?
campylobacter jejuni
Campylobacter jejuni
-gram-negative
-microaerophilic
-spiral shaped
What are the symptoms of campylobacter gastroenteritis?
-fever
-abdominal pain
-diarrhea
Is campylobacter gastroenteritis an intoxication or infection?
infection
What is the reservoir for campylobacter gastroenteritis?
chicken and cow’s milk
What is ‘Guillain-Barré Syndrome’?
-a rare complication of campylobacter gastroenteritis
-temporary paralysis
How is campylobacter gastroenteritis treated?
azithromycin
What pathogen causes peptic ulcer disease?
Helicobacter pylori
What symptoms accompany peptic ulcer disease?
duodenal and gastric ulcers
Is peptic ulcer disease an infection or intoxication?
infection
Only ___% of people infected with helicobacter pylori develop peptic ulcers and ___% develop gastric cancer
15; 3
How does helicobacter pylori move?
Flagella
Does helicobacter pylori have a toxin?
yes, exotoxin that inhibits peptic acid production and increases urease enzyme
What does urease enzyme do?
digests urea into ammonia creating an alkaline pH
How is helicobacter pylori (peptic ulcer disease) diagnosed?
-stool sample
-urea breath analysis
How is peptic ulcer disease treated?
metronidazole
What does C. difficile use to attach?
endospores
C. diff is a common n________ infection
nosocomial
C. Diff can also result from…
-long term antibiotic use
What kind of exotoxin does C. diff have?
A-B exotoxin
What is mumps caused by?
mumps virus
What are the symptoms of mumps?
-swollen parotid glands
-difficulty chewing, swallowing
-headache
What is the incubation period of mumps?
16-18 days
Is there a treatment for mumps?
no
Is there a vaccine for mumps?
MMR vaccine
Mumps can also cause viral _________
anorexia
Orchitis
-a symptom of mumps in males
-swollen testes
What are possible mumps complications?
-meningitis
-ovarian inflammation
-pancreatitis
What is hepatitis?
virus that causes inflammation of the liver
Hep A is aka “__________” form
infectious
How does Hep A transmitted?
fecal-oral route
Hep A Symptoms
-jaundice
-anorexia
-nausea
-diarrhea
-abdominal pain
-fever
-chills
Is Hep A acute or chronic?
acute
Is there a Hep A vaccine?
yes, it is in the form of the inactive virus
Hep B is aka “________” form
serum
How is Hep B transmitted?
-parenteral (blood entry)
-sexual entry (STI)
Hep B is a ________ virion
complete virus particle
Is Hep B acute or chronic?
-85% cases are acute
-15% cases are chronic and lead to cancer or cirrhosis
Is there a Hep B vaccine?
-yes, it is a recombinant vaccine made of yeast and capsid particles
-boosters needed
Hep ___ is the surrogate to Hep D
B
What is Hep C also known as?
non-A non-B Hepatitis
How is Hep C transmitted?
-parenteral via transfusion of blood, semen, saliva, intravenous drug use
Is there a vaccine for Hep C?
not yet
How is Hep C similar to AIDS?
-it kills many people
-the virus changes like HIV
What is used to treat Hep C?
-ribovirin
-interferons
Opposite to Hep B, ___% of cases are acute and ____% are chronic
15; 85
What is a disadvantage of the current Hep C treatment? (Hint: $)
it is very expensive
Hep D is aka “__________” form
defective
Hep D is very similar to Hep __
B (in terms of spread and symptoms)
Is there a vaccine for Hep D?
same as B (HBV vaccine)
Does Hep D have complete virions?
no, it is missing the capsid
After acute Hep B is cleared from the system, Hep D also _________
disappears
If the Hep B infection progressed to chronic Hep B, Hep D accompanies as a __________
superinfection; increases liver damage and fatality rate
Hep E is similar to Hep ___
A
Is there a vaccine for Hep E?
yes the HAV vaccine
Can Hep E progress to chronic form?
no, only acute
How is Hep E spread?
fecal-oral route
When is Hep E especially dangerous?
during pregnancy is has a 20% mortality rate
