Bacterial colonization and endotoxin activity during experimental acute fowl typhoid in chickens

Abstract

These parameters were assayed by means of colony forming units test (CFU) and the Limulus Amebocyte Lysate test (LAL), respectively. Birds were infected per os with 1,5 x 109 CFU/ml of wild strain of S. gallinarum isolated from a dead hen. Approximately 1,5 x 102; 1,3 x 102 and 1,2 x 102 CFU of S. gallina rum were recorded from 1 g of liver, 1 g of spleen and 1 ml of blood from the chickens on day 1 post infection. By day 4 corresponding data were 3,7 x 104 ; 4,8 x 103 and 1,1 x 103 respectively and on day 7 105 CFU were present in all three specimen types. The liver and spleen of dead birds were contaminated with more than 107 CFU per g. The endotoxin from S. gallinarum was found to have an activity of 1,5; 12,0 and 15,0 endotoxin units (EU)/ml on day 1, 4 and 7 after infection, respectively. No endotoxin activity was established in the blood of the control group (before infection) by the LAL test. This is the first time the connection between the amount of live S. gallina rum in the blood, liver and the circulating level of endotoxin in the blood during the infectious stage of experimental acute fowl typhoid, has been demonstrated.