Diagnosis of Bovine Genital Campylobacteriosis in South America

Bovine genital campylobacteriosis (BGC) is a venereal infectious disease that affects reproduction. It is caused by the Gram-negative bacillus Campylobacter fetus subspecies venerealis (Cfv), which may include the biotype intermedius. The bull is a lifelong asymptomatic carrier and transmitter of the disease. In females Cfv may cause infertility and sporadic abortion. The objective of this study is to review and discuss methods for the diagnosis of BGC, its prevalence and economic impact in South America. BGC is a worldwide distributed disease and can cause a pregnancy rate decrease of 15–25%. The farm prevalence of BGC in different regions of South American countries shows a variation between 2.3 and 100%. Discrepancies may depend on the differences on sanitary, management, and reproductive practices between farms and regions, but also on the interpretation of different diagnostic tests. Currently known laboratory tests include bacterial culture, direct immunofluorescence, immunoenzymatic assays, vaginal mucus agglutination test, PCR-based methods, histology and immunohistochemistry, which are applied and interpreted in diagnostic laboratories at different scales. Epidemiologic data of BGC in South America should be interpreted with caution. High prevalence has been reported in some studies, although the low specificity of the diagnostic tests used could lead to an overestimation of the results

The First Case of Bovine Astrovirus-Associated Encephalitis in the Southern Hemisphere (Uruguay), Uncovers Evidence of Viral Introduction to the Americas From Europe.

Astrovirus species members of the Mamastrovirus genus (family Astroviridae) have been increasingly recognized as neuroinvasive pathogens in various mammals, including humans, mink, cattle, sheep, and pigs. While cases of astrovirus-associated encephalitis have been reported in North America, Europe, and Asia, their presence has never been documented in the Southern hemisphere. This paper describes a case of astrovirus-associated encephalitis in cattle in Uruguay that broadens the geographic distribution and genetic diversity of neuroinvasive astroviruses and provides phylogeographic evidence of viral introduction to the Americas from Europe. A 22-month-old Holstein steer from a farm in Colonia Department, Uruguay developed progressive neurological signs over a 3-days period before dying. Histopathological examination of the brain and proximal cervical spinal cord revealed disseminated, moderate to severe lymphocytic, histiocytic, and plasmacytic poliomeningoencephalomyelitis with neuronal necrosis. A Mamastrovirus strain in the CH13/NeuroS1 clade, that we called bovine astrovirus (BoAstV)-Neuro-Uy, was identified by reverse transcriptase PCR followed by nearly complete genome sequencing. Additionally, BoAstV was detected intralesionally in the brain by chromogenic RNA in situ hybridization within neuronal perikarya, axons and dendrites. Phylogenetic analysis of BoAstV-Neuro-Uy revealed a close relationship to neurotropic BoAstVs within the Virginia/Human-Mink-Ovine clade, which contains a growing cadre of neuroinvasive astroviruses. Analyzing the complete coding region of neuroinvasive BoAstVs sequences available in GenBank, we estimated an evolutionary rate of 4.27 × 10-4 (95% HPD 2.19-6.46 × 10-4) nucleotide substitutions/site/year. Phylogeographic analysis suggests that the common viral ancestor circulated in Europe between 1794-1940, and was introduced in Uruguay between 1849-1967, to later spread to North America and Japan

Abortion outbreak caused by Campylobacter fetus subspecies venerealis and Neospora caninum in a bovine dairy herd

