Infecção experimental de aves de postura (Gallus gallus domesticus) por cepas de Salmonella enterica sorovar Gallinarum (SG), SGNalr SGcobS e SGcobScbiA: Anatomopatologia, hemograma e perfil bioquímico sérico

Abstract

Este trabalho objetivou avaliar a anatomopatologia, o hemograma e o perfil bioquímico sérico de aves de postura inoculadas por Salmonella Gallinarum (SG) contendo os genes cobS e cbiA inoperantes (SGcobScbiA) que mostrou ser avirulenta em trabalhos anteriores, comparando-a com cepas virulentas SGNalr e SGcobS, para mostrar se SGcobScbiA pode ser componente de vacina contra cepas selvagens de SG e S.Enteritidis. 280 pintainhas foram distribuídas em 4 grupos (G); G1 (SGcobS), G2 (SGNalr), G3 (SGcobScbiA) e G4 (controle). Com exceção do G4, os grupos receberam 0,2 mL de suas respectivas cepas contendo aproximadamente 108 UFC/mL de inóculo, aos 5 dias de idade. A eutanásia foi realizada 24h antes (1DAI) e após a inoculação (1DPI), e 3 (3DPI), 5 (5DPI), 7 (7DPI), 10 (10DPI) e 15 (15DPI) dias após a administração do inóculo, sacrificando-se, em cada momento, dez aves de cada grupo. As aves foram sacrificadas, obtendo-se amostras de sangue utilizadas para os exames hematológicos e bioquímicos. Fragmentos de fígado, baço, timo, bursa de Fabricius, rins e coração foram destinados aos exames histológicos. As aves inoculadas com a cepa SGcobS tiveram comportamento semelhante às aves inoculadas por SGNalr, porém com algumas respostas diferentes nos exames hematológicos e bioquímicos. As aves inoculadas com a cepa SGcobScbiA tiveram comportamento semelhante ao grupo controle, entretanto foi verificado alterações brandas em alguns parâmetros, mostrando que estudos futuros devem ser feitos, verificando se as alterações constatadas não irão interferir no desempenho de aves vacinadas com a cepa SGcobScbiA.

The aim of the present study was to evaluate anatomopathology, hemogram and blood serum components of commercial layers experimentally inoculated with SGcobScbiA, which is a Salmonella Gallinarum (SG) strain it shows attenuation of the virulence in previous research and it was compared with high virulence SGNalr and SGcobS strains in order to show if SGcobScbiA has potential to be use as a vaccine against SG and S. Enteritidis wild strains. 280 commercial layers were divided into 4 groups (G); G1 (SGcobS), G2 (SGNalr), G3 (SGcobScbiA) and G4 (control group). With exception of G4, all the other groups received 0,2 mL of their respective strain containing about 108 CFU/mL of the inoculum with five days of age. Birds were sacrificed 24 hours before (1DBI) and 24 hours after the inoculation (1DAI), and three (3DAI), five (5DAI), seven (7DAI) ten (10DAI), and fifteen (15DAI) days after the administration of the inoculum, slaughtering ten birds at a time in each group. Birds were submitted to euthanasia and blood samples were collected in order to make the hematological and blood serum components test. Samples of liver, spleen, thymus, bursa of Fabricius, kidneys and heart were collected for the histological test. The birds inoculated with SGcobS strain had similar behavior when compared with that ones who received SGNalr strain, however some different responses in the hematological and blood serum components were found. On the other hand, the birds inoculated with SGcobScbiA strain had similar behavior when compared with the control group, however, lower alterations in some parameters were found. Further studies must be done to verify if these alterations will not interfere in the performance of the vaccinate birds with SGcobScbiA strain.