Teores de cobre, zinco e ferro no fígado de búfalos (Bubalus bubalis) com paratuberculose

Abstract

In order to study copper, zinc and iron concentration in the liver of buffaloes with paratuberculosis (PTB), 13 buffalo cows above three years of age of the Murrah and Mediterranean races or their crosses were used. They originated from two farms in the municipalities of São Luís and São Mateus, state of Maranhão, Brazil. The animals were selected according to clinical signs of paratuberculosis, as diarrhea, dehydration and submandibular edema. Rectal biopsies for detection of Mycobacterium avium subsp. paratuberculosis (Map) through PCR in real time (qPCR) and Ziehl-Neelsen (ZN) stain were performed on all animals. Seven buffaloes revealed positive and six were negative for PTB. They were separated into two groups: Group 1 contained seven buffaloes positive for paratuberculosis, and Group 2 contained six animals negative for paratuberculosis. They were euthanized and postmortem examination was performed for the collection of various tissue samples to be fixed in 10% formalin for histopathology; also liver tissue samples were collected to be frozen for chemical analysis of trace minerals (Cu, Zn and Fe). Postmortem showed that all buffaloes with PTB had brown colored mesenteric lymphnodes, indicating hemosiderosis. One buffalo had brown spots on the mucosa of the small intestine. Histopathology revealed moderate to severe hemosiderosis of the spleen in buffaloes of Group 1. All animals positive for PTB showed micromineral levels below the reference values. The average Cu concentration in buffaloes with PTB was only 18.0ppm and the one of Zn only 68.6ppm. In Group 2, negative for PTB, the average Cu concentration was 113.7ppm and the one of Zn 110.0ppm. Fe concentrations in buffaloes of both groups were high (>669ppm). The analysis of trace elements in the liver confirmed copper deficiency, but also showed low levels of zinc and high levels of iron. Based on clinical and pathological findings, and the micromineral concentrations found in the liver, it is concluded that paratuberculosis could lead to mineral deficiency and worsen the clinical condition of the buffaloes.