The banding profiles generated by Bam H1 restriction endonuclease cleavage of bacterial DNA from clinical and reference isolates of Histophilus ovls, Haemophilus somnus and related bacteria were compared. H. ovis, H. somnus and Haemophilus agni isolates were found to have distinct similarities in banding profiles characterised by 10 common bands between 2.0 and 9.6 kilobases (kb). The close taxonomic relationship of these isolates was reinforced by these findings. The reference isolates examined In this study -Actinobacillus lignieresii, Actinobaclllus semlnis, H. agni, H. somnus, H. ovis, Haemophilus influenzae, Haemophilus parainfluenzae, Haemophilus parahaemolyficuscould be distinguished from each other on the basis of their characteristic banding profiles.Aciinobacillus sp were obsewed to have more bands between 2 and 23 kb compared with the H. ovis and Haemophilus sp isolates studied.Analysis of isolates from an experimental infection trial illustrated the potential of restriction endonuclease analysis in molecular epidemiological applications. It was possible to demonstrate by this means that the post-challenge isolates had identical banding profiles to the challenge (or infecting) isolate which had a distinctly different banding profile from that of pre-challenge H. ovis isolates. Furthermore, restriction endonuclease analysis of H. ovis isolates obtained from follow-up investigations of a recurrent problem of epididymitis in unmated rams, indicated that the H. ovis isolates implicated in epididymitis, were present as a single strain in a number of sheep over a period of time. This suggested that the mechanism of transmission was by perinatal preputial contamination. Aust Vet J 6 3 389-393
Results
Barn HI Profiles of H. ovis and Closely Related BacteriaExamples o f the banding profiles obtained from Bam HI digests o f DNA from H. ovis (Australian) and H . somnus (North American) isolates are shown in Figure 1. The profiles o f the H . somnus isolates (lanes 2 and 3) are different from $ Seakem-LE Agarose, SUMMARY Wet chemical tests have deficiencies when applied to mixtures containing silica, which are common in the uroliths of some domestic animals. Consequently, the applicability of an infrared spectroscopic method was tested on 104 uroliths obtained from cattle, sheep, goats, horses, pigs, dogs, a chicken and a rabbit during diagnostic investigations. The following components were satisfactorily identified: silica, calcium oxalate, calcium carbonate, calcium phosphate, magnesium ammonium phosphate, magnesium phosphate and urates. The Infrared characteristics of these compounds and their mixtures are described. Aust Vet J 63: 393-396