Prevalencia del virus de la rinotraqueitis infecciosa bovina en el departamento del Caquetá, Amazonía Colombiana / Prevalence of bovine infectious rhinotracheitis virus in Caquetá department, Colombian Amazon

RESUMEN La rinotraqueitis infecciosa bovina (IBR) es una enfermedad ampliamente difundida en el mundo con gran repercusión socio-económica en las ganaderías bovinas. El objetivo del presente estudio fue determinar la prevalencia de IBR en 100 hatos del departamento del Caquetá, para lo cual, se muestrearon 960 bovinos mayores de 36 meses entre enero y marzo de 2016 en predios seleccionados a partir de los criterios: a) tamaño (50-180 hectáreas), b) con más de 10 vacas en ordeño, c) disponibilidad de los productores para cooperar y d) accesibilidad de las vías. Las muestras de suero sanguíneo se remitieron al Laboratorio de Diagnóstico Clínico Veterinario del ICA y se analizaron a través la prueba Elisa de bloqueo (BHV-1) gB. Los sueros con porcentaje de bloqueo superior al 55% se consideraron positivos a anticuerpos para IBR. Se encontró alta seroprevalencia (73,13%), mayor además en machos que en hembras (p < 0,05). A nivel municipal la seroprevalencia fue mayor en los municipios de El Doncello, Puerto Rico y San Vicente del Caguán y se encontró diferencia significativa (p < 0,05) entre los nueve municipios analizados. A nivel de hatos, la prevalencia fue del 99%. En conclusión, la prevalencia del virus de la rinotraqueitis infecciosa bovina (IBR) en bovinos de doble propósito del departamento del Caquetá fue muy alta.

ABSTRACT Infectious bovine rhinotracheitis (IBR) is a disease widely spread throughout the world with great socio-economic impact on bovine livestock. The objective of this study was to determine the prevalence of IBR in 100 herds in Caqueta department, for which 960 cattle older than 36 months between January and March 2016 were sampled in farms selected from the criteria: a) size (50-180 hectares), b) with more than 10 cows in milking, c) availability of producers to cooperate and d) accessibility of roads. Blood serum samples were sent to the ICA veterinary clinical diagnostic laboratory and analyzed using the Elisa blocking test (BHV-1) gB, where sera with blocking percentage greater than 55% were considered as positive for IBR antibodies. High seroprevalence was found (73.13%), being higher in males than in females (p < 0.05). At municipal level, seroprevalence was greater in El Doncello, Puerto Rico and San Vicente del Caguán municipalities, significant difference (p<0.05) was found between the nine municipalities analyzed. At herd level prevalence was of 99%. In conclusion the prevalence of Infectious Bovine Rhinotracheitis (IBR) virus in dual-purpose cattle of Caquetá department was very high.

Soroprevalence of bovine alphaherpesvirus type 1 (BoHV-1) and risk factors associated with dairy properties of the municipality of Senador Guiomard, Acre, Brazil / Soroprevalência de alfaherpesvírus bovino tipo 1 (BoHV-1) e fatores de risco associados em propriedades leiteiras do município de Senador Guiomard, Acre, Brasil

Bovine alphaherpesvirus type 1 (BoHV-1) is the etiological agent responsible for serious infections that compromise the respiratory and genital tracts of affected cattle. In order to estimate the seroprevalence of BoHV-1 and to identify the associated risk factors in dairy farms in the city of Senador Guiomard, Acre, Brazil, the present study was carried out through the analysis of 180 blood serum samples submitted to the screening of anti-BoHV-1 by the virus neutralization test (VN) and by means of the evaluation of the epidemiological questionnaire applied in the eight investigated properties. The prevalence of seropositivity for BoHV-1 was 61.1%, ranging from 43.3 to 86.2% among the analyzed properties. The variable absence of veterinary assistance showed statistically significant association (odds ratio ­ OR = 2.10; p < 0.001) with alphaherpesvirus infection. The results demonstrate that the frequency of BoHV-1 is high and needs to be controlled through prophylactic and health management measures.(AU)

