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Vaccines Nov 2023Avian pathogenic (APEC) is one of the leading pathogens that cause devastating economic losses to the poultry industry. Type I fimbriae are essential adhesion factors...
Avian pathogenic (APEC) is one of the leading pathogens that cause devastating economic losses to the poultry industry. Type I fimbriae are essential adhesion factors of APEC, which can be targeted and developed as a vaccine candidate against multiple APEC serogroups due to their excellent immunogenicity and high homology. In this study, the recombinant strain SG102 was developed by expressing the APEC type I fimbriae gene cluster () on the cell surface of an avirulent () vector strain using a chromosome-plasmid-balanced lethal system. The expression of APEC type I fimbriae was verified by erythrocyte hemagglutination assays and antigen-antibody agglutination tests. In vitro, the level of the SG102 strain adhering to leghorn male hepatoma (LMH) cells was significantly higher than that of the empty plasmid control strain, SG101. At two weeks after oral immunization, the SG102 strain remained detectable in the livers, spleens, and ceca of SG102-immunized chickens, while the SG101 strain was eliminated in SG101-immunized chickens. At 14 days after the secondary immunization with 5 × 10 CFU of the SG102 strain orally, highly antigen-specific humoral and mucosal immune responses against APEC type I fimbriae protein were detected in SG102-immunized chickens, with IgG and secretory IgA (sIgA) concentrations of 221.50 μg/mL and 1.68 μg/mL, respectively. The survival rates of SG102-immunized chickens were 65% (13/20) and 60% (12/20) after challenge with 50 LD doses of APEC virulent strains O78 and O161 serogroups, respectively. By contrast, 95% (19/20) and 100% (20/20) of SG101-immunized chickens died in challenge studies involving APEC O78 and O161 infections, respectively. In addition, the SG102 strain effectively provided protection against lethal challenges from the virulent strain. These results demonstrate that the SG102 strain, which expresses APEC type I fimbriae, is a promising vaccine candidate against APEC O78 and O161 serogroups as well as infections.
PubMed: 38140181
DOI: 10.3390/vaccines11121778 -
Microorganisms Dec 2023subsp. serovar Gallinarum biovar pullorum ( pullorum) is an avian-specific pathogen that has caused considerable economic losses to the poultry industry. High...
subsp. serovar Gallinarum biovar pullorum ( pullorum) is an avian-specific pathogen that has caused considerable economic losses to the poultry industry. High endemicity, poor implementation of hygiene measures, and lack of effective vaccines hinder the prevention and control of this disease in intensively maintained poultry flocks. In recent years, the incidence of arthritis in chicks caused by pullorum infection has increased. In this study, four pullorum strains were identified from the livers, spleens, and joint fluids of Qingjiaoma chicken breeders with arthritis clinical signs, and an arthritis model of chicks was successfully established using SP206-2. Whole genome sequencing of the SP206-2 strain showed that the genome was 4,730,579 bp, 52.16% GC content, and contained 5007 genes, including 4729 protein-coding regions. The genomic analysis of four arthritis-causing isolates and three diarrhea-causing isolates showed that the genome of arthritis-causing isolates was subject to nonsynonymous mutations, shift mutations, and gene copy deletions. An SNP phylogenetic tree analysis showed that arthritis-causing isolates are located in a different evolutionary branch from diarrhea-causing isolates. Further differential genes analysis showed that the genome of arthritis-causing isolates had missense mutations in genes related to substance metabolism and substance transport, as a result of adaptive evolution.
PubMed: 38138130
DOI: 10.3390/microorganisms11122986 -
Molecular Therapy Oncolytics Dec 2023We report here a novel anti-cancer therapy based on an avian-host-specific serotype serovar Gallinarum () deficient in ppGpp synthesis. To monitor the tumor targeting,...
We report here a novel anti-cancer therapy based on an avian-host-specific serotype serovar Gallinarum () deficient in ppGpp synthesis. To monitor the tumor targeting, a bioluminescent ΔppGpp was constructed and injected intravenously into mice bearing syngeneic and human xenograft tumors. Strong bioluminescent signals were detected specifically in all grafted tumors at 2 days post-injection (dpi). The bacterial counts in normal and tumor tissue at 1 dpi revealed that ΔppGpp reached >10 CFU/g in tumor tissue and 10-10 CFU/g in endothelial organs; counts were much lower in other organs. At 16 dpi, ΔppGpp counts in tumor tissue decreased to ∼10 CFU/g, while those in the other organs became undetectable. A strong anti-cancer effect was observed after the injection of ΔppGpp into BALB/c mice grafted with CT26 colon cancer cells. This could be attributed to reduced virulence, which allowed the administration of at least a 10-fold greater dose (10 CFU) of ΔppGpp than other attenuated strains of serovar Typhimurium (≤10 CFU). An advantage of the avian-specific as a cancer therapeutic should be a reduced capacity to cause infections or harm in humans.
