Histopathological Changes in the Liver and Spleen of Common Carp Cyprinus carpio L. Challenge with Pseudomonas aeruginosa (Schroeter, 1872) Fed with Dietary Chitosan and Ciprofloxacin

Abstract

The current study was conducted for 90 days in order to study the efficacy of dietary chitosan and antibiotic ciprofloxacin supplement as a resistance and presentation of fishes against the bacteria (Pseudomonas aeruginosa) by effect on liver and spleen of fishes. The fishes were divided into four categories of groups at two periods; the former at infection (at 90th day of feeding period) and the latter at post infection (14 days after the challenge period). The first and second groups (T1 and T2) were considered as negative and positive controls (both fed on standard diet), respectively, while the third and fourth groups (T3 and T4) represent dietary chitosan and dietary antibiotic supplement, respectively. All groups, except T1, were challenged by bacteria at 90th day of feeding period. Liver of positive control revealed severe degeneration, especially around hepatic vein with congestion and fibrosis, while the spleen exhibited haemorrhage, lymphocytosis and lymphatic accumulation of white pulp with hemosiderin. The histopathological changes in liver of chitosan group at the infection period were characterized by vacuolation, inflammatory cells and hemorrhage, while necrosis and swelling of hepatocytes and infiltration with inflammatory cells at post infection period. The spleen at the infection period was suffered from leukocytosis, accumulation of inflammatory cells and macrophages, presence of focus from phagocytic macrophages. The liver in antibiotic group of infection period displayed narrowing of the sinusoid, swelling of hepatocytes and infiltration with inflammatory cells, hyperplasia in the bile duct, while the abnormal accumulation of lymphatic follicles. At postinfection period, the spleen showed thickness at the wall capsule, presence of homogeneous pinkish matter around arteriole in the red pulp and lymphocytosis in the white pulp. The supplemented chitosan groups showed a significant decrease in the mortality percentage . The supplemented chitosan groups showed a significant decrease in the mortality percentage.