RAPİD tnENTİFİcATtON OF BACtLLUS ANTHRACtS AND THE STRAİNS OF BRUCELLA BY MtCROSCOptCAL OBSERVA TiON OF BACTERtOPHAGE LYStS.

BaciııııS anthracis maybe distinguished from the closely rclated B. cereus by its susceptibility to a specific bacteriophage (Mc cloy, 1951)' The usual tecnique for testing a suspected strain with phage eonsists in spotting the undiluted phage on a bacterial lawn on agar, and observing for Iysis after ineubation overnight(McCloy, 1951, Brown and Cherry, 1955). It seemed that identification could be accelerated by applying the phage to the bactcrja at an earlier stage of their growth and obscrving Iysis microscopicaııy. The cxperiments reported by (P. Chadwick, 1959) Confirmed this prediction. When young growing filaments or microcolonics of Bacillus anthraeis were treated with spesific bacteriophage, fragmentation of the filaments foııowcd by complete disintegration of the microlony were visible microscopicaııy within 2-3 hr. Other Baciııus spesies wcre unaffected by the phage, This techniquc is a simple one for accclcrating the identification of Baciııus anthracis.