[Distribution of lysotypes and study of antibiotic sensitivity of Shigella flexneri 2 isolated in Iran].

152 strains of Shigella flexneri 2 isolated from the stools of patients having sporadic bacillary dysenteria have been studied for their phage types as well as for the presence of transferable resistance factor. The distribution of the phage types has shown a high predominance of lysotype 12 (67%). Proportion of Shigella flexneri 2 strains resistant to one or several antibiotics has been highest in the years 1968 and 1973. The most frequent transferable resistance pattern was found to be (Tc, Cm, Sm, Su) and the most successful transfer method was the celophane technique. Resistance loss varied according to the resistance pattern of the strains. Total loss of the resistance to Tc, Cm, Sm, Su occurred in 0,2-2 % only. Very often strains resistant to Tc, Cm, Sm, Su lost their resistance factor to Tc and Cm keeping the resistance factors for Su, Sm.