[Lysogeny in Pasteurella multocida]

Studied was the possibility of lysis-producing factors (the phenomenon of lysogeny) with 59 strains of Pastuerella multocida isolated in Bulgaria, Cuba, and Czechoslovakia. It was found that eleven of them were lysogenic in terms that a total of 12 bacteriophage strains were isolated from them; one of them yielded 2 phages. Established were three different indicator strains of Pasteurella multocida-97, SHD, and R-II--by means of which 3 different groups of P. multocida phages were isolated. The latter were stabilized and allowed to multiply up to 10(11) phage particles per 1 cc through continuous passaging, and they could be be stored at + 4 degrees C. In accordance with the host strain for multiplying the isolated P. multocida phages were divided into three different groups: phages 3, 4, 5, 6, 22, and Sl fell into group II, and phages 1075 and S-2--to group III.