[Venous and capillary diffusion of Enterococcus faecalis during experimental bacteremia in the chicken]

Capillary and venous diffusion of bacteria were studied in chickens after intravenous inoculation with a strain of Enterococcus faecalis isolated from a case of septicaemia in a human neonate. One group of 13 chickens was inoculated with 10(8) bacteria/animal and another group of 20 chickens with 10(7) bacteria/animal. The level of bacteraemia in the first group of chickens was similar in capillary and venous blood. With 10(8) E. faecalis, the clearance of bacteria was very weak. The level of bacteraemia in the second group was significantly higher (after 180 min) in capillary than in venous blood, which suggests slower bacterial clearance in capillary than in venous blood. However, clearance was more efficient with the inoculum of 10(7) E. faecalis than with the first type of inoculum. These experimental data confirm the greater sensitivity of capillary rather than venous sampling, which we have already observed in chickens, under similar experimental conditions, with Escherichia coli K12. Persistence of bacteria in the capillaries could account for the higher level of sensitivity of capillary microblood culture than venous blood culture, which is in agreement with the capillary trapping hypothesis of Knudson and Alden.