Effects of anti-Bacteroides-antibodies on Escherichia coli and different Bacteroides species in vitro and vivo.
Bacteroides species are known to cause synergistic pathogenicity in mixed infections with Enterobacteriaceae. In vitro studies showed that anaerobes may compete with aerobes for opsonisation thus interfering with the phagocytosis and killing of the latter by leukocytes. The present study investigated the effect of anti-Bacteroides-antibodies on in vitro phagocytosis of E. coli and on experimental mixed infections. It was shown that in vitro, B. fragilis suppressed the phagocytosis of E. coli by leukocytes only moderately. The addition of specific antibodies to the phagocytosis mixture could enhance this effect. However, antibodies in the absence of B. fragilis were also active suggesting a nonspecific mechanism such as blockade of Fc receptors. Prophylactic treatment with the immunoglobulin preparations failed to protect mice from experimental infections with E. coli and Bacteroides species.
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D001439:Bacteroides / Q000276:immunology*; D001442:Bacteroides Infections / Q000276:immunology; D001441:Bacteroides fragilis / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology; D005260:Female; D007116:Immunization, Passive; D051379:Mice; D010587:Phagocytosis
D000907:Antibodies, Bacterial