Clostridium-Bacillus Flashcards
Clostridium is what gram stain and shape?
Gram + rods
Does clostridium form spores?
yes
What is clostridium’s O2 requirements?
Obligate anaerobes
_____ bacteria: environment (soil) + intestinal mucus
Clostridium
____ stains endospores green
Malachite green
_____ formation is essential for all Clostridial pathogenicities who infect by stable endospores
spore
____ are very resistant against destruction or sterilization such as multiple hours of boiling
-are not subject to antibiotics
spores
_____, a severe form of food poisoning (often home canning) ►paralysis (clostridium botulinum)
Botulism
________ is also possible from soil or fecal contamination (clostridium botulinum)
wound botulism
_______ in 3-20 week infants without full intestinal flora causes muscle weakness but rarely severe and generally resolves as intestinal flora develops (clostridium botulinum)
“infant botulism”
________: blocks Acetylcholine release ►flaccid muscles including respiratory paralysis ►death (clostridium botulinum)
botulinum neurotoxin (AB-exotoxin)
What forms of clostridium act via toxins and do NOT invade tissues?
Clostridium tetani, botulinum, difficile
Is botulinum toxin heat stable or labile?
Heat labile
Anti-toxin for botulinum toxin takes how much time to take effect?
Weeks to months
______ causes botulism; main virulence factor is botulinum neurotoxin (AB-exotoxin)
clostridium botulinum
Dirty, puncture wounds (knife, bullet, tattoo) are typical opportunities for anaerobic growth of this bacteria; main virulence factor is tetanospasmin
Clostridium tetani
Which clostridium species causes muscle paralysis?
C. botulinum
Which clostridium species causes muscle spastic paralysis?
C. tetani
_______: blocks GABA(gamma-aminobutyric acid) and glycine release ►loss of inhibitory input to motor neuron excitation ►uncontrolled muscle contraction “spastic paralysis”
-Toxin effect may be localized and one-sided (on
opposite side of infection); anti-toxin usually too late
tetanospasmin (tetanus AB-exotoxin neurotoxin, plasmid-encoded)
_____ toxin prevents muscle relaxation leading to 30-50% mortality
Tetanus toxin
in what condition does Tetanus toxin prevents muscle relaxation leading to 30-50% mortality
Tetanus
Passive immunization (IgG) of pregnant women can prevent _______ death by umbilical infection (250,000/yr worldwide)
neonatal tetanus
Which clostridium species actually invades tissues and don’t act soley via toxins?
C. perfringens
\_\_\_\_ has the following virulence factors: Alpha toxin Theta toxin Capsule Collagenase Hyaluronidase
Clostridium perfringens
____ toxin causes membrane destruction: a-hemolysis (Clostridium perfringens)
Alpha toxin
___ toxin is a cytolytic toxin; B-hemolysis (Clostridium perfringens)
Theta toxin
What 2 things facilitate tissue invasion from the edges of necrotizing tissues in Clostridium perfringens?
Collagenase and Hyaluronidase
anaerobic fermentation (of amino acids)►gas(H2, CO2) causes _______ (Clostridium perfringens)
►gas gangrene
puerperal (“childbed”) fever is called _______ (Clostridium perfringens)
uterine gangrene
Is there an antibody effective against C.. perfringens?
No; amputation usually necessary
_______ results from broad-spectrum antibiotics that kill much of the other normal intestinal bacterial flora, giving resistant species like toxin-producing Clostridium difficile a chance to take over.Also observed after antimicrobial chemo-therapy (Clostridium difficile)
Antibiotic-associated pseudomembranous colitis(PMC)
____ (bacteria) is the most common cause of hospital diarrhea
Clostridium difficile
The following virulence factors are characteristic of _______:
Toxin A
Toxin B
Clostridium difficile
_______: PMN chemotaxis, inhibits intestinal tight-junctions ►fluid leak (Clostridium difficile)
toxin A (enterotoxin)
______: actin depolymerization►rounding of epithelial cells►fluid leak (Clostridium difficile)
toxin B (cytotoxin)
What gram stain and shape are bacillus species?
Gram + rods
Do bacillus sp form spores?
Yes
____ bacteria: •zoonotic infection “woolsorter’s disease”•Gram+ rods, facultative anaerobe
Bacillus anthracis
What is the O2 requirements of Bacillus anthracis?
Facultative anaerobe
The following virulence factors are characteristic of ________:
Edema factor
Lethal factor
Capsule
Bacillus anthracis
Which subunit of toxin is a protective antigen and is the target for neutralizing antibodies? (Bacillus anthracis)
B subunit
Which subunit of toxin is toxic (EF or LF)? (Bacillus anthracis)
A subunit
Which A subunit toxin of (Bacillus anthracis) modifies a regulatory protein cells causing those cells to overproduce fluids?
Edema factor
Which A subunit toxin of (Bacillus anthracis) inactivates proteins involved in cell signaling functions?
Lethal factor
_____= adenylate cyclase ►cAMP►edema(like cholera toxin) (Bacillus anthracis)
EF
_____= metallo-protease ►MAP kinase ►death (cell death with pulmonary edema)
(Bacillus anthracis)
LF
- entry lungs, uptake by lung phagocytes; –latency of 2 months or more may occur
- to lymph nodes [spore germination-phagocytes die]; –pneumonial and meningitis type symptoms are seen
- bloodstream -> powerful toxins (macrophage TNF-α: toxic shock death in 1-2 days)
Inhalation anthrax
_______: •ulcers in mouth, esophagus -> edema + sepsis
•Lethality if in lower intestines: 100%
Gastrointestinal anthrax
What is the bacterial agent of anthrax?
Bacillus anthracis
______:•redness (inflammatory cytokines), edema (EdTx) with vascular (top) and vesicle (bottom) rupture.
•Lethality: 20%
Skin anthrax
________ (an opportunistic pathogen)
•gastroenteritis, ocular infections, bacteremia
•heat-stable and heat-labile toxins, necrotic toxin
Bacillus cereus
