Four of the five Shigella species isolated from travelers to Sri Lanka hybridized with the probe for type V DHFR gene, implying a local distribution of the type V DHFR gene.
Since 58% (81 of 139) of TMPR Shigella and 36% (8 of 22) of TMPR ETEC strains examined did not contain genes encoding type I, II or III DHFR, high level TMP resistance was presumably caused by other types of DHFR genes.(ABSTRACT TRUNCATED AT 250 WORDS)