THE ISOLATION OF B. PARATYPHOSUS B FROM SEWAGE

Abstract

B. paratyphosus B (Schott-muller) was isolated by selective methods from 7 out of 20 specimens of Edinburgh sewage, 17 samples, including all the positive ones, being from 1 district. Any 1 of the 3 selective methods employed (Wilson and Blair''s "glucose-bismuth-sulphite-iron-brilliant-green medium"; Browning, Gilmour and Mackie''s brilliant green enrichment method; Rakieten and Rettger''s modification of the preceding) may fail to detect paratyphoid bacilli isolated by the others. Although it is probable that the distribution of paratyphoid bacilli is very uneven and their survival short, their presence is a potential danger, as evidenced by investigation of an outbreak subsequent to flooding of 2 byres by reflux sewage from drains, in 1927. It is suggested that "carriers" might be traced by the adoption of the methods employed, for it is considered unlikely that strains isolated were of animal origin.