Morphological changes of Escherichia coli induced by bicyclomycin

Electron microscopic studies with Escherichia coli revealed that bicyclomycin inhibits septum formation and converts the cells to filamentous forms. The antibiotic induced high undulation and numerous blebs of the outer membrane. Sometimes cytoplasmic contents leaked into the lumen of the bleb through a disrupted region of the membrane. Breakage of the outer membrane or blebs led to cell lysis. Electron-dense masses of amorphous material and vesicles were found in the cytoplasm.