Avaliação biológica, bioquímica e histopatológica das infecções experimentais causadas por Plasmodium (Bennettinia) juxtanucleare Versiani & Gomes, 1941 e Borrelia anserina (Sakharoff, 1891) em Gallus gallus L. 1758

Abstract

Plasmodium juxtanucleare and Borrelia anserina are common pathogens in domestic and wild birds, they can cause serious damages in the birds, especially those created organically, drugs free and not confined. These pathogens are related to anemia, diarrhea, inflammation, damage to vital organs, limb paralysis, anorexia, weight loss and reduction in egg production. This mixed infection can occur naturally among birds, but this subject is poorly studied, for this reason the present survey aimed to evaluate the biological, biochemical and histopathological features of infections caused by P. juxtanucleare and B. anserina in Gallus gallus. For this experiment, initially a search for birds infected by P. juxtanucleare was made in the Seropedica City, RJ. Two hundred thirty four birds, among them ducks, widgeons, geese, turkeys and chickens were sampled. Plasmodia were isolated from blood of chickens of Silky Japan’s breed for experimental inoculations. The plasmodia were characterized based on morphology and morphometry, and the species confirmed by molecular technique. Experimental infections were performed in quails and ducks for the infectivity of the P. juxtanucleare isolate studies. Thereafter, for the biological, biochemical and histopathological studies, 48 Cobb chickens with one day old were acquired. At 60 days old the chicks were divided into four groups of 12 birds each: G1-uninfected control, G2-infected by P. juxtanucleare isolated from chicken of Silky Japan's breed of the Seropédica City, G3- infected by B. anserina strain cryopreserved and maintained in the Laboratory of Parasitic Diseases, Epidemiology and Public Health Department, Veterinary Institute, Federal Rural University of Rio de Janeiro and G4- infected by the same strain of P. juxtanucleare and B. anserina previously cited. Over 45 days, daily, the birds were observed for the presence of clinical signs of infection. Throughout the experiment blood smears were made from birds to parasitemia and spirochaetemia evaluation. Weekly, the serum enzymes alanine transaminase (ALT), aspartate transaminase (AST), uric acid, creatinine, total proteins were analyzed and in the experiment end histological sections of liver and kidney of birds in each experimental group were evaluated. The prevalence of P. juxtanucleare in chickens, ducks, widgeons, geese and turkeys was 56%, 28%, 32%, 40% and 50%, respectively, and the parasitemias averaged 0.12%, 0.08%, 0.02% 0.03% and 0.1%, respectively. Biomolecular and morphometric analysis of parasites isolated from chickens of Silky Japan’s bred confirm that the specie was P. juxtanucleare. Both ducks and quails subinoculated with P. juxtanucleare became infected, but with lower values of parasitaemia in relation to the bird donor. In Cobb breed chickens, the ALT activity was significantly higher in Groups 2, 3 and 4 compared to Group 1. The AST activity fluctuated but did not vary significantly between groups. Both enzymes also served as a marker of stress in birds. In histological liver sections of birds of Group 1 no marked changes were visualized, but in the histological liver sections of birds of Groups 2, 3 and 4 inflammatory infiltrates, swollen and vacuolated hepatocytes, extensive hemorrhages, proliferation of fibrous tissue in the portal space, congestion and dilation sinusoids and intrahepatic cholestasis were demonstrated. There was significant variation between the total protein concentrations in the experimental groups, and the birds of Group 4 had a higher average in relation to the others groups, and higher than the level considered normal for healthy birds. Serum uric acid was higher in the Group 2 and serum creatinine did not differ significantly between groups. Kidney histological analysis revealed nephritis, glomerulonephritis, congestion and hemorrhages in some areas of the kidneys of birds from Groups 2, 3 and 4. We concluded that the infections caused by P. juxtanucleare and B. anserina alone or in combination cause damage to birds, which can compromise them in production. The tools combination like history, parasitological analysis, clinical chemistry and histopathology in the study of infections caused by P.juxtanucleare and B. anserina in birds allowed a realistic picture of the overall health of the birds.