of B. salmonicida from the heart blood of a fish that had died from 

 furunculosis, indicating that the phage may occur in the blood stream. 

 Besides occurring in various organs, phage was present on grovrbhs 

 from lesions. Plaques were evident as soon as grovrth was visible before 

 the characteristic brovm pigment developed. 



The occurrence of phage in primary cultures from fish dying from 

 furunculosis could not be vrell correlated with any particular phase of 

 an epizootic. Thus, in the case of a single furunculous fish talcen in 

 spring from a Scottish river, an exceedingly active phage was observed 

 in the primary cultures of B. salm.onicida ; there had been no previous 

 cases reported from this river in that year, and none occurred for some 

 time afterwards. ^iVhen phage was regularly observed to occur in primary 

 cultures during the course of an epizootic, it appeared frequently in 

 those made from fish in which the course of the infection had been 

 unusually rapid and severe. Thus, in one case, a fish appeared to be in 

 good condition as regards external appearances, but the viscera were so 

 liquefied that the individual organs could hardly be distinguished. 



Specificity 



The spscificiiy of B. salmonicida phage T/as first studied by 

 Blake (FuxTinculosis Committee 1935), who tested it on strains of 

 Escherichia coli, Shigella dysenteriae, water Vibrios , Pseudomonas 

 fluorescens, and several strains of Acltromobacter . It was found to be 

 active towards E. coli and S. dy senteriae though less markedly than 

 towards B. salmonicida , 



Christison and associates (1938) tested the phage against a 

 large number of organisms and they all vrere, Tdth one exception, 

 unaffected by the phage. This exception, a Gram-negative bacillus, was 

 very susceptible to phage action. Indole vras produced by this organism, 

 nitrates were not reduced, and no pigment was fonned. 



B. 5a.lmonic ida phage was tested against the follov/ing organisms 

 and in no case v/as any evidence of phage action obtained: Micrococcus 

 pyogenes var. aureus (two strains), S. coli (eleven strains), S. 

 .cfersen teriae Shiga, Y and Sonne, Alca li gene s fae calls, Pi-oteus morganii. 

 Vibri o comma. Salm onella typhosa, S. par atyphi, S. suipes tifer, S. 

 typhimurium, S. enteritidis, S, pullorum, Pseud om onas aer uginosa , 

 Serrati a marcescens, and P. f luoresc ens. Besides these, sevent2/-one 

 organisms isolated from water or from fish were unaffected by the phage 

 (with one exception, given above). None of the prevalent bacteria in 

 sewage were found to le carrj'-ing B. salmonicida phage. 



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