Flashcards in Lecture 8 Deck (52)
Define Cl Tetani
a soil dwelling saprophytic organism- spores wide spread in soil- slender thin rods with tennis racket appearance
Portal of entry for Cl tetani
skin-through wound-like nail prick, road accidents where there is contamination of mud, skin popping in drug addicts
WHat does Cl tetani cause?
Tetanus- lock jaw
Can Cl tetani cause infection in newborns?
can occur through umbilical cord cutting, through circumcision in developing countries-- spores germinate at the wound
What do vegetative cells of Cl Tetani produce?
exotoxin which spreads through nerve fibers to spinal cord
What does exotoxin block release of?
glycine- inhibitory neurotransmitter- in spinal synapse causing muscle spasms (tetany)
Is vaccine effective for Cl Tetani?
YES- because only one Ag variety (sero type)
How is Tetanus defined?
characterized by spasm of skeletal muscles starting from face, hardening of facial muscles results in grim face
What is the hardening of facial muscles in Cl Tetani known as
What is spasm of muscles of mastification from Cl Tetani lead to?
Lock Jaw known as trismus
What does spasming of back muscles result in?
Arching of back known as Opisthotonus
What type of poisoning resembles the condition of Cl Tetanis
How do you treat tetanus?
Tetanus antitoxin serum to neutralize unbound toxins, penicillin and metronidazole may be useful- maintain adequate airway, muscle relaxants like valium
How do you prevent tetanus?
toxoid vaccine (DTaP) is available
What is the natural habitat of Cl Botulinum?
soil- spores are found in soil, found in contaminated vegetables, alkaline vegetables, spores germinate in anaerobic conditions
What is an indication that bacteria may be growing in canned vegetables?
swollen/bloated can tins
How do you get the Cl Botulinum toxins?
ingested- absorbed from gut and carried to neuromuscular junction
What does Cl Botulinum cause in a person and how?
flaccid paralysis- blocks release of acetylcholine- can cause paralysis of ocular muscles causing vision problems- respiratory failure when pharyngeal muscles are relaxed
Will Cl Botulinum present with a fever?
Can an infant get Cl Botulinum?
yes- contaminated honey- spores germinate in gut and cause silent death of an infant
Treatment for Cl Botulinum?
Trivalent antitoxin available- antitoxin made from horses and given with respiratory support
Prevention of Cl Botulinum
The tosin is relatively heat labile so boiling vegetables/food will inactivate toxins
What are some medical uses of Cl Botulinum?
to remove wrinkles on forehead or to relieve spastic torticollis (wry neck)
Describe Cl Perfringens
Gram + rod shaped, anaerobic spore forming bacterium
What 2 diseases can Cl Perfringens cause?
Gas gangrene and food poisoning
Describe gas gangrene
vegetable forms are members of normal flora of colon and vagina- spores are found in soil
Most common mode of contamination of Gas gangrene
wound contamination with soil/mud (war wounds, automobile accidents, septic abortion
How is the gas gangrene produced?
organism grows in traumatized tissues, produced alpha toxin which causes necrosis of muscle and RB cells and enzyme degradation produces gas in tissues
Results of Gas gangrene
pain, edema and cellulitis, crepitations, massive hemolysis, jaundice, renal failure, shock and death - high mortality rate