cholerae, h. pylori, anaerobes Flashcards
virulence factors for V. cholerae(2)
PAI-encoded pilus (TCP)
Phage-encoded toxin
AB toxin comprises 5 B and 1 A subunit
ADP-ribosylation of
GTP-binding protein
Activation of adenyl cyclase
V. cholerae Dx: culture from where? which two media?
tx: what must you treat with? which two drugs?
Dx:** Stool culture** on TCBS (Thiosulfate Citrate Bile salts Sucrose) or MacConkey agars
Tx: Treat with oral hydration therapy (+ doxycycline or erythromycin)
V. vulnificus
where does it live?
how do you get it?
symptoms?
who does it most affect?(2) what does it cause in them (2)?
what is the fatality rate?
what is the tx?
Free-living in sea water
Consumption of raw oysters or wound infection (cellulitis)
symp: Vomiting, diarrhea, abdominal cramps
pt: Immunocompromised or chronic liver pts
Septicemia
Bullae
Rare, but 20% fatality rate
Doxycycline
what three aspects of health does our core microbiome influence?
Evidence that our core gut microbiome influences our body weight, CV health, and tendency to type 2 diabetes
what do anaerobeslack?
how do they derive energy?
do amines stink and in what places would they be found?
transport and growth of anaerobes?
Anaerobes lack SOD and catalase
Energy from carbohydrate fermentation or breakdown of amino acids to amines
These products stink, so
anaerobic infections STINK
Abscess and tissue necrosis,
smelly pus
Smelly breath
Many are polymicrobial
Special transport and growth
for culture
Many infections are ____________, relocalized normal flora to a sterile area
_______________are rarely cultured in patients because almost always present as normal flora
Clostridial infections usually from _________
Many infections are opportunistic, relocalized normal flora to a sterile area
Feces or sputum are rarely cultured in patients because almost always present as normal flora
Clostridial infections usually from environmental spores
B. Fragillis
what type of bacteria? capsule?
component of what part of body?
what type of pathogen?
it is MC anaerobic infection. name three of its infections(PIP)?
Gram negative coccobacillus
Antiphagocytic capsule
Major component of the human GI tract
Opportunistic pathogen
Most common anaerobic infection
Intraabdominal infections, abscesses
Pelvic Inflammatory Disease
Pulmonary infections
B. Fragilis
what % of bacteremias?
how to do you tx abscesses?
how to you treat this bacteria(4 DOC)? which abx won’t work in anaerobic conditions? which abx is it resistant to?
Cause about 10% of bacteremias
Surgical drainage of abscess
Aggressive antibiotic treatment
B. fragilis is resistant to penicillin
Aminoglycosides don’t work under anaerobic conditions
DOCs: erythromycin, clindamycin, metronidazole, 3rd gen. cephalosporins
prevotella melaninogenica
what type of bacteria?
what type of capsule?
where found(3)?
what type of pathogen? which diseases(3)?
what color colonies?
Gram negative coccobacillus
Antiphagocytic capsule
GI tract, nasopharyngeal and vaginal flora
Opportunistic pathogen, abscesses
Pulmonary
Periodontal
BLACK colonies!
clostridium
what type of bacteria?
what is special about it?
what is responsible for pathogenesis?
where found?
Gram-positive, spore-forming rods
Clostridia are the only anaerobic endospore-forming bacteria
Resistant to high heat
Resistant to harsh environment
Exotoxins and secreted hydrolytic enzymes responsible for pathogenesis
Colon and soil (spores)
C. perfrigens
what does it look like?
where found?
what causes infectins?
what two infections?
Large, “boxcar” Gram+ rods
Found in soil and intestines of humans and animals
Most human infections from spores in soil or food
Gas gangrene and cellulitis
Food poisoning
c. perfrigens
Gas gangrene
how do you get it?
which enzymes responsible?
necrosis and gas from carbo fermentation lead to what 3 things?
3 treatments?
Contamination of wound by spores
Multiple enzymes (phospholipase, collagenase, protease, etc) facilitate tissue penetration
Necrosis and gas (from carbo fermentation)–>Untreated leads to shock, renal failure, death
Treatment
Surgical debridement
Large amounts of penicillin and protein-inhibiting antibiotic
Hyperbaric oxygen chamber
C. perfringens
3rd MC _____borne illness in US
what type of toxins?
what dishes at what temps allow spores to germinate before consumption
when do you get symptoms and what are they(3)?
which two symptoms are rare?
how long to recovery?
