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Antibiotics (Basel, Switzerland) Dec 2023subsp. serovar Gallinarum (G) has two distinct biovars, Pullorum and Gallinarum. They are bacterial pathogens that exhibit host specificity for poultry and aquatic... (Review)
Review
subsp. serovar Gallinarum (G) has two distinct biovars, Pullorum and Gallinarum. They are bacterial pathogens that exhibit host specificity for poultry and aquatic birds, causing severe systemic diseases known as fowl typhoid (FT) and Pullorum disease (PD), respectively. The virulence mechanisms of biovars Gallinarum and Pullorum are multifactorial, involving a variety of genes and pathways that contribute to their pathogenicity. In addition, these serovars have developed resistance to various antimicrobial agents, leading to the emergence of multidrug-resistant strains. Due to their economic and public health significance, rapid and accurate diagnosis is crucial for effective control and prevention of these diseases. Conventional methods, such as bacterial culture and serological tests, have been used for screening and diagnosis. However, molecular-based methods are becoming increasingly important due to their rapidity, high sensitivity, and specificity, opening new horizons for the development of innovative approaches to control FT and PD. The aim of this review is to highlight the current state of knowledge on biovars Gallinarum and Pullorum, emphasizing the importance of continued research into their pathogenesis, drug resistance and diagnosis to better understand and control these pathogens in poultry farms.
PubMed: 38247582
DOI: 10.3390/antibiotics13010023 -
Microbiology Resource Announcements Sep 2023This work was performed on commercially purchased CVCC519 originally isolated from chicken intestinal content. The Sanguinarine-resistant strain XM3104 was isolated...
This work was performed on commercially purchased CVCC519 originally isolated from chicken intestinal content. The Sanguinarine-resistant strain XM3104 was isolated from Sanguinarine-induced CVCC519. To identify possible mechanisms underlying resistance, the complete genomes of CVCC519 and XM3104 were sequenced using PromethION and next-generation sequencing.
PubMed: 37594281
DOI: 10.1128/MRA.00095-23 -
National Science Review Oct 2023Understanding changes in pathogen behavior (e.g. increased virulence, a shift in transmission channel) is critical for the public health management of emerging...
Understanding changes in pathogen behavior (e.g. increased virulence, a shift in transmission channel) is critical for the public health management of emerging infectious diseases. Genome degradation via gene depletion or inactivation is recognized as a pathoadaptive feature of the pathogen evolving with the host. However, little is known about the exact role of genome degradation in affecting pathogenic behavior, and the underlying molecular detail has yet to be examined. Using large-scale global avian-restricted genomes spanning more than a century, we projected the genetic diversity of Pullorum (bvSP) by showing increasingly antimicrobial-resistant ST92 prevalent in Chinese flocks. The phylogenomic analysis identified three lineages in bvSP, with an enhancement of virulence in the two recently emerged lineages (L2/L3), as evidenced in chicken and embryo infection assays. Notably, the ancestor L1 lineage resembles the serovars with higher metabolic flexibilities and more robust environmental tolerance, indicating stepwise evolutionary trajectories towards avian-restricted lineages. Pan-genome analysis pinpointed fimbrial degradation from a virulent lineage. The later engineered -deletion mutant, and all other five fimbrial systems, revealed behavior switching that restricted horizontal fecal-oral transmission but boosted virulence in chicks. By depleting fimbrial appendages, bvSP established persistent replication with less proinflammation in chick macrophages and adopted vertical transovarial transmission, accompanied by ever-increasing intensification in the poultry industry. Together, we uncovered a previously unseen paradigm for remodeling bacterial surface appendages that supplements virulence-enhanced evolution with increased vertical transmission.