O alfaherpesvírus bovino tipo 1 (BoHV-1) é o agente etiológico responsável por graves infecções que comprometem os tratos respiratório e genital dos bovinos acometidos. Com o objetivo de estimar a soroprevalência de BoHV-1 e identificar os fatores de risco associados em propriedades leiteiras do município de Senador Guiomard, Acre, foi realizado o presente estudo, por meio da análise de 180 amostras de soro sanguíneo submetidas à pesquisa de anticorpos anti-BoHV-1 pelo teste de vírus neutralização (VN) e por meio da avaliação do questionário epidemiológico aplicado nas oito propriedades investigadas. A prevalência de soropositividade para BoHV-1 foi de 61,1% variando de 43,3 a 86,2% entre as propriedades analisadas. A variável ausência de assistência veterinária apresentou associação estatisticamente significativa (odds ratio ­ OR = 2,10; p < 0,001) com a infecção pelo alfaherpesvírus. Os resultados demonstram que a frequência de BoHV-1 é alta e precisa ser controlada através de medidas profiláticas e de manejo sanitário.(AU)

Impairment on nuclear maturation rate in oocytes from cows naturally infected by bovine herpesvirus 1 (BoHV-1) / Comprometimento na taxa de maturação nuclear em ovócitos de vacas naturalmente infectadas pelo herpesvírus bovino 1 (BoHV-1)

Bovine herpesvirus 1 (BoHV-1) is an important bovine pathogen that is responsible for causing respiratory diseases and reproductive failures. The presence of BoHV-1 in an in vitro embryo production system affects fertilization, maturation, and embryonic development. The objective of this study was to evaluate the developmental capacity of oocytes from naturally infected cows with no reproductive history. Moreover, this study investigated the presence of viral DNA in cumulus oophorus complexes (COCs). Experimental groups were differentiated by titrating the antibodies detected through seroneutralization assays, establishing three groups: seronegative animals (titer lower than 2), low titer (2 to 8), and animals with a titer above or equal to 16. COCs were obtained from 15 donors during 22 sessions of ultrasound-guided follicular aspiration. DNA was extracted from a pool of COCs obtained from all aspirations from the same donor as well as from whole blood and nested PCR reactions were performed. Only COCs with a compact layer of cumulus cells, an intact zona pellucida, and homogeneous cytoplasm were selected for in vitro culture and evaluation of nuclear maturation rate. After culturing for 24 hours, the oocytes were fixed and stained to evaluate the meiotic cell cycle stage. Oocytes that showed a chromosomal configuration in metaphase II were considered to have reached nuclear maturation. Compared with the other groups, the oocyte nuclear maturation rate in animals with a titer greater than or equal to 16 (50%) was compromised (P<0.05). However, the viral titer did not influence the maturation rate of bovine oocytes in animals exhibiting low titration (62.2%) when compared with the control group (76.7%). Viral DNA was not observed in the blood samples but was detected in the COC pool from three seropositive donors. In view of the results obtained, we conclude that natural infections by the BoHV-1 virus can compromise the nuclear maturation rate in cows, depending on the titration levels of antibodies against the virus. Moreover, viral DNA could be present in COCs, contradicting the hypothesis that seropositive animals with no history of clinical symptomatology pose a negligible risk of transmitting BoHV-1 by COCs.(AU)

Herpesvírus bovino 1 (BoHV-1) é um importante patógeno bovino, responsável por causar doenças respiratórias e falhas reprodutivas. A presença do BoHV-1 em sistema de produção in vitro de embriões afeta a fertilização, a maturação e o desenvolvimento embrionário. O objetivo deste estudo foi avaliar a capacidade de desenvolvimento de ovócitos oriundos de vacas infectadas naturalmente sem histórico reprodutivo. Além disso, este estudo investigou a presença do DNA viral em Complexos Cumulus Ooforus (COCs). Os tratamentos foram definidos a partir do título de anticorpos detectados pelos ensaios de soroneutralização, sendo estabelecidos três grupos: animais soronegativos (título menor do que 2), título baixo (2 a 8) e animais com título maior ou igual a 16. Os COCs foram obtidos de 15 doadoras durante 22 sessões de aspiração folicular guiada por ultrassom. A extração do DNA foi realizada em um pool de COCs de todas as aspirações de uma mesma doadora e no sangue total para a realização das reações de Nested-PCR. Para avaliação da taxa de maturação nuclear, foram selecionados para o cultivo in vitro somente os COCs com camada compacta de células do cumulus, zona pelúcida íntegra e citoplasma homogêneo. Após 24 horas de cultivo, os ovócitos foram fixados e corados em lâmina para a avaliação do estádio do ciclo celular meiótico. Os ovócitos que apresentaram configuração cromossômica em metáfase II foram considerados como tendo alcançado a maturação nuclear. Verificou-se comprometimento na taxa de maturação nuclear ovocitária (P<0.05) nos animais de título maior ou igual a 16 (50%). No entanto, não houve influência do título viral na taxa de maturação de ovócitos bovinos em animais que apresentaram titulação baixa (62,2%) quando comparados com o grupo controle (76,7%). O DNA viral não foi identificado nas amostras de sangue, mas foi detectado no pool de COCs de três doadoras soropositivas. Diante dos resultados encontrados conclui-se que vacas infectadas naturalmente pelo vírus BoHV-1 apresentam comprometimento na taxa de maturação nuclear, dependendo do grau de titulação de anticorpos contra o vírus. Ademais, o DNA viral pode estar presente em COCs contrariando a hipótese de que animais sorologicamente positivos e sem histórico de sintomatologia clínica oferecem risco negligível de transmissão do BoHV-1 por COCs.(AU)

