[Killing of seroresistant plasmid bearing E. coli strains in polymorphonuclear leukocytes]

Killing of 61 seroresistant E. coli strains equipped with virulence plasmids (F, Ent, Hly, Col) and resistance plasmids (R) in polymorphonuclear leukocytes (PMNL) of healthy donors was determined by the cultivation plate and fluorescence methods of phagocytosis. Killing of the control E. coli strain K12 which does not possess any plasmids was studied by the fluorescent method. Compared to the fluorescent method, the cultivation plate method yielded a significantly higher killing rate of the bacteria after opsonization by 5% (p less than 0.05) and concentrated serum (p less than 0.001). Compared to the control E. coli strain K12, the killing rate of seroresistant E. coli strains in PMNL of healthy donors was significantly lower (p less than 0.001).