engleski

Effect of amniotic fluid on bacterial growth

The purpose of the present study was to compare the antimicrobial capacity of amniotic fluid (AF) against Listeria monocytogenes and group B streptococci (GBS), both well recognized causes of intraamniotic infections and neonatal sepsis. In order to study trimester variations in the antibacterial activity, samples obtained by early transabdominal amniocentesis (16 week of gestation) and samples obtained at elective cesarean section (36-41 week of gestation) were separately tested. Immediately after sampling, specimens of AF were centrifuged to remove cells and debris and cultured in order to exclude previous contamination with aerobic/anaerobic pathogenes including mycoplasmas. Each sample was individually inoculated with 1000000 colony-forming units (cfu) of either L. monocytogenes or GBS. Inoculated samples were incubated at 37oC in a 5% CO2, humidified atmosphere. After 24, 36 and 48 hours incubation viable cells counts were determined by the plate method. The results showed only a mild bacteriostatic effect of AF against both tested microorganisms. There was no significant difference between bacteriostatic capacity of early and late AF samples for either organisms. The inefficacy of AF in defence against L. monocytogenes or GBS, may contribute to prolonged persistance of these gram positives in AF increasing the possibility of severe intrauterine infection.

amniotic fluid; Listeria; group B streptococci

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