Computational prediction of MHC class I epitopes for most common viral diseases in cattle (Bos taurus).

Viral diseases like foot-and-mouth disease (FMD), calf scour (CS), bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR) etc. affect the growth and milk production of cattle (Bos taurus) causing severe economic loss. Epitope-based vaccine designing have been evolved to provide a new strategy for therapeutic application of pathogen-specific immunity in animals. Therefore, identification of major histocompatibility complex (MHC) binding peptides as potential T-cell epitopes is widely applied in peptide vaccine designing and immunotherapy. In this study, MetaMHCI tool was used with seven different algorithms to predict the potential T-cell epitopes for FMD, BVD, IBR and CS in cattle. A total of 54 protein sequences were filtered out from a total set of 6351 sequences of the pathogens causing the said diseases using bioinformatics approaches. These selected protein sequences were used as the key inputs for MetaMHCI tool to predict the epitopes for the BoLA-A11 MHC class I allele of B. taurus. Further, the epitopes were ranked based on a proposed principal component analysis based epitope score (PbES). The best epitope for each disease based on its predictability through maximum number of predictors and low PbES was modeled in PEP-FOLD server and docked with the BoLA-A11 protein for understanding the MHC-epitope interaction. Finally, a total of 78 epitopes were predicted, out of which 27 were for FMD, 25 for BVD, 12 for CS and 14 for IBR. These epitopes could be artificially synthesized and recommended to vaccinate the cattle for the considered diseases. Besides, the methodology adapted here could also be used to predict and analyze the epitopes for other microbial diseases of important animal species.

Surveillance of neutralizing antibodies against Bovine Herpesvirus 1 in cattle herds from different farming property systems / Distribuição de anticorpos neutralizantes contra o Herpesvirus bovino 1 em propriedades bovinas de diferentes sistemas de criação

The aim of this study was to investigate the presence of neutralizing antibodies against bovine herpesvirus 1 (BoHV-1) in 722 non-vaccinated animals from eight properties that use different farming systems (extensive, semi-confinement and confinement). Serum samples were subjected to neutralization tests in order to search for anti-BoHV-1 antibodies. Serological results were categorized as negative, low titer, intermediate titer or high titer. One property showed no positive samples; while other properties presented frequency of positive samples ranging from 17.95% to 86.96%. For animals raised under confinement, the number of positive samples and neutralizing antibody titers were lower compared to others, possibly due to good sanitary practices adopted by this type of system. Altogether, our results can contribute towards the understanding of the endemic infection in Brazil.

Este trabalho teve por objetivo avaliar a distribuição de anticorpos neutralizantes contra o herpesvirus bovino 1 (BoHV-1) em 722 animais não vacinados pertencentes a oito propriedades que utilizam diferentes sistemas de criação (extensivo, semi-confinamento e confinamento). As amostras sorológicas foram submetidas ao teste de soroneutralização para pesquisa de anticorpos anti-BoHV-1. Os resultados foram classificados em títulos negativo, baixo, médio e alto. Uma propriedade não apresentou amostras positivas, enquanto que nas demais propriedades a frequência de amostras positivas variou de 17,95% a 86,96%. Os animais do sistema de criação por confinamento apresentaram menor número de amostras positivas quando comparado aos animais do outros sistemas de criação, possivelmente devido às boas práticas sanitárias adotadas por esse sistema. Dessa forma, nossos resultados podem contribuir para o entendimento dessa infecção endêmica no Brasil.

