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Pathogens (Basel, Switzerland) Oct 2021One characteristic of the few serovars that produce typhoid-like infections is that disease-free persistent infection can occur for months or years in a small number of... (Review)
Review
One characteristic of the few serovars that produce typhoid-like infections is that disease-free persistent infection can occur for months or years in a small number of individuals post-convalescence. The bacteria continue to be shed intermittently which is a key component of the epidemiology of these infections. Persistent chronic infection occurs despite high levels of circulating specific IgG. We have reviewed the information on the basis for persistence in . Typhi, . Dublin, Gallinarum, . Pullorum, . Abortusovis and also . Typhimurium in mice as a model of persistence. Persistence appears to occur in macrophages in the spleen and liver with shedding either from the gall bladder and gut or the reproductive tract. The involvement of host genetic background in defining persistence is clear from studies with the mouse but less so with human and poultry infections. There is increasing evidence that the organisms (i) modulate the host response away from the typical Th1-type response normally associated with immune clearance of an acute infection to Th2-type or an anti-inflammatory response, and that (ii) the bacteria modulate transformation of macrophage from M1 to M2 type. The bacterial factors involved in this are not yet fully understood. There are early indications that it might be possible to remodulate the response back towards a Th1 response by using cytokine therapy.
PubMed: 34684248
DOI: 10.3390/pathogens10101299 -
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 -
Genes Mar 2023Gallinarum (SG) is the causative agent of fowl typhoid (FT), a disease that is harmful to the poultry industry. Despite sanitation and prophylactic measures, this...
Gallinarum (SG) is the causative agent of fowl typhoid (FT), a disease that is harmful to the poultry industry. Despite sanitation and prophylactic measures, this pathogen is associated with frequent disease outbreaks in developing countries, causing high morbidity and mortality. We characterized the complete genome sequence of Colombian SG strains and then performed a comparative genome analysis with other SG strains found in different regions worldwide. Eight field strains of SG plus a 9R-derived vaccine were subjected to whole-genome sequencing (WGS) and bioinformatics analysis, and the results were used for subsequent molecular typing; virulome, resistome, and mobilome characterization; and a comparative genome study. We identified 26 chromosome-located resistance genes that mostly encode efflux pumps, and point mutations were found in gyrase genes ( and ), with the mutation S464T frequently found in the Colombian strains. Moreover, we detected 135 virulence genes, mainly in 15 different pathogenicity islands (SPIs). We generated an SPI profile for SG, including C63PI, CS54, ssaD, SPI-1, SPI-2, SPI-3, SPI-4, SPI-5, SPI-6, SPI-9, SPI-10, SPI-11, SPI-12, SPI-13, and SPI-14. Regarding mobile genetic elements, we found the plasmids Col(pHAD28) and IncFII(S) in most of the strains and 13 different prophage sequences, indicating a frequently obtained profile that included the complete phage Gifsy_2 and incomplete phage sequences resembling Escher_500465_2, Shigel_SfIV, Entero_mEp237, and Salmon_SJ46. This study presents, for the first time, the genomic content of Colombian SG strains and a profile of the genetic elements frequently found in SG, which can be further studied to clarify the pathogenicity and evolutionary characteristics of this serotype.
Topics: Animals; Colombia; Typhoid Fever; Genetic Profile; Salmonella Infections, Animal; Salmonella; Genomics
PubMed: 37107581
DOI: 10.3390/genes14040823 -
PloS One 2021Salmonella enterica serovar Gallinarum biovar Pullorum (bvP) and biovar Gallinarum (bvG) are the etiological agents of pullorum disease (PD) and fowl typhoid (FT)... (Comparative Study)
Comparative Study
Salmonella enterica serovar Gallinarum biovar Pullorum (bvP) and biovar Gallinarum (bvG) are the etiological agents of pullorum disease (PD) and fowl typhoid (FT) respectively, which cause huge economic losses to poultry industry especially in developing countries including India. Vaccination and biosecurity measures are currently being employed to control and reduce the S. Gallinarum infections. High endemicity, poor implementation of hygiene and lack of effective vaccines pose challenges in prevention and control of disease in intensively maintained poultry flocks. Comparative genome analysis unravels similarities and dissimilarities thus facilitating identification of genomic features that aids in pathogenesis, niche adaptation and in tracing of evolutionary history. The present investigation was carried out to assess the genotypic differences amongst S.enterica serovar Gallinarum strains including Indian strain S. Gallinarum Sal40 VTCCBAA614. The comparative genome analysis revealed an open pan-genome consisting of 5091 coding sequence (CDS) with 3270 CDS belonging to core-genome, 1254 CDS to dispensable genome and strain specific genes i.e. singletons ranging from 3 to 102 amongst the analyzed strains. Moreover, the investigated strains exhibited diversity in genomic features such as virulence factors, genomic islands, prophage regions, toxin-antitoxin cassettes, and acquired antimicrobial resistance genes. Core genome identified in the study can give important leads in the direction of design of rapid and reliable diagnostics, and vaccine design for effective infection control as well as eradication. Additionally, the identified genetic differences among the S. enterica serovar Gallinarum strains could be used for bacterial typing, structure based inhibitor development by future experimental investigations on the data generated.
