The Open Veterinary Science Journal

2007, 1 : 7-10
Published online 2007 October 30. DOI: 10.2174/1874318807001010007
Publisher ID: TOVSJ-1-7

Antibody Response to Mannheimia Haemolytica Leukotoxin in Cattle with Respiratory Tract Disease

S. Cavirani , S. Taddei , C.S. Cabassi , F. Ghidini , C. Piancastelli and C.F. Flammini
Department of Animal Health, University of Parma, Via del Taglio 8, 43100 Parma, Italy.

ABSTRACT

In order to obtain data concerning the involvement of Mannheimia haemolytica in bovine respiratory disease (BRD) outbreaks, a serological survey was carried out on paired (acute- convalescent) sera from 1310 beef and 810 dairy cattle collected in 262 BRD outbreaks in Italian herds during 2002-2006. No vaccination program to M. haemolytica A1 was applied in the investigated herds. For each outbreak, 5 to 12 animals were considered for serum sampling. An enzyme linked immunosorbent assay (ELISA) was used to determine serum antibody response to M. haemolytica leukotoxin (LKT). Seroconversion involved 467 animals (22%), 314 beef cattle (24%) and 153 dairy cattle (19%), respectively. On a serological basis, M. haemolytica involvement was detected in 162 (62%) BRD outbreaks. Prevalence of seroconversion ranged from 20% to 60%. Concurrent seroconversion to M. haemolytica and the main bovine respiratory viruses was recorded in 141 (54%) outbreaks. Seroconversion to M. haemolytica LKT involved mainly cattle not vaccinated to BRD viral agents.

Keywords:

Bovine, Mannheimia haemolytica, leukotoxin.