| Congresso Brasileiro de Microbiologia 2023 | Resumo: 741-2 | ||||
Resumo:Brucellosis, an infectious disease caused by Gram-negative bacteria of the genus Brucella, represents an infection of great importance for both animal and human health, resulting a big social and economic impacts. In Brazil, the strategies adopted by the National Program for the Control and Eradication of Brucellosis and Tuberculosis - PNCEBT aim to control and eradicate the disease by establishing measures such as vaccination of females, diagnosis and slaughter of positive animals. Diagnosis of bovine brucellosis is based mainly on serological tests using LPS (Lipopolysaccharide), part of LPS or whole cells as the antigen. In this sense, gram-negative bacteria, in particular Yersinia enterocolitica O:9 (Y. enterocolitica O:9) which presents an LPS O chain almost identical to that of Brucella spp. can induce antibody responses that cause false positive results in brucellosis tests. In view of this, the objective of this study was to evaluate the cross-reaction of brucellosis tests (AAT- buffered acidified antigen test, BPAT- buffered plate agglutination test and iELISA IDEXX-IDEXX Brucellosis Serum X2) with Y. enterocolitica O:9 by means of the calculation of diagnostic specificity (DSp). For this, cross-reactive specific sera were produced by experimental inoculation of Y. enterocolitica O:9 (3 x 10 ¹⁰ colony forming units/animal inactivated with β-propiolactone) in 12 Holstein heifers with more than 24 months of age. age, negative for bovine brucellosis. Eighty-four samples corresponding to days 7, 14, 21, 28, 35, 42 and 49 after bacterial inoculation were used. The DSp estimate was calculated by the probability of a negative result in non-ill patients (true negative). The results showed an AAT test DSp of 95.2% (95% CI - 95% confidence interval - 88.4% - 98.1%), BPAT 71.4% (95% CI: 61.0% - 79.9%) and iELISA IDEXX 60.7% ( 95% CI: 50.0% - 70.5%). From the data, it can be seen that the AAT test had the highest DSp, followed by the BPAT and iELISA IDEXX. This demonstrates the interference of Y. enterocolitica O:9 in the serology for brucellosis, reflecting in harmful effects on the control and eradication of the disease. Thus, the need to identify new diagnostic tools that are able to discriminate infected animals from cross-reactive animals to control the disease is evident.
Development agency: FAPEMIG, CNPq, CAPES, UFLA. Palavras-chave: Bacteria, Cross-reaction, Diagnosis, Zoonosis Agência de fomento:FAPEMIG, CNPq, CAPES, UFLA | |||||