Serotypes of Pasteurella haemolytica and Pasteurella trehalosi isolated from farm animals in Hungary.

The biochemical and serological characteristics of 486 P. haemolytica and 31 P. trehalosi strains (517 in total) isolated from different lesions of cattle, sheep, goats, pigs and poultry were examined. A total of 476 P. haemolytica strains (97.9%) showed the characteristics typical of the former biotype A of P. haemolytica, while 10 isolates (2.1%), all from poultry, could not be biotyped. A total of 481 strains (93.0%) could be assigned to one of the 17 serotypes of P. haemolytica-P. trehalosi and 36 strains (7.0%) could not. The majority (83.6%) of the cattle isolates were serotypes A1 and A2. Among strains isolated from sheep all serotypes of P. haemolytica could be identified with the exception of A14, but serotypes A1, A2, A6, A8 and A5 were the most frequent. The overwhelming majority (94%) of the caprine isolates were A2, other serotypes occurred only sporadically. The pig isolates, which could be isolated only very rarely, represented different serotypes, while none of the 10 strains isolated from poultry could be biotyped or serotyped.