Genetic and antigenic studies on Haemophilus parasuis

Haemophilus parasuis, an organism dependent upon nicotinamide adenine dinucleotide (NAD) or V-factor for in-vitro growth, is the causative agent of porcine polyserositis and arthritis (Glasser's disease) (Nicolet, 1992). The principal lesions associated with this disease are fibrinous or serofibrinous meningitis, serositis, pleuritis, pericarditis, peritonitis and arthritis that can occur in various combinations or occasionally singly (Nicolet, 1992)

Serological characterisation of Haemophilus parasuis isolates from Australian pigs

A total of 31 isolates of Haemophilus parasuis obtained from Australian pigs were serotyped by the Kielstein-rapp-gabrielson scheme. The isolates were assigned to serovar 1 (1 isolate), serovar 2 (1 isolate), serovar 4 (4 isolates), serovar 5 (7 isolates), serovar 9 (2 isolates), serovar 10/7 (4 isolates), serovar 12 (1 isolate) and serovar 13 (6 isolates). The remaining 5 isolates could not be assigned to a serovar. Two different serovars (5 and 13) were detected in one herd. The only 2 isolates obtained from clinically normal pigs (from the same herd) were serovar 9. The common serovars were isolated from pigs with pneumonia as well as from pigs with conditions of the Glasser's disease type. The serological heterogeneity amongst Australian isolates of H parasuits has important implications for the use of vaccines to control Glasser's disease