Pathological, microbiological and immunohistochemical characterization of avian colibacillosis in broiler chickens of Mozambique

ABSTRACT: Avian colibacillosis is an acute and globally occurring infectious disease of domestic wild birds caused by Escherichia coli, it associated with considerable economic losses mainly due to the morbidity mortality associated. The present study aimed describe pathological, bacteriological immunohistochemical aspects avian in broiler chickens Mozambique. Forty-nine chicken presented anorexia, decreased weight gain, ataxia, diarrhea, dyspnea, death a clinical course 3-5 days. were raised five farms (small, medium large farms) manual automatic breeding system, flocks ranging from 100 20,000 birds. At necropsy, all had poor body condition, pericardium Glisson’s capsule exhibited different degrees adherence often severe fibrin deposition. thoracic abdominal air sacs thickened adhered costal wall. Mild, moderate or marked hepatomegaly white pinpoint multifocal areas (100%, 49/49) mild splenomegaly 75.5% (37/49) mottled surface observed. lungs kidney enlarged reddish. Histologically, multiorgan fibrinoheterophilic polyserositis was observed cases (37/49), which characterized inflammatory infiltrates composed degenerative heterophils, macrophages plasma cells, deposits intermixed coccobacillary bacterial basophilic aggregates. These affected (28.6%, 14/49), pleura (18.4%, 9/49), (10.2%, 5/49), ventriculus (10.2, 5/33), proventriculus (8.2%, 4/49) serosa. Multifocal coalescing coagulative necrosis similar cells spleen liver (24.5%, 12/49), intestines (22.4%, 11/49). A infiltrate also affecting (16.3%, 8/49), 8/49) myocardium (14.3%, 7/49). Isolation identification E. coli obtained 12 through culture. Some organs (2 each selected submitted immunohistochemistry anti-E. positive stain tested (3/3), heart (4/4), (1/1), bursa Fabricius (1/1) tissue sections. results demonstrate that cause these Therefore, biosecurity management measures should be employed prevent control occurrence Mozambique’s poultry farming.