Influencia de Salmonella pullorum y S. gallinarum en la producción avícola y la salud pública / Influence of Salmonella pullorum and S. gallinarum on poultry production and public health

La calidad de los alimentos que consumimos se ha convertido en uno de los principales problemas de salud pública a nivel mundial, ya que son la puerta de entrada de patógenos y vectores para la trasmisión de diversas enfermedades. Se estimó que el 17,9% de las enfermedades trasmitidas por el consumo de alimentos, está relacionada con aves de corral, y el 19% de estas enfermedades, están asociadas a la contaminación por Salmonella entérica. La Salmonelosis es una enfermedad invasiva que afecta en gran medida a las poblaciones altamente vulnerables (niños, ancianos e inmunocomprometidos), causando la necesidad de hospitalización y en ocasiones la muerte. A nivel mundial se estima que anualmente hay más de 94 millones de personas afectadas por gastroenteritis causada por el consumo de aves contaminadas con Salmonella, así como más de 155.000 fallecidos. Sin embargo, los orígenes de esta cepa: Salmonella entérica y otras de mayor alcance patógeno están influenciadas muy de cerca por el control de dos cepas con poca acción en la población humana: la S. polloroum y la S. gallinarum. La casi desaparición de estos dos serovares impulsó la colonización de cepas más resistente a los antibióticos y más perjudiciales para los seres humanos(AU)

The quality of the food we consume has become one of the main public health problems worldwide, since it is the gateway for pathogens and vectors for the transmission of various diseases. It was estimated that 17.9% of diseases transmitted by food consumption are related to poultry, and 19% of these diseases are associated with contamination by Salmonella enterica. Salmonellosis is an invasive disease that greatly affects highly vulnerable populations (children, the elderly and immunocompromised), causing the need for hospitalization and sometimes death. Worldwide, it is estimated that annually there are more than 94 million people affected by gastroenteritis caused by the intake of poultry contaminated with Salmonella, as well as more than 155,000 deaths. However, the origins of this strain: Salmonella enterica and others with a greater pathogenic scope are closely influenced by the control of two strains with little action in the human population: S. polloroum and S. gallinarum. The near disappearance of these two serovars prompted the colonization of strains more resistant to antibiotics and more harmful to humans(AU)

Recombinant-attenuated Salmonella Pullorum strain expressing the hemagglutinin-neuraminidase protein of Newcastle disease virus (NDV) protects chickens against NDV and Salmonella Pullorum challenge

Newcastle disease virus (NDV) and Salmonella Pullorum have significant damaging effects on the poultry industry, but no previous vaccine can protect poultry effectively. In this study, a recombinant-attenuated S. Pullorum strain secreting the NDV hemagglutinin-neuraminidase (HN) protein, C79-13ΔcrpΔasd (pYA-HN), was constructed by using the suicide plasmid pREasd-mediated bacteria homologous recombination method to form a new bivalent vaccine candidate against Newcastle disease (ND) and S. Pullorum disease (PD). The effect of this vaccine candidate was compared with those of the NDV LaSota and C79-13ΔcrpΔasd (pYA) strains. The serum hemagglutination inhibition antibody titers, serum immunoglobulin G (IgG) antibodies, secretory IgA, and stimulation index in lymphocyte proliferation were increased significantly more (p 0.05). Moreover, the novel strain provides 60% and 80% protective efficacy against the NDV virulent strain F48E9 and the S. Pullorum virulent strain C79-13. In summary, in this study, a recombinant-attenuated S. Pullorum strain secreting NDV HN protein was constructed. The generation of the S. Pullorum C79-13ΔcrpΔasd (pYA-HN) strain provides a foundation for the development of an effective living-vector double vaccine against ND and PD.

A comparative survey between non-systemic Salmonella spp. (paratyphoid group) and systemic Salmonella Pullorum and S. Gallinarum with a focus on virulence genes / Uma investigação comparativa entre Salmonella spp. não-sistêmicas (grupo paratifoide) e sistêmicas Salmonella Pullorum e S. Gallinarum com enfoque nos genes de virulência

A comparative survey between non-systemic (paratyphoid Salmonellae) and systemic (S. Pullorum and S. Gallinarum) Salmonella strains was performed to produce a virulence gene profile for differentiation among the groups. The following virulence genes were evaluated: invA, spvC, sefC, pefA, fimY, sopB, sopE1, stn and avrA. There are substantial differences among paratyphoid Salmonellae, S. Pullorum, and S. Gallinarum regarding the genes sefC, spvC, sopE1 and avrA. A higher frequency of sefC, spvC, sopE1 and avrA genes were detected in S. Gallinarum and S. Pullorum when compared with strains from the paratyphoid group of Salmonella. These results may be useful for differentiating among different groups and serotypes.(AU)

