The Isolation of Typhoid Bacilli from Faeces by means of Brilliant Green in Fluid Medium

Abstract

(1) Brilliant green exerts an inhibitory effect on the growth of bacilli of the coli group commonly occuring in faeces, which is in general more marked than its action on B.typhosus and paratyphiod bacilli. (2) By taking advantage of this property of brilliant green a method has been devised is the inoculation B. typhosus from faeces. The procedure adopted is the inoculation of a series of tubes of peptone-water medium containing varying amounts of brilliant green, incubating for 20–24 hours, and then inoculation on a suitable solid medium from each tube. (3) The reason for employing a series of concentrations of brilliant green is that the optium concentration for the growth and isolation of B. typhosus varies from case to case, depending probably both on the proportion of typhoid bacilli present and on the number and character of the accompnying bacteria as well as on the organie faecal material. (4) The method is very easily and rapidly carried out.