In November 2015, an abortion outbreak occurred in a commercial dairy herd of 650 Holstein cows in Florida department, Uruguay. Forty-five (45) cows aborted within 3 wk. Five fetuses were subjected to gross and microscopic pathologic examination, and microbiological testing. One fetus had fibrinous epicarditis and peritonitis, and neutrophilic bronchopneumonia. Campylobacter fetus subsp. venerealis was detected by direct immunofluorescence, isolated and identified by PCR and sequencing of the 16S rDNA in the abomasal fluid and/or lung. Histologic examination of two other fetuses revealed nonsuppurative necrotizing encephalitis, lymphohistiocytic myositis and myocarditis, and lymphocytic interstitial nephritis. In these fetuses, N. caninum antigen was detected intralesionally by immunohistochemistry, and N. caninum DNA was amplified by PCR on formalin-fixed paraffin-embedded brain. Antibodies against N. caninum were detected by indirect immunofluorescence in 10 of 27 cows, with titers ranging from 1/200 to 1/3200. The results indicate that two abortigenic microorganisms may coexist and cause contemporaneous abortion in a herd. It is relevant to highlight the importance of performing multiple diagnostic tests in various aborted dams and fetuses from the same herd for the etiologic confirmation of bovine abortion syndromeEn noviembre de 2015 ocurrió un brote de abortos en un hato lechero comercial de 650 vacas Holstein en el departamento de Florida, Uruguay. Cuarenta y cinco (45) vacas abortaron en un lapso de 3 semanas. Cinco fetos fueron sometidos a un examen patológico macro y microscópico y a pruebas microbiológicas. Un feto tenía epicarditis fibrinosa y peritonitis, así como bronconeumonía neutrofílica. Se detectó Campylobacter fetus subesp. venerealis utilizando inmunofluorescencia directa; se lo aisló e identificó mediante PCR y secuenciación del 16S rDNA en el líquido abomasal y en el pulmón. El examen histológico de otros dos fetos reveló encefalitis necrotizante no supurativa, miositis linfohistiocítica y miocarditis, y nefritis linfocítica intersticial. En estos fetos se detectó intralesionalmente el antígeno de N. caninum mediante análisis inmunohistoquímico, y se amplificó el ADN de N. caninum mediante PCR en tejido cerebral fijado con formalina y embebido en parafina. Se detectaron anticuerpos contra N. caninum mediante inmunofluorescencia indirecta en 10 de 27 vacas, con títulos de entre 1/200 y 1/3200. Los resultados indican que dos microorganismos abortígenos pueden coexistir y provocar abortos contemporáneos en un hato. Subrayamos la importancia de realizar pruebas diagnósticas múltiples en diversas madres abortadas y fetos del mismo hato para obtener una confirmación etiológica del síndrome de aborto bovino.EEA BalcarceFil: Macías-Rioseco, Melissa. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Caffarena, Rubén D. Instituto Nacional de Investigación Agropecuaria; Uruguay. Universidad de la República, Facultad de Veterinaria; UruguayFil: Fraga, Martín. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Silveira, Caroline. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria; Uruguay. University of Minnesota, Veterinary Population Medicine Departament; UsaFil: Cantón, Germán. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Hecker, Yanina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Suanes, Alejandra. Ministerio de Ganadería Agricultura y Pesca. Montevideo. Dirección de Laboratorios Veterinarios; Uruguay.Fil: Riet-Correa, Franklin. Instituto Nacional de Investigación Agropecuaria; Urugua

A novel pathogenic mechanism for cerebellar lesions produced by Solanum bonariense in cattle

