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Francisella Tularensis

Francisella tularensis is a species of gram negative rods, which are non motile, non-spore forming aerobic bacteria, responsible for causing tularemia.

Portal of Entry
Humans are accidental “death-end” hosts, bitten by vectors or skin contact with wild animals. Rarely ingested in infected meat, producing gastrointestinal tularemia. Also are inhaled producing pneumonia
There is no person-to-person spread.


  • Form ulcers at the site of entry.
  • Survive in macrophages and are transported to reticuloendothelial system
  • Granulomas are formed, followed by necrosis and abscess formation.
  • Endotoxin is produced, but no exotoxin.

Virulence Factors
Lipopolysaccharide serves as endotoxin.

Predisposing Factors
•    Contact with wild animals
•    Bitten by vectors
•    Ingestion of infected meats
•    Immunocompromised persons
•    Cuts in skin

Clinical symptoms

Clinical symptoms depend upon the site of entry:

Handling infected animals

  • Slow growing ulcer at the point of contact
  • Swollen lymph nodes


  • Sudden development of headache
  • High fever
  • Chills
  • Body aches
  • Fatigue


  • Sore throat
  • Abdominal pain
  • Diarrhea
  • Vomiting
  • Eye infections
  • Ulcers
  • Pneumonia

Lab- Diagnosis

•    Gram negative rods
•    Non motile
•    Non- spore forming
•    Aerobic

Francisella tularensis
Francisella tularensis

Rarely done because of:-

  • High risk of transmission of infection to lab workers
  • Special cysteine- containing medium is required for growth is not easily available

Serological tests
•    Agglutination test with acute and convalescent phase serum sample.
•    Fluorescent –antibody staining
•    PCR

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