Cross Anerobes and H pylori Flashcards
anaerobes affecting the GI tract
Bacteroides fragilis prevotella Clostridium: perfringens tetani botulinum difficile
major phyla of anaerobes contributing to gut microbiome
Clostridia Bacteroides also in oral cavity femal Genital tract soil/spores
anaerobes lack (2) anaerobes\_\_\_\_
SOD
catalase-thus cant deal with oxygen
they stink-organic acid end products of metabolism
anaerobic infections are often _____
poly microbial
MIXED ANAEROBIC AND FACULTATIVE AEROBIC BACTERIA
-IN ABCESSES-USUALLY REFLECT THE NORMAL FLORA IN THAT SITE
INTRA ABDominal infections, abcesses, paritonitis-from break in mucosal surface during Sx or trauma
Bacteroides fragilis
decubitus ulcer
Bacteroides fragilis
found in 25% of lung abceses
b fragilis
otherwise it is below the diaphragm
tx of b fragilis
RESISTANT TO PENICILLIN
-SUSCEPTIBLE TO METRO, CARBAPENEMS, BETA LACTAM+BLINHIBITOR
PELVIC OR PER-RECTAL ABCESSES
B FRAGILIS
GRAM NEGATIVE COCCOBACILLUS
OPPORTUNISTIC PATHOGEN-IN NASAL AND ORAL CAVITIES
PREVOTELLA
A MEMBER OF BACTEROIDES
CAUSES ORAL/PERIDONTAL ABCESSES
CHRONIC OTITIS
SINUSITIS
PULMONART ABCESSES/EMPYEMAS
PREVOTELLA
GRAM POSITIVE SPORE FORMING RODS
*only anaerobe spore formers-thus resistant to harsh environment
clostridum sp.
colon and soil as spores
pathogenesis of clostridia
exotoxins secreted in hydrolytic enzymes
GAS gangrene
large box car GPR
C perfringens
ALPHA TOXIN
*3 rd leading cause of foodborne illness in US??
cases gas gangrene
ALPHA TOXIN
protal of entry is a wound site (nail) or skin popping druggies
C tetani
c tetani pathogenesis
Tetanus toxin (tetanospasmin AB toxin)-enter NMJ-transported by motor neurons to ganglia -bind irreversibly inhibiting GABA and SNARE-disinhibition of neurons that modulate excitatoryimplulses =increased msucle tone
trismus- risus sardonicus painful spasms tonic paralysis autonomic instability arched back and respiratory failure
c tetani- disinhibition of excitatory neurons
tx of tetanus
debridement
Human Tetanus Immunglobulin-neutralize
Ab’s universally given-metro, penicillin
always give the vaccine immediately after dx
home canned fruits and veggies and fish, bioterror, iatrogenic, wound
c. botulinum-AB toxin
carpets or raw honey
infantile botulism
moa for botulism-mot potent toxin we have
cleaves snares–no exocytosis of ACH-flaccid parlysis
foodborne botulism
Spores are resistant to heat, germinate after cooking and release toxin
Subsequent heating will inactivate the toxin (heat-labile)
accute symettirc descending parlaysis
botulism
N/Dry mouth/Dysphagia/ Blurred vison (ACH deficiet)
possible death by respiratory failure
Tx of GI botulism
Mechanical vent
-HORSE ANTI-toxin if over 1 year old
-hBIG-IVNO if less than 1 year
AB’s-would just spread the toxin
flobby baby syndrome
:Constipation followed by weakness, feeding difficulties, descending global hypotonia, drooling, anorexia, irritability, weak cry
infantile botulism
infection first then intoxication with the toxin
tx of wound botulism
ab’s- penicillin, or metro
H pylori is responsible for
95% of duodenal ulcers
70% gastric ulcers
*associated with adenocarcinomas and lymphomas
spread of H pylori
fecal oral and human to human
virulence factors for H pylori
Slender, curved gram negative rods Motile with polar flagella Microaerophilic VacA: vaculolating cytotoxin PAI encoding Type III secretion system Cag: rearranges cytoskeleton Urease-ammonia damages epitheliam cell-also bings up local H+ making microenvironment alkaline
ulcers for h pyori are due to
VacA
CagA
Host immune response
tx of h pylori
- PPI, clarith, amoxicillin
- PPI, clarith, metro
- PPI or H2RA, Bismuth, metro, tetracycline
dx of H pylori
Endoscopy with biopsy and culture
Stool antigen
Urea breath test
Serology
