Gram-positive or Gram-variable bacilli Sporulating Aerobic or facultatively anaerobic Catalase positive (most) Capsulated Motile by peritrichous flagella Most bacilli are saprophytes G+C content ranges from 32 to 69%.  Thermophilic (< 75°C) and psychrophilic (>5-8°C)

1. Bacillus anthracis or
Bacillus cerus
Submitted by-
• Rekha Panwar
Submitted to-
• Prof S.S.soni

2. Scientific classification
Kingdom : Bacteria
Division : Firmicutes
Class : Bacilli
Order : Bacillales
Family : Bacillaceae
Genus : Bacillus
Cohn 1872
–

3. Species
– B. cereus
– B. subtilis
– B. polymyxa
– B. sphaericus
– B. anthracis
– B. coagulans
– B. circulans
– B. mycoides
– B. pumilus
– B. macerans
– B. licheniformis
– B. piliformis

4. General Characteristics of Bacillus
• Gram-positive or Gram-variable
bacilli
• Sporulating
• Aerobic or facultatively anaerobic
• Catalase positive (most)
• Capsulated
• Motile by peritrichous flagella
• Most bacilli are saprophytes
• G+C content ranges from 32 to
69%.
• Thermophilic (< 75°C) and
psychrophilic (>5-8°C)

5. STRUCTURE
Surface of Bacillus:
Surface of a Bacillus. Transmission E.M. C=Capsule; S=S-
layer; P=Peptidoglycan. Pasteur Institute

6. (blue)
(red)

7. Diseases Associated with Bacillus

8. Bacillus anthracis

9. General Characteristics
• G+ rods with square cut ends
• Facultative anaerobe
• Thiamin growth requirement
• Glutamyl-polypeptide capsule
• Nonmotile
• Forms oval, centrally located endospores

10. Cultural characteristics
• Can not grow on MCA.
• Mucoid colony on bicarbonate agar incubated
overnight under CO₂.
• Inverted fur appearance on gelatin agar.
• White colony on PLET agar
• Lysis by gamma phage.

11. Mucoid colonies of B. anthracis.

12. SELECTIVE MEDIA –
PLET MEDIUM –POLYMYXIN, LYSOZYME, EDTA & THALLOUS ACETATE
Culture

13. Culture
• Other non-selective
media
• Nutrient agar – colonies
– medusa head
appearance on low
power microscopy
• Blood agar – usually
non-haemolytic

14. Gelatin liquefaction
Maximum liquefaction on the
surface than at the bottom
INVERTED FIR TREE APPEARANCE

15. History of Anthrax (Early history)
• Although anthrax dates back more than 3,000 years, it
was not recognized as a disease until the 18th century.
• 1500 B.C - A “plague of boils” in Egypt affected the
Pharaoh’s cattle. ‘Boils’ are symptomatic of anthrax.
• 1600s - The “Black Bane” thought to be anthrax, in
Europe kills over 60,000 cattle.

16. History (1800s)

17. History (1900s)

18. History (Recent years)

19. Anthrax
• From the Greek word anthrakos for coal
• Caused by spores
• Primarily a disease of domesticated & wild animals
– Herbivores such as sheep, cows, horses, goats
• Natural reservoir is soil
– Does not depend on an animal reservoir making it hard to eradicate
– Cannot be regularly cultivated from soils where there is an absence of
endemic anthrax
– Occurs sporadically throughout US
• Anthrax zones
– Soil rich in organic matter (pH < 6.0)
– Dramatic changes in climate

20. SUSCEPTIBILITY
• All mammals apear to be susceptible to
anthrax,ruminants such as cattle ,sheep and
goat are most susceptible,followed by horse
and swine.

21. Ant hrax Inf ecti on &Sp read
• May be spread by streams, insects, wild
animals, birds, contaminated wastes
• Animals infected by soilborne spores in food
& water or bites from certain insects
• Humans can be infected when in contact
with flesh, bones, hides, hair, & excrement
– nonindustrial or industrial
– cutaneous & inhalational most common

23. Clinical Signs
• Many species affected
– Ruminants at greatest risk
• Three forms
– Peracute
– Ruminants (cattle, sheep, goats, antelope)
– Acute
– Ruminants and equine
– Subacute-chronic
– Swine, dogs, cats

24. SYMPTOMS IN ANIMALS
• Sings are fever upto 107 F,muscle tremors,
respiratory distress and convulsion.Death
occurs quickly and often before symptoms are
observed.
• Animals that die of anthrax bloat
quickly.Blood may come from the nose and
other body openings.

