Expression of Acute Phase Protein, Glial Fibrillary Acidic Protein, Epithelial Cadherin, and S100 Protein in Brain Tissues from Natural Cases of Ovine Encephalitic Listeriosis.

Listeriosis is a disease that is induced by infection with the Gram-positive bacterium Listeria monocytogenes. Much is still unknown about the pathogenesis of encephalitic listeriosis. We aimed to identify the contribution of glial fibrillary acidic protein (GFAP), epithelial cadherin (E-cadherin), S100, and acute-phase proteins (APPs) in pathogenesis, clinical and preclinical diagnosis of natural cases of encephalitic listeriosis. Of 1,325 Ossimi sheep, 64 were suspected of having listeriosis from 2018 to 2020. Prospective cohort evaluation of clinical and postmortem findings was performed, in addition to bacterial isolation, the measurement of APPs in serum and cerebrospinal fluid (CSF), and the histopathological and immunohistochemical evaluation of GFAP, S100, and E-cadherin. Infected sheep showed nervous symptoms ranging from neck stretching to complete paralysis. APPs were significantly increased in the CSF of both clinically and preclinically diseased animals; however, serum APPs were only significantly increased in clinically diseased animals. Histopathological evaluation revealed microabscesses, meningoencephalitis, and perivascular cuffing of the brainstem of infected sheep. Immunohistochemical investigations revealed strong expression of GFAP and S100 in necrotic areas and negative expression of E-cadherin. The measurement of CSF APPs could be useful in the preclinical diagnosis of sheep listeriosis. GFAP and S100 proteins could be involved in the pathogenesis of listeriosis; however, E-cadherin does not appear to be involved.

Endothelin-1 downregulates sperm phagocytosis by neutrophils in vitro: A physiological implication in bovine oviduct immunity.

The oviduct is an active contractile tube that provides the proper environment for sperm transport, capacitation and survival. Oviductal contractions are regulated by autocrine/paracrine secretion of several factors, such as prostaglandins (PGs) and endothelin-1 (EDN-1). We have previously shown that during the preovulatory stage, sperm are exposed to polymorphonuclear neutrophils (PMNs) in the bovine oviduct, and the bovine oviduct epithelial cells (BOECs) secrete molecules including PGE2 that suppress sperm phagocytosis by PMNs in vitro. In this study, we investigated the possible effects of EDN-1 on the phagocytic activity of PMNs toward sperm. The local concentrations of EDN-1 in oviduct fluid and BOEC culture medium ranged from 10(-10) to 10(-11) M as determined by EIA. Phagocytosis and superoxide production were assayed by co-incubation of sperm pretreated to induce capacitation with PMNs exposed to EDN-1 (0, 10(-11), 10(-10), 10(-9), and 10(-8) M) for 2 h. EDN-1 suppressed dose dependently (10(-11) to 10(-8) M) the phagocytic activity for sperm and superoxide production of PMNs in response to capacitated sperm. Moreover, this suppression was eliminated by an ETB receptor antagonist (BQ-788). EDN-1 suppressed mRNA expression of EDN-1 and ETB but not ETA receptors in PMNs, suggesting the ETB receptor-mediated pathway. Scanning electron microscopic observation revealed that incubation of PMNs with EDN-1 (10(-9) M) completely suppressed the formation of DNA-based neutrophil extracellular traps for sperm entanglement. The results provide evidence indicating that EDN-1 may be involved in the protection of sperm from phagocytosis by PMNs in the bovine oviduct, supporting sperm survival until fertilization.

Hepatic biomarkers and coprology as indicators of clinical bovine fasciolosis in Chad.

BACKGROUND AND AIM: Fasciolosis is a cosmopolitan parasitic disease of food-producing animals and is typically caused by digenetic trematodes, Fasciola gigantica and Fasciola hepatica. It has a direct negative impact on the liver and consequently affects liver metabolism. It has indirect effects, including lowered milk production and effects on quality and general health conditions leading to extensive economic losses. This study aimed to focus on the link between clinical fasciolosis and some biochemical analysis of the hepatic profile of cattle in Chad. MATERIALS AND METHODS: This study was initiated in response to emerging complaints from dairy cattle owners detecting a bitter milk cream and butter taste. Furthermore, those animals had shown poor health conditions by presenting with diarrhea. Preliminary surveillance for possible causes was performed, including fecal and serum biochemical analyses and clinical observation to diagnose the possible disease. RESULTS: The results obtained, including the finding of parasite stages during the coprological examination, confirmed the role of fasciolosis. The independent sample t-test indicated highly significantly altered values of all biochemical liver indicators in the infected animals. All animals were treated with two doses of rafoxanide (3 mg/kg b.w.) S/C, at 21 days intervals, with vitamin supplements, mineral mixtures, and food additives. Surprisingly, the main complaint was restored after treatment. This is another evident clue of fasciolosis. To the best of our knowledge, this is the first recent study that diagnosed fasciolosis in Chad. CONCLUSION: This study emphasized the importance of fasciolosis, its negative impact on milk taste, and the necessity for veterinary advice regarding routine examination and prophylactic measures, especially before autumn, to minimize economic losses. However, regardless of the small sample size, this study could serve as a cornerstone for future studies on evaluating the accurate epidemiological status of fasciolosis in Chad. This study reported a close association between the alteration of liver enzymes and total protein levels in fasciolosis and the bitter milk cream taste, which could be used as a diagnostic tool for fasciolosis.