BIOVARIANTS OF ISOLATES OF PASTEURELLA FROM DOMESTIC AND WILD RUMINANTS

A total of 608 bacterial isolates previously identified as Pasteurella haemolytica biotypes A and 3, P. trehalosi, and P. multocida, were se parated into 73 distinct biovariants using 21 phenotypic characteristi cs. The largest group (54%) of wildlife isolates was identified as bio group 2 and biogroup 2 variants. Biogroup 2 and biogroup 2 variants ac counted for only 17% of isolates from domestic ruminants and were all from sheep. In contrast, 43% of isolates from domestic ruminants were identified as biogroup 1 and biogroup 1 variants, whereas only 6% of i solates from wildlife were identified in these groups. The majority of biogroup 1 isolates from wild ruminants were from 1 group of bighorn sheep in Arizona that were geographically separated from other wildlif e sampled. Similarly, 1 biogroup 2 variant, 2(E), was cultured only fr om free-ranging Dall sheep in Alaska. Twelve percent of domestic isola tes and 6% of wildlife isolates were indole positive. The remaining is olates from wildlife (33%) and domestic animals (30%) were distributed among 53 distinct biovariants. None of these individual biovariants r epresented >4% of the total isolates. Phenotypic characterization was valuable for distinguishing between isolates from different hosts and from different geographic areas and can be used to assist in epidemiol ogic studies.