We sourced the sodium hypochlorite solution used in the experiments from Merck (105614, Sigma Aldrich), stored at 4 C and diluted as appropriate for the experiments.
Each of the 3 isolates was decontaminated with 0.1%, 0.5% and 1.0% sodium hypochlorite (1,000, 5,000 and 10,000 ppm active chlorine), for 9 experimental sets in total. The decontamination procedure for each sample was as follows. 100 l of spore suspension in water at a concentration of spores/ml was mixed with 100 l of double concentrated NaOCl (0.2%, 1.0% and 2.0%) and left for 10 minutes. The biocide was then neutralised with 0.5% sodium thiosulphate as described previously [21 (link)]. The spores were then washed with deionised water, by centrifuging and discarding the supernatant twice, to remove reacted chemicals.
The reduction in viable spore count was determined by spreading 100 l culture onto BHIS-ST plates. Spores were grown in anaerobic conditions at 37 C for 48 hours and colonies were counted from a plate with appropriate dilution. There were 3 biological replicates for each experimental set.
Each of the 3 isolates was decontaminated with 0.1%, 0.5% and 1.0% sodium hypochlorite (1,000, 5,000 and 10,000 ppm active chlorine), for 9 experimental sets in total. The decontamination procedure for each sample was as follows. 100 l of spore suspension in water at a concentration of spores/ml was mixed with 100 l of double concentrated NaOCl (0.2%, 1.0% and 2.0%) and left for 10 minutes. The biocide was then neutralised with 0.5% sodium thiosulphate as described previously [21 (link)]. The spores were then washed with deionised water, by centrifuging and discarding the supernatant twice, to remove reacted chemicals.
The reduction in viable spore count was determined by spreading 100 l culture onto BHIS-ST plates. Spores were grown in anaerobic conditions at 37 C for 48 hours and colonies were counted from a plate with appropriate dilution. There were 3 biological replicates for each experimental set.
Free full text: Click here
