Anaerobiosis in oral cavity

Anaerobiosis in oral cavity
Lecter-15•
Dr.Baha,H. Al-Amiedi •
Ph.D.Microbiolgy•
Anaerobiosis in oral cavity
There have beenmany attempt to identify •
themechanismthat allow clostridia &other
Anaerobic to colonize in oral cavity •
1-It is known that the oxidation-reduction •
potential of oral cavity is suitable for species
of clostridia,such as :
1-clostridiumperfringens. •
2-clostridium histilyticum •
2-Free-flowing saliva has high positive redox •
potential which shifts towered the
Negative side with the elapse of time. •
3-salive is stagnant area, such as the •
periodental pocket and dental interproximal
space where oxygen uptakemay be
retarded,has redox potential enough to
prompte anaerobic growth
4-other factors thatmay be acting to •
promote suitable growth conditions in saliva
for oral anaerobes include the the lack of
peroxidase in saliva,the presence of salivary
catalase and the depletion of oxygen by the
aerobic flora,
. •
Clostridium
Clostridiun are gram positive,obligate •
anaerobic,the endo spore are wider than bacilli
bodiesmay be of central or terminal
In position &spherical or oval in shape •
Clostridium are widely distributed in soil and in •
the intestinal tract of human &other animals it is
responsible for disease:
1-tetanus •
2-gas gangrene •
3-botulism •
4-psedomembranoud colitis •

Clostridium tetani
Anaerobic gram-positive, spore-forming •
bacteria characteristic drumstick
appearance because the terminal spore.
Spores found in soil, animal feces;may •
persist formonths to years
Multiple toxins produced with growth of •
bacteria
Tetanospasmin estimated human lethal •
dose = 2.5 ng/kg

Transmission
Spores of clostridiumtetani are commonly •
Found in soil&intestinal tract of human& •
Animals. •
infection associated with: •
1-puncture wounds. •
2-contaminated injuries •
3-sever burns •
4-Non-sterile surgary, •