Radioactive technetium-99m labelling of Salmonella abortusovis for the assessment of bacterial dissemination in sheep by in vivo imaging.
We report the development and validation of a 99mTc-labelling technique of bacteria, applied to Salmonella abortusovis. The radioactive labelling is obtained using a pre-tinning step of the cells followed by direct incubation of S. abortusovis suspension with 99mTc-pertechnetate. Several procedures with different amounts of stannous tin (SnF2 or SnCl2) were evaluated. The selected method, respectful of bacterial viability, provided a 30% labelling yield. Viability of 99mTc-labelled bacteria was assessed by flow cytometry using rhodamine 123 and was demonstrated to be unchanged, turbidimetric measurements showing only a slight increase in the growth rate for radiolabelled cells. Incubation of 99mTc-labelled S. abortusovis with pronase, saponine and urea demonstrated labelling stability and suggested an intra-cellular localization for 99mTc. A preliminary study was also conducted in sheep to evaluate the value of the imaging of radiolabelled S. abortusovis. Spatial and temporal patterns of their in vivo dissemination in the lymphatic system after a sub-cutaneous injection were compared with control lymphoscintigraphic agents. These imaging data supported the assumption that the radioactivity detected in vivo was proportional to the number of 99mTc-labelled bacteria.
Perin
F
F
Laboratoire de Biophysique Cellulaire et RMN, CNRS-INSERM U316, Faculté de Médecine, Tours, France. SPIN37@aol.com
Laurence
D
D
Savary
I
I
Bernard
S
S
Le Pape
A
A
D000818:Animals; D005434:Flow Cytometry / Q000379:methods; D005456:Fluorescent Dyes; D007553:Isotope Labeling / Q000379:methods; D015203:Reproducibility of Results; D020112:Rhodamine 123; D012235:Rhodamines; D012475:Salmonella / Q000254:growth & development / Q000302:isolation & purification*; D012756:Sheep / Q000382:microbiology*; D013670:Sodium Pertechnetate Tc 99m / Q000493:pharmacokinetics
D005456:Fluorescent Dyes; D012235:Rhodamines; D020112:Rhodamine 123; D013670:Sodium Pertechnetate Tc 99m