Bacillaceae

Question 1

Special staining method for Bacillus

Answer 1

Wirtz-Conclin (spores)
Giemsa-Romanovsky for capsule

Question 2

Patogenicity of Bacillus

Answer 2

Most are saprophytes with no pathogenic potential
Produce highly resistant endospore

Question 3

Most important pathogenin bacillus for animal and man

Answer 3

Bacillus anthracis

Question 4

Pathogenic Bacillus for insects (4)

Answer 4

Bacillus thuringiensis
Bacillus pupillae
Bacillus larvae
Bacillus alvei

Question 5

Tyzzer’s disease in rodents is caused by

Answer 5

Bacillus piliformis

Question 6

Which Bacillus are facultative pathogens?

Answer 6

Bacillus cereus
Bacillus subtilis
Bacillus licheniformis

Question 7

Which applications are Bacillus produced for?

Answer 7

Medical
Agricultural
Pharmaceutical
Enzymes, antibiotics and other metabolites

Question 8

Which antibiotics may be produced by Bacillus?

Answer 8

Bacitracin (Bacillus licheniformis and bacillus subtilis)
Polymyxin (Bacillus polymyxa)
Gramicidin (Bacillus brevis)

Question 9

What does Bacillus Anthracis cause and in which animals?

Answer 9

Fatal peracute or acute septicaemic antrax in cattle and sheep

Question 10

What does Bacillus larvae cause and in which species?

Answer 10

American foulbrood in bees

Question 11

What is an endospore?

Answer 11

Endospore is a resistant structure formed by Gram + bacteria (in dormant stage)

Question 12

What is the function of the endospore?

Answer 12

Ensure survival of bacterium through periods of environmental stress.

Question 13

What causes antrax?

Answer 13

Bacillus anthracis

Question 14

Virulent strain of Bacillus

Answer 14

Bac. anthracis.
Capsule composed of poly-D-glutamic acid and plasmid-encoded tripartite protein toxin

Question 15

The tripartite protein toxin in Bac. anthracis consists of?

Answer 15

3 antigen components:
Factor I - oedema
Factor II - protective and
Factor III - lethal

They act synergistically

Question 16

What forms of antrax is known in man? (3)

Answer 16

Cutaneus form
Pulmonary form
Gastrointestinal form

Question 17

Characterize Bacillus Cereus

Answer 17

Saprophyte
Facultative pathogen
Cause: septicaemia, meningitis, respiratory tract infections, myonecrosis and food poisoning.
TL toxin –> diarrheal syndrome (meat, milk products, cereals)
TS toxin –> emetic syndrome (cooked or boiled rice)

Question 18

Characterize Bacillus Thuringiensis

Answer 18

Pathogen of larvae - crop protection against harmful insects
Produce protein crystals (protoxin) - delta-endotoxin.
Used in commercial insecticides.

Question 19

Microscopical examination of Bacillus

Answer 19

Gram +
Motile (except Bac. Anthracis)
Large rods
Cells occur singly in pairs or long chains

Question 20

Bac. Anthracis and Bac. Cereus growth under aerophilic conditions

Answer 20

R form
Bac. anthracis - no capsule - weak virulence

Question 21

Bac. Anthracis under microaerophilic conditions

Answer 21

S form
Capsule
Fully virulent

Question 22

Cultivation properties of Bacillus

Answer 22

Aerobic or microaerophilic
37 degrees C (10-45C, 25-40C for pathogenic)
24-48 hours

Question 23

Bacillus on meat-peptone-broth

Answer 23

Sediment

Question 24

Bacillus on meat-peptone-agar (7)

Answer 24

R form
Large
Flat, dry
Greyish colonies
Curled outgrowths (Medusa’s head)

Question 25

Bacillus on blood agar

Answer 25

R form B. anthracis - no haemolysis B. cereus - b-hemolysis

Question 26

Special agar for Bacillus

Answer 26

Nutrient agar with 0.7% NaHCO3. In microaerophilic conditions bacillus anthracis grows in S/M form and produce a capsule

Question 27

Bacillus reaction for catalase and oxidase

Answer 27

Catalase +, oxidase -

Question 28

Lectinase activity of bacillus on egg yolk agar

Answer 28

Bac. anthracis - weak opaque zone Bac. cereus - strong

Question 29

Bacillus reaction on gelatine

Answer 29

Bac. anthracis - inverted Others - strong

Question 30

Serology of Bacillus (3)

Answer 30

Somatic O antigen Capsular K antigen Anthrax toxin - protective antigen

Question 31

Which special reaction is for Bac. anthracis?

Answer 31

Ascoli's thermoprecipitation reaction - antiserum against Bac. anthracis

Question 32

Special examination methods for Bacillus

Answer 32

Susceptibility to penicillin (Bac. anthracis is sensitive) Jensen-Kleenmayer's test (pearl test, Bac. anthracis on blood agar with PNC --> looses cell wall --> protoplast arranged in chains) DNA methods

Question 33

Characterize Bacillus Anthracis

Answer 33

Non-motile No haemolysis Sensitive to penicillin Weak and slow lectinase activity on egg yolk Lysis on gamma phage Causes death within 24-48 hours Capsule + Ascoli reaction + Pearl test +

Question 34

Characterize Bacillus Cereus

Answer 34

Motile Haemolysis Resistant to penicillin Strong and rapid lecithinase activity on egg yolk Lysis on gamma phage is rare No effect on animals Capsule - Ascoli - Pearl test -