Homing kinetics of indium-111 labelled bacteria: detection of organ specificities as revealed by scintigraphy

Species differences in the clearance of Staphylococcus aureus bacteremia

Studies on vascular graft infections may be influenced by species differences in bacteria clearance. The present study compares the bloodstream elimination of Staphylococcus aureus (S. aureus) in dogs and pigs. Four mongrel dogs and four Yorkshire pigs received a 20-min infusion of 10(6) S. aureus labeled with indium-131. Through a catheter placed in the infrarenal aorta, blood samples were removed at intervals for 5 h after infusion. The liver, spleen, and lungs were biopsied at 5 h. Blood and tissue samples were then counted in a gamma counter. The calculated phagocytotic index, k, for dogs was 8.6 X 10(-4), while for pigs it was 1.5 X 10(-3), indicating significantly faster bacterial clearance in pigs (p = .009). After 2 1/2 h, significantly fewer counts were present in pigs at most time points (p less than .05). Organ counts indicated higher counts in the dog liver and spleen and in the lungs of pigs (p less than .0001). This study indicates that S. aureus bacteremia is cleared faster by pigs, primarily by the lungs, compared to dogs, in which liver-spleen clearance predominated. These differences should be considered when the results of graft infection studies are compared.

Effect of acute burn trauma on reticuloendothelial system phagocytic activity in rats. II: Comparison of uptake of radiolabelled colloid and bacteria

The uptake of radiolabelled colloid or bacteria was compared in normal rats and animals subjected to acute burn trauma. The uptake of colloid by the liver was unaffected by burn trauma, but uptake of the labelled bacteria was reduced. Spleen uptake of both colloid and bacteria was reduced by burn trauma while lung uptake was increased. These data are consistent with the hypothesis that acute burn trauma alters reticuloendothelial system phagocytic activity in the rat towards both inert particles and live bacteria.

In-111 Pseudomonas aeruginosa: a simple method of labeling live bacteria with a gamma-emitting radioisotope

We describe a simple and reliable technique for labeling Pseudomonas aeruginosa with a readily available commercial preparation of indium-111 (111In) oxine. Labeling of a heavy bacterial suspension with 500 mu Ci of commercially prepared 111In-oxine resulted in a yield of 0.0004 mu Ci of cell-associated 111In per 10(6) colony-forming units (CFU). The label was 88% bacterially associated and did not effect viability of the organism. Radiolabeling a gram-negative organism with 111In-oxine provides a non-toxic, stable gamma-emitting bacterial tracer.