Final answer:
Amniocentesis can detect an intra-amniotic infection by analyzing the amniotic fluid for infectious agents through culture methods and molecular testing, such as PCR and nucleic acid amplification of specific bacterial sequences.
Step-by-step explanation:
Amniocentesis is able to detect an intra-amniotic infection through the analysis of amniotic fluid. This procedure involves drawing out a small amount of amniotic fluid from the mother’s abdomen, which not only contains fetal cells that can be examined for genetic defects but also can be cultured or tested using molecular methods, such as PCR (Polymerase Chain Reaction), to identify infectious agents like bacteria or parasites. For example, diagnosis of congenital infections can be achieved by detecting T. gondii DNA in amniotic fluid, which is the causative agent of toxoplasmosis. Additionally, the presence of pathogens can be verified through molecular tests based on the nucleic acid amplification of specific bacterial RNA or DNA signature sequences, like the 16S ribosomal RNA of Listeria monocytogenes, which can cross the placenta and cause listeriosis.