Gustavo Rodrigues Queiroz

Molecular characterization of encephalitic bovine listeriosis from southern Brazil.

Reports of bovine listeriosis in Brazil are uncommon, being restricted to citations within retrospective studies, resulting in scarce documented information of this important disease of cattle. This manuscript describes the molecular findings associated with spontaneous encephalitic listeriosis in two steers from distinct herds within the state of Paraná, southern Brazil. Both animals demonstrated altered consciousness suggestive of brain stem dysfunctions and died a few days after the initial onset of disease. Polymerase chain reaction (PCR) assays were designed to target specific genes of infectious neurological agents of cattle. These included bovine herpesvirus 1 and 5 (BoHV-1 and BoHV-5), ovine herpesvirus 2 (OvHV-2), Listeria monocytogenes, and Histophilus somni. Rabies virus was discarded in evaluations done at the official state diagnostic laboratory. Gross alterations were insignificant; histopathology demonstrated rhombencephalitis associated with macrophage-predominant, multifocal to coalescing microabscesses and extensive perivascular cuffings in both steers. The L. monocytogenes PCR assay amplified the 172-bp amplicon of the listeriolysin gene from the brain stem of both animals and from the telencephalon, thalamus, and cerebellum of one of them. Phylogenetic analyses demonstrated that the strains derived from this study clustered with known strains of L. monocytogenes lineage I. The BoHV-1 and BoHV-5, OvHV-2, and H. somni PCR assays were negative. These results confirm the participation of L. monocytogenes lineage I in the etiopathogenesis of the neurological disease herein described and represent the first complete description of encephalitic listeriosis in cattle from Brazil.

Intoxicação espontânea de bovinos por Senna obtusifolia no Estado do Paraná

Plants of the genus Senna cause a degenerative myopathy in cattle and most of the reports refer to Senna occidentalis. The aim of this paper is to report, for the second time in Brazil, an outbreak of natural poisoning by Senna obtusifolia. It happened in the northwestern Parana in a herd of 200 cows, 45 to 152 months of age, which had been placed into a feedlot to improve their nutritional status before the calving period. The cows stayed for eight days in this feedlot infested by the plant. Four to nine days after they got into the feedlot, 20 cows became ill and only one recovered. The clinical signs consisted of myoglobinuria, incoordination and permanent sternal recumbency. The affected cows showed increased activity of creatine phosphokinase, aspartate aminotransferase, gama-glutamyltransferase, and alkaline phosphatase. The main postmortem changes were in skeletal muscles of the hind limbs characterized by pale areas. The histological alterations were multifocal segmental necrosis of skeletal muscles and hepatic multifocal paracentral necrosis. Epidemiological, clinical and pathological data led to the diagnosis of Senna obtusifolia poisoning. The plant showed miotoxic and hepatotoxic effects on the poisoned animals and the disease was almost always lethal.

Cerebral Cryptococcomas in a Cow

Cerebral cryptococcomas are described in a 5-year-old mixed-breed cow without manifestations of systemic cryptococcosis. Two cryptococcomas were observed grossly. Microscopical examination revealed accumulations of yeast that were morphologically consistent with Cryptococcus neoformans. Immunohistochemistry characterized the organisms as C. neoformans var. grubii.

Meningoencefalite trombótica-induzida por Histophilus somni em bovinos da região norte do Paraná

Thrombotic meningoencephalitis (TME) is a fatal neurological disease of cattle, predominantly from North America, that is caused by Histophilus somniwith sporadic descriptions from other countries. This manuscript describes the occurrence of spontaneous TME in cattle from northern Parana, Brazil. Most cattle had acute neurological manifestations characteristic of brain dysfunction. Hematological and cerebrospinal fluid analyses were not suggestive of bacterial infections of the brain. Histopathology revealed meningoencephalitis with vasculitis and thrombosis of small vessels that contained discrete neutrophilic and/or lymphocytic infiltrates admixed with fibrin at the brainstem, cerebral cortex, and trigeminal nerve ganglion of all animals. All tissues from the central nervous system used during this study were previously characterized as negative for rabies virus by the direct immunofluorescence assay. PCR and RT-PCR assays investigated the participation of infectious agents associated with bovine neurological disease by targeting specific genes of H. somni, Listeria monocytogenes, bovine herpesvirus -1 and -5, bovine viral diarrhea virus, and ovine herpesvirus-2. PCR and subsequent sequencing resulted in partial fragments of the 16S rRNA gene of H. somni from brain sections of all animals with histopathological diagnosis of TME; all other PCR/RT-PCR assays were negative. These findings confirmed the participation of H. somni in the neuropathological disease observed in these animals, extend the geographical distribution of this disease, and support previous findings of H. somni from Brazil.

Presence of BoHV-5 genome in cerebrospinal fluid of cattle with herpetic meningoencephalitis

The diagnosis of bovine herpesvirus 5 (BoHV-5) encephalitis is confirmed after death by laboratory methods applied to brain fragments. Alternative methods to confirm ante-mortem diagnosis are important because the disease is not always lethal. The aim of this study was to investigate whether the presence of the virus genome in the cerebrospinal fluid (CSF) detected by polymerase chain reaction (PCR) might be admitted as a method for ante-mortem diagnosis. CSF samples were taken from 14 animals suffering from BoHV-5 encephalitis, diagnosed by characteristic histopathological lesions in the brain and by identification of the virus genome by PCR in different portions of the brain. Virus DNA was detected in the CSF of 21.42% (3/14) of the evaluated animals. Ante-mortem detection of the virus genome in the CSF showed low sensitivity to confirm the diagnosis. The diagnosis is confirmed by a positive result but a negative one does not discard the disease.

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

Abstract The objective of this study was to describe and compare the changes in the cerebrospinal fluid (CSF) of cattle affected by rabies or BoHV-5 meningoencephalitis and correlating them with the severity of central nervous system (CNS) inflammation. Samples of CSF and CNS tissues from cattle naturally infected with rabies virus (n = 17) and BoHV-5 (n = 17) were examined. Histologically, meningitis was classified according to the type and quantity of inflammatory cells. The lesions observed in the brain parenchyma and in the spinal cord that defined the presence of inflammatory process were perivascular cuffs, gliosis and glial nodules. CSF mononuclear pleocytosis and high protein concentration were present in both diseases, but 47% of rabies cattle had no changes, and the median number of leukocytes was 5.4 fold higher (p