Cerebrospinal fluid changes in cattle with rabies or with BoHV-5 meningoencephalitis and its correlation with the severity of CNS inflammatory process

Fosfomycin modifies the replication kinetics of bovine alphaherpesvirus-1 and reduces the timing of its protein expression on bovine (MDBK) and human (SH-SY5Y) cell lines

Bovine alphaherpesvirus 1 (BoAHV-1) predisposes cattle to respiratory secondary bacterial infections, which can be treated with the broad-spectrum antibiotic fosfomycin. This drug also suppresses NF-kB activity and pro-inflammatory responses. Therefore, cattle may be exposed to an interaction between the virus and the antibiotic which may have effects on it. The aim of this study was to determine the effect of calcium fosfomycin (580 µg/mL) on BoAHV-1 (moi = 0.1) replication. Two cell lines (MDBK and SH-SY5Y) were used in this study. Our results show that fosfomycin has novel properties. By MTT assay we have shown that it is non-cytotoxic for any of the cell lines. Extracellular and intracellular viral titers demonstrated that fosfomycin has a cell-type and time-dependent effect on BoAHV-1 replication. By direct immunofluorescence it was shown that it reduces the timing of BoAHV-1 protein expression, and by qPCR, we found that its effect on NF-kB mRNA expression depends on the cell type.

Cerebrospinal fluid analysis in 58 ruminants showing neurological disorders

ABSTRACT: Ruminants may be affected by a wide variety of central nervous system (CNS) diseases. Cerebrospinal fluid (CSF) analysis forms the basis for ante mortem diagnostic evaluation of ruminants with clinical signs involving the CNS. Despite its importance as a tool to aid diagnosis, data regarding CSF examinations in spontaneous cases of CNS diseases in ruminants from Brazil are limited, and most reports involve experimental studies. Therefore, this study aimed to report the results of CSF analysis in 58 ruminants showing signs of neurological disorders. CSF samples for analysis were obtained from 32 cattle, 20 sheep, and 6 goats by cerebello-medullary cistern (n=54) or lumbosacral space (n=4) puncture. These ruminants showed neurological signs related to viral (n=13), mycotic (n=3), or bacterial (n=15) infections, and toxic (n=21), traumatic (n=4), or congenital disorders (n=2). CSF analysis from ruminants with viral infections presented lymphocytic pleocytosis, even though CSF showed no changes in several cases of rabies. Neutrophilic pleocytosis, cloudiness, presence of fibrin clots, and abnormal coloration were evident in the CSF of most cases of CNS bacterial infection, such as meningoencephalitis, meningitis, abscesses, myelitis, and a case of conidiobolomycosis. On the other hand, CSF was unchanged in most cases of toxic disorders, as botulism and hepatic encephalopathy. Elevated CSF density was observed in 60% of ruminants diagnosed with polioencephalomalacia. Our findings show that evaluation of CSF is a valuable diagnostic tool when used in association with epidemiological, clinical and pathological findings for diagnosis of CNS diseases in ruminants.

Immunohistochemical Detection of Intralesional Antigens of Ovine Gammaherpesvirus-2 in Cattle with Sheep-associated Malignant Catarrhal Fever

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe lymphoproliferative disease of ruminants caused by ovine gammaherpesvirus-2 (OvHV-2). Since the initial identification of SA-MCF there has been extensive research related to the pathogenesis of OvHV-2, based primarily on serological and molecular assays associated with typical histopathological findings. The monoclonal antibody (MAb-15A) binds to a common epitope in MCF viruses and is used frequently in serological investigations. However, the utilization of this antibody to detect antigens of OvHV-2 in tissues has not been examined. Accordingly, this study standardized an immunohistochemical assay using MAb-15A to identify antigens of OvHV-2 in tissues of cattle (n = 5) with SA-MCF. All animals developed acute neurological signs, without ocular and nasal manifestations, and had nucleic acids of OvHV-2 in brain tissue detected by polymerase chain reaction. The principal histopathological findings were lymphocytic nephritis (n = 5), widespread arterial proliferation and vasculitis (n = 5), lymphocytic portal hepatitis (n = 3), non-suppurative meningoencephalitis (n = 2) and atrophic enteritis with cryptal necrosis and dilation (n = 2). Intralesional intracytoplasmic antigens of OvHV-2 were identified within multiple epithelial cells of the kidneys of all animals, the intestines of animals with and without atrophic enteritis, and within epithelial cells of bile ducts in animals with lymphocytic hepatitis. Additionally, there was positive intracytoplasmic immunoreactivity within histiocytes and lymphocytes in several tissues. These findings suggest that the MAb-15A detects antigens of OvHV-2 within epithelial cells and leucocytes in several organs. Moreover, this assay would contribute significantly towards understanding of the pathogenesis of SA-MCF and may be used for retrospective studies. Additionally, angiopathy in SA-MCF may be a progressive lesion, which may terminate in luminal occlusion and probably occurs irrespectively of the eye and head form of MCF.