Topics: Animals; Bacterial Proteins; Chickens; Genomics; India; Poultry Diseases; Salmonella Infections, Animal; Salmonella enterica; Serogroup
PubMed: 34411120
DOI: 10.1371/journal.pone.0255612 -
Veterinary World Jun 2022has been identified as one of the most widely distributed zoonotic pathogens in broiler litter. Multidrug-resistant strains have been isolated from salmonellosis...
BACKGROUND AND AIM
has been identified as one of the most widely distributed zoonotic pathogens in broiler litter. Multidrug-resistant strains have been isolated from salmonellosis outbreaks, compromising the success of their treatment. This study aimed to isolate and identify spp. serovars in healthy broiler litter in Tolima (Colombia), determine their resistance to different antimicrobials, and detect genes associated with b-lactam resistance that could be useful to control spp. in poultry.
MATERIALS AND METHODS
In total, 45 broiler litter samples were collected. spp. was isolated and identified using selective and differential culture media and biochemical tests. Molecular confirmation of the pathogen was performed with the invA gene and serotyping by Kauffman-White scheme. Antimicrobial susceptibility to 15 antibiotics was determined by Kirby-Bauer method. In cefotaxime-resistant strains, -F, , , and genes were evaluated by polymerase chain reaction (PCR).
RESULTS
In total, 817 presumptive strains were obtained from xylose lysine deoxycholate and agars and subcultured on xylose-lysine-tergitol 4 and MacConkey agars, from which 150 strains were isolated; 29 of these strains were presumptive for spp. after performing biochemical tests and 16 were confirmed by PCR as Infantis (15) and Gallinarum (1). All strains were found to be multiresistant to antibiotics, showing three different profiles and isolates resistant to cefotaxime, and the gene was detected.
CONCLUSION
This is the first study to isolate . Infantis from broiler litter in Colombia. All isolates exhibited resistance to the evaluated antimicrobials, suggesting the misuse of antimicrobials in small- and medium-sized poultry farms. The presence of serovar Infantis is a public health problem. Thus, regular monitoring of poultry litter is recommended, as these bacteria can be transmitted to humans through animal products or contaminated environments.
PubMed: 35993060
DOI: 10.14202/vetworld.2022.1557-1565 -
Frontiers in Veterinary Science 2024serovar Gallinarum () is an important host-specific pathogen that causes fowl typhoid, a severe systemic, septicemic, and fatal infection, in chickens. causes high...
serovar Gallinarum () is an important host-specific pathogen that causes fowl typhoid, a severe systemic, septicemic, and fatal infection, in chickens. causes high morbidity and mortality in chickens and poses a significant burden and economic losses to the poultry industry in many developing countries. However, the virulence factors and mechanisms of -induced systemic infection in chickens remain poorly understood. In this study, we constructed a pathogenicity island-14 (SPI-14) mutant strain (mSPI-14) of and evaluated the pathogenicity of mSPI-14 in the chicken systemic infection model. The mSPI-14 exhibited the same level of bacterial growth and morphological characteristics but significantly reduced resistance to bile acids compared with the wild-type (WT) strain . The virulence of mSPI-14 was significantly attenuated in the chicken oral infection model . Chickens infected with WT showed typical clinical symptoms of fowl typhoid, with all birds succumbing to the infection within 6 to 9 days post-inoculation, and substantial increases in bacterial counts and significant pathological changes in the liver and spleen were observed. In contrast, all mSPI-14-infected chickens survived, the bacterial counts in the organs were significantly lower, and no significant pathological changes were observed in the liver and spleen. The expression of interleukin (IL)-1β, IL-12, CXCLi1, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in the liver of mSPI-14-infected chickens were significantly lower than those in the WT-infected chickens. These results indicate that SPI-14 is a crucial virulence factor in systemic infection of chickens, and avirulent mSPI-14 could be used to develop a new attenuated live vaccine to prevent infection in chickens.
PubMed: 38846788
DOI: 10.3389/fvets.2024.1401392 -
Poultry Science Jul 2024An effective vaccine strategy is indispensable against infectious bronchitis virus (IBV) and fowl typhoid (FT), both of which threaten the poultry industry. This study...
A low-endotoxic Salmonella enterica Gallinarum serovar delivers infectious bronchitis virus immunogens via a dual-promoter vector system that drives protective immune responses through MHC class-I and -II activation in chickens.
