Numerical Taxonomy of Haemophilus and Related Bacteria

Abstract

A numerical taxonomic study of named strains of Haemophilus Winslow et al., A ctinobacillus Brumpt , and Pasteurella Trevisan was made using 134 characters covering a wide range of properties. The strains fell into four main clusters.Three of these represented Haemophilus. Cluster 1 contained strains requiring X factor and usually also V factor and corresponded t o H. influenzae (Lehmann and Neumann) Winslow et al. and closely allied organisms. Cluster 2 contained strains that required only V factor and corresponded t o H. parainfluenza Rivers and similar organisms. Cluster 3 contained strains with a requirement for a raised COz tension and contained H. aphrophilus Khairat and H. paraphrophilus Zinnemann. Cluster 4 contained strains of Actinobacillus and Pasteurella but not Yersinia van Loghem. The three genera Actinobacillus, Pasteurella, and Hae.mophilus have a close phenetic relationship and are facultative anaerobes that can acidify glucose fermentatively. They might best be separated from the other genera of the family Brucellaceae Breed et al. Winslow et al. 1917, which are similar in although of considerable medical importance, many ways to H. aphrophilus Khairat 1940. H. has received relatively little detai.led study, as agni Kennedy et al. 1958, which causes a shown by the paucity of comparative data in septicaemia of lambs, also appears t o resemble works such as the 7th edition of Bergey 's H. aphrophilus, and similar organisms have been Manual (7). Some species once included in the isolated from meningoencephalitis of cattle (25, genus have been segregated as a separate genus, 46). Bordetella; the remainder have been studied The genus HaemophilusHaemophilus pleuropneumoniae Shope 1963, mainly with respect t o rather few properties, a very pleomorphic, V-requiring organism causnotably growth requirements and hemolysis. ing pleuropneumonia of swine, is similar t o the The taxonomic structure within the genus, and strains of influenza bacilli from swine that its relation t o other genera, is uncertain, and we require V factor only (47), and thus it is therefore present this brief report in the hope probably similar t o H. parainfluenzae and to that it will stimulate further comparative work the recently described species H. paragallinarum on the group.

Inter- and Intrafamilial Similarities of rRNA Cistrons of the Pasteurellaceae

“…The genus Haemophilus also appears to be very heterogeneous. Sneath and collaborators (9,65) 49,1986) detected six DNA groups in this genus. The genus Haemophilus has been restricted to a DNA homology group with a degree of DNA binding of at least 58% D and contains Haemophilus influenzae, Haemophilus aegyptius, Haemophilus haemolyticus, Haemophilus parainfluenzae, and "Haemophilus interrnedius."…”

“…(ll), since members of these three unaffiliated genera exhibited complex genomic relationships. Previously, evidence that these organisms might constitute a family has been presented on the basis of a phenetic numerical analysis (65). All members of the family are parasites and often are pathogenic in mammals, including humans, birds, and reptiles.…”

Significance of V-Factor Dependency in the Taxonomy of Haemophilus Species and Related Organisms

“…In this way, A. pleuropneumoniae biotype 2 and also P. multocida, P. haemolytica, and P. ureae resemble H. haemoglobinophilus, suggesting in turn that these organisms possess similar pathways for the biosynthesis of NAD. Note, however, that while A. pleuropneumoniae biotype 2 and P. multocida can be shown to exhibit V-factor-dependent growth in that NAD can substitute for NAm (1,29), 40, 1990 MINIREVIEW 3 it appears, on the basis of apparently unpublished data, that this is not the case for H . haemoglobinophilus (23); on the other hand, we do not know whether NMN or NR can support the growth of the latter organism.…”

“…40,1990 MINIREVIEW 3 it appears, on the basis of apparently unpublished data, that this is not the case for H . haemoglobinophilus (23); on the other hand, we do not know whether NMN or NR can support the growth of the latter organism.…”

“…These three genera are closely related, with Pasteurella and Actinobacillus being particularly ditficult to differentiate (3,24,27,33,40,41); such difficulties have led to the suggestion that the genera Pasteurella and Actinobacillus should be combined to form one genus (40,41). On the other hand, organisms of the genus Haemophilus have been distinguished, traditionally, by their requirement for X factor or V factor or both (15).…”