Microbiology In Upper GI Tract (Quiz) Flashcards
is Bacteroides anaerobic or aerobic
- anaerobic
is Acitnomyces anaerobic or aerobic
- anaerobic
is Clostridium anaerobic or aerobic
- anaerobic
what is the most common cause of infectious esophagitis
often associated with
what is its aerobic status
- Candida albicans
- uncontrolled HIV or immunocompromisation
- facultative anaerobe
which are greater in number, aerobes or anerobes
- anaerobes
- >1000:1
which are the prominent phyla of anaerobes in the GI Tract
- bacteroidetes
- firmicutes
most anaerobic infections are
- mixed infections containing both anaerobic and aerobic bacteria
plaque is composed of
what do they secrete
- bacterial biofilms
- exopolysaccharides
which bacteria causes SUPRAgingival plaque associated biofilm
- actinomyces
A IN SUPRA STARTS THE A HERE
which bacteria causes SUBgingival plaque associated biofilm
- Bacteroides
B IN SUB STARTS THE B HERE
classification of bacteroides
- gram negative
- non-spore forming
- anaerobic
- bacilli
Bacteroides found where
- oropharynx
- intestinal tract
- female genital tract
what is the most predominant bacteria found in the GI tract
esp
- Bacteroides
- B. fragilis
what is the most common genus isolated from anaerobic infections
what specific bug
- Bacteroides
- B. fragilis
for bacteroides to cause disease, what is required
- breach of epithelial cell barrier allowing access to deeper tissues.
- unable to invade cells or tissues itself
- requires synergy with other bacteria
classification of Actinomyces species
- gram positive
- non-spore forming
- anaerobic
- bacilli
Actinomyces is usually associated with
why
are adults or children more affected
- following dental procedures (odontogenous)
- part of normal oral flora
- adults more than children
Actionmyces Israelii causes
characteristics of infection
treatment
- lumpy jaw
- abscesses, mass lesion, or swelling of soft tissues
- sulfur granules drained from them
- long term antibiotic therapy
clostridium is part of what phylum
full classification of clostridium
- Firmicutes
- gram positive
- spore forming
products of clostridium fermentation have what characteristic
- foul odor
which clostridia are associated with gas gangrene
how can they spread
- perfringens
- septicum - spread via bloodstream
which clostridia are associated with food poisoning and wound infection
- botulinum
which clostridia are associated with antibiotic- associated diarrhea and colitis
- difficile
endotoxins are part of what type of bacteria
how so
- gram negative
- part of LPS (lipid A + polysaccharide)
what is an exotoxin
- any secreted toxin
what is an enterotoxin
- a secreted toxin that targets enteric cells
what kind of toxins do C. tetani and C. bolulinum have
- A - active
- B - binding
tetanus toxin causes what
- prevents release of inhibitory neurotransmitter
- causes spasticity (tetanus spasm)
botulinum toxin causes what
- prevents release of stimulatory neurotransmitter
- causes paralysis
toxin of C perfringens
what does it do
- alpha toxin
- lecithinase degrades tissue and cell membrane
toxins of C. difficile
what do they do
- A and B toxins
- glucosylate Rho GTPase
- cytotoxic and inflammatory
traumatic gas gangrene is caused by
what allows the bug to metabolize and contaminate the wound
- clostridium perfringens
- tissue damage
spontaneous gas gangrene caused by
what allows the gut to enter the bloodstream
- clostridium septicum
- breaks in GI mucosa
between traumatic gas gangrene and spontaneous gas gangrene, which is the most deadly
- clostridial myonecrosis spontaneous gas gangrene
- mortality up to 100%
what results from compromised intestinal barrier function
- peritonitis
organisms responsible for intra-abdominal infections
role of capsular polysaccharide fragment
- Enterobacteriaceae
- B. fragilis - PMN recruitment
why do we use a woundvac in treatment of anaerobic infections
- allows antibiotics to penetrate better
what antibiotics are always active against anaerobes
- metronidazole
- carbapenems
- beta-lactams
Make Bacteria Cry
what antibiotics are never active against anaerobes
- aminoglycosides (-mycin)
- Tmp/Smx
- Aztreonom
Always Too Awkward so they won’t do it
how to treat candidiasis
- fluconazole
what does H. pylori use to colonize
- flagellar motility
H. pylori replicates at pH as high as
- 7.6
how H. pylori causes damage
- mucinases and injected effectors damage epithelial cells and induce inflammation
diversity of H. pylori virulence factors
- cytotoxin associated genes and type 4 secretion system genes on mobile Cag pathogenicity islands
treatment of H. pylori
- combination of antibiotics
- proton pump inhibitors
- bismuth subsalicylate
low solubility of O2 and poor diffusibility means what about anaerobes
- they can be really close to the surface
appropriate specimens for collection
- aspirates of abscesses, tissue, blood
