title: Nanobacteria may be linked to calcification in placenta.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  For the first time isolated, cultured, and identified nanobacteria in placental calcification indicated that nanobacteria infection is related to placental calcification.
authors.affiliation: Department of Pathobiology, Chong Qing Medical University, Chongqing 400016, People's Republic of China. lhluhe@163.com
authors.forename: He
authors.initials: H
authors.lastname: Lu
authors.forename: Ya-nan
authors.initials: YN
authors.lastname: Guo
authors.forename: Sheng-nan
authors.initials: SN
authors.lastname: Liu
authors.forename: De-chun
authors.initials: DC
authors.lastname: Zhang
mesh_terms: D000328:Adult; D059587:Calcifying Nanoparticles / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D002114:Calcinosis / Q000378:metabolism / Q000473:pathology*; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal; D005109:Extracellular Matrix / Q000648:ultrastructure; D005260:Female; D006801:Humans; D010920:Placenta / Q000378:metabolism / Q000473:pathology*; D010922:Placenta Diseases / Q000378:metabolism / Q000473:pathology*; D011247:Pregnancy; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D059587:Calcifying Nanoparticles; D004269:DNA, Bacterial; D004275:DNA, Ribosomal