[Effect of ultrasonic treatment on the adhesiveness of E. coli]

Electron microscopy and the hemagglutination test were used to study the effect of low-frequency and low-amplitude ultrasound (26.5 kHz, 30 m) on the adhesiveness of E. coli cells, strain 815, possessing Type I pili. Mild sonication providing the assanation effect during intraoperational treatment of the infected peritonium was found to remove the majority of flagella and pili, despite the fact that the cells seemed to be unimpaired. After sonication the ability of bacteria to cause mannose-sensitive hemagglutination of guinea-pig red blood cells decreased more than 8-fold. The data obtained suggest that the diminution of adhesiveness might be a possible mechanism of the sonication-induced assanation effect.