[Effectiveness evaluation of inactivated vaccines against bovine viral diarrhea and infectious bovine rhinotracheitis]

Bovine viral diarrhea [BVD] and infectious bovine rhinotracheitis [IBR] are two of the most important diseases responsible for major economic losses in the Iranian dairy industry. Since there are not in-house vaccines, the evaluations of the effectiveness of imported commercial vaccines are imperative. The purpose of the present study was to assess the clinical effectiveness of commercial inactivated Bovine viral diarrhea virus [BVDV] and Bovine herpes virus type 1 [BHV-1] vaccines to reduce the occurrence of culling and diseases, as well as their impact on milk production and prevention of birth of calves persistently infected [PI] with BVDV. A blind randomized controlled trial was performed. Animals were assigned to treatment [n=342] and control [n=351] groups by systematic randomization. Animals in the treatment group were inoculated with inactivated BVDV and BHV-1 vaccines [Intervet-Schering Plough]. One and seven months later, vaccination was repeated. Over a one-year period, the incidence of disease, death and culling, birth of PI calves and milk production were recorded and compared. All statistical analyses were done with IBM SPSS statistics 20 software. At the start of the study, the two groups showed no significant differences in the means of age [day], parities, days in milk, milk production and preexisting antibodies of BVDV and BHV-1. In addition, significant difference was not observed between treatment and control groups during the period of study. Unlike previous years, there were no reports of BHV-1 respiratory disease and birth of PI calves in the herd as a whole. Although the efficacies of the mentioned vaccines were approved previously, effectiveness was not augmented in our study. Evidence-based Vaccinology in the developing countries should be performed by implementation of effectiveness studies

Analysis of isotype-specific antibody responses to bovine herpesviruses 1.1 and 1.2a allows to estimate the stage of infection

Specific IgM, IgA, IgG1, IgG2, as well as neutralizing antibody responses were evaluated in sera of calves experimentally infected with two isolates of bovine herpesvirus type 1 (BoHV1) of distinct subtypes (subtype 1, BoHV1.1; subtype 2a, BoHV-1.2a). No significant differences were observed in the antibody responses induced by each BoHV-1 subtype. The antibody responses following primary acute infection were characterized by an increase in specific IgM and IgA levels between days 2 and 14 post inoculation (pi). IgG1 was detected from days 11 to 30 pi. IgG2 was detected on the sample taken on day 30 pi. Reactivation of infection following dexamethasone administration induced a significant rise in IgA levels, whereas IgG1 and IgG2 levels, which were at high levels from the beginning of the reactivation process, showed a slight alteration after corticosteroid treatment. These results suggest that it is possible to estimate the dynamics of BoHV-1 infections with basis on the analysis of class- and subclass-specific antibody responses. Such information may be particularly useful for the study of the kinetics of the infection in a herd and to aid in the adoption of appropriate control measures..

Induction of humoral responses to BHV-1 glycoprotein D expressed by HSV-1 amplicon vectors

Herpes simplex virus type-1 (HSV-1) amplicon vectors are versatile and useful tools for transferring genes into cells that are capable of stimulating a specific immune response to their expressed antigens. In this work, two HSV-1-derived amplicon vectors were generated. One of these expressed the full-length glycoprotein D (gD) of bovine herpesvirus 1 while the second expressed the truncated form of gD (gDtr) which lacked the trans-membrane region. After evaluating gD expression in the infected cells, the ability of both vectors to induce a specific gD immune response was tested in BALB/c mice that were intramuscularly immunized. Specific serum antibody responses were detected in mice inoculated with both vectors, and the response against truncated gD was higher than the response against full-length gD. These results reinforce previous findings that HSV-1 amplicon vectors can potentially deliver antigens to animals and highlight the prospective use of these vectors for treating infectious bovine rhinotracheitis disease.

Clinical and epidemiological and serological studies on bovine viral diarrhea [BVD] and infectious bovine rhinotrachitis [IBR] in some dairy farms in behera governorate

This study was done on 1134 cattle present in five private dairy cattle farms at Behera governorate. 823 animals were apparently healthy while 311 ones showed one or more of the following signs, fever, bloody diarrhea, dehydration, cough, nasal discharges, oral lesions and/or bilateral corneal opacity. Serum samples were collected from all animals, also 148 Buffy coat samples, 160 nasal swabs and 163 fecal swabs were collected from diseased animals. These samples were taken at autumn and winter seasons. From 1134 animals, 828 animals were vaccinated against BVD and IBR while 306 animals were not vaccinated. All serum samples [1134] were subjected to serum neutralization test [SNT], [47.7%, and 42.1%] of non vaccinated animals and [63%, 48.7%] of vaccinated animals showed antibodies against BVDV and IBR, respectively. BVDV was isolated from [24.1%, 14.3%, and 11.7%] and [21%, 25.3%, 16.3%] of Buffy coat samples, nasal swabs and fecal swabs from non vaccinated and vaccinated animals respectively. IBR was isolated from [17.2%, 9%, 51%] and [21%, 24%, 13.9%] of Buffy coat samples, nasal swabs and fecal swabs from non vaccinated and vaccinated animals respectively. From the obtained results we can conclude that bovine viral diarrhea and infectious bovine rhinotracheitis viruses are prevalent in many dairy cattle farms in Behera governorate. Also vaccination of late pregnant animals only is not sufficient to prevent persistent BVDV infection and vaccination against BVD and IBR viruses shall be done before conception to prevent the occurrence of persistent BVD infection and it can be repeated before parturition to protect the newly born calves from infection