25. Three forms of Anthrax in humans
• Cutaneous anthrax
– Skin
– Most common
– Spores enter to skin through small lesions
• Inhalation anthrax
– Spores are inhaled
• Gastrointestinal (GI) anthrax
– Spores are ingested
– Oral-pharyngeal and abdominal

27. Pathogenesis
• The infectious dose of B.
anthracis in humans by any
route is not precisely known.
– Rely on primate data
– Minimum infection dose of ~
1,000-8,000 spores
– LD50 of 8,000-10,000 spores
for inhalation
• Virulence depends on 2 factors
– Capsule
– 3 toxins http://www.kvarkadabra.net/index.html?/biologija/teksti/biolosko_orozje.htm

28. Capsule
• Glycocalyx
– Sticky, gelatinous polymer external
to cell wall
• pX02 plasmid
• Made up of D-glutamic acid
• Non-toxic on its own
• Only encapsulated B. anthracis virulent
• Most important role during
establishment of disease
– Protects against phagocytosis &
lysis during vegetative state
http://textbookofbacteriology.net/BSRP.html

29. Toxins
• pX01 plasmid
• AB model
– Binding
– Activating
• Protective antigen (PA), edema
factor (EF) & lethal factor (LF)
– Make up 50% of proteins in
the organism
• Individually non-toxic
– PA+LF  lethal activity
– EF+PA  edema
– EF+LF  inactive
– PA+LF+EF  edema &
necrosis; lethal
http://www.rcsb.org/pdb/molecules/pdb28
_1.html

30. MECHANISM OF INFECTION

31. Genetics
• 1 chromosome
– 5.2 million bp
– Ames strain sequenced
• 2 plasmids
– px01
– 184 kbp
– Pathogenicity island
– pX02
– 95.3 kbp
– Capsule
• Anthrax receptor
– Occurs > than ten thousendfold on
macrophage cell
– ATR/TEM8 gene
– Chromosome 4 gib.genes.nig.ac.jp/single/ main.php?spid=Ban

32. Diagnosis
• Gram stain
• Culture of B. anthracis from the blood, skin lesions, vesicular fluid, or respiratory
secretions
• X-ray and Computed Tomography (CT) scan
• Rapid detection methods
- PCR for detection of nucleic acid
- ELISA assay for antigen detection
- Other immunohistochemical and immunoflourescence
examinations
- These are available only at certain labs

34. Gram Stain Analysis
Bacillus anthracis in Gram stain

35. McFadyean's reaction
Blood from ear vein
prepare smear
polychrome methylene blue
capsule pink
cell blue

36. Ascoli’s test

37. Vaccination
• Livestock in endemic areas
• Sterne strain
– Live encapsulated spore vaccine
• No U.S. vaccine for pets
– Used in other countries
– Adjuvant may cause reactions
• Working dogs may be at risk

38. TREATMENT
Many antibiotics are effective against
anthrax in humans, but treatment
must be started early.
Ciprofloxacin is recommended for
treatment; penicillin G, along with
gentamicin or streptomycin, has
previously been used to treat anthrax.

39. Recent research
• The Ames ancestor chromosome was sequenced in
2003 and contributes to the identification of genes involved
in the virulence of B. anthracis
• . Recently, B. anthracis isolate H9401 was isolated from a
Korean patient suffering from gastrointestinal anthrax. The
goal of the Republic of Korea is to use this strain as a
challenge strain to develop a recombinant vaccine against
anthrax.
Chun, J.-H.; Hong, K.-J.; Cha, S. H.; Cho, M.-H.; Lee, K. J.; Jeong, D. H.; Yoo, C.-K.; Rhie, G.-e. (18
July 2012).
"Complete Genome Sequence of Bacillus anthracis H9401, an Isolate from a Korean Patient with A
. Journal of Bacteriology.

42. Bacillus cerus
• The word Bacillus means ‘Small rod’ and
cereus means ‘Wax- like’.
• It is derived from Latin language.
• The name itself reflects the morphology of
B.cereus

45. TOXINS
• B.cereus produces one type of emetic toxin and three types of
enterotoxin.
• Three pore forming enterotoxin responsible for diarrhoeal
syndrome are 1. Hemolysin bl (Hbl)
• 2. Non – Hemolytic enterotoxin (Nhe)
• 3. Cytotoxin K (cyt K)
• Hbl consists three different protein components L1, L2, B.

46. SYNDROME
• B.cereus is an opportunistic pathogen cause
infections like
• 1. Diarrhoeal syndrome
• 2. Emetic syndrome
• Transmission is predominantly foodborne for
both.

48. PREVENTION