Disinfection of woollen blanket

Abstract

The efficiencies of bactericides in destroying bacteria on woollen blanket were investigated on a laboratory scale. The bactericides were not effective when tested with new blanket; this low efficiency was found to be related to the rapid adsorption of the bactericides by the wool. Pretreatment of the wool with concentrated solutions of bactericides depressed the rate of depletion of the bactericides from subsequent washing liquors with bactericides at customary concentrations, and led to more satisfactory rates of kill (inactivation factors about 106).The test organisms,Staphylococcus aureusandEscherichia coli, were applied to the blanket as a powder, and the relative densities of bacteria on the blanket were determined using a procedure based on maceration of the fabric. The bactericides, 4-chloro-3, 5-xylenol (P.C.M.X.), cetyl trimethyl ammonium bromide (C.T.A.B.) and bis-(4-chlorophenyl diguanido)-hexane diacetate (chlorhexidine diacetate) were tested in the presence of appropriate detergents.Cultures were kindly supplied by Dr Hildred Butler of the Royal Women's Hospital, Melbourne.

Radiation and Health

“…Two procedures, exposure to formal-dehyde3 and rinsing in disinfectant after normal laundering,4" give blankets that are nearly sterile, though rinses are iess effective for first than for subsequent treatments because previously untreated blanket-fibres adsorb disinfectant and reduce the bactericidal action of the wash-liquor. 9 Adsorption of disinfectants by wool fibres had earlier given hope that it might confer self-sterilizing properties on blankets. But though fibres shaken from a treated blanket inhibit staphylococci on a culture plate, 7 bacteria are not killed under natural conditions, because there is not enough moisture to carry disinfectant from the fibres into the bacterial cells.…”

Industry and Health

“…The Medical Research Council's research group has already shown the value of the technique in the first of its series of carefully controlled chemotherapeutic trials. 9 Another important advance has been by C. C. Shepard,"' working in the U.S. Public Health Service, Atlanta, who found that human leprosy can be successfully transmitted in the foot-pads of mice. The infection can then be used for assessing anti-leprosy drugs."…”