PubMed: 37965675
DOI: 10.1093/nsr/nwad228 -
Journal of Epidemiology and Global... Dec 2023Salmonella is a foodborne zoonotic bacterium, and the antimicrobial-resistant strains of Salmonella are a worldwide health concern. Herein, we employed a meta-analysis... (Meta-Analysis)
Meta-Analysis Review
Salmonella is a foodborne zoonotic bacterium, and the antimicrobial-resistant strains of Salmonella are a worldwide health concern. Herein, we employed a meta-analysis to determine the pooled prevalence of Salmonella and its antimicrobial resistance status in human, animal, and environmental isolates in South Asia. To this end, we followed the standard guideline of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements for searching literature in three databases namely PubMed, Google Scholar, and CAB abstracts, and a total of 100 eligible datasets were finally included which were published from January 2010 to June 2021. In the pooled prevalence of Salmonella in South Asia, the random model effect was 14.47% (95% CI: 10.17-20.19) with a high degree of heterogeneity (I, 99.8%) and overall antimicrobial resistance was 70% (95% CI: 63.0-76.0) with a heterogeneity of 23.6%. The temporal distribution of the overall antimicrobial resistance (%) against Salmonella was increased from 53 to 77% within 10 years. Out of 18 distinct Salmonella serotypes, S. enterica was highly prevalent (14.22%, 95% CI: 4.02-39.64) followed by S. pullorum (13.50%, 95% CI: 5.64-29.93) with antimicrobial resistance (%) were 86.26 and 90.06, respectively. Noteworthy, nalidixic acid (74.25%) and tetracycline (37.64%) were found mostly resistant to Salmonella whereas ceftriaxone (1.07%) and cefixime (1.24%) were sensitive. This systematic review demonstrated that overall antibiotic resistance profiles of Salmonella are increasing over time in South Asia. Thus, adequate hygienic practices, proper use of antimicrobials, and implementation of antibiotic stewardship are imperative for halting the Salmonella spread and its antimicrobial resistance.
Topics: Animals; Humans; Anti-Bacterial Agents; Prevalence; Asia, Southern; Drug Resistance, Bacterial; Salmonella; Microbial Sensitivity Tests
PubMed: 37883006
DOI: 10.1007/s44197-023-00160-x -
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 -
Frontiers in Microbiology 2023Pullorum disease is one of the common bacterial infectious diseases caused by (), which can result in a decrease in the reproductive performance of laying hens, thus...
INTRODUCTION
Pullorum disease is one of the common bacterial infectious diseases caused by (), which can result in a decrease in the reproductive performance of laying hens, thus causing considerable economic losses. However, studies about the characteristics of intestinal microbiota with pullorum and their potential association with reproductive performance in hens are still limited. This study was to identify the gut microbiota associated with in poultry.
METHODS
A total of 30 hens with -negative (PN) and 30 hens with -positive (PP) were analyzed for hatching eggs laid in 2 weeks (HEL), fertilization eggs (FE), chick number (CN), and microbial structure.
RESULTS
There were significant differences in HEL ( < 0.01), FE ( < 0.01), and CN ( < 0.01) between PP and PN. Histomorphological observations showed abnormal morphology of the ovaries and fallopian tubes and low integrity of epithelial tissue in the ileum and cecum in PP. 16S rRNA gene sequencing revealed that beneficial cecal microbes, such as , and , were positively correlated with reproductive performance and had lower abundance in PP ( = 0.001). Furthermore, diminished phosphotransferase system (PTS) and pentose phosphate pathway, butanoate metabolism and oxidative phosphorylation were also found in PP.
DISCUSSION
Taken together, this study clarified the morphological characteristics of the reproductive tract and intestines of chickens infected with and preliminarily explored the potential association between cecal microbiota and reproductive performance in hens. Our data may provide a reference for revealing the intestinal microbial characteristics of hens in resisting pullorum and exploring novel approaches to infection control in future studies.
PubMed: 37577434
DOI: 10.3389/fmicb.2023.1216542 -
Microbiology Spectrum Jun 2023The host-specific Salmonella serovar . Pullorum (SP) modulates the chicken immune response to a Th2-biased response associated with persistent infection. This is...
