Pulsed-field gel electrophoresis is more efficient than ribotyping and random amplified polymorphic DNA analysis in discrimination of Pasteurella haemolytica strains

One hundred thirty-three strains of Pasteurella haemolytica of both biotype s (90 and 43 strains of biotypes A and T, respectively) and almost all the serotypes were subjected to ribotyping, random amplified polymorphic DNA (R APD) analysis, and pulsed-field gel electrophoresis (PFGE) analysis for epi demiological purposes. A total of 15 patterns recorded as ribotypes HA to W O were found for the P. haemolytica biotype A strains, with ribotypes WA, H C, and HD being encountered most often (66 strains [74%]); and 20 ribotypes , designated HA' to HT', that were clearly distinct from those observed for biotype A strains were observed for strains of biotype T, RAPD analysis ge nerated a total of 44 (designated Rp1 to Rp44) and 15 (designated Rp1' to R p 15') unique RAPD patterns for biogroup A and biogroup T, respectively. An alysis of the data indicated that a given combined ribotype-RAPD pattern co uld be observed for biotype A strains of different serotypes, whatever the zoological or geographic origin, whereas this was not the case for biotype T strains. PFGE appeared to be more efficient in strain discrimination sinc e selected strains from various zoological or geographical origins harborin g the same ribotype-RAPD group were further separated into unique entities.