Experimental infection of commercial layers with wild or attenuated Salmonella Gallinarum mutant strains: anatomic pathology, total blood cell count and serum protein levels

Abstract

The aim of the present study was to comparatively evaluate hemogram, blood serum components and anatomopathologic alterations in commercial layers experimentally challenged with an attenuated vaccine candidate strain (SGDcobSDcbiA) and other two pathogenic strains (SGDcobS and SGNal r) of Gallinarum (SG). In total, 280 commercial layers were randomly divided into 4 groups (G1, G2, G3 and G4). At five days of age, birds from groups G1 received approximately 10 7 colony forming units (CFU) of SGDcobS; meanwhile birds from group G2 and G3 received the same dose of SGNal r and SGDcobSDcbiA, respectively. Birds from G4 were not infected. At 24 hours before (DBI) and 24 hours after (1 DAI), and three (3 DAI), five (5 DAI), seven (7 DAI) ten (10 DAI), and fifteen (15 DAI) days after the infection, 10 birds of each group were humanely killed and blood samples collected to hematological and serum tests. Samples of liver, spleen, thymus, bursa of Fabricius, kidney and heart were also collected for the histological examination. Birds inoculated with SGDcobS and SGNal r showed similar alterations in hemogram, blood serum components and anatomopathologic exams. On the other hand, the exams of birds inoculated with SGDcobSDcbiA strain were similar to those of the uninfected birds. However, changes could be noticed in levels of uric acid and cholesterol during the course of the infection of birds from G3. Decrease in levels of light IgG 3 DAI was also observed in birds from this group. Pyknosis in kidney cells was a microscopic alteration found in birds from G3. Further studies must be done to verify if these alterations will not interfere in the performance of the vaccinate birds with SGDcobSDcbiA strain.

Corticosterone, inflammation, immune status and telomere length in frigatebird nestlings facing a severe herpesvirus infection

“…For instance, an increased plasma concentration of haptoglobin was found in chickens infected by Escherichia coli and Eimeria tenella (Georgieva et al ., 2010) or Salmonella enterica (Garcia et al ., 2013), in domestic canaries exposed to Plasmodium relictum (Cellier-Holzem et al ., 2010) or in wandering albatrosses ( Diomedea exulans ) with a higher density of Ixodes uriae on the head plumage (Costantini et al ., 2015). Likewise, broiler chickens infected by bronchitis virus showed significantly higher haptoglobin than healthy individuals (Asasi et al ., 2013), whereas Japanese quails ( Coturnix japonica ) infected by aspergillosis had a lower haptoglobin concentration than control birds (Goetting et al ., 2013).…”

Modulations of growth performance, gut microbiota, and inflammatory cytokines by trehalose on Salmonella Typhimurium-challenged broilers

“…The serum ALT level was considered more specific for liver damage compared with serum AST ( Harr, 2002 ). A recent study also found that the serum AST level in layers was increased after the Salmonella inoculation ( Garcia et al., 2013 ). Therefore, serum AST and ALT levels were analyzed to depict the serum profile of ST-inoculated broilers.…”

Clinical signs in Japanese quails (Coturnix coturnix) experimentally infected with Salmonella Gallinarum

“…A presença de sinais clínicos foi observada apenas nas aves inoculadas a partir do quarto dia após a administração do inóculo (13/32). Garcia et al (2013), também observaram que os sinais clínicos em galinhas inoculadas experimentalmente com SG se iniciaram no quarto dia após inoculação e alguns foram semelhantes aos verificados neste trabalho, como apatia, prostração, penas eriçadas e diarreia. Além desses sinais clínicos, também foi observado no presente experimento que a ave permanecia no canto da gaiola e com os olhos fechados e relutava em mover-se, mesmo sendo estimuladas a se deslocarem.…”

“…Vários fatores bacterianos (lipopolissacarídeos, flagelos, fímbrias e algumas proteínas da membrana externa) têm sido apontados como iniciadores na adesão e/ou invasão do epitélio do trato alimentar por Salmonella (Berndt et al, 2007). O lipopolissacárido (LPS), uma endotoxina bacteriana, presente na membrana externa das bactérias Gram-negativas, pode iniciar a resposta inflamatória sistêmica através da ativação de leucócitos, estimulando a libertação de citocinas pró-inflamatórias (Garcia et al, 2013).…”

“…Isto estimula uma resposta imune forte e induz uma reação antígeno-anticorpo, que provoca uma endotoxemia, que pode ser responsável por sinais clínicos mais fortes e morte das aves (Garcia et al, 2013). Segundo Kokosharov (2002), a endotoxina de SG é um fator chave na patogênese da febre tifoide, pois está diretamente relacionada com a virulência do micro-organismo.…”