Bacterial vs. fungal spore resistance to peroxygen biocide on inanimate surfaces

Abstract

A sporicidal agent formula based on a mixture of peroxyacetic acid and hydrogen peroxide was assessed for its efficacy on a representative sample of vinyl surface material. Vinyl is the construction material of wall and floor lining in pharmaceutical plants. The experimental manipulations; applied herein, simulated the actual biocidal agent preparation and were carried out using USP purified water, test temperature was 20-25°C, RH% was 40-60% and pH was 3.08 and 2.86 for 1% and 2% (v/v) respectively. Following the selection of the optimum method of antimicrobial activity neutralization, two disinfectant concentrations were examined for their sporicidal activity. The results of carrier test revealed that the disinfectant concentration (2%) (v/v) was significantly effective as a sporicidal agent after 5 and 10 min for Aspergillus brasiliensis and Bacillus subtilis subsp. spizizenii, respectively, while the concentration of 1% (v/v) did not achieve even one logarithmic reduction after 20 min. The agent was able to achieve more than 100 times reduction from the initial bioburden on the surfaces when used in the concentration of 2% (v/v) after 10 min of contact time. The ideal kinetics of microbial death usually follows 2 parts (by averaging the responses with time for the 3 replicates): initial slow rate of death followed by higher rate. The initial sigmoidal part was only observed with B. subtilis upon exposure to 2% (v/v) sporicidal agent. Elimination time for B. subtilis spores was 15 min which was about double the time required for eradication of A. brasiliensis.ª 2014 Production and hosting by Elsevier B.V. on behalf

Disinfection efficiency test for contaminated surgical mask by using Ozone generator

“…The bacteria-contaminated masks were cultured in sterile nutrient broth and placed on a Mueller–Hinton agar (MHA) surface. Then, the samples were incubated at 37 °C overnight to check the sterility of the contaminated masks [ 12 , 13 ].…”

Indoor air quality analysis in naturally ventilated university training laboratories: a health risk assessment

“…Surprisingly, the same effect was not observed for bacterial counts, which could be explained by the presence of airborne sporulated bacteria. It is well known that fungal spores are part of the normal life cycle of fungi, and therefore, are less resistant to chemicals and adverse environmental conditions than bacterial spores (Eissa et al 2014).…”

Biocidal Resistance in Clinically Relevant Microbial Species: A Major Public Health Risk

“…In fungal species, the development of AMR is resultant from similar mechanisms as those in bacterial species, including altering target proteins/enzymes, efflux pumps, altering membrane permeability/drug uptake and biofilm formation [ 55 ], and is regulated by resistance genes. Fungal species also make spores as part of their reproductive life cycle; however, these are less biocidal resistant than bacterial spores [ 56 ]. Fungal efflux pumps are major contributors to drug and biocidal resistance in yeast ( Saccharomyces species) and fungal species ( Aspergillus, Neurospora and Cryptococcus species).…”