unit 13 Flashcards
Normal flora of digestive tract
- few microbes in small intestines/stomach
- flatus: intestinal gas
microbes in mouth
streptococcus salivarus
S mutans
Lactobacillus
Candidas albicans
microbes in large intestines
E.coli
Enterobacter
lactobacillus sp.
Candida albicans
Dental caries or cavities (bacterial disease of mouth)
-tooth decay
- softening of the enamal/dentin
-sugar -> lactic acid (breaks down ca)
-due to streptococcus mutans/ lactobacillus sp.
Gastroenteritis
-disease causing inflammation of the stomach / intestinal mucosa
- most contracted through contaiminated water/food
- diarrhea/ vomitting = defense mechanisms
Infections
-pathogens -> gi tract and multiplies
- can penetrate intestinal mucous/ pass to organs
- incubation = 12 hrs-> 2 weeks
-causes fever
- treatment = rehydration/ antibiotics
- typhoid fever = example
Intoxications
ingestion of preformed toxins
-very sudden/ upsets gi in hours
- incubation 1-48 hrs
- no fever
- treatment = only rehydration (antibiotics dont work)
Staphlyococcal aureus
- intoxication
- disease = nasal passages -> hand -> food
= food stored in room temp: enterotoxin produced - incubation = 1-6 hrs
- treatment = rehydration
- resistant to osmotic pressure
Salmonellosis
- salmonella sp.
- causes gastroenteritis
- incubation = 12-36 hrs
- consumption of poultry/ raw eggs
- prevention = cook throughly/ no cross contamination
- treatment = rehydration
- 90% of reptiles carry the microbe
Typhoid fever
-salmonella typhi
- very invasive/ rids body of phagocytic cells
- disease in 1st week = high fever
-disease in 2nd/3rd week = diarrhea
- only found in humans
- transmission = fecal-oral / food / contaminated water
- incubation = 2->3 weeks
what is treatment for typhoid fever
cephalosporins
Why is typhoid fever prevelent
- how we raise chickens
- closer quarter chicken cages
- dont go outside (chickens)
Shigellosis (bacillary dysentery)
-shigella sp. (gram -)
- blood/ mucous in stools
- 20 bowel movements a day
- intoxication and infection
- treatment = rehydration and antibiotics
- stomach acid does not affect shigella
-a traveller’s disease
Cholera
-vibrio cholera
- exotoxin produced
- rice water stool
- blood become viscous
-violent vomitting
-most serious gi disease
-endemic to asia/india
-halophile
-associated with natural disasters
Diagnosis for cholera
rice water stools
Treatment for cholera
tetracycline / rehydration
Vibrio parahaemolyticus
-halophile
- uncooked/contaminated shellfish
-treatment = antibiotics/ rehydration
- found in costal waters of US
-low mortality
E.coli gastroenteritis
- normal inhabitant of gi tract (part of normal flora)
- some strains = pathogenic
- traveler’s diarrhea
- found in raw meat , lettuce, spinach, tomatoes
- pathogenic strains -> endotoxin
Camplyobacter gastroenteritis
- camypylobacter jejuni
- inhabits intestinal tract
- poultry products
- leading cause of diarrhea in US
- causes infection
- recovery in 1 week (or longer)
Clostridium perfringens
- gram + anaerobic endospores
- enterotoxins
- incubation = 12 hrs
- most cases mild
- meat/stew contaminated
-causes gas gangrene - associated with instituitional cooking
Clostridium difficles- associated diarrhea
- gram positive rod (anaerobic / endospores)
-enterotoxins - nocosomial disease
- symptoms = mild diarrhea / life threatening colitis
- associated with extended antibiotic use
Diagnosis for c. diff
detection of toxins in stools
Treatment for c.diff
rehydration
metronidazole
fecal transplant
stop precipitating antibiotic
Viral disease of digestive system
mumps
all hepatitis
Rotavirus (viral gastroenterisits)
Norovirus or Norwalk (viral gastroenteritis)
Mumps (paramyxovirus)
-inflammation of parotid glands
- viremia
- transmission = RT
- incubation= 16 -> 18 days
- vaccine = MMR
- fever/ swelling of parotids
Hep A
- HAV or infectious hepatitis
- transmission = fecal- oral / contaminated water and food
- incubation = 2-> 6 weeks
- recovery = 4-> 6 weeks
- uncooked/ contaminated shellfish
- carriers are rare / no chronic form
Treatment for Hep A
vaccine as preventative
gamma/ immune globlin if exposed
Diagnosis for Hep A
Detection of IgM anti-Hav
Hep B
-HBV or serum hepatitis
- transmission = blood/blood products , contaminated syringes , saliva , sweat , semen (STDs)
