Attempted isolation of Nanobacterium sp. microorganisms from upper urinary tract stones

A single team has reported isolation of nanobacteria in human and bovine blood products, as well as, more recently, kidney stones. This has raised controversy. To confirm the data, we searched for nanobacteria from 10 aseptically removed upper urinary tract (UUT) stones. We used scanning electronic microscopy (SEM) with four stones and culture of stones on either 3T6 fibroblast monolayers or liquid RPMI medium. Detection of nanobacteria was made with a commercially available monoclonal antibody, 16S ribosomal DNA amplification with specific primers, and transmission electronic microscopy (TEM) of inoculated cells. SEM showed nanoparticles in four of four UUT stones similar to those recently described. TEM of inoculated 3T6 cell monolayers has shown transient intracytoplasmic vacuolar formations containing 200- to 500-nm particles in 3 of 10 cell cultures. Gimenez staining, Hoechst staining, and specific monoclonal immunofluorescence failed to reveal nanobacteria. Finally, we could not grow Nanobacterium sp. microorganisms by the techniques described. Although with SEM, we observed nanoparticles morphologically similar to nanobacteria, we failed to isolate Nanobacterium sp. microorganisms in culture and to prove the bacterial nature of these nanoparticles in stones.