title: Culture media for the differentiation of isolates of Yersinia ruckeri, based on detection of a virulence factor.
abstract: Strains of the bacterial fish pathogen Yersinia ruckeri were identified with the API 20E system and distinguished on the basis of whole cell agglutination with antisera, sorbitol fermentation and polymyxin B sensitivity. Strains which were shown to possess the virulence-associated heat-sensitive factor (HSF) were shown to grow preferentially on culture media containing sodium dodecyl sulphate (SDS) and to produce a creamy deposit around the colonies. By contrast, strains lacking this factor (HSF-) grew poorly and without forming a deposit. Enhancement of the differentiation between the two types was shown by the incorporation of Coomassie brilliant blue dye into agar containing 1% SDS, and the uptake of Coomassie blue and Congo red was shown to be temperature-dependent. Most strains tested were shown to belong to serotype I, and were sensitive to polymyxin and did not ferment sorbitol. With the medium developed most serotype I strains but not those of other serotypes were shown to possess HSF. It is suggested that the medium is used in epidemiological studies of Y. ruckeri.
authors: Department of Biological Sciences, University of Plymouth, UK.
authors: M D
authors: MD
authors: Furones
authors: M L
authors: ML
authors: Gilpin
authors: C B
authors: CB
authors: Munn
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques; D004396:Coloring Agents; D003470:Culture Media; D005393:Fish Diseases / Q000382:microbiology; D005399:Fishes / Q000382:microbiology; D006358:Hot Temperature; D013045:Species Specificity; D014774:Virulence; D015007:Yersinia / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity
chemical_list: D004396:Coloring Agents; D003470:Culture Media