Aislamiento delvvirus herpes bovino tipo 1 en bovinos del departamento de córdoba - Colombia / Isoation of boviine herpes virus type 1 from cattle in cordoba - Colombia

Objetivo. Realizar el aislamiento del virus herpes bovino tipo 1 (BHV-1) en ganado bovino con antecedentes de infertilidad. Materiales y métodos. A partir de 85 animales, provenientes de diferentes áreas rurales del departamento de Córdoba, Colombia, sin antecedentes de vacunación y con titulos neutralizantes contra la enfermedad de la rinotraqueitis bovina infecciosa (IBR) por seroneutralización, se escogieron dos toros y una vaca para hacer aislamiento de HVB-1. Los animales fueron inmunosuprimidos con Dexametasona, y se obtuvieron muestras con hisopos nasales, oculares y de lavado prepucial en los toros y vaginales en la vaca respectivamente. Resultados. Se observó un efecto citopático a las 3 horas después de la inoculación de las células MDBK con el lavado genital de la vaca y a las 24 horas en los toros, con exposición del efecto en "racimo" a las 48 horas. El aislamiento en ambos tipos de muestras, sugiere que la reactivación viral fue seguida por una fase de viremia y excreción del virus en las secreciones naturales. Conclusiones. El aislamiento del virus HVB-1 en los reproductores aparentemente sanos pero con títulos a la prueba de seroneutralización, establece la presencia de latencia viral en éstos animales, importante factor epidemiológico en la difusión de la enfermedad a nivel de campo. Se deben iniciar los estudios necesarios para establecer el subtipo de virus actuante en el campo, para conocer sus características antigénicas y su correspondencia con las cepas vacunales.

Objective. Bovine herpes virus type 1 (BHV-1) was isolated from beef cattle with history of infertility. Materials and methods. We chose 85 unvaccinated animals, from different rural areas of Cordoba Department that had evidence of infectious bovine rhinotracheitis (IBR) by serum neutralization. Two bulls and one cow were chosen to attempt isolation of HVB-1. The three bovines were immunosupressed with glucocorticoids (dexamethasone) and samples of prepucial washing (males) vaginal washing (female), and nasal and ocular swaps were obtained. Results. Cytopathic effect was detected 3 hours post-inoculation in the MDBK cells inoculated with vaginal washing of the cow and 24 hours post-inoculation in the cells inoculated with washings from the bulls. A "racime effect" appeared after 48 hours. Successful isolation from both types of samples, suggests that viral reactivation was followed by viremia and shedding of virus in natural secretions and excretions. Conclusions. The isolation of BHV-1 from apparently normal reproductive animals confirms the presence of viral latency in these animals. Latency is an important epidemiological factor in the spread of the disease among farm animals. Studies should be initiated to identify the viral subtype circulating understand its antigenic characteristics and match the virus to a vaccine strain.

Coeficientes de correlación dentro de hatos y efectos de diseño para seropositividad a brucelosis, diarrea voral y rinotraqueitis infecciosa bovina de hatos lecheros / Intra-cluster correlation coeficients and desing effects for seropositivity to brucelosis, viral bovine diarrhea and infectious bovine rhinotracheitis

La estimación de los coeficientes de correlación dentro de hatos (CCI) o el efecto de diseño (D) para enfermedades infecciosas puede ser de interés en el diseño de encuestas y para calcular factores de inflación de varianza para estimadores de prevalencia en muestreos por conglomerados. Los valores de CCI y D para brucelosis, diarrea viral bovina (DVB) y rinotraqueitis infecciosa bovina (RIB) se calcularon utilizando los métodos de Bennett y análisis de varianza (VARCOMP). Los valores de CCI para brucelosis, DVB y RIB utilizando dichos métodos fueron 0,162 y 0,153; 0,044 y 0,015; y 0,110 y 0,128; y los valores de D fueron 3,33 y 3,09; 1,63 y 1,21; y 2,58 y 3,02; respectivamente. En conclusión, los valores de CCI y D para brucelosis, DVB y RIB fueron diferentes, según el método utilizado y para cada una de estas infecciones, por lo que se requieren tamaños de muestra diferentes para obtener la misma precisión en la estimación de sus prevalencias. El reporte de los valores de CCI y D sería de gran ayuda para la planeación y diseño de estudios epidemiológicos

