Comparative efficacies of commonly used disinfectants and antifungal pharmaceutical spray preparations against dermatophytic fungi

Abstract

Arthroconidia from five fungal strains belonging to three Trichophyton species, Trichophyton mentagrophytes, T. raubitschekii and T. tonsurans, were tested against commercial chemical disinfectants and pharmaceutical antifungal agents. The chemical disinfectants included chlorine, phenol, sodium dodecyl sulphate and several quaternary ammonium salts, while the two pharmaceutical preparations contained bifonazole and terbinafine as active agents. Arthroconidia were exposed to the antifungal agent either in a suspension solution for a given period of time and assayed for kill rate, or on a sprayed agar plate and monitored for surviving colonies over a period of 14 days. Chlorine (1%) and terbinafine (0.01%) were found to be high level disinfectants bringing about a rapid inactivation of conidia in all five strains. Phenol was equally effective against T. raubitschekii and T. tonsurans; however, T. mentagrophytes cells were able to survive for up to 1 h in 5% phenol. Quaternary ammonium compounds were less rapid in their action against dermatophytes and were needed at a level of about 0.5% to be completely fungicidal. Three commercial spray formulations with a range of 0.1 to 0.3% quaternary ammonium salts were fungistatic against T. mentagrophytes strains. Bifonazole (1%) was also fungistatic in its action against T. mentagrophytes. Sodium dodecyl sulphate (0.5%) was largely ineffective against Trichophyton arthroconidia.

Evaluation of Strategies for the Decontamination of Equipment for Geomyces destructans, the Causative Agent of the White-Nose Syndrome (WNS)

“…As such, much lower concentrations of disinfectants, used for longer periods, may reduce the fungal spore burden down to a level that is considered safe (Gupta et al, 2001). At this time, no information is available about spore loading during human visits to a cave or the minimum infective dose of G. destructans to initiate WNS in bats or contaminate the cave environment.…”

Moderne Antimykotika

“…In einer frühe-ren Untersuchung konnten wir zeigen, dass die minimale fungizide Konzentration von Terbinafin gegen den gleichen Pilzstamm in der Ruhephase um das 1.000fa-che höher ist als in der Wachstumsphase [30]. Gupta et al [16] zeigten, dass eine 0,01%ige Terbinafinlösung innerhalb von 15 min Arthrosporen von T.mentagrophytes, T. raubitschekii und T. tonsurans zu 100% abzutöten vermag. Das bedeutet, dass Terbinafin gegen Dermatophyten über einen weiteren Wirkungsmechanismus verfügen muss, der wahrscheinlich unabhängig von der Ergosterolbiosynthese ist.…”

“…Die hier zitierten Arbeiten zeigen,dass es beträchtliche Unterschiede in der fungiziden Potenz der Antimykotika zwischen Pilzen in der Ruhe-und der Proliferationsphase gibt.Wie sich diesbezüglich die Desinfektionsmittel verhalten, die ja in erster Linie gegen ruhende Pilze wirken müssen,ist weitgehend ungeklärt.Die Prüfung der gelisteten Desinfektionsmittel erfolgt gegen T. mentagrophytes und C. albicans an proliferierenden Zellen. Gupta et al [16] prüften einige Desinfektionsmittel und Antimykotika auf ihre fungizide Wirkung gegen Arthrokonidien von T.mentagrophytes.Nach einer Expositionszeit von 15 min führten eine 1%ige Natriumhypochlorid-und eine 0,01%ige Terbinafinlösung zu 100% Fungizidie. Phenollösung 5% zeigte nach 1 h Einwirkzeit vollständige Fungizidie.0,5% Benzalkoniumchlorid,0,5% Natriumdodecylsulphat und 0,5% Hexadecyltrimethylammoniumbromid bewirkten auch nach 24 h keine 100% Fungizidie.…”

Fungicidal activity of AKWATON and in vitro assessment of its toxic effects on animal cells

“…Preparing a proper dilution can also be problematic, as the concentration of commercial products may vary between 3 and 8 % (Moriello et al, 2013). Gupta et al (2001) reported that the spores of T. mentagrophytes showed resistance against quaternary ammonium compounds. The commercial spray formulations with concentrations ranging from 0.1 to 0.3 % were fungistatic.…”