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Xinan Jiao - One of the best experts on this subject based on the ideXlab platform.
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loss and gain in the evolution of the salmonella enterica serovar gallinarum biovar Pullorum genome
mSphere, 2019Co-Authors: Zhenyu Wang, Bin Qiang, Xiang Chen, Xinan JiaoAbstract:ABSTRACT Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the etiological agent of Pullorum Disease, causing white diarrhea with high mortality in chickens. There are many unsolved issues surrounding the epidemiology of S. Pullorum, including its origin and transmission history as well as the discordance between its phenotypic heterogeneity and genetic monomorphism. In this paper, we report the results of whole-genome sequencing of a panel of 97 S. Pullorum strains isolated between 1962 and 2014 from four countries across three continents. We utilized 6,795 core genome single nucleotide polymorphisms (SNPs) to reconstruct a phylogenetic tree within a spatiotemporal Bayesian framework, estimating that the most recent common ancestor of S. Pullorum emerged in ∼914 CE (95% confidence interval [95%CI], 565 to 1273 CE). The extant S. Pullorum strains can be divided into four distinct lineages, each of which is significantly associated with geographical distribution. The intercontinental transmissions of lineages III and IV can be traced to the mid-19th century and are probably related to the “Hen Fever” prevalent at that time. Further genomic analysis indicated that the loss or pseudogenization of functional genes involved in metabolism and virulence in S. Pullorum has been ongoing since before and after divergence from the ancestor. In contrast, multiple prophages and plasmids have been acquired by S. Pullorum, and these have endowed it with new characteristics, especially the multidrug resistance conferred by two large plasmids in lineage I. The results of this study provide insight into the evolution of S. Pullorum and prove the efficiency of whole-genome sequencing in epidemiological surveillance of Pullorum Disease. IMPORTANCE Pullorum Disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of Pullorum Disease.
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purification of recombinant ipaj to develop an indirect elisa based method for detecting salmonella enterica serovar Pullorum infections in chickens
BMC Veterinary Research, 2019Co-Authors: Yue Zhu, Chao Yin, Kequan Yin, Jingwei Ren, Yu Yuan, Xinan JiaoAbstract:Salmonella enterica serovar Pullorum is a host-restricted serotype causing infection in poultry. The pathogen can not only cause acute infection in young chicks with high mortality and morbidity, but also persist in adult chickens without evident clinical symptoms and lead to vertical transmission. To eradicate S. Pullorum in poultry farms, it is necessary to establish an efficient method to monitor the prevalence of the pathogen in adult chickens. The protein IpaJ is a specific immunogen in S. Pullorum and is not detected in closely related serotypes, such as S. Gallinarum and S. Enteritidis. In the present study, IpaJ was expressed as a recombinant fusion protein MBP-IpaJ in E. coli. The purified MBP-IpaJ was used as a coating antigen to develop an indirect ELISA assay, which was applied to the detection of S. Pullorum infection in chickens. The indirect ELISA assay demonstrated that antibodies produced against IpaJ were detectable in antisera of chickens infected with S. Pullorum in the second week, stably increased until the tenth week, and persisted at a high level in the following two weeks. Furthermore, the ELISA method detected four positive samples out of 200 clinical antiserum samples collected from a poultry farm, and the positive samples were confirmed to be reacted with S. Pullorum using the standard plate agglutination test. The established indirect ELISA using the IpaJ protein is a novel method for specific detection of S. Pullorum infection, and contribute to eradication of Pullorum Disease in the poultry industry.
