A simple modification of Wilson and Blair's medium for the isolation of typhoid and paratyphoid bacilli

Abstract

A simple modification of Wilson & Blair's medium for the isolation of typhoid and paratyphoid bacilli has been evolved.1. Instead of the original six ingredients, this modification contains only three, namely, brilliant green, bismuth-ammonium-citrate and sodium sulphite, and may therefore be conveniently termed “B.B.S. medium”.2. The glucose, sodium phosphate and ferrous sulphate of the original medium are eliminated. The bismuth-ammonium-citrate solution is made without caustic soda.3. The B.B.S. medium keeps well for several weeks. Deterioration can easily be detected and readily rectified.4. The inhibitory action towards B. aerogenes is greatly improved in the B.B.S. medium. This is particularly advantageous in countries where this organism is frequently encountered.5. B. typhosus and B. paratyphosus grow readily. The colonies are sufficiently characteristic and can be picked out early for confirmatory tests.6. Using B.B.S. medium a complete diagnosis should be possible within 48 hr.