The host-specific Salmonella serovar . Pullorum (SP) modulates the chicken immune response to a Th2-biased response associated with persistent infection. This is different from the Th1-biased immune response induced by the genetically close serovar, . Enteritidis (SE). Based on core genome differences between SP and SE, we used three complementary bioinformatics approaches to identify SP genes, which may be important for stimulation of the immune response. Defined mutants were constructed in selected genes, and the infection potential and ability of mutants to stimulate cytokine production in avian derived HD11 macrophages were determined. Deletion of large genomic regions unique to SP did not change infection potential nor immune stimulation significantly. Mutants in genes with conserved single nucleotide polymorphisms (SNPs) between the two serovars in the region 100 bp upstream of the start codon (conserved upstream SNPs [CuSNPs]) such as , , , a putative immune antigen, and a putative persistent infection factor, exhibited differences in induction of inflammatory cytokines compared to wild-type SP, suggesting a possible role of these CuSNPs in immune regulation. Single nucleotide SP mutants correcting for the CuSNP difference were constructed in the upstream region of and . The SNP corrected mutant expressed at a higher level than the wild-type SP strain, and the mutant differentially caused upregulation of proinflammatory cytokines. It suggests that this CuSNP is important for the suppression of proinflammatory responses. In conclusion, this study has identified putative immune stimulating factors of relevance to the difference in infection dynamics between SP and SE in avian macrophages. Salmonella Pullorum is host specific to avian species, where it causes life-threatening infection in young birds. It is unknown why it is host restricted and causes systemic disease, rather than gastroenteritis normally seen with Salmonella. In the present study, we identified genes and single nucleotide polymorphisms (SNPs; relative to the broad-host-range type Salmonella Enteritidis), which affected survival and immune induction in macrophages from hens suggesting a role in development of the host specific infection. Further studies of such genes may enable understanding of which genetic factors determine the development of host specific infection by Pullorum. In this study, we developed an approach to predict candidate genes and SNPs for development of the host-specific infection and the specific induction of immunity associated with this infection. This study flow can be used in similar studies in other clades of bacteria.
Topics: Animals; Female; Chickens; Persistent Infection; Salmonella; Macrophages; Cytokines; Immunologic Factors; Salmonella Infections, Animal; Poultry Diseases; Salmonella enterica
PubMed: 37191575
DOI: 10.1128/spectrum.00786-23 -
Frontiers in Veterinary Science 2023Most cases of chicken salmonellosis are caused by serovar Gallinarum biovars Gallinarum and Pullorum, which lead to a significant morbidity and fatality rate. Although...
Most cases of chicken salmonellosis are caused by serovar Gallinarum biovars Gallinarum and Pullorum, which lead to a significant morbidity and fatality rate. Although the conventional Kaufmann-White scheme is the reliable method for the serotyping of , it does not distinguish between closely related biotypes like . Pullorum and . Gallinarum. Herein, we conducted a single one-step multiplex PCR assay that can identify and distinguish between . Pullorum and . Gallinarum in an accurate manner. This PCR method was based on three genes, including for . Pullorum identification, for . Gallinarum identification, and as the genus-level reference gene for . By comparing . Pullorum to . Gallinarum and other serovars of study revealed that only the former has a deletion of 126 bp-region in the carboxyl terminus of . The gene does not exist in . Gallinarum. However, it is present in all other serotypes. The multiplex PCR approach utilizes unique sets of primers that are intended to specifically target these three different genes. The established PCR method was capable of distinguishing between the biovars Pullorum and Gallinarum from the 29 distinct serotypes as well as the 50 distinct pathogens that are not , showing excellent specificity and exclusivity. The minimal amount of bacterial cells required for PCR detection was 100 CFU, while the lowest level of genomic DNA required was 27.5 pg/μL for both . Pullorum and . Gallinarum. After being implemented on the clinical isolates collected from a poultry farm, the PCR test was capable of distinguishing the two biovars Pullorum and Gallinarum from the other strains. The findings of the PCR assay were in line with those of the traditional serotyping and biochemical identification methods. This new multiplex PCR could be used as a novel tool to reinforce the clinical diagnosis and differentiation of . Pullorum and . Gallinarum, particularly in high-throughput screening situations, providing the opportunity for early screening of infections and, as a result, more effective management of the illness among flocks.
PubMed: 37476820
DOI: 10.3389/fvets.2023.1220118 -
Frontiers in Veterinary Science 2023The study explored the biofilm (BF) formation capacity, BF-related gene profiles, and the trends in antimicrobial resistance (AMR) of (SP) strains over several years. A...
