Johanson W G, Kennedy M G, Bonte F J
Appl Microbiol. 1973 Apr;25(4):592-4. doi: 10.1128/am.25.4.592-594.1973.
The suitability of technetium ((99m)Tc), a gamma emitter, for labeling of Diplococcus pneumoniae in studies of lung bacterial clearance was examined. A killed bacterial slurry with high specific activity was obtained with a ferric ascorbate reducing system. Approximately 5.5% of radioactive counts dissociated from labeled bacteria in 6 h. Rats were exposed to a uniformly mixed aerosol of untagged, viable pneumococci and killed, (99m)Tc-tagged pneumococci. The aerodynamic behavior of labeled and unlabeled pneumococci was similar. Viable bacterial counts and radioactive counts were determined in lung homogenates at intervals following exposure, and rates of bacterial killing and disappearance of radioactive counts were plotted. Radioactive counts did not increase in the liver during the period of observation, suggesting that the decrease in lung radioactivity represents mucociliary clearance and not release of isotope to the systemic circulation. The use of (99m)Tc for bacterial labeling provides advantages of technical simplicity and personnel safety compared to the use of beta-emitting isotopes.
对γ射线发射体锝（（99m）Tc）在肺部细菌清除研究中标记肺炎双球菌的适用性进行了研究。通过抗坏血酸铁还原系统获得了具有高比活度的死菌悬液。在6小时内，约5.5%的放射性计数从标记细菌中解离。将大鼠暴露于未标记的活肺炎球菌和经杀死的、（99m）Tc标记的肺炎球菌的均匀混合气溶胶中。标记和未标记肺炎球菌的空气动力学行为相似。在暴露后的不同时间间隔测定肺匀浆中的活菌计数和放射性计数，并绘制细菌杀灭率和放射性计数消失率曲线。在观察期内肝脏中的放射性计数没有增加，这表明肺部放射性的降低代表了黏液纤毛清除，而不是同位素释放到体循环中。与使用发射β射线的同位素相比，使用（99m）Tc进行细菌标记具有技术简单和人员安全的优点。
