Detection and isolation of nanobacteria-like particles from urinary stones: long-withheld data.

Objectives: To report our experimental results on detection and isolation of nanobacteria-like particles (NLP) from urinary stone samples.

Methods: From March 2001 to August 2003, 47 urinary stone samples from Japanese patients and 18 from Paraguayan patients were collected and used for compositional analysis, direct survey of NLP by scanning electron microscopy (SEM) and their cultural isolation. For the isolation, culturing was carried out using strict aseptic techniques. Dulbecco's modified Eagle medium with 10% gamma-irradiated fetal bovine serum was used based on the original method described by Kajander and Ciftçioglu.

Results: Positive NLP detection rates for Japanese and Paraguayan patient samples were 61.7% (29/47) and 66.7% (12/18), respectively. Positive NLP isolation rates for Japanese patient samples were 20.6% (7/34) and 20.0% (2/10) for Paraguayan patient samples. In the initial isolation, markedly different periods of incubation time were needed for each of the nine cases (6-220 days; median 36 days). Positive detection and isolation were obtained in stone samples with or without calcium phosphate. Growth modes and morphogenesis of NLP were divided into two phases; rod-shaped NLP was detected mainly as a floating form growing in culture medium and spherical NLP with a characteristic apatite shell was detected as an attached form growing on the surface of culture dishes.

Conclusions: Lifeless calcifying nanoparticles can be isolated from various human urinary stones, cultured in cell culture mediums and show two characteristic growth phases.