The role of immunoglobulins in amniotic fluid growth inhibition of Bacteroides fragilis, herpes simplex, coxsackie B 5 and cytomegalovirus.

In serum and amniotic fluid (AF) from 30 pregnant women, antibodies against the anaerobe Bacteroides fragilis were determined by enzyme-linked immunosorbent assay (ELISA) and the results were compared with those of previously performed tests of B. fragilis growth inhibition by AF. The neutralizing effects of serum and AF against herpes simplex virus (HSV), cytomegalovirus (CMV) and coxsackie B 5 virus were also investigated, and antibody titres were determined by ELISA. No correlation could be demonstrated between the growth-inhibitory capacity of AF and the presence of antibodies against B. fragilis in serum or AF. Neutralizing antibodies against HSV and coxsackie B 5 virus were found in 73% and 51%, respectively, of the sera and in 36% and 13%, respectively, of both serum and corresponding AF. In no case could an AF neutralizing effect upon HSV, coxsackie B5 or CMV be demonstrated without a corresponding positive serum neutralization. It is concluded that the growth-inhibitory effect of AF on viruses in antibody-mediated, while AF inhibition of B. fragilis, and possibly other bacteria as well, seems to depend upon other antimicrobial mechanisms.