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Loss and Gain in the Evolution of the Salmonella enterica Serovar Gallinarum Biovar Pullorum Genome
American Society for Microbiology, 2019Co-Authors: Zhenyu Wang, Bin Qiang, Xiang Chen, Xinan JiaoAbstract:Pullorum Disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of Pullorum Disease.Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the etiological agent of Pullorum Disease, causing white diarrhea with high mortality in chickens. There are many unsolved issues surrounding the epidemiology of S. Pullorum, including its origin and transmission history as well as the discordance between its phenotypic heterogeneity and genetic monomorphism. In this paper, we report the results of whole-genome sequencing of a panel of 97 S. Pullorum strains isolated between 1962 and 2014 from four countries across three continents. We utilized 6,795 core genome single nucleotide polymorphisms (SNPs) to reconstruct a phylogenetic tree within a spatiotemporal Bayesian framework, estimating that the most recent common ancestor of S. Pullorum emerged in ∼914 CE (95% confidence interval [95%CI], 565 to 1273 CE). The extant S. Pullorum strains can be divided into four distinct lineages, each of which is significantly associated with geographical distribution. The intercontinental transmissions of lineages III and IV can be traced to the mid-19th century and are probably related to the “Hen Fever” prevalent at that time. Further genomic analysis indicated that the loss or pseudogenization of functional genes involved in metabolism and virulence in S. Pullorum has been ongoing since before and after divergence from the ancestor. In contrast, multiple prophages and plasmids have been acquired by S. Pullorum, and these have endowed it with new characteristics, especially the multidrug resistance conferred by two large plasmids in lineage I. The results of this study provide insight into the evolution of S. Pullorum and prove the efficiency of whole-genome sequencing in epidemiological surveillance of Pullorum Disease
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Purification of recombinant IpaJ to develop an indirect ELISA-based method for detecting Salmonella enterica serovar Pullorum infections in chickens
BMC, 2019Co-Authors: Yue Zhu, Chao Yin, Kequan Yin, Jingwei Ren, Yu Yuan, Xinan JiaoAbstract:Abstract Background Salmonella enterica serovar Pullorum is a host-restricted serotype causing infection in poultry. The pathogen can not only cause acute infection in young chicks with high mortality and morbidity, but also persist in adult chickens without evident clinical symptoms and lead to vertical transmission. To eradicate S. Pullorum in poultry farms, it is necessary to establish an efficient method to monitor the prevalence of the pathogen in adult chickens. The protein IpaJ is a specific immunogen in S. Pullorum and is not detected in closely related serotypes, such as S. Gallinarum and S. Enteritidis. Results In the present study, IpaJ was expressed as a recombinant fusion protein MBP-IpaJ in E. coli. The purified MBP-IpaJ was used as a coating antigen to develop an indirect ELISA assay, which was applied to the detection of S. Pullorum infection in chickens. The indirect ELISA assay demonstrated that antibodies produced against IpaJ were detectable in antisera of chickens infected with S. Pullorum in the second week, stably increased until the tenth week, and persisted at a high level in the following two weeks. Furthermore, the ELISA method detected four positive samples out of 200 clinical antiserum samples collected from a poultry farm, and the positive samples were confirmed to be reacted with S. Pullorum using the standard plate agglutination test. Conclusions The established indirect ELISA using the IpaJ protein is a novel method for specific detection of S. Pullorum infection, and contribute to eradication of Pullorum Disease in the poultry industry
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identification and discrimination of salmonella enterica serovar gallinarum biovars Pullorum and gallinarum based on a one step multiplex pcr assay
Frontiers in Microbiology, 2018Co-Authors: Dan Xiong, Zhiming Pan, Li Song, Xinan JiaoAbstract:Salmonella enterica serovar Gallinarum biovars Pullorum (S. Pullorum) and Gallinarum (S. Gallinarum) can result in Pullorum Disease and fowl typhoid in avian species, respectively, and cause considerable economic losses in poultry in many developing countries. Conventional Salmonella serotyping is a time-consuming, labor-intensive and expensive process, and the two biovars cannot be distinguished using the traditional serological method. In this study, we developed a rapid and reliable one-step multiplex polymerase chain reaction (PCR) assay to simultaneously identify and discriminate the biovars Pullorum and Gallinarum. The multiplex PCR method focused on three specific genes, stn, I137_08605 and ratA. Based on bioinformatics analysis, we found that gene I137_08605 was present only in S. Pullorum and S. Gallinarum, and a region of difference (ROD) in ratA was deleted only in S. Pullorum after comparison with that of S. Gallinarum and other Salmonella serovars. Three pairs of primers specific for the three genes were designed for the multiplex PCR system and their selectivity and sensitivity were determined. The multiplex PCR results showed that S. Pullorum and S. Gallinarum could be identified and discriminated accurately from all tested strains including 124 strains of various Salmonella serovars and 42 strains of different non-Salmonella pathogens. In addition, this multiplex PCR assay could detect a minimum genomic DNA concentration of 67.4 pg/μL, and 100 colony forming units. The efficiency of the multiplex PCR was evaluated by detecting natural-occurring Salmonella isolates from a chicken farm. The results demonstrated that the established multiplex PCR was able to identify S. Gallinarum and S. Pullorum individually, with results being consistent with traditional serotyping and biochemical testing. These results demonstrated that a highly accurate and simple biovar-specific multiplex PCR assay could be performed for the rapid identification and discrimination of Salmonella biovars Gallinarum and Pullorum, which will be useful, particularly under massive screening situations.