Intoxication with Solanum bonariense in cattle causes cerebellar cortical degeneration with perikaryal vacuolation, axonal swelling, and death primarily of Purkinje cells, with accumulation of electron-dense residual storage bodies in membrane-bound vesicles. The pathogenesis of this disease is not fully understood. Previously, we proposed that inhibition of protein synthesis in Purkinje cells among other altered metabolic pathways could lead to cytoskeletal alterations, subsequently altering cell-specific axonal transport. In the present study, immunohistochemical and histochemical methods were used to identify neuronal cytoskeletal alterations and axonal loss, demyelination, and astrogliosis in the cerebellum of intoxicated bovines. Samples of cerebellum from 3 natural and 4 experimental cases and 2 control bovines were studied. Immunoreactivity against neurofilament (NF)-200KDa confirmed marked loss of Purkinje neurons, and phospho-NF protein, β-tubulin, and affinity reaction against phalloidin revealed an altered perikaryal distribution of neuronal cytoskeletal proteins in the remaining Purkinje cells in intoxicated cattle. Reactive astrogliosis in every layer of the cerebellar cortex was also observed with anti–glial fibrillary acidic protein immunohistochemistry. In affected cattle, demyelination and axonal loss in the cerebellar white matter, as well as basket cell loss were demonstrated with Klüver–Barrera and Bielschowsky stains, respectively. Based on these results, we propose that neuronal cytoskeletal alterations with subsequent interference of the axonal transport in Purkinje cells may play a relevant role in the pathogenesis of this neurodegenerative disorder, and also that demyelination and axonal loss in the cerebellar white matter, as well as astrogliosis in the gray matter, likely occur secondarily to Purkinje cell degeneration and death.Facultad de Ciencias Veterinaria

Serological evidence of human infection with Coxiella burnetii after occupational exposure to aborting cattle

Cattle are broadly deemed a source of Coxiella burnetii; however, evidence reinforcing their role in human infection is scarce. Most published human Q fever outbreaks relate to exposure to small ruminants, notably goats. Anti-phase II C. burnetii IgG and IgM were measured by indirect fluorescent antibody tests in 27 farm and veterinary diagnostic laboratory workers to ascertain whether occupational exposure to cattle aborting due to C. burnetii was the probable source of exposure. Four serological profiles were identified on the basis of anti-phase II IgG and IgM titres. Profile 1, characterised by high IgM levels and concurrent, lower IgG titres (3/27; 11.1%); Profile 2, with both isotypes with IgG titres higher than IgM (2/27; 7.4%); Profile 3 with only IgG phase II (5/27; 18.5%); and Profile 4, in which neither IgM nor IgG were detected (17/27; 63.0%). Profiles 1 and 2 are suggestive of recent C. burnetii exposure, most likely 2.5–4.5 months before testing and, hence, during the window of exposure to the bovine abortions. Profile 3 suggested C. burnetii exposure that most likely predated the window of exposure to aborting cattle, while Profile 4 represented seronegative individuals and, hence, likely uninfected. This study formally linked human Q fever to exposure to C. burnetii infected cattle as a specific occupational hazard for farm and laboratory workers handling bovine aborted material

Identification of a pegivirus (GBV-like virus) that infects horses

The recent identification of nonprimate hepaciviruses in dogs and then in horses prompted us to look for pegiviruses (GB virus-like viruses) in these species. Although none were detected in canines, we found widespread natural infection of horses by a novel pegivirus. Unique genomic features and phylogenetic analyses confirmed that the tentatively named equine pegivirus (EPgV) represents a novel species within the Pegivirus genus. We also determined that EPgV causes persistent viremia whereas its clinical significance is undetermined

Phylogenetic analyses of rotavirus a from cattle in uruguay reveal the circulation of common and uncommon genotypes and suggest interspecies transmission

