Differential Complement Resistance Mediates Virulence of Haemophilus influenzae Type b

摘要: Studies were undertaken to gain insight into the virulence of type b in contrast other Haemophilus influenzae capsular types. A relationship was found between comparative H. types humans and their resistance bactericidal effect antibody-free complement. Type most resistant The could be divided three groups based upon susceptibility complement; this grouping also related structural similarities. No association either biotype, source isolate, vitro with peripheral polymorphonuclear leukocytes, or total amount polysaccharide found. However, among strains, higher levels cell-associated associated increased relative six infant rat model generally similar that humans. After intraperitoneal challenge, a strains had lowest 50% effective doses for bacteremia, removed by several logs from values By intranasal produced rates bacteremia than did strains. High natural antibodies c e adult female rats; finding alone not account differences model. We propose is due greater activity serum complement alone. Resistance disease requires antibody induce complement-mediated reaction.