Micro: H. Pylori, Vibrio, Campylobacter, and Anaerobes Flashcards
What is the main cause of ulcers?
h pylori
how is h pylori spread
person to person fecal to oral
what types of cancers is h pylori associated with
gastic adenocarcinomas and lymphomas
What are the virulence factors of h pylori?
It's a slender, curved, gram- rod with motile polar flagella, that is microaerophilic. It has a VacA - vacuolating cytotoxin PAI encoding Type III secretion system Cag - rearranges cytoskeleton Urease
Pathogenesis of h pylori?
makes urease, allowing persistance, has mcular needle injecting Cag and VacA, leadining to inflammation
What exactly causes the ulcers in h pylori?
the cell destruction by VacA, Cag and immune response
What is the most common bacterial GI infection in developed nations?
Campylobacter jejuni
What is the reservoir for c jejuni? How many cells are needed for infxn?
sheep, cattle, chickens wild birds dogs
only a few hundred
What is the structure of c jejuni
thin spiral chaped gram-negative rods, with gull-winged appearance
what are the symptoms of c jejuni infxn/
fever, appendicits-like lower abdominal pain, watery diarrhea that progresses to dysentery with blood and pus
What microbe is associated with Guillen-Barre Syndrome?
c jejuni think “camplybarre”
Why is campylobacter infxn self-limiting while h pylori can last for decades?
the pathogenesis of h pylori in creating urease allows for a maintenance of hospitable environment. also, lower GI where c jejuni targets has a better clearance mechanism
microbiology of vibrio/
curved gram- rods motile with flagellum, oxidase positive, saltwater in warm months
what are the three significant vibrio classes
cholarea parahaemolyticus and vulnificus
Where is cholera most present?
asia, africa, s america, india
what serogroups of cholera are responsible for the pandemicss?
o1 and o139
what is the infxs dose of cholera/
more than 10^8
What is the presentation of cholera
abrupt onset of vomiting and high volume watery diarrhea
what is the characteristic description of cholera stool?
rice-water stools, speckled with mucus and loaded with bugs
what are the virulence factors of cholera
pai-encodid pilus
phage-encoded toxin
describe the toxin of cholera
ab toxin comprised of 5b and 1a subunit, causing adpp-ribosylation of gtp-biding protein. activation of adenyl cycle leading to activation of cftr
what are the symptoms of vibrio parahaemolyticus
water diarrhea often with abdom cramps, n/v low grade fever 24 hrs post-exposure,
when do we see v vulnificus
free-living in sea water with consumption of raw oysters and wound infection, leads to immunocompromised or chronic liver pts getting septicemia and bullae
what are the symptoms of v vulnificus
vomiting, diarrhea and abdom cramps