• Membrane-disrupting toxins or type II toxins
• Lyse host’s cells by:
• Making protein channels in the plasma
membrane (e.g., leukocidins, hemolysins)
• Disrupting phospholipid bilayer
• Plasmids may carry genes for antibiotic resistance,
toxins, capsules, and fimbriae
• Lysogenic conversion (new properties due to lysogenic
phage) can result in bacteria with virulence factors,
such as toxins or capsules