East Coast Fever Caused by Theileria parva Is Characterized by Macrophage Activation Associated with Vasculitis and Respiratory Failure

Respiratory failure and death in East Coast Fever (ECF), a clinical syndrome of African cattle caused by the apicomplexan parasite Theileria parva, has historically been attributed to pulmonary infiltration by infected lymphocytes. However, immunohistochemical staining of tissue from T. parva infected cattle revealed large numbers of CD3- and CD20-negative intralesional mononuclear cells. Due to this finding, we hypothesized that macrophages play an important role in Theileria parva disease pathogenesis. Data presented here demonstrates that terminal ECF in both Holstein and Boran cattle is largely due to multisystemic histiocytic responses and resultant tissue damage. Furthermore, the combination of these histologic changes with the clinical findings, including lymphadenopathy, prolonged pyrexia, multi-lineage leukopenia, and thrombocytopenia is consistent with macrophage activation syndrome. All animals that succumbed to infection exhibited lymphohistiocytic vasculitis of small to medium caliber blood and lymphatic vessels. In pulmonary, lymphoid, splenic and hepatic tissues from Holstein cattle, the majority of intralesional macrophages were positive for CD163, and often expressed large amounts of IL-17. These data define a terminal ECF pathogenesis in which parasite-driven lymphoproliferation leads to secondary systemic macrophage activation syndrome, mononuclear vasculitis, pulmonary edema, respiratory failure and death. The accompanying macrophage phenotype defined by CD163 and IL-17 is presented in the context of this pathogenesis

Investigation of Lesions In Goat Brain Collected From Abattoirs in Rajshahi Metropolitan Area

Brain lesions are important cause of morbidity and reduced productivity in goats worldwide. Works on brain lesion in goats are extremely rare in Bangladesh and remain to be investigated. We investigated lesions in goat brains collected from abattoirs in Rajshahi Metropolitan area by gross and microscopic examination. Randomly selected 57 goat brains were investigated of which 24.56% brains showed gross and histopathologic lesions. Prevalence of brain lesions were higher in Jamnapari goats (29.41%) compared to in Black Bengal goats (22.50%) and female goats (26.47%) were more affected than male goats (21.74%). Age-wise prevalence were 31.25%, 21.43%, 12.50%, and 40.00% in the age of up to 2 years, 2-3 years, 3-4 years, and above 4 years old goats, respectively. Goats were more affected in the rainy (35.29%) season in contrast to in the winter (23.53%) and in the summer (10.52%) seasons. The brains collected from goats with Gid disease showed uni or multilocular cysts containing clear fluid and multiple scolices, the rest of the brains were apparently healthy by macroscopic examination. Histopathologically, pyogranuloma, perivascular cuffing, gliosis, neuronal degeneration, hemorrhages, congestion and thrombus were evident. J. Bio-Sci. 29(1): 49-58, 2021 (June)</jats:p

Salinity negatively correlates with the production and immunity of chicken: A molecular insight for food security and safety issues

Salinity intrusion into the freshwater system due to climate change and anthropogenic activities is a growing global concern, which has made humans and domesticated animals more susceptible to diseases, resulting in less productivity. However, the effects of salinity on domesticated and wild birds, especially in terms of production and immunity, have not been fully elucidated yet. Therefore, this study was designed to examine the effects of salinity on the production and immunity of birds and the mechanisms by which immunity is compromised. Broiler chicks were subjected to different concentrations of salty water (control = normal water, treatment = 5 g/L, treatment = 10 g/L, and treatment = 15 g/L). The collected blood and organs from different groups of broilers were biochemically and histopathologically examined. Birds in salt-treated groups consumed significantly less feed than the control group, while the feed conversion ratio (FCR) was significantly higher. Body weight gain was significantly lower in salt-treated groups compared to control. Serum analysis revealed a lower systemic antibody titer in the salt-treated groups compared to the control. Primary lymphoid organs (thymus and bursa of Fabricius) were reduced in size in the salt-treated group due to cellular migration and depletion from these organs. Importantly, most of the parenchyma of lymphoid organs was replaced with fibrotic tissue. Gut microbes, Escherichia coli (E. coli) and Salmonella spp., from salt-treated groups, showed less viability but developed antibiotic resistance. Levels of salinity were significantly and negatively correlated with feed intake, body weight gain, antibody titer, lymphoid organ size, and viable count of gut microbes, while FCR, fibrosis of lymphoid organs, and antibiotic resistance were significant positively correlated. In conclusion, increased salinity is a possible threat to food security and safety as it decreases body weight gain, reduces immunity, and influences the development of multi-drug resistance in gut microbes