Gram Positive Bacilli: Clostridia Flashcards
Which is false?
A. Clostridium tetani is an obligate anaerobe.
B. Aerotolerant anarobes use oxygen in their metabolism.
C. Facultative anaerobes can make ATP in the presence of oxygen.
D. Microaerophilrs can only tolerate 2-10% oxygen.
B. Aerotolerant anarobes use oxygen in their metabolism.
They do not use oxygen in metabolism
False about anaerobes A. Do not use oxygen B. Gain energy via redox reactions C. Make use of inorganic electron acceptors (nitrate, sulfate) D. Cannot grow on wounds
D. Cannot grow on wounds
They can grow on wounds because of symbiotic relationship with aerobic bacteria. Why? They lower redox potential! Since they can grow on wounds, they give wounds a foul smell.
Which is false?:
A) Anaerobes grow quickly (18-24 hours)
B) Clostridium botulinum can withstand 100 degrees Celsius
C)Most Clostridia are saprophytes
D)Clostridium botulinum diminishes at acid pH or high salt concentration
A) bec their growth period is 48-96 hours
Substance responsible for heat resistance of anaerobic endospores
Dipicolinate/dipicolinic acid
Clostridium botulinum’s primary toxin prevents release of , resulting in (_____).
: acetylcholine
(______): flaccid paralysis
Most virulent and heat-resistant botulin type; it cleaves SNAP 25
Botulinum toxin Type A
Botulinum toxin Type B cleaves __
Synaptobrevin
Which is false?
A. Both Botulinum toxin types E and F cleave SNAP 25
B. Both Botulinum toxin types E and F cause infant botulism
C. Botulinism is an intoxication illness and not an infection
A. Both Botulinum toxin types E and F cleave SNAP 25
E and A dapat.
Which is false about botulin?
A.The toxin binds to the receptors of presynaptic membrance of sensory neurons of PNS + cranial nerves
B. The toxin does not cause antitoxin to develop in blood
C. The toxin is not immunogenic
A.The toxin binds to the receptors of presynaptic membrance of sensory neurons of PNS + cranial nerves
Motor dapat
Infant botulism is diagnosed via contents of A. Serum B. Blood C. Bowel D. All of the above
C.bowel
False about treatment of botulinism
A. Prepared in humans
B. Trivalent (A, B and E) administered intravenously
C. Recovery phase: nerve endings regenerate
D.none of the above
A. Prepared in humans
Horses dapat
Use of \_\_\_ prevents C.botulinum growth folowing germination of endospores A. Nitrites B. Nitrates C. Sulfites D. Sulfates
B. Nitrates
Main toxin in Clostridium tetani is called __
Tetanospasmin
All aid in spore germination and vegetative organism development of C.tetani except;
A. Calcium salts
B. Associated pyogenic infections (with pus)
C. Necrotic tissue
D. High redox potential
D. High redox potential
C.tetani favors low redox potential
Which is false?
A. C.tetani is an invasive organism
B. Tetanus Infection occurs only if site is anaerobic
C. Tetanospasmin causes spastic paralysis
D. Tetanospasmin invades CNS via peripheral nerves/blood
A. C.tetani is an invasive organism
It is not invasive; infection is localized in tissue into which spores have been introduced
Sequence the ff steps of tetanospasmin’s mechanism of action
A. Blocks release of gamma-aminobutyric acid & glycine
B. Migrates to spinal cord and brain stem
C. Binds to receptors on presynaptic membranes of motor neurons
D. Degrades synaptobrevin
C B D A
Which is not a clinical manifestation of tetanus? A. Muscular spasm B. Abdominal pain and diarrhea C. Lockjaw D. Opisthonos
B. Abdominal pain and diarrhea
What is opistohonos?
Spasms of back muscles causing head and eels to bow backward
Which is false?
A. May be diagnosed as such when neutralization by specific antitoxin is successful
B. Both toxoids and tetanus immune globulin aid in active immunization
C. Administration of penicillin helps, since C.tetani is Gram positive
D. Tetanospasmin has tropism for inhibitory motor neurons of CNS
B. Both toxoids and tetanus immune globulin aid in active immunization
The latter is for passive immunization
False about Clostridium perfringes
A. May grow on warm meat dishes
B. Cannot cause Endogenous infections
C. Causes gas gangrene(gas formed at deep wound or injury) and food poisoning
B. Cannot cause Endogenous infections
Endogenous infections may occur since Clostridium perfringes is also part of gut’s normal flora
Predisposing condition of gas gangrene
Deep penetrating wound contaminate by clostridial spores
This toxin of C.perfringes is responsible for tissue damage by hydrolyzing lecithin in cell membranes
Alpha toxin
This toxin of C.perfringes increases permeability of GI Wall
Epsilon toxin
All are part of enterotoxin's action except A. Nausea and vomiting B. Abdominal pain and diarrhea C. Opisthonos D.none of the above
C. opisthonos
This toxin of C.perfringes hydrolyzes RBC
Theta toxin
This toxin of C.perfringes hydrolyzes WBC
Nu toxin
This toxin of C.perfringes causes RBC agglutination
Neuraminidase
Another name for hyaluronic acid
Spreading factor
C.perfringes produce spores that germinate at ___ redox potential
A. High
B. Low
C. Any
B.low
Which is not a typical host response to C.perfringes? A. Fasciitis B. Crepitation in subCT tissue C. Trismus D. Cellulitis
C. Trismus
Trismus: lockjaw! Lockjaw c/o C.tetani
Which is false?
A. C.perfringens is found in genital tract of 5% of women
B. Lecithinase activity is tested via precipitation test around colonies grown on blood agar plate
C. Both are false
B. Lecithinase activity is tested via precipitation test around colonies grown on blood agar plate
BAP? Nope, egg yolk media :)
Reaction that determins alpha toxin of C.perfringes
Nagler reaction
Disease produced by Clostridium difficile; can lead to ulceration of intestinal wall
Pseudomembranous colitis
False about Toxin A of C.difficile A. Causes bloody diarrhea (hemorrhagic necrosis + intestinal inflammation) B. Potent cytotoxin C. Both of the above D. None of the above
B. Potent cytotoxin
It is an enterotoxin, causing fluid accumulation in the bowel. Yung Toxin B=cytotoxin
C.difficile Lab identification methods include all except
A. Immunoassay
B. Nucleic acid amplification
C. Cell culture (cytopathic effect determined)
D. Using egg yolk media
D. Using egg yolk media —> for C.perfringes
History of antibiotic use helps in diagnosis of C.difficile
Which is false?
A. Cephalosporin and quinolones are narrow-spectrum antibiotics
B. They kill lots of normal flora species
C. Cephalosporin inhibits cell wall synthesis
D. Quinolone inhibits DNA synthesis
A. Cephalosporin and quinolones are narrow-spectrum antibiotics
Broad dapat
True about antibiotic-assoc diarrhea
A. Usually due to clindamycin and ampicillin
B.less severe than classic form of pseudomembranous colitis
C. Both are true
D. Both are false
C.both are true