Paul Barrow - One of the best experts on this subject based on the ideXlab platform.
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evaluation of pathogenicity of salmonella gallinarum strains harbouring deletions in genes whose orthologues are conserved pseudogenes in s Pullorum
PLOS ONE, 2018Co-Authors: Diego Felipe Alves Batista, Paul Barrow, Oliveiro Caetano Freitas Neto, Adriana Maria De Almeida, Grazieli Maboni, Tatiane Furtado De Carvalho, Thaynara Parente De Carvalho, A BerchieriAbstract:: The Diseases caused by Salmonella Gallinarum and S. Pullorum in chickens known as fowl typhoid and Pullorum Disease, respectively, pose a great threat to the poultry industry mainly in developing countries, since they have already been controlled in the developed ones. These bacteria are very similar at the genomic level but develop distinct host-pathogen relationships with chickens. Therefore, a deep understanding of the molecular mechanisms whereby S. Gallinarum and S. Pullorum interact with the host could lead to the development of new approaches to control and, perhaps, eradicate both Diseases from the chicken flocks worldwide. Based on our previous study, it was hypothesised that metabolism-related pseudogenes, fixed in S. Pullorum genomes, could play a role in the distinct host-pathogen interaction with susceptible chickens. To test this idea, three genes (idnT, idnO and ccmH) of S. Gallinarum str. 287/91, which are pseudogenes on the S. Pullorum chromosomes, were inactivated by mutations. These genetically engineered strains grew well on the solid media without any colony morphology difference. In addition, similar growth curves were obtained by cultivation in M9 minimal medium containing D-gluconate as the sole carbon source. Infection of chickens with idnTO mutants led to increased numbers of bacteria in the livers and spleens at 5 days post-infection, but with slightly decreased heterophil infiltration in the spleens when compared to the wild-type strain. On the other hand, no significant phenotypic change was caused by mutation to ccmH genes. Apart from the above-mentioned alterations, all S. Gallinarum strains provoked similar infections, since mortality, clinical signs, macroscopic alterations and immune response were similar to the infected chickens. Therefore, according to the model applied to this study, mutation to the idnTO and ccmH genes showed minor impact on the fowl typhoid pathogenesis and so they may be relics from the ancestor genome. Our data hints at a more complex mechanism driving the distinct host-pathogen interaction of S. Gallinarum/Pullorum with chickens than differential inactivation of a few genes.
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identification and characterization of regions of difference between the salmonella gallinarum biovar gallinarum and the salmonella gallinarum biovar Pullorum genomes
Infection Genetics and Evolution, 2015Co-Authors: Diego Felipe Alves Batista, Marcos T Oliveira, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Antônio Sérgio Ferraudo, Angelo BerchieriAbstract:Salmonella Gallinarum is the causative agent of fowl typhoid, a severe septicaemic Disease that affects birds of all ages, whereas S. Pullorum causes Pullorum Disease, a systemic disorder affecting primarily young birds. A proportion of birds with Pullorum Disease become carriers and are thereby able to transmit S. Pullorum vertically. Although these two pathogens cause distinct Diseases, they are otherwise phenotypically and genetically similar. Therefore, the small variations that lead to the differences in virulence must have a genetic basis which currently is unknown. In the present study, we compared the genome sequences of S. Gallinarum (strains: SG287/91 and SG9) and S. Pullorum (strains: SP_CDC, SP_RKS, SP_FCAV, SP_S06) and identified 223 regions of difference (RODs), characterized by indels which were detected by using the software Artemis Comparison Tool. Some of the RODs led to pseudogenes frequently formed by frameshifts and premature stop codons in genes primarily involved in virulence and metabolism. We further verified the presence of some conserved RODs by PCR in 26 isolates of S. Gallinarum and 17 of S. Pullorum in order to extrapolate data analyses from genome comparison to field strains. The variations observed in virulence-related genes of S. Gallinarum and S. Pullorum appear not to be sufficient to explain the differences between the distinct biology of infection of fowl typhoid and Pullorum Disease. Thus, we suggest that the identified pseudogenes affecting metabolism might play a greater role during infection than previously thought.
