REP-PCR ANALYSIS OF PASTEURELLA-MULTOCIDA ISOLATES THAT CAUSE HEMORRHAGIC SEPTICEMIA

Amplification of multiple P multocida genomic DNA fragments by outward ly-directed primers based on the repetitive extragenic palindromic (RE P) consensus sequence, generated complex profiles in a PCR-based finge rprinting method known as REP-PCR. Polymorphisms within REP-PCR profil es were used to characterise 38 isolates of P multocida. The high degr ee of homogeneity observed among haemorrhagic septicaemia (HS) strains of serotype B and E provided evidence of a disease-associated REP pro file that may serve as a novel method for the identification of Hs str ains regardless of serotype. REP-PCR profiles of other P multocida ser otypes were highly variable, illustrating the potential of this techni que for the molecular fingerprinting of fowl cholera or atrophic rhini tis isolates. A specific amplified REP fragment was isolated and used to probe membrane-bound digested P multocida genomic DNA. Hybridisatio n patterns not only distinguished HS-causing isolates from non-HS P mu ltocida, but also demonstrated a degree of relatedness between HS and HS-like strains.