In vitro survival of Listeria monocytogenes in human amniotic fluid

A Listeria monocytogenes strain (CA01/93), haemolytic and virulent in mice, was inoculated in 16 samples of sterile human amniotic fluid to study the growth curves and to provide more information about the pathophysiology of the microorganism in pregnancy. A control test for every analysis was performed with an Escherichia coli st rain (CN 02/5). Regardless of the amniotic fluid samples were taken at 34(th)-39(th) week o f gestation, when it expresses maximum ability to inhibite growth of E. col i, the growth curves of L. monocytogenes do not show any bactericidal (only bacteriostatic) activity of the amniotic fluids against the tested strain. This gives an interesting result about the pathogenesis of the infection i n pregnancy and about the potential environmental contamination due to long surviving times of the microrganism in amniotic fluid.