Aims: Placental calcification is a common pathologic condition in obstetrics. To detect the bacteria infection mechanisms for calcification, an experiment was performed to isolate, culture, and identify the nanobacteria in placental calcification.
Method: Sixteen cases of placental calcification of pregnant women were collected for the purpose of the isolation of nanobacteria, cultivation, and identification of 16S rDNA sequence.
Result: Under transmission electron microscope, novel oval-shape nanobacteria-like particles (NLP) in extracellular matrix of calcified placenta tissues were found with 50-500 nm in diameter, and among hydroxyapatite crystals aggregation existed. After about 4 weeks of culturing and isolating NLP from these calcified tissues, all calcified placental tissue samples and one adjacent tissue of calcified placental tissue samples showed white granular depositions, which were firmly attached to the bottom of the culture tubes and visible to the naked eyes. In the control group they could not be seen. After PCR was amplified a 1407-bp fragment was obtained and submitted to GenBank after sequencing with accession number JN029830. The 16S rDNA sequence homology between the isolation strain and strain nanobacteria (X98418) was 92% in GenBank.
Conclusion: For the first time isolated, cultured, and identified nanobacteria in placental calcification indicated that nanobacteria infection is related to placental calcification.