Probable Identity of a Group D Hemolysin With a Bacteriocine

Abstract

Bloomington) AND JOSEPH M. DAVIE. Probable identity of a group D hemolysin with a bacteriocine. J. Bacteriol. 86:708-712. 1963.-All strains of Streptococcus zymogenes (S. faecalis var. zymogenes) produce a bacteriocine which is active against lactic acid bacteria and most other grampositive bacteria. Mutants which have lost the hemolytic characteristic lose at the same time their bacteriocine-producing ability. A strain which was resistant to the bacteriocine but which was nonhemolytic and nonbacteriocinogenic was irradiated, and two hemolytic mutants were isolated from it. These mutants were also bacteriocinogenic. Thus, the two activities are gained or lost together by mutation. Both activities are destroyed by chloroform vapors and are antagonized by lecithin. Both activities are destroyed at the same rate by treatment at 45 C under mildly acid conditions, and both activities are stable when heated in agar. The two activities are produced in parallel during the growth cycle, and disappear in parallel. The possible ecological role of a substance which is both a hemolysin and a bacteriocine is discussed.

The Enterococcus faecalis cytolysin: a novel toxin active against eukaryotic and prokaryotic cells

“…The authors further speculated that the bacteriocin and haemolysin produced by haemolytic E. faecalis were the same entity . The first evidence linking these two activities to a common physical entity was provided by Brock and Davie (1963), who showed that, after exposure to UV irradiation, the haemolysin and bacteriocin activities were simultaneously lost, and simultaneously regained by reversion. Granato and Jackson (1969) forwarded the first evidence that the cytolysin consists of multiple components.…”

“…In this study, patients infected with cytolytic, gentamicin/kanamycin-resistant strains were at a fivefold increased risk of acutely terminal outcome regardless of the treatment regimen (of patients dying within 3 weeks of culture, 71% were infected with a cytolytic strain; Huycke et al ., 1991). Brock and Davie (1963) first suggested that the bacteriocin activity of the cytolysin might play a significant role in the virulence of enterococci by providing a competitive advantage to cytolytic strains over non-cytolytic strains, or other Gram-positive bacteria in the gastrointestinal tract, the likely staging ground for infection of distant anatomical sites (Hancock and Gilmore, 2000). They observed that cytolytic strains were able to outgrow non-cytolytic strains in vitro, even when the non-cytolytic strain was initially 100-fold higher in concentration (Brock and Davie, 1963).…”

“…Brock and Davie (1963) first suggested that the bacteriocin activity of the cytolysin might play a significant role in the virulence of enterococci by providing a competitive advantage to cytolytic strains over non-cytolytic strains, or other Gram-positive bacteria in the gastrointestinal tract, the likely staging ground for infection of distant anatomical sites (Hancock and Gilmore, 2000). They observed that cytolytic strains were able to outgrow non-cytolytic strains in vitro, even when the non-cytolytic strain was initially 100-fold higher in concentration (Brock and Davie, 1963). To test this hypothesis in vivo , fed a 1:1 mixture of cytolytic and non-cytolytic strains of E. faecalis to mice pretreated with spectinomycin and streptomycin to destabilize commensal flora, and enumerated bacteria in stool samples after 1 or 7 days.…”

Streptococcal and enterococcal inhibition of endocervical lactobacilli

“…In several studies, enterococci have been reported to comprise a substantial component of the vaginal microbiota, particularly at the time of menses [16][17][18]. Pohunek [19] demonstrated that some streptococcal and (in particular) enterococcal strains were inhibitory to vaginal lactobacilli in vitro.…”

Genetic and physical studies of Streptococcus faecalis hemolysin plasmids

“…Streptococcus faecalis species are divided into subspecies on the basis of gelatinase production (S. faecalis subsp, liquefaciens) and hemolytic activity (S. faecalis subsp, zymogenes). The hemolytic activity (Hly) has been reported to be linked to bacteriocin production (Bcn) [1][2][3], to be transferred by conjugation at a high frequency into nonhemolytic and non-bacteriocinogenic strains of S. faecalis and to be coded for by plasmids with Mrs of 34. 10 6 to 38.…”