Mononuclear Leucocytes in Blood of Guinea Pigs Experimentally Infected with Pneumococcus

Abstract

In view of the importance attached by many observers to the role of mononuclear cells in recovery from infection and especially the concepts advanced by Robertson and his coworkers1234 in pneumococcal infection in dogs, the changes in the mononuclear cells in the circulating blood have been studied in guinea pigs that died and that recovered spontaneously from experimental pneumococcal infection. The animals were infected by intraabdominal injection of 0.25 cc of an 18-hour dextrose-serum-broth culture of Type I pneumococcus. Of 100 animals so infected 47 survived the infection. In this study of the mononuclear leucocytes 14 animals that died from 60 hours to 30 days after infection (Group C), 18 that recovered at 5 to 9 days after infection (Group D), and 14 that recovered on the fourth day (Group E) are considered. Recovery was assumed to have occurred on the day a negative culture was obtained from the peritoneal exudate.At 6 hours after infection there was a decrease in the number of circulating monon...