32. Genera Bacillus and Paenibacillus (except B. anthracis).

Question 1

Genus Bacillus Key points?

Answer 1

genus BACILLUS
Key points:
- the genus comprise more than 330 species
- large, Gram-positive rods up to 10 μm in length
- endospores are produced
- obligate aerobic or facultative anaerobic
- they are catalase-positive, oxidase-negative and motile
- most species are saprophytes (contamination of
specimens and media) - B. anthracis is the most important pathogen

Question 2

Bacillus Habitat?

Answer 2

1. Habitat: widely distributed in the environment,
   soil (highly resistant endospores)

Question 3

Other Bacillus species?

Answer 3

Clinical manifestation of other
Bacillus species
• B. cereus cattle – mastitis (rare)
humans – food poisoning
(GI infections)– eye infections
• B. licheniformis cattle, sheep: sporadic abortion
• Paenibacillus larvae honey bees: American foulbrood

Question 4

American foulbreed of honey -penicellabus larvae?

Answer 4

Larvae up to 3 days old become infected by ingesting spores that are present in their food.
- Young larvae less than 24 hours old are most susceptible to infection.
- Spores germinate in the gut of the larva and the vegetative form of the bacteria begins to
grow, taking its nourishment from the larva.
- Spores will not germinate in larvae over 3 days old.
- Infected larvae normally die after their cell is sealed.
- The vegetative form of the bacterium will die but not before it produces many millions of
spores.
- Each dead larva may contain as many as 100 million spores.
- Infected larvae darken and die.

Question 5

Saprophyte Bacilli?

Answer 5

Saprophyte Bacilli

• B. subtilis
• B. megaterium
• B. cereus
• B. licheniformis/subtilis: bacitracin
• B. thuringiensis: insect pathogen, pest-control • Paenibacillus (B.) polymyxa: polymyxins
• Geobacillus (B.) stearothermophilus: heat resistant test organism

Question 6

Differentation of the most Important Bacillus sp?

Answer 6