Frequent loss of Shiga-like toxin genes in clinical isolates of Escherichia coli upon subcultivation.

摘要: Forty-five consecutive patients with various gastrointestinal disorders were identified as having Shiga-like toxin (SLT)-producing Escherichia coli infections. This was shown by the cytotoxic effect of stool extracts in Vero cell cultures which neutralizable antibodies to SLTs and isolation E. that hybridized DNA probes complementary SLT-I SLT-II sequences. When we tested same strains for SLT genes after subcultivation, isolates from 15 became negative colony hybridization polymerase chain reaction failed produce SLTs. The instability warrants direct screening methods clinical material development new culture prevent loss genes. Images