Читать книгу Genetic Disorders and the Fetus - Группа авторов - Страница 110

Although bacteria may occasionally be isolated from the AF of asymptomatic patients,^{385, 386} the rarity of infection following millions of amniocenteses during the second and third trimesters of pregnancy clearly suggests a protective mechanism against bacterial infection in AF. The implication was that AF has specific antibacterial activity. Some investigators have concluded that AF has some antibacterial activity,^{386, 387} whereas others maintain that it has none or that it actually provides a good culture medium.^{388, 389} A substance bactericidal for Bacillus subtilis was found in about 17 percent of AF samples in one study.³⁹⁰