PubMed: 38053546
DOI: 10.1016/j.omto.2023.100745 -
Iranian Journal of Microbiology Oct 2023Antibiotic resistance is an indicator of the passively acquired and circulating resistance genes. Gallinarum significantly affects the poultry food industry. The...
BACKGROUND AND OBJECTIVES
Antibiotic resistance is an indicator of the passively acquired and circulating resistance genes. Gallinarum significantly affects the poultry food industry. The present study is the first study of the Gallinarum biofilm in Iran, which is focused on the characterization of the Gallinarum serovars and their acquired antibiotic resistance genes circulating in poultry fields in central and northwestern Iran.
MATERIALS AND METHODS
Sixty isolates of . Gallinarum serovar were collected from feces of live poultry. The bacteria were isolated using biochemical tests and confirmed by Multiplex PCR. Biofilm formation ability and the antibacterial resistance were evaluated using both phenotypic and genotypic methods. The data were analyzed using SPSS software.
RESULTS
According to Multiplex PCR for , and genes, all 60 . Gallinarum serovars were Gallinarum biovars. In our study, the antibiotic resistance rate among isolated strains was as follows: Penicillin (100%), nitrofurantoin (80%), nalidixic acid (45%), cefoxitin (35%), neomycin sulfate (30%), chloramphenicol (20%), and ciprofloxacin (5%). All isolates were susceptible to imipenem, ertapenem, ceftriaxone, ceftazidime, and ceftazidime+clavulanic acid. All sixty isolates did not express the resistance genes , , and . On the other hand, they expressed (85%), (75%), (70%), (60%), (20%), (15%), (10%), (5%), and (5%). All Gallinarum isolates formed biofilm and expressed gene.
CONCLUSION
Considering that the presence of this bacteria is equal to the death penalty to the herd, the distribution of resistance genes could be a critical alarm for pathogen monitoring programs in the region. This study showed a positive correlation between biofilm formation and 50% of tested resistance genes. Also, it was found that the most common circulating biovars are multidrug-resistant.
PubMed: 37941876
DOI: 10.18502/ijm.v15i5.13869 -
Archives of Microbiology Oct 2023In bacteria and primitive eukaryotes, sulfonamide antibiotics block the folate pathway by inhibiting dihydropteroate synthase (FolP) that combines para-aminobenzoic acid...
In bacteria and primitive eukaryotes, sulfonamide antibiotics block the folate pathway by inhibiting dihydropteroate synthase (FolP) that combines para-aminobenzoic acid (pABA) and dihydropterin pyrophosphate (DHPP) to form dihydropteroic acid (DHP), a precursor for tetrahydrofolate synthesis. However, the emergence of resistant strains has severely compromised the use of pABA mimetics as sulfonamide drugs. Salmonella enterica serovar Gallinarum (S. Gallinarum) is a significant source of antibiotic-resistant infections in poultry. Here, a sulfonamide-resistant FolP mutant library of S. Gallinarum was generated through random mutagenesis. Among resistant strains, substitution of amino acid Arginine 171 with Proline (R171P) in the FolP protein conferred the highest resistance against sulfonamide. Substitution of Phe28 with Leu or Ile (F28L/I) led to modest sulfonamide resistance. Structural modeling indicates that R171P and Phenylalanine 28 with leucine or isoleucine (F28L/I) substitution mutations are located far from the substrate-binding site and cause insignificant conformational changes in the FolP protein. Rather, in silico studies suggest that the mutations altered the stability of the protein, potentially resulting in sulfonamide resistance. Identification of specific mutations in FolP that confer resistance to sulfonamide would contribute to our understanding of the molecular mechanisms of antibiotic resistance.
Topics: Dihydropteroate Synthase; 4-Aminobenzoic Acid; Anti-Bacterial Agents; Sulfanilamide; Sulfonamides; Mutation
PubMed: 37906281
DOI: 10.1007/s00203-023-03696-5 -
Poultry Science Dec 2023This study aimed to assess the effects of a Lactobacillus helveticus ATCC 15009-derived postbiotic in mitigating experimental Salmonella Gallinarum infection. For this...
This study aimed to assess the effects of a Lactobacillus helveticus ATCC 15009-derived postbiotic in mitigating experimental Salmonella Gallinarum infection. For this purpose, a sample of Lactobacillus sp. was inoculated in 2 different media, each containing different postbiotics (sensitized and nonsensitized). Both inocula had their antagonistic effect over S. Gallinarum tested through the spot-on-the-lawn method. It revealed that the sensitized postbiotic had a higher action potential over Lactobacillus sp. than the nonsensitized one (P < 0.05). Then, 48 day of hatch chicks were divided into 4 groups: A = Lactobacillus sp. (10 CFU/mL) inoculum on the 18th day; B = Lactobacillus sp. (10 CFU/mL) inoculum on the 18th day and postbiotic inoculum on the 19th day; C = postbiotic inoculum on the 19th day; and D = sterile saline inoculum on 18th and 19th days. On the 21st day, all chicks were infected with S. Gallinarum (10 CFU/mL). On the 23rd day, the animals were euthanized by cervical dislocation, and the ceca and liver were aseptically removed. Bacterial count of S. Gallinarum with serial decimal dilution was performed with these organs. It revealed that the prophylactic treatment with the postbiotic that modulates the intestinal microbiota was as efficient as the probiotic administration in reducing S. Gallinarum in the cecum and liver of chicks (P < 0.05). These data point to a new range of alternatives for preventing S. Gallinarum, which might help the poultry industry produce safer food for human consumption.
