[Salmonella typhi lysotypes in Iraq (1974-1979)]

The distribution of phage-types was studied among 434 strains of S. typhi from Bagdad, Amara and Bassora. Biotypes, colicinogeny, tetrathionate-reductase activity (TTR) and susceptibility to Salmonella phage O.I. were also studied. The most frequent phage-types in Irak were A, D1, E1 alpha, F1, M1, O, T, 46 and two other large groups of strains (I + IV and Vi degraded strains). Only 4.38% of S. typhi were TTR-; the strains of phage-type 53 were TTR+. Colicinogeny was demonstrated in 2.5% of S. typhi (lysotype 40, group I + IV and Vi degrades strains). All strains were lysed by Salmonella phage O.I, with the exception of three strains of phage-type T. Comparisons were made with the S. typhi phage-type in Iran and evidence was found for one regional epidemiological community in respect to the distribution of phage-types.