An effective vaccine strategy is indispensable against infectious bronchitis virus (IBV) and fowl typhoid (FT), both of which threaten the poultry industry. This study demonstrates a vector system, pJHL270, designed to express antigens in prokaryotic and eukaryotic cells. The vector system stimulates immune responses via synchronized antigen presentation to MHC class-I and -II molecules to produce balanced Th1/Th2 responses. The vaccine antigens were crafted by selecting the consensus sequence of the N-terminal domain of the spike protein (S1-NTD) and a conserved immunogenic region of the nucleocapsid protein (N-) from IBV strains circulating in South Korea. The vaccine antigen was cloned and transformed into a live-attenuated Salmonella Gallinarum (SG) strain, JOL2854 (∆lon, ∆cpxR, ∆rfaL, ∆pagL, ∆asd). Western blot analysis confirmed concurrent antigen expression in Salmonella and eukaryotic cells. Oral immunization with the SG-based IBV vaccine construct JOL2918 induced IBV antigen and Salmonella-specific humoral and cell-mediated immune responses in chickens. PBMCs collected from immunized chickens revealed that MHC class-I and -II expression had increased 3.3-fold and 2.5-fold, respectively, confirming MHC activation via bilateral antigen expression and presentation. Immunization induced neutralizing antibodies (NAbs) and reduced the viral load by 2-fold and 2.5-fold in the trachea and lungs, respectively. The immunized chickens exhibited multifaceted humoral, mucosal, and cell-mediated responses via parallel MHC class-I and -II activation as proof of a balanced Th1/Th2 immune response. The level of NAbs, viral load, and gross and histological analyses provide clear evidence that the construct provides protection against IBV and FT.
Topics: Animals; Chickens; Infectious bronchitis virus; Poultry Diseases; Coronavirus Infections; Salmonella enterica; Viral Vaccines; Serogroup; Genetic Vectors; Promoter Regions, Genetic; Histocompatibility Antigens Class I
PubMed: 38795516
DOI: 10.1016/j.psj.2024.103844 -
International Journal of Molecular... Feb 2023Pure cultures of chicken intestinal microbial species may still be crucial and imperative to expound on the function of gut microbiota, and also contribute to the...
Pure cultures of chicken intestinal microbial species may still be crucial and imperative to expound on the function of gut microbiota, and also contribute to the development of potential probiotics and novel bioactive metabolites from gut microbiota. In this study, we isolated and identified 507 chicken intestinal bacterial isolates, including 89 previously uncultured isolates. Among these, a total of 63 strains, belonging to , , , , , and , exhibited antibacterial activity against . Acid tolerance tests showed strain YPG14 ( strain YPG14) has a particularly strong tolerance to acid. We further characterized other probiotic properties of strain YPG14. In simulated intestinal fluid, the growth of strain YPG14 remained stable after incubation for 4 h. The auto-aggregation test showed the auto-aggregation percentage of strain YPG14 was recorded as 15.0 ± 0.38%, 48.3 ± 2.51%, and 75.1 ± 4.44% at 3, 12, and 24 h, respectively. In addition, the mucin binding assay showed strain YPG14 exhibited 12.07 ± 0.02% adhesion to mucin. Antibiotic sensitivity testing showed that strain YPG14 was sensitive to the majority of the tested antibiotics. The anti- Pullorum (. Pullorum) infection effect in vivo revealed that the consumption of strain YPG14 could significantly improve body weight loss and survival rate of chicks infected by . Pullorum; reduce the loads of . Pullorum in the jejunum, liver, spleen, and feces; and alleviate the jejunum villi morphological structure damage, crypt loss, and inflammatory cell infiltration caused by . Pullorum. Overall, this study may help us to understand the diversity of chicken intestinal microflora and provide some insights for potential probiotic development from gut microbiota and may find application in the poultry industry.
Topics: Animals; Gastrointestinal Microbiome; Chickens; Intestines; Limosilactobacillus reuteri; Anti-Bacterial Agents; Probiotics; Mucins
PubMed: 36769368
DOI: 10.3390/ijms24033045 -
Journal of Food Science and Technology Mar 2022spp causes foodborne diseases related to the consumption of contaminated foods, especially poultry products. This study aimed to investigate the occurrence of spp....
spp causes foodborne diseases related to the consumption of contaminated foods, especially poultry products. This study aimed to investigate the occurrence of spp. serovars in raw eggs from supermarkets and street food markets in southern Brazil, to analyze virulence genes, resistance profiling to antimicrobials and sanitizers, and to determine the susceptibility of the isolates to extract. Among 160 samples analyzed, just two (1.25%) were positive for spp.. One positive sample was from egg yolk (. serovar Gallinarum, isolate S28), and another one was from eggshell (. serovar Panama, isolate S37). Regarding the virulence genes, the isolate S37 harbored all the genes evaluated ( and ), while the isolate S28 did not harbor the gene. The isolate S28 was resistant to tobramycin, azithromycin, and trimethoprim, while the isolate S37 showed resistance profile just to nalidixic acid. However, none of the resistance genes evaluated were identified. Both isolates showed resistance to benzalkonium chloride, chlorhexidine digluconate, sodium hypochlorite, and peracetic acid, presenting high MIC values for these sanitizers. In contrast, extract showed antimicrobial activity against the isolates S28 and S37, however, more studies are needed to prove its potential as a natural antimicrobial compound.
PubMed: 35153327
DOI: 10.1007/s13197-021-05113-5 -
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