Clostridium Flashcards 1
What is clostridiums oxygen requirement?
Strictly aerobic
Is clostridium gram +/-?
Gram positive
Does clostridium produce endospores?
Yes
What is clostridiums method for producing disease symptoms?
Production of endotoxins. SOME also have tissue invasiveness
What disease is related to Clostridium difficile?
Pseudomembranous colitis (PMC) - Yellow plaques containing fibrin and cellular debris in ulcers of colonic mucosa.
What is the leading cause of nosocomial (hospital aquired) diarrhea?
Pseudomembranous colitis
What causes Clostridium difficile spores to become active?
Use of braod spectrum antibiotics which removes competing bacteria for GI tract.
What is Toxin A in Clostridium difficile?
Enterotoxin - fluid production and damage to the mucosa
What is Toxin B in Clostridium difficile?
Cytotoxin - Rounding of tissue culture cells (leads to death)
What is the major pathogen of wound infection?
Clostridium perfringens
Does Clostridium perfingens have invasive properties?
Absolutely
What conditions are necessary for Clostridium perfringens spores to germinate?
Anaerobic, compromised blood supply, calcium ions, availability of peptides and amino acids
What is the major toxin associated with Clostridium perfringens? What does it cause?
Alpha-toxin (lecithinase) - causes gas gangrene
Will antibiotics cure a Clostridium perfingens infection?
It can get rid of the bacteria BUT THE TOXIN REMAINS!!!
What toxin does Clostridium perfiringens produce that causes food poisoning?
Enterotoxin
Why is Clostridium botulinum so hard to prevent?
Heat-resistant spores which can survive food processing
Why is Clostridium botlinum such a serious infection?
Produce nine neurotoxin (BoNT) serotypes A-G. A, B, E (fish) are most common that are among the most poisonous substance known to humans.
What does BoNT do?
Prevents release of acetylcholine neurotransmitter (by cleaving proteins involved in docking of neurotransmitter vesicles) resulting in FLACCID PARALYSIS
What treatment is available for Clostridium botulinum infection?
Trivalent antitoxin isolated from horses does exist but can result in hypersensitivity problems
What is the most common mode of Clostridium tetani infection?
Traumatic wounds (Neonatal contamination of umbilical cord)
What is the major toxin of Clostridium tetani?
Tetanospasmin - only toxin. responsible for all symptoms.
What does tetanospasmin do?
- Inhibits neurotransmitter release acid and normal inhibitory input resulting in REFLEX SPASMS / SPASTIC PARALYSIS.
- Eventually leads to lockjaw and eventually to respiratory failure.
What treatment is available for Clostridium tetani?
- Completely preventable with DPT vaccine.
- Antitoxin and penicillin G should be administered - can prevent further paralysis.
- Surgical debridement of the wound - prevents further bacterial growth