Seroepidemiología de la rinotraqueitis infecciosa bovina en el municipio de Montería, Colombia / Seroepidemiology of the infectious bovine rhinotracheitis in the municipality of Montería, Colombia

Objetivo. Estudiar la sero prevalencia de IBR en ganado bovino con antecedentes de infertilidad. Materiales y métodos. Se recolectaron 150 muestras de sangre de hembras con antecedentes de infertilidad y sin historia de vacunación contra IBR, pertenecientes a 32 fincas distribuidas en el municipio de Montería. adicionalmente, se obtuvieron muestras al azar de 20 toros pertenecientes a las mismas fincas. Se analizaron anticuerpos contra IBR mediante la prueba de ELISA. Resultados. Los resultados mostraron una seroprevalencia de 74.7 por ciento para rinotraqueitis infecciosa bovina. Seencontraron diferencias significativas en cuanto a prevalencía para las variables sexo y edad de los animales (p<0.05). No hubo diferencias significativas en prevalencía para las variables raza, zona, tipo de explotación y alteraciones reproductivas (p>0.05). Conclusión. La alta prevalencia de la infección por IBR en vacas podrían correlacionarse con la infección en toros, lo cual tiene un significado relevante, ya que la infección es de transmisión venérea. Estos resultados deben alertar a las autoridades sanitarias para que implementen estrategias de prevención y control

Objective. To study the seroprevalence of IBR in livestock bovine with infertility antecedents. Materials and methods. Blood samples were collected from 150 animals with infertility antecedents and nonvaccinated history against IBR, belonging to 32 farms in Monteria municipality and samples at random of 20 bulls belonging to the same farms. Antibodies were analyzed against IBR by using ELISA test. Results. The results showed a seroprevalence of 74.7% for bovine rhinotracheitis infectious. They were significant differences with regard to prevalence for sex and age variables of animals (p<0.05). There were not significant differences in prevalence for the variable race, area, type of exploitation and reproductive alterations (p>0.05). Conclusion. The high prevalence of the infection for IBR in cows could be associated with the infection in bulls, which has an outstanding meaning, since the infection is of venereal transmission. These results should alert to sanitary authorities in order to implement prevention and control strategies.

Determinación de la asociación entre Chlamydia trachomatis y Neisseria gonorrhoeae, en muestras de orina mediante técnicas de biología molecular / Determine the association Between Chlamydia Trachomatis and Neisseriae Gonorrhoeae

En el presente estudio se evaluó la asociación entre Chlamydia trachomatis (CT) y Neisseriae gonorrhoeae (NG), utilizando la técnica de COBAS AMPLICOR CT/NG Molecular System, en muestras de orina de 355 mujeres con un promedio de edad de 23.9 años; 20 muestras fueron positivas para CT, informándose una prevalencia de de 5.63porciento. Aunque estudios epidemiológicos han reportado relación entre la infección por Chlamydia trachomatis y las causadas por otros microorganismos como Neisseriae gonorrhoeae; en este estudio no se encontró asociación. Factores como el tipo de muestra y la presencia de inhibidores en la orina disminuyen la sensibilidad en la detección de Neisseriae gonorrhoeae.

Efecto de la infección con los virus de rinotraqueitis infecciosa bovina y diarrea viral bovina sobre la reproducción en bovinos no vacunados / Effect nof infectious bovine rhinotracheitis virus and bovine viral diarrhea virus infections on reproduction in a non-vaccinated cattle herd

