Bacillus

Question 1

General characteristics

Answer 1

• motile (except for B. anthracis)
• B. anthracis is endospore forming

Question 2

Major Bacillus species & corresponding diseases reus:

Answer 2

• 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

Question 3

How to kill/disinfect B. Anthracis

Answer 3

• Disinfectant: aldehyde, oxidizing, and chlorinating disinfectants propiolactone and ethylene oxide
• Kill: autoclaving 121 degrees celsius/15 mins or dry heat 150 degrees celsius/ hr

Question 4

Describe main cellular products of bacillus

Answer 4

• protective agent binds to cell surface, forms channel in membrane, lets edema factor and lethal factor in cell

Question 5

Which cellular products are medically important

Answer 5

• edema factor
• protective antigen
• lethal factor

Question 6

Explain forms of anthrax

Answer 6

• cutaneous: black lesions on skin
• pulmonary: most deadly; inhalation of spores
• GI: ingestion of contaminated H2O or meat

Question 7

Describe disease pattern of anthrax in ruminants

Answer 7

• Main signs: staggering, trembling, trouble breathing, convulsions, death, bloating
• bacteria from bodily fluids form spores that contaminate soil and vegetation

Question 8

Disease pattern of anthrax in horses

Answer 8

• colic, diarrhea,edema @ point of infection or throat, asphyxiation
• may be septicemic

Question 9

Disease pattern of anthrax in pigs

Answer 9

• localization in pharyngeal tissues
• cutaneous form aka “bull nose”

Question 10

Disease pattern of anthrax in birds

Answer 10

• low risk
• reports in ostriches, crows, canaries, and ducks

Question 11

Dx of B. Anthracis

Answer 11

• 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

Question 12

Antibiotics for anthrax control & prevention

Answer 12

• control: penicillin & oxytetracycline
• prevention: ciprofloxacin & doxycycline

Question 13

What does spore-forming mean?

Answer 13

Organism can enter dormant phase until favorable conditions regained

Question 14

Why does sporulation happen & what’s the importance

Answer 14

Happens when an organism is put in an unfavorable environment so it can survive

Question 15

Is there a vx for anthrax? If so is there an animal and human form?

Answer 15

Yes in humans (Biothrax)

(In animals: anthrax spore vx)

Question 16

Anthrax Spore Vx

Answer 16

• live-spore vx for domestic farm animals
• inexpensive
• widely avail.
• 1cc SQ neck
• uses Sterne strain

Question 17

Sterne strain

Answer 17

• Cured B. Anthracis wild type strain of pXO2

Question 18

Which 2 plasmids are required for anthrax infectiousness

Answer 18

• pX02(CAPSULE GENES)

-pX01(TOXIN GENES)