Background: This study was carried out to identify important zoonotic diseases of beef cattle at slaughter in Bangladesh. Methods: A total of 20 slaughtered cattle of both sexes, different ages and breeds were taken under investigation from Nilphamari, Rajshahi and Mymensingh district, Bangladesh during July to October, 2017. Detailed ante-mortem and post-slaughter lesions were inspected and the tissues from the lungs, liver, kidney and spleen were collected aseptically for histopathological examination. The tissue sections were processed and stained with hematoxylin and eosin (H&E) stain, acid fast stain and Gram stain. To detect the presence of specific microorganism in the tissues, the genomic DNA was extracted and polymerase chain reaction (PCR) was carried out. Results: Grossly, liver appeared as most affected organ followed by lungs, kidney and spleen. Wide spread necrosis and pipe steam liver due to fascioliasis (n=4), hydatidosis in lungs (n=3), congestion in the kidney (n=4) and petechial hemorrhage (n=2) in the spleen were the predominant lesions observed in the slaughtered cattle. H&E staining of tissue sections revealed granulomas in two liver and one lungs. Lung section stained with acid fast stain detected the acid fast bacilli in a case. Tissue sections stained with Gram stain showed cocci bacteria in the liver of two cattle. The PCR confirmed the presence of Mycobacterium tuberculosis in a cattle. Conclusions: Fascioliasis, hydatidosis and important zoonotic disease like tuberculosis are prevalent in the slaughtered cattle in Bangladesh. PCR technology appeared as a sensitive and specific screening test to diagnose tuberculosis. However, screening of large number of samples is necessary to detect the presence of important zoonotic diseases in cattle for safe beef production.

Objective: Here, we developed and tested the efficacy of a vaccination protocol based on a commercially available live attenuated Salmonella enterica serovar Gallinarum (Salmonella galli¬narum) in layer chickens. Materials and Methods: 50 layer chickens of 16 weeks age were obtained and divided into two groups (n = 25), control and vaccinated. The vaccinated group received Salmonella vaccine at 0.2 ml/bird, s/c route at 16, 18, 30, and 42 weeks of age. At 21 weeks of age, birds from both groups were challenged with S. gallinarum orally at 4 × 107 colony-forming unit per bird. Results: Both rapid serum plate agglutination and enzyme-linked immunosorbent assay demonstrated a rising rate of seroconversion in vaccinated birds across the study period, with a 4% positive rate at 18 weeks, 56% at 21 weeks, 60% at 30 weeks, and 64% at each time point of 42 and 54 weeks. The vaccine showed 100% clinical protection and reduced the Salmonella shedding in the feces and eggs of the challenged birds. On the contrary, the unvaccinated challenged birds showed clinical signs and lesions typical of Salmonella infections with morbidity and mortality rates of 36% and 20%, respectively, and had high rates of Salmonella shedding in feces and eggs. Conclusions: With the proposed vaccination schedule Salmonella shedding was prevented, and a high seroconversion was confirmed. To prevent Salmonella infections in laying flocks, a 3-month interval immunization program is advised starting at the pre-laying stage.