Se realizó un estudio para determinar si las infecciones por los virus de rinotraqueitis infecciosa bovina (VRIB) y diarrea viral bovina (VDVB) afectaban el comportamiento reproductivo de un rebaño de alto mestizaje Brahman, no vacunado contra ambos virus. El manejo reproductivo se basó en una estación de servicio (ES) con inseminación artificial (IA), al inicio, y monta natural (MN) posteriormente. Para ello, una muestra de 80 vientres se categorizó en dos grupos para efectos de comparación: 1) Desempeño deficiente (DD) y 2) Desempeño ideal (DI), conformados por 35 y 45 animales, respectivamente. Todos los animales fueron objetos de monitoreo serológico para ambos virus, antes y durante la ES, medinte kits de ELISA comerciales (SVANOVA, Biotech). Los resultados muestran que el 51 por ciento de los animales, de ambos grupos, se infectaron con VRIB antes de la ES. El 26 por ciento de los animales de los grupos DD y el 16 por ciento del grupo DI se infectaron durante la ES y de los mismos, quedaron preñados y parieron normalmente el 78 y 100 por ciento, respectivamente. En relación al VDVB, el 86 por ciento y el 78 por ciento de los animales de los grupos DD y DI, respectivamente, se infectaron antes de la ES y, escasamente, 3 y 7 por ciento de ellos se infectaron durante la ES. La prueba de Fisher indicó que no hubo asociación entre la ocurrencia de infección por VRIB y VDVB con la condición de preñez (P menor o igual 0,62 y P menor o igual 0,60, respectivamente). Estos hallazgos indican que las infecciones por estos virus no interfirieron con el desempeño reproductivo del rebaño

Efecto del período de incubación virus/suero (1 y 24 horas) sobre la sensibilidad y especificidad de la prueba de seroneutralización para rinotraqueitis infecciosa bovina / Effect of virus/serum incubation period (1 and 24 hours) on the sensitivity and specificity of the serum neutralization test for infectious bovine rhinotracheitis

En base a reportes que señalan una baja sensibilidad de la prueba de seroneutralización (SN), con 1 hora de incubación, para Rinotraqueitis Infecciosa Bovina (RIB), se realizó un ensayo para comparar el desempeño de la SN, para la detección de anticuerpos contra dicho virus, con dos períodos de incubación virus/suero (1 y 24 horas), usando como referencia un kit de ELISA. La concordancia de ambas pruebas de SN (1 y 24 horas) con el ELISA fue de 82 por ciento (kappa=0,77) y 98,5 por ciento (kappa=0,98), respectivamente. La sensibilidad y especificidad fueron de 66,7 y 100 por ciento, respectivamente, en 1 hora, en comparación con 100 y 96,6 por ciento en 24 horas. La seropositividad de 65 sueros bovinos probados por SN, en ambos períodos, se comparó entre sí, para lo cual los títulos seroneutralizantes se agruparon en 6 clases. El porcentaje de seropositivos fue menor con 1 hora que con 24 horas, 37 y 57 por ciento, respectivamente (0,05 > P > 0,02). El 96 por ciento de los sueros procesados con 1 hora quedaron agrupados en las clases 1 y 2, mientras que con 24 horas de incubación el 57 por ciento de ellos se ubicaron en la clase 6, correspondiendo ésta a la de mayores niveles de anticuerpos. Estos resultados indican que la prueba de SN, para detección de anticuerpos contra RIB, es más confiable cuando se utiliza un período de incubación de 24 horas

Comparative pathogenicity of bovine herpesvirus 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a)

O presente estudo teve como objetivo examinar a capacidade de duas amostras de herpesvírus bovino tipo 1 (BHV-1) de diferentes subtipos (amostra EVI 123/96: BHV-1.1; amostra SV265/98: BHV-1.2a) de induzir doença respiratória em bovinos. Estas duas amostras são representativas de subtipos de BHV-1 prevalentes no Brasil. Os subtipos das amostras foram confirmados por análises com anticorpos monoclonais e com enzimas de restrição. As amostras foram inoculadas por via intranasal em sete bezerros de três meses de idade (quatro com BHV-1.1, três com BHV-1.2a), soronegativos para BHV-1, sendo outros três animais mantidos como controles não infectados. Nos dois grupos de animais inoculados, os sinais clínicos observados foram consistentes com o quadro de rinotraqueíte infecciosa bovina (IBR), incluindo febre, apatia, anorexia, descargas mucopurulentas nasais e oculares, conjuntivite, erosões e hiperemia na mucosa nasal, dispnéia, tosse, estridor traqueal e aumento dos linfonodos retrofaríngeos, submandibulares e cervicais. Não foram observadas diferenças significativas entre os escores clínicos atribuídos aos animais nos dois grupos. Igualmente, foram similares as quantidades de vírus re-isoladas dos animais infectados, à exceção de uma diferença significativa na disseminação de vírus pelas secreções nasais, a qual foi maior nos animais infectados com BHV-1.1 nos dias 1 a 3 pós-inoculação. Após reativação induzida por corticosteróides, foi observado recrudescimento dos sinais clínicos, os quais foram também similares em ambos os grupos. Em conclusão, as amostras de BHV-1 dos subtipos 1 e 2a não apresentaram diferenças significativas em sua patogenicidade sobre o trato respiratório nos animais inoculados, tanto após a infecção primária como após a reativação.