Uma investigação comparativa entre amostras de Salmonella não-sistêmicas (grupo paratifoide) e sistêmicas (S. Pullorum and S. Gallinarum) foi desenvolvida para produzir um perfil de genes de virulência para diferenciação entre os grupos. Os seguintes genes de virulência foram avaliados invA, spvC, sefC, pefA, fimY, sopB, sopE1, stn e avrA. Detectou-se uma diferença substancial entre Salmonella do grupo paratifoide, S. Pullorum e S. Gallinarum considerando os genes sefC, spvC, sopE1 e avrA. Os genes sefC, spvC, sopE1 e avrA foram detectados, em maior número, em S. Gallinarum e S. Pullorum quando comparados com as amostras de Salmonella do grupo paratifoide. Estes resultados podem ser úteis para a diferenciação entre os diferentes grupos e sorotipos de Salmonella.(AU)

Construction of Salmonella Pullorum C79-13ΔcrpΔasd mutant balanced-lethal host-vector system and its biological features / 中国免疫学杂志

In order to develop a safer vaccine strain exploit Salmonella Pullorum vaccine strain as a live vaccine vector.Methods:AΔcrpΔasd mutant of S.pullorum C79-13 strain was constructed and it was developed E.coli donor strain mutant was generated through the two-step method introduced by χ7213 ( pREΔasd) was conjugated with the recipient of C 79-13Δcrp.The C79-13ΔcrpΔasd the transduction of recombinant suicide plasmid .Results:PCR and sequencing results showed that ΔsipBSL1344 was suc-cessfully constructed.The further study indicated that foreign DAP must be supplied for the ΔcrpΔasd mutant to grow,in addition,the asd gene was transmitted stably .Compared with C79-13 strain,the O antigens was identical to C79-13 strain,but the growth velocity was reduced significantly ,significantly reduced virulence .Conclusion: The ΔcrpΔasd mutant can accept asd+plasmid to construct host-vector balance lethal system , and this system can be used to express foreign gene efficiently and to develop potential oral multivalent vaccines.

Molecular differentiation between Salmonella enterica subsp enterica serovar Pullorum and Salmonella enterica subsp enterica serovar Gallinarum / Diferenciação molecular entre Salmonella enterica subsp enterica serovar Pullorum e Salmonella enterica subsp enterica serovar Gallinarum

S. Pullorum (SP) and S. Gallinarum (SG) are very similar. They are the agents of pullorum disease and fowl typhoid, respectively, and the two diseases are responsible for economic losses in poultry production. Although SP and SG are difficult to be differentiated in routine laboratory procedures, the ability to metabolize ornithine is a biochemical test that may be used to achieve this aim. While SP is able to decarboxylate this amino acid, SG is not. However, the isolation of strains showing atypical biochemical behavior has made this differentiation difficult. One of the genes associated with the metabolization of the amino acid ornithine is called speC, and is found in both serovars. The analysis of 21 SP and 15 SG strains by means of PCR did not enable the differentiation of the two serovars, because fragments produced were identical. However, after enzymatic treatment with restriction enzyme Eco RI, the band pattern of each serovar showed to be different, even in samples of atypical biochemical behavior. This fact enabled the standardization of the technique for a quick and safe differentiation of serovars Pullorum and Gallinarum.

A S. Pullorum (SP) é muito semelhante à S. Gallinarum (SG), agentes da Pulorose e Tifo aviário, respectivamente, sendo que as duas enfermidades são responsáveis por perdas econômicas no setor avícola. SP e SG são de difícil diferenciação em procedimento laboratorial rotineiro, mas uma prova bioquímica muito utilizada na distinção das duas refere-se à capacidade de assimilar o aminoácido ornitina: SP descarboxila este aminoácido enquanto SG não. No entanto, o isolamento de cepas com comportamento bioquímico atípico, tem dificultado tal diferenciação. Um dos genes relacionados à assimilação do aminoácido ornitina, denomina-se gene speC, o qual está presente nos dois sorovares. Analisando 21 amostras de SP e 15 de SG com a utilização da PCR não foi possível realizar a diferenciação dos dois sorovares pois os fragmentos gerados eram idênticos. Posteriormente, com o uso da técnica de tratamento enzimático com a enzima de restrição Eco RI, foi possível observar que o padrão de bandas gerado em cada sorovar era diferente, mesmo quando amostras que apresentavam comportamento bioquímico atípico eram analisadas. Tal fato permitiu a padronização da técnica para ser utilizada na diferenciação entre os sorovares Pullorum e Gallinarum de maneira rápida e segura.