Further studies on the antibiotic resistance of Shigella sonnei: II. The acquisition of transferable antibiotic resistance in vivo

Abstract
A method is described for the testing of strains of Sh. sonnei for antibiotic resistance, colicine type and drug resistance transfer using a multiple inoculator.The examination of 731 strains of Sh. sonnei isolated from convalescent cases and their family contacts showed that about 5% of individuals were excreting organisms which differed from the infecting strain by a single transferable antibiotic resistance determinant. It is suggested that the acquisition of such resistance may occur in 13% of family incidents.