Morphological and ultrastructural changes in the cell structure of enterohaemorrhagic Escherichia coli O157:H7 following treatment with Quercus infectoria nut galls.

摘要: Some information is available on the oak (Quercus infectoria) nut gall as an effective medicinal plant against Shiga toxin-producing Escherichia coli (STEC) O157:H7. However, its antibacterial mechanisms have not yet been elucidated. In this study, some actions STEC O157:H7 were investigated by observing cell viability well morphological and ultrastructural changes. An ethanolic extract of Q. infectoria demonstrated inhibitory bactericidal effects all strains tested with minimal inhibition concentrations (MICs) at 0.78-1.56 mg ml(-1) (MBCs) 1.56-3.12 ml(-1). Cell numbers treated 4MIC decreased least two log-fold within 4 h completely killed 12 h. Scanning electron microscopy illustrated a complete loss surface appendages pronounced changes MIC 2MIC. The whole collapsed 4MIC. Ultrastructural from corresponding transmission micrographs further verified that damages in cells increased increase concentrations. At (0.78 ml(-1)), there was evidence cytoplasmic membranes E. bulging and/or ruptured, appeared to be discharging intracellular materials. 2MIC, outer membrane which attached wall became separated wall. Disruption membranes, especially polar regions occurred vacuolization appeared. 4MIC, damage extensive, their cellular integrity.