The study explored the biofilm (BF) formation capacity, BF-related gene profiles, and the trends in antimicrobial resistance (AMR) of (SP) strains over several years. A total of 627 SP strains were isolated from 4,540 samples collected from chicken farms in Guangxi, China during 2018-2022. The BF-forming capacity of these isolates was assessed using crystal violet staining, and the presence of eight BF-related genes (, and ) in BF formation-positive strains was determined through Polymerase Chain Reaction (PCR) analysis. Antimicrobial susceptibility test was conducted to investigate the AMR of the isolates. Minimum Inhibitory Concentration (MIC) and Minimal Biofilm Eradication Concentration (MBEC) of nine SP-BF strains were determined using the broth microdilution method to assess the impact of BF formation on AMR. Additionally, the Optimal Biofilm Formation Conditions (OBFC) were investigated. The results indicated that 36.8% (231/627) of the strains exhibited a positive BF-formation capacity. Among these, 24.7% (57/231) were strong BF producers, 23.4% (54/231) were moderate BF producers, and 51.9% (120/231) were weak BF producers. Analysis of the eight BF-related genes in SP-BF strains revealed that over 90% of them were positive for all the genes. Antimicrobial susceptibility test conducted on the isolates showed that 100% (231/231) of them exhibited resistance to at least one antibiotic, with 98.3% (227/231) demonstrating multidrug resistance (MDR). Both MIC and MBEC measurements indicated varying degrees of increased AMR after BF formation of the bacteria. The optimal conditions for BF formation were observed at 37°C after 48 h of incubation, with an initial bacterial concentration of 1.2 × 10 CFU/mL. Notably, NaCl had a significant inhibitory effect on BF formation, while glucose and Trypticase Soy Broth (TSB) positively influenced BF formation. The results of the study emphasized the need for effective preventive and control strategies to address the challenges posed by the BF formation and MDR of SP in the field.
PubMed: 37720478
DOI: 10.3389/fvets.2023.1248584 -
Veterinary Research May 2024The lasso peptide microcin Y (MccY) effectively inhibits various serotypes of Salmonella in vitro, but the antibacterial effect against S. Pullorum in poultry is still...
The lasso peptide microcin Y (MccY) effectively inhibits various serotypes of Salmonella in vitro, but the antibacterial effect against S. Pullorum in poultry is still unclear. This study was the first to evaluate the safety and anti-S. Pullorum infection of MccY in specific pathogen-free (SPF) chicks. The safety test showed that the body weight, IgA and IgM levels of serum, and cecal microbiota structure of 3 groups of chicks orally administrated with different doses of MccY (5 mg/kg, 10 mg/kg, 20 mg/kg) for 14 days were not significantly different from those of the control group. Then, the chicks were randomized into 3 groups for the experiment of anti-S. Pullorum infection: (I) negative control group (NC), (II) S. Pullorum-challenged group (SP, 5 × 10 CFU/bird), (III) MccY-treated group (MccY, 20 mg/kg). The results indicated that compared to the SP group, treatment of MccY increased body weight and average daily gain (P < 0.05), reduced S. Pullorum burden in feces, liver, and cecum (P < 0.05), enhanced the thymus, and decreased the spleen and liver index (P < 0.05). Additionally, MccY increased the jejunal villus height, lowered the jejunal and ileal crypt depth (P < 0.05), and upregulated the expression of IL-4, IL-10, ZO-1 in the jejunum and ileum, as well as CLDN-1 in the jejunum (P < 0.05) compared to the SP group. Furthermore, MccY increased probiotic flora (Barnesiella, etc.), while decreasing (P < 0.05) the relative abundance of pathogenic flora (Escherichia and Salmonella, etc.) compared to the SP group.
Topics: Animals; Chickens; Gastrointestinal Microbiome; Poultry Diseases; Salmonella Infections, Animal; Bacteriocins; Administration, Oral; Salmonella; Specific Pathogen-Free Organisms; Animal Feed; Anti-Bacterial Agents; Random Allocation; Intestinal Barrier Function
PubMed: 38778424
DOI: 10.1186/s13567-024-01321-x