Evaluación de un ELISA para estudios epidemiológicos de rinotraqueítis infecciosa bovina a través de muestras de leche de cántaras / Evaluation of an ELISA for epidemiological studies of infectious bovine rinotracheitis virus by using bulk churn milk samples

Se llevó a cabo un estudio en cuatro fincas lecheras, a objeto de evaluar la utilidad de un Kit de ELISA comercial para estimar la prevalencia de anticuerpos contra el virus herpes bovino tipo 1 (VHB-1), mediante el análisis de muestras de leche de cántaras. Para ello se realizó un muestreo simultáneo de suero y leche en 80 vacas, durante un proceso de ordeño. Además, los productos del ordeño se acopiaron en siete cántaras, se registraron las vacas asignadas a cada cántara y se recolectó una muestra de leche de cada una de ellas. Las muestras de suero, leche individual de cántara se procesaron para la detección de anticuerpos contra el VHB-1 mediante el kit, siguiendo las recomendaciones del fabricante, quedando el Punto de Corte para la leche en 0,07. No se detectaron anticuerpos en ninguna de las 35 muestras de leche recolectadas de vacas que resultaron sin anticuerpos en suero. En relación a las vacas que resultaron seropositivas se observó un incremento en los anticuerpos en leche, a medida que se incrementaron los mismos en suero, lo cual fue indicativo de una tendencia hacia una relación lineal entre los valores de ambas variables, aunque no hubo correlación (r= 0,4324; P= 0,0348). Los títulos de anticuerpos de las muestras de leche de las cántaras mostraron una moderada asociación con las proporciones de vacas seropositivas cuyas leches se acopiaron en ella, lo que sugiere que es factible utilizar el kit de ELISA para estudios epidemiológicos de rinotraqueitis infecciosa bovina, a través de muestras de la leche de cántaras o tanque

Distribuiçäo de anticorpos para herpesvírus bovino 1 em rebanhos bovinos / Distribution of antibodies to bovine herpesvirus 1 in cattle herds

A distribuiçäo de anticorpos neutralizantes para o herpesvirus bovino 1 (HVB 1) foi estudada em quatro faixas etárias de bovinos, em 21 rebanhos de leite e de corte. Os resultados da sorologia foram analisados e relacionados com as respostas de questionários aplicados aos responsáveis pelos rebanhos. As taxas de freqüência de anticorpos neutralizantes para o HVB 1 foram comparadas segundo a aptidäo e a faixa etária. Fatores como tipo de manejo e idade dos animais influenciaram na distribuiçäo de anticorpos para o HVB 1

Construction and characterization of a glycoprotein E deletion mutant of bovine herpesvirus type 1.2 strain isolated in Brazil

This paper describes the construction and characterization of a Brazilian strain of bovine herpesvirus type 1.2a (BoHV-1.2a) with a deletion of the glycoprotein E (gE) gene. The deletion was introduced by co-transfection of a deletion fragment containing the 5 and 3 gE flanking regions and genomic DNA of wild type BoHV-1 into bovine cells. Isolation of gE deletion mutant was performed by immunoperoxidase staining with an anti-gE monoclonal antibody. Viral clones were plaque purified and further examined by restriction endonuclesase digestion and Southern blot hybridization. This gE deletion mutant will be evaluated as a vaccinal virus, in order to determine its potential use for a differential vaccine

Actualización de los viejos enigmas y visión de futuro de la RIB en Colombia / Old enigmas actualization and future vision of IBR in Colombia

La historia de la RIB en Colombia, ha sido una historia más de encuestas serológicas (con porcentajes relativamente altos de anticuerpos contra el HVB-1 en algunas zonas), que de aislamientos y demostraciones de sintomatología clínica específica. Varios gruposde investigación han tratado de definir el impacto de esta enfermedad en el medio. Se ha avanzado en la estandarización de técnicas de diagnóstico eficientes y se propuso la hipótesis de que en Colombia circulan cepas de baja virulencia; sin embargo, recientemente, se introdujo una vacuna sin tener en cuenta los avances que se habian logrado en este campo en el país. Ahora el problema ha dado un giro total, debemos definir: el impacto de la enfermedad, el impacto de la vacuna y, como mínimo, proponer a las autoridades nacionales un plan de manejo pertinente con las necesidades y particularidades del problema en el país.