SPORE FORMERS: BACILLUS AND CLOSTRIDIUM

3 March 2006, 30 July 2007, 15 Aug 07

Bauman 2^nd: 542-550

Two important spore forming Gram positive bacteria

BACILLUS:    large non-motile rods, facultative anaerobes, common in soil, most non pathogenic

             Bacillus anthracis           p 543   animal disease, transmitted to human

                                                                 large bacillus (8 um) central spores, germ warfare

             Bacillus thuringiensis    produces intracellular diamond shaped xyls upon sporulation, kills insects.

             Bacillus cereus              common, can cause food poisoning in starchy foods like rice.

CLOSTRIDIUM          fastidious obligate anaerobe, req. neutral pH, rich medium.

                                       Spores resist to 120°C, 15'

C. perfringens   11 toxins, causes gas gangrene, anaerobic tissue infected, myonecrosis, produce H₂, terrible foul odor, bubbles "snap, crackle and pop" when patient is moved. Debridement, penicillin (p 545)

C. botulinum     “Slipper” morphology. (sausage) fr non-acid home canned foods, esp beans & grn peppers. Spores more resistant than any other anaerobe, resist 6 hr boiling.

             Intoxication:     Toxin coded for by lysogenic phage.

             Most potent toxin known:           p 546: binds to synaptic know membrane, prevents release of acetylcholine, causes flaccid paralysis. floppy baby syndrome.

C tetani:            “lollipop” morphology. (P 548) exotoxin

term. spores, germinate, non-invasive, upon death & lysis, release toxin 4-10 days. Prevents re-uptake of acetylcholine: spastic paralysis, protect with toxoid.

Toxicity:

Tetanus toxin prevents release of inhibitory neurotransmitter in opposing antagonistic muscle. Both contract at the same time, clonic contraction = tetanus (to stretch)

                          [Prevents re-uptake of acetylcholine???]: spastic paralysis, protect with toxoid.

Inactive toxin = toxoid

isolated antitoxin injected if you have tetanus

             Veillonella:      normal oral flora, component of plaque