cleanser/disinfecting(Steri-X)

タイトルまたは説明

An 0.1 ml volume of Steri-X was applied and evenly distributed across the surface of the wells of a polystyrene *-well plate. A control plate was set up with an equal volume of sterile distilled water. These were allowed to dry with the lids off in a class II laminar flow cabinet for 1 hour at room temperature. The lids were replaced and the plates were maintained in a temperature controlled room for the ‘incubation period’ at *0?C +/- 2?C. The cultures were prepared by inoculation onto a tryptone soya agar (TSA) slope, grown up overnight at *6?C+/*1?C and the next day, the day before the experiment, re-inoculated onto a fresh TSA slope and grown up overnight as before. The bacterial lawn was gently washed from the slope with a 2.0 ml volume of Tryptone-NaCI and disaggregated by repeated pepetting with a *0ml serological pipette. The absorbance of the culture at **0 nm was adjusted to 1.0 by dilution in tryptone NaCI. The cell suspension density was estimated to be 2.0 x **8 cfu/ml. This was later confirmed by a viable count by diluting the cell suspension to ***6 and ***7, then inoculating 1.0 ml into a TSA pour plate (molten *3.5 ml TSA deeps had been previously prepared and maintained at *0?C) A 0.1 ml volume of culture *0 x **7 cfu was then applied to the surface of the wells treated and a well of the mock treated plates for each incubation time point. These were evenly distributed over the surface of the plate. In one well, bacteria were maintained in contact with the surface at *0?C for 1 minute and the other well for 5 minutes for the Steri-X treated wells and 5 minuets for the mock treated plates. The contact was terminated from the Steri-X treated plates by removal of 0.1 ml into duplicate filter funnels containing *0 ml of universal neutraliser. Bacteria were trapped onto 0.*2?m filters and washed with **0 mls of tryptone NaCI (see EN***6). The filters were transferred onto TSA plates and incubated overnight at *6?C +/- 1?C. For mock treated plates, the mixture was first diluted to ***6 and then a k0.1 ml volume applied to a filter funnel containing *0 ms of diluent. These plates were incubated at *6?C +/- 1?C overnight and counted the next day.