The influence of pyrithione on the growth of micro‐organisms

Abstract

Pyrithione was active against a range of micro-organisms, the most resistant being Gram-negative bacteria. The growth curves for Klebsiella pneumoniae and Bacillus licheniformis showed a drug-dependent lag phase. Candida albicans grew with a drug-dependent growth rate. EDTA antagonized the effects of pyrithione.

Pyrithione biocide interactions with bacterial phospholipid head groups

“…The metabolically inactive isomers of amino acids and carbohydrates were used to ensure that the extracellular pools of these compounds would not enhance the growth of the test micro-organisms during the course of the experiment. EDTA was chosen as a potential neutralizer of the pyrithiones in order to repeat the observed neutralization of the pyrithiones as reported by Khattar et al (1988). Control experiments indicated that the EDTA had no antimicrobial effect against either test micro-organism at the concentrations used in this experiment.…”

“…More recently, the effect of NaPT on the membrane electropotential of Neurospora crassa has been exhibited (Ermolayeva et al 1995). In bacteria, the inhibition of thymidine and uracil transport processes has been reported (Khattar et al 1988(Khattar et al , 1989. Previous work performed in this laboratory suggests that both pyrithiones induce the leakage of intracellular material from exposed cultures of Escherichia coli and Pseudomonas aeruginosa as well as affecting nutrient uptake in bacteria by the inhibition of membrane-bound metabolic processes (Dinning et al 1998).…”

“…The ability of the pyrithione biocides to chelate metal cations would allow the pyrithiones to disrupt membrane structure by chelating the divalent metal cations which maintain bacterial membrane conformation. Transchelation may also explain the neutralization of the growth inhibitory action of ZnPT by compounds such as EDTA (Khattar et al 1988).…”

Pyrithione biocides as inhibitors of bacterial ATP synthesis

“…This is indicated by the inhibition of uptake of several unrelated substrates in both bacteria and fungi (Chandler and Segel 1978;Friedman 1981;Khattar et al 1988 ;Khattar and Salt 1993) and the observed depolarization of the transmembrane electrical potential in Neurospora crassa (Ermolayeva et al 1995). The effects of an antimicrobial agent on substrate transport and related metabolism may be used as indicators of the membrane activity of the test agent (Gilbert et al 1991).…”

“…1) are the sodium salt and zinc chelate of 1-hydroxy-2-pyridinethiol (Shaw et al 1950 ;Albert et al 1956 ;Hyde and Nelson 1984). Both NaPT and ZnPT have been shown to possess a wide spectrum of antimicrobial activity against fungal and bacterial species (Pansy et al 1953 ;Albert et al 1956 ;Hyde and Nelson 1984 ;Khattar et al 1988). They are widely used as cosmetic preservatives (Nelson and Hyde 1981 ;Hyde and Nelson 1984) and are incorporated as anti-dandruff agents in shampoos (Fredriksin and Feargeman 1983 ;Hyde and Nelson 1984).…”