- incubation 4-> 26 weeks
- symptoms similar to Hep A
- can lead to sever liver damage
diagnosis for Hep B
serum for antibody to HBs AG
treatment for Hep B
vaccination part of childhood
Hep C (HCV)
- Non Hep A / Non Hep B
-instant killer / triggers immune response - NO VACCINE
- transmission = blood, IV drug use, Possible STD
-leading cause of liver transplants in US
Treatment for Hep C
- interferon
- ribavirin
Diagnosis for Hep C
Blood tested for HCV antibodies
Hep D (delta)
- co- infection with Hep B
- transmission = blood
- most virulent of all hepatitis types
- HBV vaccine is protective
Hep E
- endemic in asia/india
- similar to HAV
- fecal-oral = transmission
Rotavirus (viral gastoenterisits)
- common in small children
- vaccine = 2, 4 ,6 moa
- treatment = rehydration
- 5->8 day infection (low grade fever/ diarrhea and vomitting)
Diagnosis for rotavirus
Viral antigens in feces
Norovirus or Norwalk virus (viral gastroenteritis)
- can live on environmental surfaces for up to 3 weeks
- tranmission = fecal-oral
- incubation = 12->48 hrs
- treatment = rehydration
-milder symptoms than rotavirus
giardiasis (protozoa)
found in GI tract/ fecal matter of grassland mammals
attacks intestinal walls of GI tract
-affects food absorption
life cycle stages = cysts/ trophozoite
has no mitochondria
stomach acids do not destroy cysts
-waterbourne diarrhea epidemic
-causes prolonged diarrhea
is Giardia lamblia resistant to chlorine
true
How can Giardiasis be prevented
boiling/filtering water
Mode of infection for Giardiasis
-contaminated water / food
- hand to hand
-fecal / oral
lab diagnosis for Giardiasis
stool sample / O& P ( need 3 samples)
why are 3 samples of O &P needed for Giardiasis
because protozoa do not suddenly reproduce
false positive could occur
Treatment for Giardiasis
metronidiazole
Balantidiasis (protozoa)
only pathogenic cillilated protzoa
causes sever dysentery
mode of infection = fecal/ oral
Amoebiasis (protozoa)
caused by entamoeba histolytica
-affects GI tract
- only pathogenic in humans
-primary foods = rbc’s / intestinal tract tissue
-causes loose stool/ diarrhea
- stomach acid does not destroy cysts
What causes transmission for amoebic dysentery
house flys that pick microbes from fecal matter
Why can entamoeba histolytica live outside of host
due to cysts
what is entamoeba histolytica not resitant to
chlorine
what is the life cycle for entamoeba histolytica
trophozoite / cysts stages
Mode of infection for amoebic dysentery
contaminated water
human contact/ food contact
mechanical vectors
vegetables fertilized with human manure
Lab diagnosis for amoebic dysentery
stool sample / serology test
Metronidiazole / Iodoquinol
treatment for amoebic dysentery
TInea saginata (beef tapeworm)
worldwide (common in US)
adult worm can live in human intestine for 25 years / reach 18 ft long
-mode of entry = ingestion of uncooked beef / hand -> hand / ingestion of uncooked eggs
Symptoms of Taenia saginata
-seldom causes symtpoms
- can cause abdominal / pyschological distress
lab diagnosis for Taenia saginata
stool sample O/P
Niclosamide (deworming medication)
treatment for Taenia saginata
Taenia solium (pork tapeworm)
worldwide / non existent in hogs raised in US
mode of entry = ingestion of uncooked pork / hand -> hand
lifecycle / diagnosis / treatment / symptoms same as beef tapeworm
Pin worm (enterbius vermicularis)
most prevalent worm infection in US / worldwide
need both male/ female reproductive organs
found in large intestine
symptoms = itchy anus , trouble sleeping , restlessness
mode of entry for pinworms
ngestion of eggs
-contaminated clothes/ sharing clothes
bedsheets
Treatment for pinworms
mebendazole
lab diagnosis for pinworms
scotch tape method
Hook worm ( necator americanus )
worldwide / in US
warm / moist climates
mode of entry = skin penetration
-life cycle = eggs in poop / larvae hatc in soil
feeds on blood/ tissues
-attaches to small intestines
treatment for hookworm
mebendazole
Mode of entry for hookworm
skin penetration
Aflatoxin
found on peanuts/corn crops
-dangerous to humans/animals
-carcinogenic/ liver damage
Aspergillus produces what
aflatoxin
Ergot poisoning
found on grain crops (wheat crops)
restricts blood flow
causes hallucinogenic symptoms similar to LSD
Claviceps Purpurea is causes what
ergot poisoning