Topics: Humans; Animals; Chickens; Lactobacillus helveticus; Salmonella; Cecum; Salmonella Infections, Animal; Poultry Diseases
PubMed: 37832187
DOI: 10.1016/j.psj.2023.103095 -
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 -
Developmental and Comparative Immunology Dec 2023The H9N2 avian influenza virus significantly affects the health of poultry and humans. We identified a prokaryotic and eukaryotic dual-expression vector system, pJHL270,...
Salmonella delivers H9N2 influenza virus antigens via a prokaryotic and eukaryotic dual-expression vector and elicits bivalent protection against avian influenza and fowl typhoid.
The H9N2 avian influenza virus significantly affects the health of poultry and humans. We identified a prokaryotic and eukaryotic dual-expression vector system, pJHL270, that can provide simultaneous MHC class I and II stimulation of the host immune system, and we designed vaccine antigens by selecting the consensus HA1 sequence and M2e antigens from H9N2 virus circulating in South Korea from 2000 to 2021. The genes were cloned into the pJHL270 vector, and the cloned plasmid was delivered by a live-attenuated Salmonella Gallinarum (SG) strain. The immunity and protective efficacy of the SG-based H9N2 vaccine construct, JOL2922, against avian influenza and fowl typhoid (FT) were evaluated. The Ptrc and CMV promoters conferred antigen expression in prokaryotic and eukaryotic cells to induce balanced Th-1/Th-2 immunity. Chickens immunized with JOL2922 yielded high antigen-specific humoral and mucosal immune responses. qRT-PCR revealed that the strain generated polyfunctional IFN-γ and IL-4 secretion in immunized chickens. Furthermore, a FACS analysis showed increased CD3CD4+ and CD3CD8+ T-cell subpopulations following immunization. Peripheral Blood Mononuclear Cells (PBMCs) harvested from the immunized chickens significantly increased MHC class I and II expression, 3.5-fold and 2.5-fold increases, respectively. Serum collected from the immunized groups had an evident hemagglutinin inhibition titer of ≥6 log. Immunization reduced the lung viral titer by 3.8-fold within 5 days post-infection. The strain also generated SG-specific humoral and cellular immune responses. The immunized birds all survived a virulent SG wild-type challenge. In addition, the bacterial burden was reduced by 2.7-fold and 2.1-fold in spleen and liver tissue, respectively, collected from immunized chickens. Our data indicate that an attenuated SG strain successfully delivered the dual-expression vector system and co-stimulated MHC class I and II antigen presentation pathways via exogenous and endogenous antigen presentation, thereby triggering a balanced Th-1/Th-2-based immune response and conferring effective protection against avian influenza and FT.
PubMed: 37714394
DOI: 10.1016/j.dci.2023.105058 -
Comparative Immunology, Microbiology... Oct 2023Our study was undertaken to determine the best samples and selective-differential plating media to be used for Salmonella spp. isolation. We also compared hematological...
Our study was undertaken to determine the best samples and selective-differential plating media to be used for Salmonella spp. isolation. We also compared hematological and serum biochemical values, Salmonella biovar Gallinarum (SG) detection (isolation and serological test), and inflammatory intestinal response (fecal leukocyte) in laying hens with naturally occurring fowl typhoid outbreaks. Furthermore, we looked for a biomarker of SG infection. Spleen, liver, ovarian follicle content, and bone marrow were found to be the best samples for SG isolation and the agreement between MacConkey-Salmonella Shigella agar was slight to excellent. The laying hens with SG isolation and rapid serum plate agglutination positive results showed a higher percentage of heterophils, heterophil/lymphocyte ratio and total white blood cells, and a lower percentage of lymphocytes than those with negative results. Furthermore, the positive fecal leukocyte samples had a higher percentage of heterophils, gamma-glutamyl transferase, total protein and globulin values than negative samples. Five biomarkers' cut-offs are proposed to distinguish between laying hens positive and negative to SG isolation.
PubMed: 37657160
DOI: 10.1016/j.cimid.2023.102055 -
Poultry Science Oct 2023
Corrigendum to Mikolajczyk-Martinez, A. et al. 2023. Unraveling the role of type 1 fimbriae in Salmonella pathogenesis: insights from a comparative analysis of Salmonella Enteritidis and Salmonella Gallinarum. Poult. Sci. 102:102833.
PubMed: 37598550
DOI: 10.1016/j.psj.2023.102999