Mannheimia haemolytica

Also known as: Pasteurella haemolytica — M. haemolytica

Introduction

Mannheimia haemolytica is a species of the Mannheimia genus. It is the cause of epizootic pneumonia in cattle known as Shipping Fever, Transit Fever or pneumonic pasteurellosis. 90% is caused by Mannheimia haemolytica Biotype A, serotype 1 but also Pasteurella multocida. It is usually secondary to viral infections such as parainfluenza - 3 or IBR, bacterial infections such as Mycoplasma or environmental stress.

M. haemolytica may contribute to Enzootic pneumonia of calves; Enzootic pneumonia of lambs and peritonitis in sheep. It also causes gangrenous mastitis in sheep.

M. haemolytica is beta-haemolytic on blood agar and grows weakly on MacConkey agar. It is odourless. All are Mannheimia A biotypes and the strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants. Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia.

Mannheimia haemolytica Learning Resources
Literature Search Search for recent publications via CAB Abstract (CABI log in required)	Mannheimia haemolytica publications since 2000

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