ABSTRACT
Brucellosis is a zoonose produced by bacterial species from the Brucella genus. Its isolation and identification in food using classical microbiological techniques is not practical due to its slow growth rate. Therefore, it is necessary to establish fast and specific methods for the detection of the bacteria in food. The goal of this work was the production and characterization of monospecific polyclonal antibodies in chicken (IgY) against synthetic peptides from Brucella abortus OMP25 and BP26 proteins, suitable for an antigen-capture assay. Conformational as well as antigenic predictions were performed using the ANTHEPROT package. Chemical synthesis was carried out by the multiple manual synthesis using the t-boc strategy. The peptides were used as antigens for the preparation of polyclonal antibodies in chicken. Experimental animals produced specific antibodies against the OMP25 and BP26 peptides constructs determined by ELISA and MABA assays showing correspondence between the predictive study and the immunogenicity obtained in chicken. The IgY proved to be able to recognize B. abortus by MABA assays. The binding activity and specificity of antibodies was determined by Western blot with cell extract from B. abortus. In this study, we demonstrated that OMP25 and BP26 peptides constructs are good candidates for production of specific IgY antipeptide antibodies capable of recognizing proteins from sonicated B. abortus strain S19, indicating the potential usefulness of the IgY antibody for development of immunoassays for detection of Brucella abortus.
La brucelosis es una zoonosis producida por especies del género Brucella. El aislamiento e identificación de la bacteria en alimentos usando las técnicas clásicas de microbiología no es práctico debido a su lenta tasa de crecimiento. Por lo tanto, es necesario establecer métodos rápidos para la detección de la bacteria en alimentos. En el presente trabajo se desarrollaron y caracterizaron anticuerpos policlonales monoespecíficos en gallinas (IgY) contra péptidos sintéticos de las proteínas OMP25 y BP26 de Brucella abortus, que puedan ser utilizados en un ensayo de captura. Para ello, se realizaron estudios conformacionales y de predicción de epítopes en la selección de los péptidos, los cuales se utilizaron como antígenos para la producción de las IgY. Los animales desarrollaron anticuerpos específicos contra los péptidos, mostrando correspondencia entre los estudios predictivos y la inmunogenicidad obtenida. Las IgY reconocieron a B. abortus en un ensayo de MABA y la actividad de unión y especificidad fue determinada por western blot con extracto celular de B. abortus. En este estudio, demostramos que los péptidos de las proteínas OMP25 y BP26 de B. abortus son buenos candidatos para la producción de anticuerpos IgY especificos capaces de reconocer proteínas de extracto de B. abortus cepa S19, indicando el potencial uso de anticuerpos IgY para el desarrollo de inmunoensayos para la detección de Brucella abortus.
ABSTRACT
Relata-se um caso de espondilodiscite por Brucella em um paciente do sexo masculino, 56 anos, fazendeiro, com manifestações sistêmicas da doença. O diagnóstico foi realizado por sorologia com título de 1/160, hemocultura positiva, o VHS foi elevado, bem como alterações radiológicas mostraram espondilodiscite ao nível de T8/T9 compatíveis com a patologia. O paciente foi tratado com estreptomicina 1gIM/dia por 15 dias, doxaciclina e rifampicina por seis semanas, com melhora clínica do quadro. O envolvimento vertebral na brucelose é uma complicação de ocorrência variável na literatura, mas considerado pouco freqüente, de difícil diagnóstico principalmente em regiões com alta prevalência de tuberculose, visto que esta pode mimetizar o quadro de brucelose. Chama-se atenção a um caso raro de espondilodiscite por brucelose, dada a necessidade de diagnóstico precoce e tratamento a fim de se evitar possíveis seqüelas.
A case of spondylodiscitis due to Brucella with systematic manifestation of the disease, in a 56-year-old male patient who was a farmer, is reported. The diagnosis was made from serological tests, with a titer of 1/160. The blood culture was positive and the blood sedimentation rate was high. Radiological abnormalities showed spondylodiscitis at the T8/T9 level that were compatible with this disease. The patient was treated with streptomycin at 1g IM/day for 15 days, and doxycycline plus rifampicin for six weeks, with a clinical improvement in the condition. Vertebral involvement in brucellosis is a complication of variable occurrence in the literature. However, it is considered to be infrequent and difficult to diagnose, particularly in regions with high prevalence of tuberculosis, given that this may mimic conditions of brucellosis. Attention is drawn to this rare case of spondylodiscitis due to brucellosis, given the need for early diagnosis and treatment in order to avoid possible sequelae.