Uruguay is one of the main exporters of beef and dairy products, and cattle production is one of the main economic sectors in this country. Rotavirus A (RVA) is the main pathogen associated with neonatal calf diarrhea (NCD), a syndrome that leads to significant economic losses to the livestock industry. The aims of this study are to determine the frequency of RVA infections, and to analyze the genetic diversity of RVA strains in calves in Uruguay. A total of 833 samples from dairy and beef calves were analyzed through RT-qPCR and sequencing. RVA was detected in 57.0% of the samples. The frequency of detection was significantly higher in dairy (59.5%) than beef (28.4%) calves (p < 0.001), while it did not differ significantly among calves born in herds that were vaccinated (64.0%) or not vaccinated (66.7%) against NCD. The frequency of RVA detection and the viral load were significantly higher in samples from diarrheic (72.1%, 7.99 log10 genome copies/mL of feces) than non-diarrheic (59.9%, 7.35 log10 genome copies/mL of feces) calves (p < 0.005 and p = 0.007, respectively). The observed G-types (VP7) were G6 (77.6%), G10 (20.7%), and G24 (1.7%), while the P-types were P[5] (28.4%), P[11] (70.7%), and P[33] (0.9%). The G-type and P-type combinations were G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), and the uncommon genotype G24P[33] (1.8%). VP6 and NSP1-5 genotyping were performed to better characterize some strains. The phylogenetic analyses suggested interspecies transmission, including transmission between animals and humans.Fil: Castells, Matías. Universidad de la República; UruguayFil: Caffarena, Rubén Darío. Universidad de la República; UruguayFil: Casaux, María Laura. Universidad de la República; UruguayFil: Schild, Carlos. Universidad de la República; UruguayFil: Miño, Samue. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Castells, Felipe. Universidad de la República; UruguayFil: Castells, Daniel. Universidad de la República; UruguayFil: Victoria, Matías. Universidad de la República; UruguayFil: Riet Correa, Franklin. Universidad de la República; UruguayFil: Giannitti, Federico. Universidad de la República; UruguayFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; ArgentinaFil: Colina, Rodney. Universidad de la República; Urugua

White muscle disease in three selenium deficient beef and dairy calves in Argentina and Uruguay

White muscle disease (WMD), nutritional myodegeneration or enzootic muscular dystrophy, is a nutritional condition associated with selenium and/or vitamin E deficiency in ruminants. These elements are constituents of the major body antioxidant systems. Depletion of selenium results in oxidative damage to cardiac and skeletal muscle cells, resulting in myodegeneration and myonecrosis, typical lesions of WMD. Selenium deficiency is common in South America, but WMD is underreported. This research describes clinical, biochemical and pathological findings in two episodes of WMD associated with selenium deficiency in beef and dairy calves in Argentina and Uruguay with concurrent copper deficiency in one of them, which resulted in spontaneous calf mortality. Further studies are necessary to estimate the true incidence and economic impact of clinical and subclinical mineral deficiencies in livestock production systems in the southern cone of South America.Doença do músculo branco (DMB), miodegeneração nutricional ou distrofia muscular enzoótica é uma condição nutricional associada à deficiência de selênio e/ou vitamina E em ruminantes. Esses elementos são constituintes dos principais sistemas antioxidantes do corpo. O esgotamento de selênio resulta em dano oxidativo às células musculares cardíacas e esqueléticas, resultando em miodegeneração e mionecrose, lesões típicas da DMB. A deficiência de selênio é comum na América do Sul, mas a DMB está subnotificada. Este trabalho descreve os achados clínicos, bioquímicos e patológicos em dois surtos de DMB associados à deficiência de selênio em bezerros para carne e leite na Argentina e Uruguai com concomitante deficiência de cobre em um surto, que resultaram em mortalidade espontânea de bezerros. São necessários mais estudos para estimar a verdadeira incidência e impacto econômico das deficiências minerais clínicas e subclínicas nos sistemas de produção pecuária no sul da América do Sul.EEA Cuenca del SaladoFil: Rodriguez, Alejandro Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cuenca del Salado; ArgentinaFil: Schild, Carlos Omar. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; UruguayFil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Riet‐Correa, Franklin. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; UruguayFil: Armendano, Joaquín Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Caffarena, Rubén Dario. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; UruguayFil: Brambilla, Emilio Cesar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: García, Juan Agustín. Universidad de la República. Centro Universitario Regional Este; UruguayFil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Poppenga, Robert. University of California at Davis. School of Veterinary Medicine. California Animal Health and Food Safety (CAHFS). Laboratory; Estados UnidosFil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; Uruguay. University of Minnesota. College of Veterinary Medicine. Veterinary Population Medicine Department; Estados Unido

