Investigating Field Efficacy and Safety of Conjunctival Brucella abortus S19 Vaccine in Cattle

Background: Vaccination is the most fundamental strategy in the control and eradication of brucellosis. Several vaccination programs with different vaccines have been carried out in many countries in which brucellosis continues to be a problem in livestock. One of the recommended vaccines against brucellosis in cattle is the live Brucella abortus S19 vaccine. The aim of this study is to evaluate the results of field safety and efficacy trials for the conjunctival Brucella abortus S19 vaccine prior to the mass vaccination program. Methods: In this study, 81 female cattle were vaccinated with a reduced dose of Brucella abortus S19 vaccine with the conjunctival route. The immune response after vaccination was investigated by suggested serological tests; namely, Rose Bengal Plate Test, Serum Agglutination Test and Complement Fixation Test. Result: No adverse effect was observed within the scope of safety. Isolation of vaccine strain was observed only in a milk sample of lactating animals. Excluding the diagnosis criteria of the serological tests, humoral immune response was observed in most of the animals by all the serological tests one month after vaccination. Antibody levels lasted approximately 4 months after vaccination. In conclusion, the results of this study demonstrated that besides vaccine-induced antibodies, the vaccine including changes in dose and administration way in this study did not cause any significant risks for the target animals.

Post translational modifications of Trifolitoxin: a blue fluorescent peptide antibiotic*

Trifolitoxin (TFX, C41H63N15O15S) is a selective, ribosomally-synthesized, post-translationally modified, peptide antibiotic, produced by Rhizobium leguminosarum bv. trifolii T24. TFX specifically inhibits α-proteobacteria, including the plant symbiont Rhizobium spp., the plant pathogen Agrobacterium spp. and the animal pathogen Brucella abortus. TFX-producing strains prevent legume root nodulation by TFX-sensitive rhizobia. TFX has been isolated as a pair of geometric isomers, TFX1 and TFX2, which are derived from the biologically inactive primary amino acid sequence: Asp-Ile-Gly-Gly-Ser-Arg-Gln-Gly-Cys-Val-Ala. Gly-Cys is present as a thiazoline ring and the Arg-Gln-Gly sequence is extensively modified to a UV absorbing, blue fluorescent chromophore. The chromophore consists of a conjugated, 5-membered heterocyclic ring and side chain of modified glutamine.

Brucella abortus Encodes an Active Rhomboid Protease: Proteome Response after Rhomboid Gene Deletion

Rhomboids are intramembrane serine proteases highly conserved in the three domains of life. Their key roles in eukaryotes are well understood but their contribution to bacterial physiology is still poorly characterized. Here we demonstrate that Brucella abortus, the etiological agent of the zoonosis called brucellosis, encodes an active rhomboid protease capable of cleaving model heterologous substrates like Drosophila melanogaster Gurken and Providencia stuartii TatA. To address the impact of rhomboid deletion on B. abortus physiology, the proteomes of mutant and parental strains were compared by shotgun proteomics. About 50% of the B. abortus predicted proteome was identified by quantitative proteomics under two experimental conditions and 108 differentially represented proteins were detected. Membrane associated proteins that showed variations in concentration in the mutant were considered as potential rhomboid targets. This class included nitric oxide reductase subunit C NorC (Q2YJT6) and periplasmic protein LptC involved in LPS transport to the outer membrane (Q2YP16). Differences in secretory proteins were also addressed. Differentially represented proteins included a putative lytic murein transglycosylase (Q2YIT4), nitrous-oxide reductase NosZ (Q2YJW2) and high oxygen affinity Cbb3-type cytochrome c oxidase subunit (Q2YM85). Deletion of rhomboid had no obvious effect in B. abortus virulence. However, rhomboid overexpression had a negative impact on growth under static conditions, suggesting an effect on denitrification enzymes and/or high oxygen affinity cytochrome c oxidase required for growth in low oxygen tension conditions.

Brucella abortus em Humanos: revisão de literatura

A brucelose é uma importante zoonose causada por bactérias pertencentes ao gênero Brucella (Brucellaceae). Brucella abortus tem como seu reservatório natural os bovinos e bubalinos, é o principal agente etiológico da brucelose nos mesmos e o homem é acidentalmente afetado. Essa zoonose apresenta alta morbidade e baixa mortalidade; todavia é um problema de saúde pública, pois grupos profissionais como veterinários, ordenhadores, tratadores de gado, funcionários de matadouro e indústrias lácteas, adquirem brucelose com relativa frequência. Essa doença vem causando danos em humanos por todo o mundo, que por vezes estão sendo subnotificados e assim se torna negligenciada pelos profissionais da saúde.

Design of Epitope Based Peptide Vaccine against Brucella Abortus OmpW Family Protein using Immunoinformatics

Brucella abortus is a small aerobic, non-spore-forming, non-motile intracellular coccobacilli localized in the reproductive organs of host animals and causes acute or chronic disorders. It infects approximately 200 cases per 100,000 of the population and has become endemic in many countries. OmpW family protein is an outer membrane protein involved in the initial interaction between the pathogen and its host. This study predicts an effective epitope-based vaccine against OmpW family protein of Brucella abortus using immunoinformatics tools. Sequences were obtained from NCBI and prediction tests were accomplished to analyze possible epitopes for B and T cells. Seven B cell epitopes passed the antigenicity, accessibility and hydrophilicity tests. Forty-three MHC I epitopes were the most promising, while 438 from MHC II. For the population coverage, the epitopes covered 99.97% of the alleles worldwide excluding certain MHC II alleles. We recommend invivo and invitro studies to prove its effectiveness.

Evaluación del índice de frecuencia, sensibilidad y especificidad entre iELISA y PAL en el diagnóstico de brucelosis bovina en tanque de leche / Evaluation of the frequency, sensitivity and specificity index between iELISA and PAL in the diagnosis of bovine brucellosis in a milk tank

El objetivo del presente proyecto fue diagnosticar brucelosis bovina en tanque de leche con la Prueba Anillo de Leche (PAL) y ELISA indirecto (iELISA), así el índice de frecuencias para determinar una comparativa entre ambas pruebas para establecer costo beneficio, tiempo de análisis, precisión en los resultados. Se seleccionó una población de 276 bovinos hembra adultos lecheros raza Holstein-Friesian de 38 a 48 meses de edad. La brucelosis se diagnosticó en muestras de leche con la prueba PAL y iELISA, bajo los protocolos establecidos. Los resultados obtenidos con la técnica PAL se tuvieron 77 muestras negativas, 15 positivas y 4 control de la placa 1 con un total de 96 muestras; se obtuvieron 86 negativos, 6 positivos y 4 control de la placa 2 con un total de 96 muestras; y 83 negativos, 9 positivos y 4 control de la placa 3 con un total de 96 muestras. Se tuvo mayor porcentaje de detección 82.8% a Brucella abortus en las muestras analizadas por medio de iELISA que con las muestras analizadas con PAL 46.92%. Se concluye que el índice de frecuencias para determinar una comparativa entre ambas pruebas para determinar costo beneficio, entre PAL y iELISA, tiempo de análisis la PAL es más específica 48.93% que la prueba iELISA 19.83% y adicionalmente la prueba iELISA es más sensible 76.92% que PAL 14.85% para diagnosticar brucelosis bovina en tanque de leche. Se deduce que la prueba iELISA presento más frecuencias positivas, por lo que es una prueba más sensible que la PAL. Sin embargo, PAL es más rápida de realizar y es menos costosa que iELISA.