Phage resistance and altered growth habit in a strain of Streptococcus bovis

Summary

Bacteriophage (φSb01) of Streptococcus bovis, isolated from pooled rumen fluid of cattle, was a small siphovirus of morphotype B1. It contained double-stranded DNA of length 30.9 kb, which was digested by the restriction endonucleases, EcoRI, HinIII, and PvuII. Bacteria which survived φSb01 infection (strain 2BAr) grew in long chains (100–200 cells), ultimately forming large clumps of cells. This growth habit was in distinct contrast to that of the parent host strain which grew predominantly in the form of single cells or diplococci. Strain 2BAr was genetically stable, resistant to φSb01 attack, and the observed differences in the growth characteristics of the parent strain and 2BAr indicated that cells of 2BAr were more adherent.

Bacteriophage, Streptococcus bovis, Phage resistance