Pasteurella Multocida

Pasteurella multocida is a gram negative coccobacillus, which is non-motile and pencillin sensitive, responsible for causing zoonotic infections.

Transmission:
Pasteurella are part of normal flora found in mouth of domestic cats and dogs. They are transmitted by biting.

Pathogenesis:

Pathogenesis is not fully understood. Capsule has anti phagocytic properties. Endotoxin is produced but there is no exotoxin.

Virulence factors:
•    Endotoxin – lipopolysacchide
•    Capsule

Predisposing factors:
•    Sutured animal bites
•    Immunocompromised patients

Clinical symptoms:

•    Rapidly spreading cellulitis at the site of animal bite
•    Local wound infection
•    Lymphadenitis
•    Sub acute to chronic infections of lower respiratory tract

Lab diagnosis:

Specimen:
•    Sample from wound site

Microscopy:
•    Gram negative rods
•    Short
•    Encapsulated
•    Bipolar staining

Serological test:
•    PCR

Treatment:

Penicillin G or ampicillin to prevent P. multocida infection when bitten.