A SELECTIVE MEDIUM FOR THE ISOLATION OF BRUCELLAE FROM CONTAMINATED MATERIALS1
Journal of Bacteriology
65 65 65 0 0 16 16 16 0 0 20 20 20 0 0 100 95 100 40 50 40 22 15 0 0 The investigation of the properties of bacterial viruses associated with Bacillus megaterium in(licated that some of these properties were not coincident with the serological and morphological girouping (Friedman and Cowles, J. Bact., 66, 379, 1953). It was of interest to determine the response of these viruses to mono-and div-alent ions in order to examine further the relationship between the serology and morphology of these
... orphology of these viruses. All mateiials and methods are identical with those described in a previous paper (Friedman and Cowles, J. Bact., 66, 379, 1953). The inactivations were carried out at 37 C. W;\hen it was necessary to suspen(1 the phages in a medium containing two salts, the salts were added prior to the addition of the viius. Fromi the results in table 1, it appears that all the phages except M4 are inactivated rapidly in the presence of the 0.1 M monovalent ions, Na+ and K+ having similar potencies. MI, M2, anll M3 are protecte(l completely by the addi-tioIn of any one of the dlivalent ions testecl, wlhile M\4 anid M5 are protected only partially. The inactivations wer e apparently of a permanent nature since after the inaetivation had occurred, no active virus could be recovered either by the addition of biroth or of var ious concentrations of divalent ioIns to the inactivrated vir'us solutions. The data in table 2 sh1ow that there is a critical eoncentration of NaCl which completely inaetivates Ml, M2, M3, and M5. For MI, M2, and M3 the critical coneentration for salt inactivation is between 5 X 10-2 M and 10-1 M, while M5 appears to be inactivated at a concentration of 5 X 10-l M as well. M4 is but partially inactivated at those concentrations of NaCl which completely destroy the infectivity of the other phages. It is of initerest to note that the inactivation of the viruses by 0. I M NaCI1 seems to follow the moiphological classification (MI, M2, M3, M5), while complete plrotection against monovalent ioIn inactivation by di(valent ions appears to follow only the ser ological gr oupinlg (MI, M2, andl M13).