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virulence determinants of salmonella gallinarum biovar Pullorum identified by pcr signature tagged mutagenesis and the spic mutant as a candidate live attenuated vaccine
Veterinary Microbiology, 2014Co-Authors: Shizhong Geng, Paul Barrow, Xinan Jiao, Xiang ChenAbstract:Abstract Salmonella Gallinarum biovar Pullorum ( S. Gallinarum biovar Pullorum) is the causative agent of Pullorum Disease (PD) in chickens which results in considerable economic losses to the poultry industries in developing countries. PCR-Signature Tagged Mutagenesis was used to identify virulence determinants of S. Gallinarum biovar Pullorum and novel attenuated live vaccine candidates for use against this Disease. A library of 1800 signature-tagged S. Gallinarum biovar Pullorum mutants was constructed and screened for virulence-associated genes in chickens. The attenuation of 10 mutants was confirmed by in vivo and in vitro competitive index (CI) studies. The transposons were found to be located in SPI-1 (2/10 mutants), SPI-2 (3/10), the virulence plasmid (1/10) and non-SPI genes (4/10). One highly attenuated spiC mutant persisted in spleen and liver for less than 10 days and induced high levels of circulating antibody and protective immunity against oral challenge in young broiler chickens. The spiC mutant is a potential new vaccine candidate for use with chickens against this Disease.
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polymerase chain reaction assay based on rata gene allows differentiation between salmonella enterica subsp enterica serovar gallinarum biovars gallinarum and Pullorum
Journal of Veterinary Diagnostic Investigation, 2013Co-Authors: Diego Felipe Alves Batista, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Priscila Diniz Lopes, Angelo BerchieriAbstract:Salmonella Pullorum and Salmonella Gallinarum are classified as biovars of Salmonella enterica subsp. enterica serovar Gallinarum. These salmonellae are the causative agents of Pullorum Disease and fowl typhoid, respectively, and are widely distributed throughout the world. Although many developed countries have eradicated these Diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. When serovar Gallinarum is isolated, it is difficult to immediately differentiate between biovars because they are antigenically identical by serotyping. However, they cause distinct Diseases with different epidemiology, and therefore it is important to differentiate them. This may be done biochemically but takes 2 to 3 days. In the present study, S. Pullorum and S. Gallinarum whole genomes were compared, and 1 genomic region of difference, which is part of the ratA gene, was chosen as a molecular marker for a polymerase chain reaction assay to differentiate rapidly between these organisms. In all, 26 strains of S. Gallinarum and 17 S. Pullorum strains were tested and successfully differentiated by the assay.
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early immune dynamics following infection with salmonella enterica serovars enteritidis infantis Pullorum and gallinarum cytokine and chemokine gene expression profile and cellular changes of chicken cecal tonsils
Comparative Immunology Microbiology and Infectious Diseases, 2012Co-Authors: Ahmed Setta, Paul Barrow, Peter K Kaiser, Michael JonesAbstract:Salmonella enterica subspecies enterica infection remains a serious problem in a wide range of animals and in man. Poultry-derived food is the main source of human infection with the non-host-adapted serovars while fowl typhoid and Pullorum Disease are important Diseases of poultry. We have assessed cecal colonization and immune responses of newly hatched and older chickens to Salmonella serotypes Enteritidis, Infantis, Gallinarum and Pullorum. S. Enteritidis and S. Infantis colonized the ceca more efficiently than S. Gallinarum and S. Pullorum. Salmonella infection was also associated with increased staining for B-lymphocytes and macrophages in the cecal tonsils of infected birds. S. Enteritidis infection in newly hatched birds stimulated the expression of CXCLi1 and CXCLi2 chemokines in the cecal tonsils, while S. Gallinarum up-regulated the expression of LITAF. In older chickens, S. Enteritidis infection resulted in a significantly higher expression of CXCLi2, iNOS, LITAF and IL-10 while S. Pullorum appeared to down-regulate CXCLi1 expression in the cecal tonsils. Data from spleens showed either no expression or down-regulation of the tested genes.
Xiang Chen - One of the best experts on this subject based on the ideXlab platform.
