The ability of campylobacter media supplements to neutralize photochemically induced toxicity and hydrogen peroxide

Abstract

Nutrient agar plates stored in light and air for 48 h became inhibitory for C. jejuni, C. coli and nalidixic acid-resistant, thermophilic campylobacter (NARTC) strains. All 5 campylobacter test strains showed > 5 log reduction in counts on media which had been stored in light and air. Media stored in the dark and/or in a reduced atmosphere did not become inhibitory and supported the growth of campylobacters. Ferrous sulfate, sodium pyruvate, blood, charcoal or sodium metabisulfite, compounds frequently used as supplements in campylobacter media, were added to nutrient agar prior to storage of media in light and air. All additivites except sodium metabisulfite prevented the accumulation of photochemically generated toxic O2 derivatives and allowed growth of test strains. In qualitative tests to determine the ability of supplements to neutralize H2O2, blood was the most active, charcoal and sodium pyruvate slightly less active and ferrous sulfate and sodium metabisulfite the least active. Thus, supplements in campylobacter media act as quenching or detoxifying agents and not as enrichment factors.