Bacillus Flashcards
General characteristics
- motile (except for B. anthracis)
- B. anthracis is endospore forming
Major Bacillus species & corresponding diseases reus:
- B. Anthracis: causative agent of anthrax; zoonotic
- B. Cereus: human & K9 food poisoning; rare cases bovine mastitis
- B. Thuringiensis: naturally in soil; lepidopteran insect pathogen
- B. Subtilis: model organism; ropiness in bread; prod. & secrete antibiotics
- B. Coagulans: food spoilage in tomato based products
How to kill/disinfect B. Anthracis
- Disinfectant: aldehyde, oxidizing, and chlorinating disinfectants propiolactone and ethylene oxide
- Kill: autoclaving 121 degrees celsius/15 mins or dry heat 150 degrees celsius/ hr
Describe main cellular products of bacillus
- protective agent binds to cell surface, forms channel in membrane, lets edema factor and lethal factor in cell
Which cellular products are medically important
- edema factor
- protective antigen
- lethal factor
Explain forms of anthrax
- cutaneous: black lesions on skin
- pulmonary: most deadly; inhalation of spores
- GI: ingestion of contaminated H2O or meat
Describe disease pattern of anthrax in ruminants
- Main signs: staggering, trembling, trouble breathing, convulsions, death, bloating
- bacteria from bodily fluids form spores that contaminate soil and vegetation
Disease pattern of anthrax in horses
- colic, diarrhea,edema @ point of infection or throat, asphyxiation
- may be septicemic
Disease pattern of anthrax in pigs
- localization in pharyngeal tissues
- cutaneous form aka “bull nose”
Disease pattern of anthrax in birds
- low risk
- reports in ostriches, crows, canaries, and ducks
Dx of B. Anthracis
- in BSL 3 labs
- necropsy and opening carcass NOT RECOMMENDED
-Gram stain
- McFayden’s methylene blue for capsule stain
- ascoli precipitin test: detection of thermostable anthrax antigen in tissue
Antibiotics for anthrax control & prevention
- control: penicillin & oxytetracycline
- prevention: ciprofloxacin & doxycycline
What does spore-forming mean?
Organism can enter dormant phase until favorable conditions regained
Why does sporulation happen & what’s the importance
Happens when an organism is put in an unfavorable environment so it can survive
Is there a vx for anthrax? If so is there an animal and human form?
Yes in humans (Biothrax)
(In animals: anthrax spore vx)