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loss and gain in the evolution of the salmonella enterica serovar gallinarum biovar Pullorum genome
mSphere, 2019Co-Authors: Zhenyu Wang, Bin Qiang, Xiang Chen, Xinan JiaoAbstract:ABSTRACT Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the etiological agent of Pullorum Disease, causing white diarrhea with high mortality in chickens. There are many unsolved issues surrounding the epidemiology of S. Pullorum, including its origin and transmission history as well as the discordance between its phenotypic heterogeneity and genetic monomorphism. In this paper, we report the results of whole-genome sequencing of a panel of 97 S. Pullorum strains isolated between 1962 and 2014 from four countries across three continents. We utilized 6,795 core genome single nucleotide polymorphisms (SNPs) to reconstruct a phylogenetic tree within a spatiotemporal Bayesian framework, estimating that the most recent common ancestor of S. Pullorum emerged in ∼914 CE (95% confidence interval [95%CI], 565 to 1273 CE). The extant S. Pullorum strains can be divided into four distinct lineages, each of which is significantly associated with geographical distribution. The intercontinental transmissions of lineages III and IV can be traced to the mid-19th century and are probably related to the “Hen Fever” prevalent at that time. Further genomic analysis indicated that the loss or pseudogenization of functional genes involved in metabolism and virulence in S. Pullorum has been ongoing since before and after divergence from the ancestor. In contrast, multiple prophages and plasmids have been acquired by S. Pullorum, and these have endowed it with new characteristics, especially the multidrug resistance conferred by two large plasmids in lineage I. The results of this study provide insight into the evolution of S. Pullorum and prove the efficiency of whole-genome sequencing in epidemiological surveillance of Pullorum Disease. IMPORTANCE Pullorum Disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of Pullorum Disease.
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Loss and Gain in the Evolution of the Salmonella enterica Serovar Gallinarum Biovar Pullorum Genome
American Society for Microbiology, 2019Co-Authors: Zhenyu Wang, Bin Qiang, Xiang Chen, Xinan JiaoAbstract:Pullorum Disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of Pullorum Disease.Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the etiological agent of Pullorum Disease, causing white diarrhea with high mortality in chickens. There are many unsolved issues surrounding the epidemiology of S. Pullorum, including its origin and transmission history as well as the discordance between its phenotypic heterogeneity and genetic monomorphism. In this paper, we report the results of whole-genome sequencing of a panel of 97 S. Pullorum strains isolated between 1962 and 2014 from four countries across three continents. We utilized 6,795 core genome single nucleotide polymorphisms (SNPs) to reconstruct a phylogenetic tree within a spatiotemporal Bayesian framework, estimating that the most recent common ancestor of S. Pullorum emerged in ∼914 CE (95% confidence interval [95%CI], 565 to 1273 CE). The extant S. Pullorum strains can be divided into four distinct lineages, each of which is significantly associated with geographical distribution. The intercontinental transmissions of lineages III and IV can be traced to the mid-19th century and are probably related to the “Hen Fever” prevalent at that time. Further genomic analysis indicated that the loss or pseudogenization of functional genes involved in metabolism and virulence in S. Pullorum has been ongoing since before and after divergence from the ancestor. In contrast, multiple prophages and plasmids have been acquired by S. Pullorum, and these have endowed it with new characteristics, especially the multidrug resistance conferred by two large plasmids in lineage I. The results of this study provide insight into the evolution of S. Pullorum and prove the efficiency of whole-genome sequencing in epidemiological surveillance of Pullorum Disease
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genetic analysis of salmonella enterica serovar gallinarum biovar Pullorum based on characterization and evolution of crispr sequence
Veterinary Microbiology, 2017Co-Authors: Yachen Hu, Shizhong Geng, Xinan Jiao, Lijuan Xu, Yang Li, Qiuchun Li, Yaohui Xu, Yun Chen, Xiang ChenAbstract:Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the cause of Pullorum Disease, characterized by white diarrhea, which leads to high mortality in poultry. In this study, we aimed to assess the genetic diversity of 655 S. Pullorum strains from 1962 to 2015 in China, Europe, and South America. A sequence typing scheme based on clustered regularly interspaced short palindromic repeats (CRISPR) was used to reveal the genetic relationships among these strains in this study. Overall, a total of 20 Pullorum sequence types (PSTs) of CRISPR were identified in the 655 isolates with PST7 (74%, 486/655) and PST3 (13%, 86/655) to be the most two frequent PSTs belonging to two different lineages, which confirmed the genetic conservation of S. Pullorum strains isolated from six provinces and two direct-controlled municipalities (Beijing and Shanghai) in China. However, the identification of seven new PSTs distributed in strains isolated since 2001 implied that genetic variation continues to develop in S. Pullorum. Interestingly, the whole-genome single-nucleotide polymorphism typing (WGST) of 96 strains out of the 655 isolates divided them into four lineages based on SNP analysis of core genomic sequence and exhibit good correspondence with the CRISPR subtyping method. Notably, 22 out of 26 isolates from Europe and South America were distributed in five distinctive PSTs (with no Chinese strains). Additionally, CRISPR data of spacers and their arrangement exhibit subtle but distinct specificity between different strains, and the dynamic adaptive nature of CRISPR loci provides critical insights into the evolution of S. Pullorum as the bacteria are influenced by their environment.
