Comparative pathogenicity of Listeria isolates

The pathogenic potential of 30 Listeria spp. isolates from female reproduct ive disorders in buffaloes, cows, goats and sheep were tested in mice and g uinea pigs. The infected mice that succumbed to infection during 2-5 days w ere mostly identified as L. monocytogenes and whereas those identified as L . ivanovii died during 7-13 DPI. The infected mice that did not succumb to infection were sacrificed one each on 13th and on 20th DPI and invariably w ere L. grayi, L. welshimeri and L. innocua. All the mice were subjected to necropsy, the intensity of gross lesions on liver, spleen and heart compris ed congestion, haemorrhages and scattered necrotic foci. The histopathologi cal investigations of these tissues confirmed the gross lesions. The reisol ation of the organisms from infected mice were invariably successful.