Effert Of Lactoperoxidase and Thiocyanate on the Growth of Streptococcus pyogenes and Streptococcus agalactiae in a Chemically Defined Culture Medium

Abstract

SUMMARYA chemically defined culture medium was used to study the effect of purified lactoperoxidase and thiocyanate on the growth of several cultures of Streptococcus pyogenes and S. agalactiae. While not inhibited by either component alone, S. pyogenes growth was completely inhibited when both components were present in the medium. The growth inhibition was annulled completely by glutathione, thioglycollic (mercaptoacetic) acid or catalase. S. pyogenes glyceraldehyde phosphate dehydrogenase was inhibited by lactoperoxidase when hydrogen peroxide was present. The inhibition was annulled with cysteine and glutathione which suggested t h i s dehydrogenase to be a possible site of inhibition. The inhibition was postulated to be a peroxidatic conversion of essential enzymic sulphydryl p u p s to inactive disulphide groups, thus interfering with the energy metabolism of S. pyogenes. With S. agalactiae cultures a delay in growth inhibition up to 6 hr resulted instead of complete growth inhibition.Catalase neutralized this effect. The extent of growth inhibition was greatest in those strains which were unable to adapt to an oxidative pathway for their energy supply. In becoming independent of the fermentative pathway, the cultures were no longer as sensitive to peroxidase, thiocyanate and hydrogen peroxide. The necessity for thiocyanate in the inhibitory system is not yet clear. Thiouracil and thiourea were ineffective replacements for thiocyanate.

Influence of a model human defensive peroxidase system on oral streptococcal antagonism

“…In contrast to the large number of studies of the effects of the LPO and related systems on S. mutans, there have been relatively few studies of the effect on S. sanguinis (formally sanguis) (Carlsson, 1980;Carlsson et al, 1983;Courtois et al, 1995;van der Hoeven & Camp, 1993), and we are not aware of any efforts to quantify the effects of the peroxidase systems on S. gordonii. Nonetheless, a number of other streptococcal species have been shown to be susceptible to inhibition by OSCN 2 in sufficient concentration, including Streptococcus oralis (van der Hoeven & Camp, 1993), Streptococcus mitior (Donoghue et al, 1987), Streptococcus rattus (Donoghue et al, 1987), Streptococcus uberis (Marshall et al, 1986), Streptococcus dysgalactiae (Mickelson & Brown, 1985), Streptococcus agalactiae (Mickelson, 1979) and Streptococcus pyogenes (Mickelson, 1966). Importantly, many factors determine susceptibility to inhibition by OSCN 2 , including pH, the flux of the peroxidase system (availability of H 2 O 2 ), cell thiol content, stored carbohydrate content, and the ability of the medium to quench OSCN 2 .…”

Comparison of the Antibacterial Activity of the Hypothiocyanite Anion towards Streptococcus lactis and Escherichia coli

“…Oram & Reiter (1966) and Mickelson (1966) suggested that the LP system, by oxidizing the thiol groups of a number of enzymes, interfered with glycolysis in some streptococci. More recently, Aune et al (1977) have examined the binding of the thiocyanate anion to bovine serum albumin in the presence of the LP system and have found that this involved the thiol groups of the protein.…”

Fermenter Growth of Streptococcus agalactiae and Large-scale Production of CAMP Factor

“…To our knowledge, reports studying the growth conditions of S. agalactiae have been rare in the literature (Mickelson, 1966(Mickelson, , 1976Bernheimer et al, 1979). Thus, rigorous investigation of the production of high amounts of extracellular products by group B streptococci or high bacterial densities exceeding A660 values of 2.5-3.0 have so far not been reported.…”