H2O2 formation by Streptococcus mitis was measured by the catalase-dependent conversion of [14C]formate to 14CO2 ; it was optimal at pH 6.0–6.5 and required glucose. The H2O2 formed by S. mitis could be employed as a component of an antimicrobial system that also included lactoperoxidase (LPO) and either iodide or thiocyanate ions in the concentrations present in saliva. The antimicrobial effect of the LPO-iodide-S. mitis system was measured by the decrease in the viable cell count of the target organisms (Escherichia coli, Staphylococcus aureus, Candida tropicalis). The antimicrobial effect of the LPO-thiocyanate-S. mitis system was measured by the decrease in the rate of growth or the rate of uptake of [14C]valine by the target organisms (E. coli, S. aureus). Mixed or parotid saliva could replace LPO and thiocyanate ions in the S. mitis-dependent inhibition of bacterial growth and valine uptake. The presence in saliva of a peroxidase-mediated, antimicrobial system dependent on microbial metabolism for H2O2 and its role as a natural host defense mechanism are considered.
Article|
February 01 1973
A PEROXIDASE-MEDIATED, STREPTOCOCCUS MITIS-DEPENDENT ANTIMICROBIAL SYSTEM IN SALIVA
Charles B. Hamon,
Charles B. Hamon
From the Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98195
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Seymour J. Klebanoff
Seymour J. Klebanoff
From the Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98195
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Charles B. Hamon
From the Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98195
Seymour J. Klebanoff
From the Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98195
Received:
September 05 1972
Online ISSN: 1540-9538
Print ISSN: 0022-1007
Copyright © 1973 by The Rockefeller University Press
1973
J Exp Med (1973) 137 (2): 438–450.
Article history
Received:
September 05 1972
Citation
Charles B. Hamon, Seymour J. Klebanoff; A PEROXIDASE-MEDIATED, STREPTOCOCCUS MITIS-DEPENDENT ANTIMICROBIAL SYSTEM IN SALIVA . J Exp Med 1 February 1973; 137 (2): 438–450. doi: https://doi.org/10.1084/jem.137.2.438
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