3rd most common food-borne illness in US
Enterotoxin-producing strains
Rich meat dishes at low temperatures allows spores to germinate before consumption
8-24 hrs post consumption you get: Nausea, abdominal pain, diarrhea
No fever, vomiting rare
Full recovery within 24 hrs
C. tetani
how do you get it?
what type of toxin is tetanospasmin(tetanus toxin)?
how does the toxin work?
what does toxin cut? prevents release of which two neurotransmitters?
Spore contamination of wounds
Tetanospasmin (tetanus toxin) is an AB neurotoxin
Enters at neuromuscular junction and is transported by motor neurons to ganglia
Incubation time depends on distance of wound from CNS
Cuts a V-snare–>Vesicle with neurotransmitter cannot fuse with neuron membrane—>Prevents release of inhibitory neurotransmitters (glycine and GABA), blocking postsynaptic inhibition of spinal motor reflexes
name 4 symptoms of tetanus?
how does death occur (2)
what is the treatment?
why is sedation a recommended part of the tx?
what tx has not been proven useful?
- *symptoms: 1,2. **Trismus (lock jaw) first+Risus sardonicus
3. Generalized intermittent spasms
4. Patient is aware and sensitive to stimuli
Death can occur from exhaustion and respiratory failure
Treat with HTIG to soak up excess toxin
Sedation, wait for generation of new axon terminals
Antibiotics not of proven usefulness
Tetanus prophylaxis
how do you treat clean minor wounds of a person with fewer than 3 doses? 3 or more previous doses
fewer than 3 doses: give vaccine
3 or more doses: no need to vaccinate unless >10years since last dose
tetanus prophylaxis(Tdap)
how would you treat all other wounds with fewer than 3 doses of previous tetanus immunization? greater than 3 doses?
fewer than 3: give vaccine and TIG
3 or more: give vaccine if >5 years from last does
how do you get C. botulinum toxin?
how do infants get it?
the only other way left?
describe the toxin of C. botulinum?(5)
how many antigenic types?
how much could kill 1 million ppl
what does it cleave? prevents release of?
Consumption of contaminated food
Infants: ingesting spores from carpets
Infection of wounds with spores
**Toxins: **
AB toxins
Seven (A-G) antigenic types
May be the most toxic bacterial exotoxin
1 g could kill 1 million people
Cleave V- and/or T-snares
Prevent release of acetylcholine
classic botulism(food poision)
how do you get the toxin?
what type of condition do you get?
when do symptoms of the conditon begin? what are the symptoms? (5)
how do you die?
Consumption of toxin-contaminated food
Spores are resistant to heat, germinate after cooking
Release toxin; subsequent heating will inactivate the toxin (heat-labile)
Acute, symmetric descending flaccid paralysis
Symptoms begin 12-36 hrs post ingestion
** Nausea, dry mouth, diarrhea, then blurred vision**
** Paralysis descends to respiratory muscles, trunk, and extremities**
Possible death by respiratory failure
how do you tx classic botulism(2)
how do you prevent (2)
Treatment
Mechanical ventilation
Horse anti-toxin
Prevention
Proper cooking/canning
Vaccine for military only
other name for infant botulism?
how old are the infants?
what comes first?
how do the infants get the toxin?
what are the symptoms(3)
“Floppy baby syndrome”
Infants 3 weeks to 8 months
Infection first, then intoxication
Inhalation of spores +/- Ingestion of spores (honey)
symp:Constipation, poor muscle tone, feeding problems
C. diff
Normal GI flora in______of population
Most common ________ infection
Most common _________ disease associated with -__________ use (creates niche)
Endogenous or hospital spores are source
Toxins A and B work synergistically to produce disease
A: enterotoxin >> _________
B: cytotoxin >> ___________
“Super strains” emerging
Normal GI flora in 5% of population
Most common nosocomial infection
Most common diarrheal disease associated with antibiotic use (creates niche)
Endogenous or hospital spores are source
Toxins A and B work synergistically to produce disease
A: enterotoxin >> diarrhea
B: cytotoxin >> inflammation
“Super strains” emerging
C. diff
What are the symptoms?(3)
how do you Dx? (2)
tx:? (2)
Fever
Watery diarrhea that can become bloody
Pseudomembranous colitis=Ulcerative lesion in colon
Diagnosis
Detection of Tox B activity from stools on tissue culture cells
RADT detection of Tox A or B in stools
Treatment
Discontinue antibiotic, possible enema
Acute cases may require metronidazole
