SEROTYPING AND ENZYME CHARACTERIZATION OF PASTEURELLA-HAEMOLYTICA ANDPASTEURELLA-MULTOCIDA ISOLATES RECOVERED FROM PNEUMONIC LUNGS OF STRESSED FEEDER CALVES

Ninety-one isolates of Pasteurella multocida (Pm) and 124 of Pasteurel la haemolytica (Ph) were recovered from the lungs of calves that died of bovine respiratory tract disease (BRTD). Nine Pm enzyme profiles (A through I) and 9 Ph enzyme profiles (J through R) were determined for the Pasteurella isolates. The Pm isolates were relatively evenly divi ded among the enzyme profiles, with one exception, profile I. The Ph i solates were not evenly distributed among the profiles, Fifty of the 9 1 Pm isolates were serotyped. Forty-two Pm isolates were positive for capsule type A, and 8 were untypable, Five somatic type antigen profil es (3; 3,4; 3,7; 3,4,7; and 4) were identified among the 50 serotyped Pm isolates; one isolate was untypable. The Ph isolates were further d ivided through serotyping and grouped as follows: 74 (60%) Pasteurella haemolytica A1 (PhA1), 12 (10%) PhA2, 4 (3%) PkAS, and 34 (27%) PhA6. Eighty-one percent of the Ph serotypes were clustered in the M and N enzyme profile. The P enzyme profile was almost unique to PhA2 (8 of 1 2, 67% of PhA2 isolates), Results of this study indicate a need to col lect more data on Ph serotypes at the state veterinary diagnostic labo ratories.