ERYTHROCYTE OSMOTIC FRAGILITY IN ZEBU CATTLE EXPERIMENTALLY INFECTED WITH Clostridium chauvoei

摘要

The mechanisms underlining the response of erythrocytes to osmotic stress (erythrocyte osmotic fragility EOF) in blackleg are poorly understood. In the present study, 14 Zebu cattle were experimentally administered Clostridium chauvoei (n=4), neuraminidase (n=4) and toxins (n=3) produced by C. chauvoei, including a control group (n=3) to determine the possible role of neuraminidase produced by the bacteria in the pathogenesis of deranged erythrocyte osmotic fragility. It was observed that on day zeroof the experiment, the erythrocytes of Zebu cattle in all the experimental groups investigated were highly resistant to haemolysis in physiological saline (PSS). The percentage haemolysis of erythrocytes in PSS increased or decreased as the experiment progressed, with peak values recorded on day 3 in the C. chauvoèi-infected (56.98±1.13%) and neuraminidase-administered (53.68±9.58%), compared to the toxin-administered (0.17±0.08%) and control (0.17±0.08%) groups respectively. The erythrocytes of the C. chauvoei-infected and neuraminidase-administered groups remained fragile up to day 21 when the experiment was terminated. The possible role of neuraminidase in the increased EOF observed is discussed.