title: Variation in cultural, morphological, biochemical properties and infectivity of Australian isolates of Dermatophilus congolensis.
abstract: Recent vaccination studies with Dermatophilus congolensis showed that variation of challenge strains had a considerable influence on protection afforded by the vaccines. In this study cultural, morphological and biochemical properties of 30 D. congolensis isolates from throughout Australian were investigated. The infective dose required to produce lesions of equivalent severity by these isolates for sheep, rabbits and guinea pigs was also examined and the isolates were grouped into four clusters of similar infectivity ranking. Analysis of the relationship between cultural, morphological and biochemical characteristics and infectivity rankings of clusters was undertaken to determine if certain properties were linked to infectivity. Considerable variability was found in haemolytic activity on blood agar, mucoid nature of colonies, motility, flagella density and polarity, capsule width, restriction enzyme profiles of bacterial DNA, protein electropherotype, carbohydrate content, and enzymic activity against proteins, maltose, chondroitin-4-sulphate, phospholipids and lipids. Of these properties haemolytic activity and enzyme activity against casein, chondroitin-4-sulphate and lipids showed some link with infectivity ranking for these isolates.
authors.affiliation: Animal Health Laboratories, Department of Agriculture, Baron-Hay Court, South Perth, Australia.
authors.forename: T M
authors.initials: TM
authors.lastname: Ellis
authors.forename: A M
authors.initials: AM
authors.lastname: Masters
authors.forename: S S
authors.initials: SS
authors.lastname: Sutherland
authors.forename: J M
authors.initials: JM
authors.lastname: Carson
authors.forename: A R
authors.initials: AR
authors.lastname: Gregory
mesh_terms: D000192:Actinomycetales / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D000193:Actinomycetales Infections / Q000382:microbiology / Q000662:veterinary*; D000818:Animals; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D004798:Enzymes / Q000096:biosynthesis; D006168:Guinea Pigs; D006461:Hemolysis; D006868:Hydrolysis; D008297:Male; D008854:Microscopy, Electron; D011817:Rabbits; D015183:Restriction Mapping; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004798:Enzymes