A Numerical Taxonomic Study of Actinobacillus, Pasterella and Yersinia

1 Department of Microbiology, Leicester University, Leicester LE1 7RH, UK 2 Public Health Laboratory, Leicester Royal Infirmary, Leicester LE1 5WW, UK ABSTRACT Summary: A numerical taxonomic study of strains of Actinobacillus, Pasteurella and Yersinia , with some allied bacteria, showed 23 reasonably distinct groups. These fell into three major areas. Area A contained species of Actinobacillus and Pasteurella: A. suis, A. equuli, A. lignieresii, P. haemolytica biovar A. P. haemolytica biovar T, P. multocida, A. actinomycetemcomitans, P. bettii. "A. seminis". P. ureae and P. aerogenes. Also included in A was a composite group of Pasteurella pneumotropica and P. gallinarum , together with unnamed groups referred to as "BLG", "Mair". "Ross" and "aer-2". Area B contained species of Yersinia: Y. enterocolitica, Y. pseudotuberculosis. Y. restis and a group "ent-b" similar to Y. enterocolitica. Area C contained non-fermenting strains: Y. philomiragia, Moraxella anatipestifer and a miscellaneous group "past-b". There were also a small number of unnamed single strains.