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virulence determinants of salmonella gallinarum biovar Pullorum identified by pcr signature tagged mutagenesis and the spic mutant as a candidate live attenuated vaccine
Veterinary Microbiology, 2014Co-Authors: Shizhong Geng, Paul Barrow, Xinan Jiao, Xiang ChenAbstract:Abstract Salmonella Gallinarum biovar Pullorum ( S. Gallinarum biovar Pullorum) is the causative agent of Pullorum Disease (PD) in chickens which results in considerable economic losses to the poultry industries in developing countries. PCR-Signature Tagged Mutagenesis was used to identify virulence determinants of S. Gallinarum biovar Pullorum and novel attenuated live vaccine candidates for use against this Disease. A library of 1800 signature-tagged S. Gallinarum biovar Pullorum mutants was constructed and screened for virulence-associated genes in chickens. The attenuation of 10 mutants was confirmed by in vivo and in vitro competitive index (CI) studies. The transposons were found to be located in SPI-1 (2/10 mutants), SPI-2 (3/10), the virulence plasmid (1/10) and non-SPI genes (4/10). One highly attenuated spiC mutant persisted in spleen and liver for less than 10 days and induced high levels of circulating antibody and protective immunity against oral challenge in young broiler chickens. The spiC mutant is a potential new vaccine candidate for use with chickens against this Disease.
Angelo Berchieri - One of the best experts on this subject based on the ideXlab platform.
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Transcription of the cytokine-related genes evaluated in this study by RT-qPCR.
2018Co-Authors: Diego Felipe Alves Batista, Oliveiro Caetano Freitas Neto, Adriana Maria De Almeida, Grazieli Maboni, Tatiane Furtado De Carvalho, Thaynara Parente De Carvalho, Paul Andrew Barrow, Angelo BerchieriAbstract:Chickens were orally infected with the strains here tested on the 15 day of age. Samples of caecal tonsils and spleen tissues were collected at 1, 3 and 5 dpi. (*) This symbol shows groups whose mRNA transcription statistically differs by one-way ANOVA followed by Tukey’s test (* P < 0.05 / ** P < 0.01). CXCLi2: CXC-like chemokine previously named as interleukin 8; IL6: Interleukin 6; IFN: Interferon gamma; (CT): Caecal tonsil; (SP): Spleen; Control: Non-infected chickens; SP449/87: Chickens infected with S. Pullorum str. 449/87 (Pullorum Disease positive control); SG287/91: Chickens infected with S. Gallinarum str. 287/91 (fowl typhoid positive control); SGΔccmH: Chickens infected with SGΔccmH; SGΔidnTO: Chickens infected with SGΔidnTO; SGΔccmHidnTO: Chickens infected with SGΔccmHidnTO.
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identification and characterization of regions of difference between the salmonella gallinarum biovar gallinarum and the salmonella gallinarum biovar Pullorum genomes
Infection Genetics and Evolution, 2015Co-Authors: Diego Felipe Alves Batista, Marcos T Oliveira, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Antônio Sérgio Ferraudo, Angelo BerchieriAbstract:Salmonella Gallinarum is the causative agent of fowl typhoid, a severe septicaemic Disease that affects birds of all ages, whereas S. Pullorum causes Pullorum Disease, a systemic disorder affecting primarily young birds. A proportion of birds with Pullorum Disease become carriers and are thereby able to transmit S. Pullorum vertically. Although these two pathogens cause distinct Diseases, they are otherwise phenotypically and genetically similar. Therefore, the small variations that lead to the differences in virulence must have a genetic basis which currently is unknown. In the present study, we compared the genome sequences of S. Gallinarum (strains: SG287/91 and SG9) and S. Pullorum (strains: SP_CDC, SP_RKS, SP_FCAV, SP_S06) and identified 223 regions of difference (RODs), characterized by indels which were detected by using the software Artemis Comparison Tool. Some of the RODs led to pseudogenes frequently formed by frameshifts and premature stop codons in genes primarily involved in virulence and metabolism. We further verified the presence of some conserved RODs by PCR in 26 isolates of S. Gallinarum and 17 of S. Pullorum in order to extrapolate data analyses from genome comparison to field strains. The variations observed in virulence-related genes of S. Gallinarum and S. Pullorum appear not to be sufficient to explain the differences between the distinct biology of infection of fowl typhoid and Pullorum Disease. Thus, we suggest that the identified pseudogenes affecting metabolism might play a greater role during infection than previously thought.
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polymerase chain reaction assay based on rata gene allows differentiation between salmonella enterica subsp enterica serovar gallinarum biovars gallinarum and Pullorum
Journal of Veterinary Diagnostic Investigation, 2013Co-Authors: Diego Felipe Alves Batista, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Priscila Diniz Lopes, Angelo BerchieriAbstract:Salmonella Pullorum and Salmonella Gallinarum are classified as biovars of Salmonella enterica subsp. enterica serovar Gallinarum. These salmonellae are the causative agents of Pullorum Disease and fowl typhoid, respectively, and are widely distributed throughout the world. Although many developed countries have eradicated these Diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. When serovar Gallinarum is isolated, it is difficult to immediately differentiate between biovars because they are antigenically identical by serotyping. However, they cause distinct Diseases with different epidemiology, and therefore it is important to differentiate them. This may be done biochemically but takes 2 to 3 days. In the present study, S. Pullorum and S. Gallinarum whole genomes were compared, and 1 genomic region of difference, which is part of the ratA gene, was chosen as a molecular marker for a polymerase chain reaction assay to differentiate rapidly between these organisms. In all, 26 strains of S. Gallinarum and 17 S. Pullorum strains were tested and successfully differentiated by the assay.
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molecular differentiation between salmonella enterica subsp enterica serovar Pullorum and salmonella enterica subsp enterica serovar gallinarum
Brazilian Journal of Microbiology, 2009Co-Authors: Simone Alves Mendes Ribeiro, Jacqueline Boldrin De Paiva, Fabio Zotesso, Manoel Victor Franco Lemos, Angelo BerchieriAbstract: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.
Oliveiro Caetano Freitas Neto - One of the best experts on this subject based on the ideXlab platform.
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evaluation of pathogenicity of salmonella gallinarum strains harbouring deletions in genes whose orthologues are conserved pseudogenes in s Pullorum
PLOS ONE, 2018Co-Authors: Diego Felipe Alves Batista, Paul Barrow, Oliveiro Caetano Freitas Neto, Adriana Maria De Almeida, Grazieli Maboni, Tatiane Furtado De Carvalho, Thaynara Parente De Carvalho, A BerchieriAbstract:: The Diseases caused by Salmonella Gallinarum and S. Pullorum in chickens known as fowl typhoid and Pullorum Disease, respectively, pose a great threat to the poultry industry mainly in developing countries, since they have already been controlled in the developed ones. These bacteria are very similar at the genomic level but develop distinct host-pathogen relationships with chickens. Therefore, a deep understanding of the molecular mechanisms whereby S. Gallinarum and S. Pullorum interact with the host could lead to the development of new approaches to control and, perhaps, eradicate both Diseases from the chicken flocks worldwide. Based on our previous study, it was hypothesised that metabolism-related pseudogenes, fixed in S. Pullorum genomes, could play a role in the distinct host-pathogen interaction with susceptible chickens. To test this idea, three genes (idnT, idnO and ccmH) of S. Gallinarum str. 287/91, which are pseudogenes on the S. Pullorum chromosomes, were inactivated by mutations. These genetically engineered strains grew well on the solid media without any colony morphology difference. In addition, similar growth curves were obtained by cultivation in M9 minimal medium containing D-gluconate as the sole carbon source. Infection of chickens with idnTO mutants led to increased numbers of bacteria in the livers and spleens at 5 days post-infection, but with slightly decreased heterophil infiltration in the spleens when compared to the wild-type strain. On the other hand, no significant phenotypic change was caused by mutation to ccmH genes. Apart from the above-mentioned alterations, all S. Gallinarum strains provoked similar infections, since mortality, clinical signs, macroscopic alterations and immune response were similar to the infected chickens. Therefore, according to the model applied to this study, mutation to the idnTO and ccmH genes showed minor impact on the fowl typhoid pathogenesis and so they may be relics from the ancestor genome. Our data hints at a more complex mechanism driving the distinct host-pathogen interaction of S. Gallinarum/Pullorum with chickens than differential inactivation of a few genes.
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Transcription of the cytokine-related genes evaluated in this study by RT-qPCR.
2018Co-Authors: Diego Felipe Alves Batista, Oliveiro Caetano Freitas Neto, Adriana Maria De Almeida, Grazieli Maboni, Tatiane Furtado De Carvalho, Thaynara Parente De Carvalho, Paul Andrew Barrow, Angelo BerchieriAbstract:Chickens were orally infected with the strains here tested on the 15 day of age. Samples of caecal tonsils and spleen tissues were collected at 1, 3 and 5 dpi. (*) This symbol shows groups whose mRNA transcription statistically differs by one-way ANOVA followed by Tukey’s test (* P < 0.05 / ** P < 0.01). CXCLi2: CXC-like chemokine previously named as interleukin 8; IL6: Interleukin 6; IFN: Interferon gamma; (CT): Caecal tonsil; (SP): Spleen; Control: Non-infected chickens; SP449/87: Chickens infected with S. Pullorum str. 449/87 (Pullorum Disease positive control); SG287/91: Chickens infected with S. Gallinarum str. 287/91 (fowl typhoid positive control); SGΔccmH: Chickens infected with SGΔccmH; SGΔidnTO: Chickens infected with SGΔidnTO; SGΔccmHidnTO: Chickens infected with SGΔccmHidnTO.
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identification and characterization of regions of difference between the salmonella gallinarum biovar gallinarum and the salmonella gallinarum biovar Pullorum genomes
Infection Genetics and Evolution, 2015Co-Authors: Diego Felipe Alves Batista, Marcos T Oliveira, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Antônio Sérgio Ferraudo, Angelo BerchieriAbstract:Salmonella Gallinarum is the causative agent of fowl typhoid, a severe septicaemic Disease that affects birds of all ages, whereas S. Pullorum causes Pullorum Disease, a systemic disorder affecting primarily young birds. A proportion of birds with Pullorum Disease become carriers and are thereby able to transmit S. Pullorum vertically. Although these two pathogens cause distinct Diseases, they are otherwise phenotypically and genetically similar. Therefore, the small variations that lead to the differences in virulence must have a genetic basis which currently is unknown. In the present study, we compared the genome sequences of S. Gallinarum (strains: SG287/91 and SG9) and S. Pullorum (strains: SP_CDC, SP_RKS, SP_FCAV, SP_S06) and identified 223 regions of difference (RODs), characterized by indels which were detected by using the software Artemis Comparison Tool. Some of the RODs led to pseudogenes frequently formed by frameshifts and premature stop codons in genes primarily involved in virulence and metabolism. We further verified the presence of some conserved RODs by PCR in 26 isolates of S. Gallinarum and 17 of S. Pullorum in order to extrapolate data analyses from genome comparison to field strains. The variations observed in virulence-related genes of S. Gallinarum and S. Pullorum appear not to be sufficient to explain the differences between the distinct biology of infection of fowl typhoid and Pullorum Disease. Thus, we suggest that the identified pseudogenes affecting metabolism might play a greater role during infection than previously thought.
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polymerase chain reaction assay based on rata gene allows differentiation between salmonella enterica subsp enterica serovar gallinarum biovars gallinarum and Pullorum
Journal of Veterinary Diagnostic Investigation, 2013Co-Authors: Diego Felipe Alves Batista, A.m. De Almeida, Paul Barrow, Oliveiro Caetano Freitas Neto, Priscila Diniz Lopes, Angelo BerchieriAbstract:Salmonella Pullorum and Salmonella Gallinarum are classified as biovars of Salmonella enterica subsp. enterica serovar Gallinarum. These salmonellae are the causative agents of Pullorum Disease and fowl typhoid, respectively, and are widely distributed throughout the world. Although many developed countries have eradicated these Diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. When serovar Gallinarum is isolated, it is difficult to immediately differentiate between biovars because they are antigenically identical by serotyping. However, they cause distinct Diseases with different epidemiology, and therefore it is important to differentiate them. This may be done biochemically but takes 2 to 3 days. In the present study, S. Pullorum and S. Gallinarum whole genomes were compared, and 1 genomic region of difference, which is part of the ratA gene, was chosen as a molecular marker for a polymerase chain reaction assay to differentiate rapidly between these organisms. In all, 26 strains of S. Gallinarum and 17 S. Pullorum strains were tested and successfully differentiated by the assay.
