Genetic Basis of Streptococcin A-FF22 Production

Abstract

Spontaneous, low-frequency loss of ability to produce streptococcin A-FF22 (SA) by group A streptococcus strain FF22 was observed. The proportion of non-SA-producing (SA − ) derivatives occurring in strain FF22 cultures grown in Todd Hewitt broth supplemented with 1% of yeast extract (THBY) was increased on treatment with ethidium bromide, acriflavin, or rifampin. The highest incidence of SA − organisms, however, was found in untreated THBY cultures that had been aging by incubation at 37°C for several months. The possibility of selective effects in these experiments, operating to enhance the apparent frequency of SA − bacteria, was discounted. The survival of SA − derivatives in association with populations of SA + bacteria was dependent upon the use of culture conditions inimical to SA activity, since a consistent finding was that the loss of ability to produce SA was associated with loss of immunity to the killing action of this bacteriocin. Whereas selective killing of SA − derivatives was evident in mixed cultures of SA + and SA − strains in tryptic soy broth, no such effect was demonstrable in THBY. In these experiments, elimination of SA − cells seemed directly related to the presence of active SA. Purified clones of SA − substrains did not seem revertible to SA production, either spontaneously or on treatment with nitrosoguanidine. It is suggested that the property of production of SA by group A streptococcus strain FF22, together with that of host cell immunity to the homologous bacteriocin, may be mediated by plasmid-borne genetic determinants.

Production of a bacteriocine-like substance by group-A streptococci of M-type 4 and T-pattern 4

“…Immunity breakdown in bacteria exposed to high concentrations of homologous bacteriocine is commonly observed in grampositive species including streptococci (Tagg et al, 1973b;Tagg, Dajani and Wannamaker, 1975). However, inhibitor-negative derivatives of the M4T4 strains were more sensitive to the specific inhibitor than the parent strain; this suggests a possible plasmid-type linkage between the genes for production and those for immunity similar to that reported for streptococcin A-FF22 (Tagg and Wannamaker, 1976). Sherwood et al (1954), Diebel(l963) and Liu et al (1963) have shown that production of streptococcal proteinase is favoured under anaerobic conditions.…”

Elucidation of the structure of SA‐FF22, a lanthionine‐containing antibacterial peptide produced by Streptococcus pyogenes strain FF22

“…Further studies showed that the genetic determinant(s) that controlled SA-FF22 production appeared to be lost spontaneously in aged cultures or through the use of plasmid 'curing' agents, suggesting that SA-FF22 production was encoded on a plasmid. Addition-ally, non-producing derivatives were more sensitive to SA-FF22 than the parent strain and SA-FF22 could be transduced to non-SA-FF22-producing or cured strains of S. pyogenes [4]. These latter results established a specific genetic basis for the production of the agent and suggested that a specific self-protection or 'immunity' phenomenon may be associated with SA-FF22 production.…”

Salivaricin E and abundant dextranase activity may contribute to the anti-cariogenic potential of the probiotic candidate Streptococcus salivarius JH

“…The nine standard indicator bacteria (I1-I9) used for BLIS P-typing have been described previously (Tagg & Bannister, 1979). S. pyogenes strain EB1 (Tagg & Wannamaker, 1976) is a bacteriocin-negative derivative of S. pyogenes strain FF22 (standard indicator I2) (Tagg & Wannamaker, 1976). The EPS-producing S. mutans strain MT703 was used in the in vitro biofilm model.…”