Comparison of DNA fingerprints and somatic serotypes of serogroup B and E Pasteurella multocida isolates.

The DNA fingerprint profiles and somatic serotypes of 71 Pasteurella multocida capsule serogroup B isolates, 13 capsule serogroup E isolates, and 16 somatic reference serotype strains were compared. Each of the 16 reference somatic serotypes had a unique DNA fingerprint profile with the HhaI restriction endonuclease. Fifty-four serogroup B isolates (isolated from classical cases of hemorrhagic septicemia) reacted with somatic serotype 2 or 5 antiserum and had DNA fingerprint profiles which resembled that of the serotype 2 reference strain. Seven DNA fingerprint profiles were found among 16 serogroup B strains representing other somatic serotypes. The DNA fingerprints of these isolates were different from the fingerprints of the 16 somatic reference serotype strains. All 13 serogroup E isolates had identical somatic serotypes and identical DNA fingerprint profiles when the HhaI endonuclease was used. The HhaI fingerprint profile of the serogroup E isolates did not match any fingerprint profile of the reference somatic serotype strains. Following DNA profiling with the HhaI endonuclease, the 13 serogroup E isolates were differentiated sequentially with HpaII restriction endonuclease. A descriptive identification epithet for P. multocida isolates was constructed. The descriptive epithet consists of serologic identification and sequential DNA profiles with restriction endonucleases HhaI and HpaII, respectively. DNA fingerprinting of P. multocida is a precise characterization method. In conjunction with serologic typing, it can further classify P. multocida isolates for epidemiologic studies.