Complete genome sequence of Campylobacter fetus isolated from a sheep

Campylobacter fetusis an important reproductive pathogen of ruminantsthat occasionally infects humans. Here, we describe the complete circularized genomeof a strain ofCampylobacter fetussubsp.fetusisolated from a sheep. Thefinal assem-bly consisted of a unique contig with a length of 1,849,237 bp

A comparative study of commercial ELISAs for antibody detection in the diagnostic investigation of Neospora caninum-associated abortion in dairy cattle herds in Uruguay

A pesar de su importancia, el diagnóstico etiológico del aborto en bovinos representa un desafío técnico para los veterinarios clínicos y laboratoristas, en parte debido a la dificultad de recuperar los fetos abortados en condiciones extensivas de campo. Dicha dificultad limita la posibilidad de detectar tempranamente los vientres abortados y de efectuar la investigación patológica y microbiológica de los abortos. Neospora caninum es un protozoario cosmopolita identificado como uno de los principales agentes abortigénicos en bovinos. En este estudio proponemos una aproximación seroepidemiológica para diagnosticar abortos por N. caninum en bovinos lecheros usando kits de ELISA comerciales. Se procesaron muestras de entre 12 y 93 vacas y/o vaquillonas con (casos) y sin (controles) historia reciente de aborto en 4 tambos comerciales de Uruguay. La proporción controles:casos analizados varió entre 1:1 y 4,6:1. Las muestras (n=230) fueron analizadas mediante 3 kits comerciales para la detección de anticuerpos IgG anti-N. caninum. En los 4 tambos la proporción de vacas y/o vaquillonas seropositivas por cualquier kit fue significativamente mayor en los casos respecto de los controles (odds ratio=5,13 a 36; p=0,0002 a 0,0485). La concordancia entre los kits varió de débil a fuerte (coeficiente Kappa de Cohen=0,58 a 0,83). Concluimos que, a pesar de la imperfecta concordancia entre estos kits, el empleo de todos ellos permitió arribar a conclusiones similares respecto de la asociación estadísticamente significativa entre seropositividad a N. caninum y aborto, lo que demuestra la utilidad de estos kits para la aproximación diagnóstica del aborto a nivel poblacional en condiciones de campo.Bovine abortion causes considerable economic losses to the livestock industry worldwide and is of concern for public health and food safety, given that many abortigenic infectious agents of cattle are zoonotic. Despite its importance, the etiological diagnosis of abortion in cattle is challenging both for veterinary practitioners and laboratory technicians, partly due to the difficulty in recovering aborted fetuses under extensive field conditions for pathological and microbiological diagnostic investigation, and in the early identification of aborted dams. Neospora caninum is a cosmopolitan protozoon identified as one of the main abortigenic agents in cattle worldwide. In this study we propose a comparative seroepidemiological approach for the diagnosis of abortion by N. caninum in dairy cattle. Samples from 12 to 93 cows/heifers with and without recent history of abortion (cases and controls) in four commercial dairy farms were tested. The ratio of controls to cases tested varied from 1:1 to 4.6:1. All samples (n=230) were analyzed by three commercial ELISA kits for the detection of anti-N. caninum antibodies. In all four dairy farms, the proportion of seropositive cows and/or heifers per kit was significantly higher in the cases than in the controls (Odds Ratios=5.13 to 36, p=0.0002 to 0.0485). The agreement among the three kits varied from weak to strong (Coheńs kappa coefficients=0.58 to 0.83). We conclude that, despite the imperfect agreement between these kits, all of them allowed to arrive at similar conclusions regarding the statistical association between N. caninum seropositivity and abortion, thus representing a useful tool for the diagnostic approach at the population level under field conditions.EEA BalcarceFil: da Silva Silveira, Caroline. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay.Fil: Armendano, Joaquín Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Moore, Dadín Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Macías Riosecoa, Melissa. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay.Fil: Riet Correa, Franklin. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay.Fil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay