-
Veterinary Microbiology Mar 2023Salmonella enterica serovar Gallinarum biovar Gallinarum is an avian-adapted pathogen causing fowl typhoid and leading to enormous economic loss in the global poultry...
Salmonella enterica serovar Gallinarum biovar Gallinarum is an avian-adapted pathogen causing fowl typhoid and leading to enormous economic loss in the global poultry industry. Two-component systems (TCSs) are crucial for bacteria survival, virulence, sensing and responding to the environment. 23 pairs of TCSs classified into five families were found in S. Gallinarum strain 287/91, of which the CitB family contains three pairs of TCSs, namely CitA/CitB, DcuS/DcuR and DpiB/DpiA, whose functions remained unaddressed. Thus, four mutants of S. Gallinarum strain U20, ΔcitAB (Δcit), ΔdcuSR (Δdcu), ΔdpiBA (Δdpi) and ΔcitABΔdcuSRΔdpiBA (Δ3), were constructed. The results suggested that the CitB family did not affect the growth or the metabolic capacities tested, while different TCSs exerted various effects on biofilm formation and antimicrobial resistance against multiple drug classes. Furthermore, the CitB family negatively impacted the tolerance of environmental stress, contributing to compromised virulence in chicken embryos and in vivo survival of S. Gallinarum. Collectively, this research provided new knowledge of how the CitB family is involved in the pathogenicity of S. Gallinarum.
Topics: Chick Embryo; Animals; Salmonella enterica; Serogroup; Salmonella; Virulence; Salmonella Infections, Animal; Chickens; Poultry Diseases
PubMed: 36645991
DOI: 10.1016/j.vetmic.2023.109659 -
Polish Journal of Microbiology Jun 2023genus harbors five Type VI Secretion System (T6SS) gene clusters. The T6SS encoded in SPI-6 (T6SS) contributes to Typhimurium colonization of chickens and mice, while...
genus harbors five Type VI Secretion System (T6SS) gene clusters. The T6SS encoded in SPI-6 (T6SS) contributes to Typhimurium colonization of chickens and mice, while the T6SS encoded in SPI-19 (T6SS) of Gallinarum contributes to chicken colonization. Interestingly, the T6SS of Gallinarum complemented the defect in chicken colonization of a Typhimurium strain that lacks the T6SS, suggesting that both T6SSs are interchangeable. Here we show that the transfer of Gallinarum T6SS complemented the defect in mice colonization of a Typhimurium ΔT6SS strain, indicating that both T6SSs are functionally redundant during host colonization.
Topics: Animals; Mice; Salmonella typhimurium; Chickens; Multigene Family
PubMed: 37314360
DOI: 10.33073/pjm-2023-017 -
Microbial Pathogenesis Sep 2023Salmonella enterica serovar Gallinarum causes Fowl Typhoid in poultry, and it is host specific to avian species. The reasons why S. Gallinarum is restricted to avians,...
Salmonella enterica serovar Gallinarum causes Fowl Typhoid in poultry, and it is host specific to avian species. The reasons why S. Gallinarum is restricted to avians, and at the same time predominately cause systemic infections in these hosts, are unknown. In the current study, we developed a surgical approach to study gene expression inside the peritoneal cavity of hens to shed light on this. Strains of the host specific S. Gallinarum, the cattle-adapted S. Dublin and the broad host range serovar, S. Enteritidis, were enclosed in semi-permeable tubes and surgically placed for 4 h in the peritoneal cavity of hens and for control in a minimal medium at 41.2 °C. Global gene-expression under these conditions was compared between serovars using tiled-micro arrays with probes representing the genome of S. Typhimurium, S. Dublin and S. Gallinarum. Among other genes, genes of SPI-13, SPI-14 and the macrophage survival gene mig-14 were specifically up-regulated in the host specific serovar, S. Gallinarum, and further studies into the role of these genes in host specific infection are highly indicated. Analysis of pathways and GO-terms, which were enriched in the host specific S. Gallinarum without being enriched in the two other serovars indicated that host specificity was characterized by a metabolic fine-tuning as well as unique expression of virulence associated pathways. The cattle adapted serovar S. Dublin differed from the two other serovars by a lack of up-regulation of genes encoded in the virulence associated pathogenicity island 2, and this may explain the inability of this serovar to cause disease in poultry.
Topics: Animals; Female; Cattle; Serogroup; Chickens; Transcriptome; Salmonella enterica; Salmonella Infections, Animal; Salmonella enteritidis
PubMed: 37419218
DOI: 10.1016/j.micpath.2023.106236 -
PloS One 2013Salmonella serovars Enteritidis and Gallinarum are closely related, but their host ranges are very different: the former is host-promiscuous and the latter can infect... (Comparative Study)
Comparative Study
BACKGROUND
Salmonella serovars Enteritidis and Gallinarum are closely related, but their host ranges are very different: the former is host-promiscuous and the latter can infect poultry only. Comparison of their genomic sequences reveals that Gallinarum has undergone much more extensive degradation than Enteritidis. This phenomenon has also been observed in other host restricted Salmonella serovars, such as Typhi and Paratyphi A. The serovar Gallinarum can be further split into two biovars: Gallinarum and Pullorum, which take poultry as their common host but cause distinct diseases, with the former eliciting typhoid and the latter being a dysentery agent. Genomic comparison of the two pathogens, with a focus on pseudogenes, would provide insights into the evolutionary processes that might have facilitated the formation of host-restricted Salmonella pathogens.
METHODOLOGIES/PRINCIPAL FINDINGS
We sequenced the complete genome of Pullorum strains and made comparison with Gallinarum and other Salmonella lineages. The gene contents of Gallinarum and Pullorum were highly similar, but their pseudogene compositions differed considerably. About one fourth of pseudogenes had the same inactivation mutations in Gallinarum and Pullorum but these genes remained intact in Enteritidis, suggesting that the ancestral Gallinarum may have already been restricted to poultry. On the other hand, the remaining pseudogenes were either in the same genes but with different inactivation sites or unique to Gallinarum or Pullorum, reflecting unnecessary functions in infecting poultry.
CONCLUSIONS
Our results support the hypothesis that the divergence between Gallinarum and Pullorum was initiated and facilitated by host restriction. Formation of pseudogenes instead of gene deletion is the major form of genomic degradation. Given the short divergence history of Gallinarum and Pullorum, the effect of host restriction on genomic degradation is huge and rapid, and such effect seems to be continuing to work. The pseudogenes may reflect the unnecessary functions for Salmonella within the poultry host.
Topics: Animals; Bacterial Typing Techniques; Base Sequence; Chickens; Genetic Speciation; Genome, Bacterial; Genomics; Host Specificity; Humans; Molecular Sequence Data; Mutation; Phylogeny; Poultry Diseases; Pseudogenes; Salmonella; Sequence Analysis, DNA; Species Specificity
PubMed: 23555032
DOI: 10.1371/journal.pone.0059427 -
Gene Jan 2024Salmonella Gallinarum (SG) provokes fowl typhoid, an infectious disease of acute clinical course that affects gallinaceous of any age and leads to high mortality rates....
Salmonella Gallinarum (SG) provokes fowl typhoid, an infectious disease of acute clinical course that affects gallinaceous of any age and leads to high mortality rates. During the typhoid-like systemic infection of S. Typhimurium (STM) in mice, the bacterium expresses the mgtC gene, which is encoded in the Salmonella Pathogenecity Island - 3 (SPI-3). In this serovar, the function is linked to bacterial replication within macrophages, and its absence attenuates the pathogen. We hypothesized that deleting mgtC from SG genome would alter the microorganism pathogenicity in susceptible commercial poultry in a similar manner. Thus, the present study sought to elucidate the importance of mgtC on SG pathogenicity. For this, a mgtC-mutant lacking S. Gallinarum mutant was constructed (SG ΔmgtC). Its ability to replicate in medium that mimicries the mgtC-related intracellular environment of macrophages as well as in primary macrophages from chicken was evaluated. Moreover, the infection of susceptible chickens was performed to elucidate its pathogenicity and the elicited immune responses by measuring key interleukins by qRT-PCR and the population of macrophages and lymphocytes T CD4 and CD8 by means of immunohistochemistry. It was observed that mgtC was required for S. Gallinarum replication in acidified low-Mg media and survival within macrophages. However, unlike its requirement for initial phase of STM infection in mice, lower bacterial counts were only observed at the late stage of macrophage infection without affecting the citotoxicity. Experiments showed that knocking-out the mgtC gene neither altered bacterial uptake by macrophages nor affects bacterial counts in liver and spleen and total chicken mortality. However, plotting a survival curve and analyzing the clinical-pathologic conditions, it was observed a slower progression of the disease in chickens infected by SG ΔmgtC compared to those challenged by the wild-type strain. Furthermore, the mRNA expression of IFN-γ and LITAF were similar between the infected chickens, but higher than in the uninfected group. The same was observed in macrophages and lymphocytes T CD4 populations. On the other hand, the presence of lymphocytes T CD8 was increased in the initial phase of the disease provoked by the wild-type strain over the mutant strain. We concluded that the role of mgtC in Fowl Typhoid in susceptible chickens differs from the role in typhoid-like infections in mammals. Thus, the deletion of mgtC gene from S. Gallinarum genome does not affect the overall pathogenicity, but slightly alters the pathogenesis.
Topics: Animals; Mice; Chickens; Salmonella enterica; Typhoid Fever; Salmonella Infections, Animal; Salmonella; Poultry Diseases; Mammals
PubMed: 37748627
DOI: 10.1016/j.gene.2023.147827 -
Vaccine Oct 2013Salmonella enterica subspecies enterica serotype Gallinarum can cause severe systemic disease in chickens and a live Salmonella Gallinarum 9R vaccine (SG9R) has been...
Salmonella enterica subspecies enterica serotype Gallinarum can cause severe systemic disease in chickens and a live Salmonella Gallinarum 9R vaccine (SG9R) has been used widely to control disease. Using whole-genome sequencing we found point mutations in the pyruvate dehydrogenase (aceE) and/or lipopolysaccharide 1,2-glucosyltransferase (rfaJ) genes that likely explain the attenuation of the SG9R vaccine strain. Molecular typing using Pulsed Field Gel Electrophoresis and Multiple-Locus Variable number of tandem repeat Analysis showed that strains isolated from different layer flocks in multiple countries and the SG9R vaccine strain were similar. The genome of one Salmonella Gallinarum field strain, isolated from a flock with a mortality peak and selected on the basis of identical PFGE and MLVA patterns with SG9R, was sequenced. We found 9 non-silent single-nucleotide differences distinguishing the field strain from the SG9R vaccine strain. Our data show that a Salmonella Gallinarum field strain isolated from laying hens is almost identical to the SG9R vaccine. Mutations in the aceE and rfaJ genes could explain the reversion to a more virulent phenotype. Our results highlight the importance of using well defined gene deletion mutants as vaccines.
Topics: Animals; Chickens; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genes, Bacterial; Genome, Bacterial; Genotype; Minisatellite Repeats; Molecular Typing; Mutation; Polymorphism, Single Nucleotide; Poultry Diseases; Salmonella Infections, Animal; Salmonella Vaccines; Salmonella enterica; Sequence Analysis, DNA
PubMed: 23994381
DOI: 10.1016/j.vaccine.2013.08.033 -
Scientific Reports Aug 2021Salmonella enterica serovar Gallinarum is a host-restricted bacterial pathogen that causes a serious systemic disease exclusively in birds of all ages. Salmonella...
Salmonella enterica serovar Gallinarum is a host-restricted bacterial pathogen that causes a serious systemic disease exclusively in birds of all ages. Salmonella enterica serovar Typhimurium is a host-generalist serovar. Dendritic cells (DCs) are key antigen-presenting cells that play an important part in Salmonella host-restriction. We evaluated the differential response of chicken blood monocyte-derived dendritic cells (chMoDCs) exposed to S. Gallinarum or S. Typhimurium. S. Typhimurium was found to be more invasive while S. Gallinarum was more cytotoxic at the early phase of infection and later showed higher resistance against chMoDCs killing. S. Typhimurium promoted relatively higher upregulation of costimulatory and other immune function genes on chMoDCs in comparison to S. Gallinarum during early phase of infection (6 h) as analyzed by real-time PCR. Both Salmonella serovars strongly upregulated the proinflammatory transcripts, however, quantum was relatively narrower with S. Gallinarum. S. Typhimurium-infected chMoDCs promoted relatively higher proliferation of naïve T-cells in comparison to S. Gallinarum as assessed by mixed lymphocyte reaction. Our findings indicated that host restriction of S. Gallinarum to chicken is linked with its profound ability to interfere the DCs function. Present findings provide a valuable roadmap for future work aimed at improved vaccine strategies against this pathogen.
Topics: Animals; B7-1 Antigen; CD40 Antigens; Chickens; Cytokines; Cytotoxicity, Immunologic; Dendritic Cells; Gene Expression; Host-Pathogen Interactions; Microbial Viability; Monocytes; Salmonella; Salmonella typhimurium; Species Specificity; T-Lymphocytes; Toll-Like Receptors
PubMed: 34446765
DOI: 10.1038/s41598-021-96527-w -
Avian Pathology : Journal of the W.V.P.A Feb 2022In Europe, monitoring of breeding stock for Pullorum (SP) or a Gallinarum (SG) infections is compulsory at the point of lay. Vaccinations against Enteritidis (SE) and...
In Europe, monitoring of breeding stock for Pullorum (SP) or a Gallinarum (SG) infections is compulsory at the point of lay. Vaccinations against Enteritidis (SE) and Typhimurium (ST) are increasingly administered in Europe. These vaccines might induce cross-reactions in the rapid plate agglutination (RPA) SP/SG test due to shared O-antigens, possibly resulting in a lower test specificity. The extent to which the specificity of SP/SG serological tests is influenced by SE and/or ST vaccinations in the field has not been reported. In this paper, we report the diagnostic and flock specificity of the commercially available RPA SP/SG test using 1:2-1:16 serum dilutions on four panels of sera: SPF sera, field sera from flocks of varying age and SE/ST vaccination status, and reference sera from an international proficiency testing scheme. The results showed that the use of live SE/ST vaccines did not influence the specificity of the RPA SP/SG test. Inactivated vaccines showed a drop of the diagnostic specificity to 96.54% and a flock specificity of 34.1% when the 1:2 serum dilution was used. The 1:8 serum dilution showed a diagnostic specificity of 99.41% and a flock specificity of 86.4%. In conclusion, the use of SE/ST vaccines has either no effect or a modest effect on the specificity of the RPA SP/SG test used to monitor flocks. The main factors are the type of vaccine, and the serum dilution used for testing and a cut-off.
Topics: Agglutination Tests; Animals; Chickens; Poultry Diseases; Salmonella Infections, Animal; Salmonella enteritidis; Salmonella typhimurium; Vaccination
PubMed: 34633242
DOI: 10.1080/03079457.2021.1990854 -
Veterinary Research Aug 2014Salmonella Gallinarum and Salmonella Enteritidis are genetically closely related however associated with different pathologies. Several studies have suggested that S....
Salmonella Gallinarum and Salmonella Enteritidis are genetically closely related however associated with different pathologies. Several studies have suggested that S. Gallinarum is less invasive in vitro than S. Enteritidis. In this study we confirm that the S. Gallinarum strains tested were much less invasive than the S. Enteritidis strains tested in cells of avian or human origin. In addition, the S. Gallinarum T3SS-1-dependent ability to invade host cells was delayed by two to three hours compared to S. Enteritidis, indicating that T3SS-1-dependent entry is less efficient in S. Gallinarum than S. Enteritidis. This was neither due to a decreased transcription of T3SS-1 related genes when bacteria come into contact with cells, as transcription of hilA, invF and sipA was similar to that observed for S. Enteritidis, nor to a lack of functionality of the S. Gallinarum T3SS-1 apparatus as this apparatus was able to secrete and translocate effector proteins into host cells. In contrast, genome comparison of four S. Gallinarum and two S. Enteritidis strains revealed that all S. Gallinarum genomes displayed the same point mutations in each of the main T3SS-1 effector genes sipA, sopE, sopE2, sopD and sopA.
Topics: Animals; Bacterial Adhesion; Cell Line; Cell Line, Tumor; Chickens; Humans; Poultry Diseases; Salmonella Infections; Salmonella Infections, Animal; Salmonella enterica; Salmonella enteritidis
PubMed: 25175996
DOI: 10.1186/s13567-014-0081-z -
Veterinary Immunology and... Nov 2022Fowl typhoid is an important disease of chickens and turkeys, which is caused by Salmonella Gallinarum (S. Gallinarum). Vaccines with high levels of protective effects...
Fowl typhoid is an important disease of chickens and turkeys, which is caused by Salmonella Gallinarum (S. Gallinarum). Vaccines with high levels of protective effects against fowl typhoid need to be developed for the poultry industry. In this study, a S. Gallinarum strain, named SG01, was isolated from a poultry farm in Mashan region of Wuxi City, China, and identified through biochemical tests and specific PCR amplifications. Then, safety evaluations of the SG01 strain were performed in young chickens. No clinical symptom including depression and diarrhea and gross lesion involved in the cardiac nodule, hepatic necrotic lesion and splenic necrotic lesion, was determined on fifteen-day-old chickens after immunization with 1 × 10 CFU of the SG01 strain through the oral route. However, diarrhea symptoms and hepatic lesions were identified from chickens immunized with the commercial vaccine strain SG9R by the same dose and route. At 14 days post inoculation, SG01 strain was eliminated in the liver and spleen from SG01-immunized chickens, while the SG9R strain still could be identified from SG9R-immunized chickens. After challenge with the virulent S. Gallinarum strain, significant reduction of the morbidity rate was found in the SG01 immunized group (20 %) compared to the challenge group (100 %) according to signs scoring systems for clinical symptoms and gross lesions. Additionally, immunization with the SG01 strain could provide more than 8 weeks of protection periods against fowl typhoid. These results demonstrate the SG01 strain is avirulent to young chickens and might be safer compared to the SG9R strain. In addition, SG01 strain is a potential vaccine candidate against fowl typhoid in young chickens.
Topics: Animals; Chickens; Salmonella Infections, Animal; Salmonella Vaccines; Poultry Diseases; Typhoid Fever; Salmonella; Vaccines, Attenuated; Poultry; Diarrhea
PubMed: 36332427
DOI: 10.1016/j.vetimm.2022.110501