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

Abstract

Bacteriophage (phi Sb01) 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, HindIII, and PvuII. Bacteria which survived phi Sb01 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 phi Sb01 attack, and the observed differences in the growth characteristics of the parent strain and 2BAr indicated that cells of 2BAr were more adherent. In the rumen ecosystem, the selection of phage-resistant bacteria with altered growth characteristics may be a factor in modifying bacterial phenotypes, and thus increasing variability among bacteria which are closely related genetically.

Genetic homogeneity and phage susceptibility of ruminal strains of Streptococcus bovis isolated in Australia

“…The production of turbid colony‐centred plaques suggests they also lysogenized this host. By comparison phages 2BV and φSb01 are known to be lytic ( Iverson & Millis 1976a; Klieve & Bauchop 1991), but still only infected an additional one and two S. bovis strains, respectively. Unlike the other strains of Strep.…”

“…Phages used in the work were φSb01 ( Klieve & Bauchop 1991), 2BV ( Iverson & Millis 1976a) φSb02, φSb03 and φSb04. The latter three isolates were isolated in this study from samples of abattoir waste‐water run‐off from the kill floor of two abattoirs located in South‐east Queensland, and from the anaerobic settling pond of a third abattoir.…”

“…intermedius AR36 were used as potential host strains for phage isolation. The isolation procedure used was the same as used previously to isolate φSb01 ( Klieve & Bauchop 1991). Phage stocks were prepared from confluently lysed plates, stored at both 4 °C and –20 °C; and the titre determined as previously described ( Maniatis et al .…”

“…Host animal species and diet Location 1 Literature reference ( Klieve and Bauchop 1991). Phage stocks were prepared from confluently lysed plates, stored at both 4°C and -20°C; and the titre determined as previously described (Maniatis et al 1982;Klieve et al 1989;Klieve and Bauchop 1991).…”

The role of ciliate protozoa in the lysis of methanogenic archaea in rumen fluid

“…Substantial lysis of Methanobrevibacter MF1 occurred in cell-free rumen fluid and this lysis could be abolished by autoclaving. In view of the high number of bacteriophages in rumen fluid (Klieve and Swain 1993) and susceptibility of ruminal bacteria, including acetogens, to phage-induced lysis (Klieve and Bauchop 1991 ;Jiang et al 1995), it is tempting to suggest a role for phages in the lysis of archaea in rumen fluid.…”