Bacillus anthracis or Bacillus cerus

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Bacillus anthracis or Bacillus cerus

• Submitted by-

• Submitted to-

• Rekha Panwar

• Prof S.S.soni

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Scientific classification

• Kingdom Bacteria
• Division Firmicutes
• Class Bacilli
• Order Bacillales
• Family Bacillaceae
• Genus Bacillus Cohn 1872

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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

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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
• GC content ranges from 32 to 69. 
• Thermophilic (lt 75C) and psychrophilic (gt5-8C)

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STRUCTURE
Surface of Bacillus
Surface of a Bacillus. Transmission
E.M. CCapsule SS-layer PPeptidoglycan.
Pasteur Institute
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(blue)
(red)
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Diseases Associated with Bacillus
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Bacillus anthracis
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General Characteristics

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

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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.

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Mucoid colonies of B. anthracis.
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Culture
SELECTIVE MEDIA PLET MEDIUM POLYMYXIN,
LYSOZYME, EDTA THALLOUS ACETATE
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Culture

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

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Gelatin liquefaction
Maximum liquefaction on the surface than at the
bottom
INVERTED FIR TREE APPEARANCE
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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 Pharaohs cattle. Boils are symptomatic of
  anthrax.
• 1600s - The Black Bane thought to be anthrax,
  in Europe kills over 60,000 cattle.

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History (1800s)
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History (1900s)
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History (Recent years)
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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 lt 6.0)
• Dramatic changes in climate

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SUSCEPTIBILITY

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

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Anthrax Infection Spread

• 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

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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

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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.

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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

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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/t
eksti/biolosko_orozje.htm
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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
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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
• PALF ? lethal activity
• EFPA ? edema
• EFLF ? inactive
• PALFEF ? edema necrosis lethal

http//www.rcsb.org/pdb/molecules/pdb28_1.html
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MECHANISM OF INFECTION
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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 gt than ten thousendfold on macrophage cell
• ATR/TEM8 gene
• Chromosome 4

gib.genes.nig.ac.jp/single/ main.php?spidBant_AME

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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

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Gram Stain Analysis
Bacillus anthracis in Gram stain
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McFadyean's reaction
Blood from ear vein
prepare smear

• polychrome methylene blue

capsule pink cell blue
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Ascolis test
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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

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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.

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Recent research
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 Anthrax". Journal of
Bacteriology. 

•  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.

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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

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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.

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SYNDROME

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

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PREVENTION
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