Bactericidal Activity of Aerobic and Anaerobic Polymorphonuclear Neutrophils

Abstract

Human polymorphonuclear neutrophils (PMN) were made anaerobic by nitrogen washout (oxygen saturation <1%, Eh < −42 mV at pH 7.0), and the ability of the cells to kill bacteria was assayed and compared to the bactericidal activity of aerobic PMN. Anaerobic PMN were able to kill Staphylococcus epidermidis, Enterococcus , viridans streptococci, Pseudomonas aeruginosa, Peptostreptococcus anaerobius, Bacteroides fragilis, Clostridium perfringens , and Peptococcus magnus normally. Organisms that were not killed normally by anaerobic PMN included Staphylococcus aureus (strains Wood 46 and 502a), Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Proteus vulgaris , and Salmonella typhimurium. These findings suggest that mechanisms other than those dependent on hydrogen peroxide may be important in the killing of some bacteria.