Utilização de proteínas quiméricas de Bartonella henselae para desenvolvimento de testes diagnósticos em felinos

Abstract

Bartonella henselae is of great importance in one health, as it causes acute and chronic complications in domestic, wild and human animals. Although most cases are self-limiting or asymptomatic, severe and even fatal conditions can occur, especially in immunosuppressed patients. Persistent ones can produce diverse clinical manifestations, still poorly characterized in felines, in addition to being the species with the greatest zoonotic potential. The diagnosis of bartonellosis is still challenging, since the techniques currently used have presented limitations. Therefore, the search for new assays for the indirect diagnosis of B. henselae infection is of considerable interest. Thus, the objective was to evaluate the antigenic activity of recombinant chimeric proteins synthesized from immunogenic epitopes of B. henselae for detection of specific antibodies in feline samples. The chimeras were developed from bioinformatics tools and epitopes identified as the most immunogenic antigens of B. henselae, whose qualitative characterization and evaluation of antigenicity was evaluated by Western Blot. The anti-Bartonella recognition activity of the chimeras in 145 feline sera was verified by indirect ELISA, by the test entitled ELISA Feline Bartonella (EFB). An EFB adherence analysis was performed using the metrics of accuracy, sensitivity, specificity and Area Under the ROC Curve (AUROC). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the EFB for detecting anti-bartonella henselae antibodies were compared with the results of the Indirect Immunofluorescence test (IFA), to analyze its possible application as a method of screening and/or confirmation in the serological diagnosis of feline bartonellosis. The chimeric proteins were effective in detecting the presence of antibodies against B. henselae in samples of feline sera, and yet, all reactive samples for bartonellosis in the proposed test (n = 4) were also reactive in the gold standard test (IFA). There were 04 reactive samples for the two tests and another 04 reactive samples only for the IFA. When analyzing feline samples from socially vulnerable communities in Pelotas-RS, the presence of infection by B. henselae was identified. In the evaluation of hematological and biochemical parameters between the IFA-reactive and non-reactive groups, the only alteration found was in albumin levels, not showing clinical relevance. In summary, the recombinant chimeric proteins showed promise, and could be used as a tool for the diagnosis of feline bartonellosis.