-
Vaccines Apr 2024Bacterial ghosts (BGs) are hollow bacterial cell envelopes with intact cellular structures, presenting as promising candidates for various biotechnological and...
Bacterial ghosts (BGs) are hollow bacterial cell envelopes with intact cellular structures, presenting as promising candidates for various biotechnological and biomedical applications. However, the yield and productivity of BGs have encountered limitations, hindering their large-scale preparation and multi-faceted applications of BGs. Further optimization of BGs is needed for the commercial application of BG technology. In this study, we screened out the most effective lysis protein ID52-E-W4A among 13 mutants based on phage ID52 lysis protein E and optimized the liquid culture medium for preparing Nissle 1917 (EcN). The results revealed a significantly higher lysis rate of ID52-E-W4A compared to that of ID52-E in the 2xYT medium. Furthermore, EcN BGs were cultivated in a fermenter, achieving an initial OD as high as 6.0 after optimization, indicating enhanced BG production. Moreover, the yield of ID52-E-W4A-induced BGs reached 67.0%, contrasting with only a 3.1% yield from φX174-E-induced BGs. The extended applicability of the lysis protein ID52-E-W4A was demonstrated through the preparation of pullorum ghosts and choleraesuis ghosts. Knocking out the molecular chaperone gene and revealed that ID52-mediated BGs could still undergo lysis. Conversely, overexpression of integral membrane enzyme gene resulted in the loss of lysis activity for ID52-E, suggesting that the lysis protein ID52-E may no longer rely on SlyD or DnaJ to function, with MraY potentially being the target of ID52-E. This study introduces a novel approach utilizing ID52-E-W4A for recombinant expression, accelerating the BG formation and thereby enhancing BG yield and productivity.
PubMed: 38793723
DOI: 10.3390/vaccines12050472 -
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 -
Microorganisms Apr 2024The development of probiotics capable of quickly colonizing the intestines of animals is important in promoting the healthy growth of livestock. The aim of this study...
The development of probiotics capable of quickly colonizing the intestines of animals is important in promoting the healthy growth of livestock. The aim of this study was to screen lactic acid bacteria (LAB) from the intestinal microbiota of chickens with potential applications, and to evaluate their probiotic properties and antagonistic abilities against , , and . The results showed that a total of 79 strains with the characteristics of LAB were isolated from the chicken cecum microbiota, of which 7 strains exhibited strong inhibitory activity against . , , and . Performing 16s rDNA sequencing revealed that these seven strains were ( = 1), ( = 3), ( = 1), ( = 1), and ( = 1). Among them, R26 and R32 exhibited superior antibacterial activity. These two strains demonstrated high lactic acid production ability, with survival rates of 86.29% and 87.99% after 3 h of treatment at pH 1.5, 86.66% and 85.52% after 3 h of treatment with 0.5% bile salts, 90.03% and 88.16% after 2 h of treatment with simulated gastric fluid, and 98.92% and 98.22% after 2 h of treatment with simulated intestinal fluid, respectively. Co-cultivation with R26 for 24 h resulted in 50% of the pathogens being antagonized, while almost complete inhibition was observed following 72 h of co-cultivation. In conclusion, R26 and R32 exhibited high antibacterial activity and acid production capability, while also demonstrating satisfactory tolerance to low pH values and high concentrations of bile salts and digestive fluid. The probiotic characteristics and stress resistance of R26 were slightly superior to those of R32, indicating its potential for development as a probiotic.
PubMed: 38674739
DOI: 10.3390/microorganisms12040795 -
Poultry Science Apr 2024Plant extracts are increasingly recognized as potential prophylactic agents in poultry production due to their diverse bioactive properties. This study investigated the...
Plant extracts are increasingly recognized as potential prophylactic agents in poultry production due to their diverse bioactive properties. This study investigated the phytochemical and biological properties of Libidibia ferrea (L. ferrea), a plant species native to the Caatinga region of northeastern Brazil. The aim of this study was to identify secondary metabolites and to demonstrate the antimicrobial, antioxidant and protective effects of the plant extract. Three extracts were produced: EHMV, a hydroalcoholic extract from the maceration of pods, and EEMC and EEMV ethanolic extracts from the maceration of peels and pods, respectively, from L. ferrea. High-performance liquid chromatography (HPLC-MS/MS) and atomic absorption spectroscopy (AAS) were used to characterize the metabolites and metals. The antimicrobial activity against Salmonella Galinarum (SG), Salmonella pullorum (SP), Salmonella Heidelberg (SH) and Avian pathogenic Escherichia coli (APEC) was evaluated alone and in combination with probiotic bacteria (Bacillus velenzensis) using agar diffusion and the bactericidal minimum concentration (CBM). The antioxidant potential of the extracts was evaluated in 5 in vitro assays and 6 assays in 3t3 cells. The toxicity of EHMV was tested, and its ability to combat SP infection was demonstrated using a chicken embryo model. The results showed that EHMV exhibited significant antimicrobial activity. The combination of EHMV with BV had synergistic effects, increased antimicrobial activity and induced bacterial sporulation. Composition analysis revealed the presence of 8 compounds, including tannins and phenolic compounds. In vitro antioxidant tests demonstrated that total antioxidant capacity(TAC) activity was increased, and the extract had strong reducing power and notable metal chelating effects. Analysis of 3T3 cells confirmed the protective effect of EHMV against oxidative stress. Toxicity assessments in chicken embryos confirmed the safety of EHMV and its protective effect against SP-induced mortality. EHMV from L. ferrea is rich in proteins and contains essential metabolites that contribute to its antimicrobial and antioxidant properties. When associated with probiotic bacteria such as B. velezensis, this extract increases the inhibition of SH, SG, SP, and APE. The nontoxic nature of EHMV and its protective effects on chicken embryos make it a potential supplement for poultry.
PubMed: 38631232
DOI: 10.1016/j.psj.2024.103668 -
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 -
Animals : An Open Access Journal From... Dec 2023This study investigates the potential role of Cold-pressed Valencia Terpeneless citrus oil (CO), as a natural antimicrobial, in controlling causative agents of pullorum...
This study investigates the potential role of Cold-pressed Valencia Terpeneless citrus oil (CO), as a natural antimicrobial, in controlling causative agents of pullorum disease and fowl typhoid in floor materials for poultry farming, specifically wooden chips. The study addresses the issues that have arisen as a result of the reduction in antibiotic use in poultry farming, which has resulted in the re-emergence of bacterial diseases including salmonellosis. CO efficiently inhibits the growth of pathogens including various serovars of (SE), including SE serovar Gallinarum () and SE serovar Pullorum (), in a dose-dependent manner. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of CO showed potential for controlling diverse and isolates. Growth inhibition assays demonstrated that 0.4% (/) CO eliminated and from 24 h onwards, also impacting poultry gut microbiota and probiotic strains. Floor material simulation, specifically wooden chips treated with 0.4% CO, confirmed CO's effectiveness in preventing and growth on poultry house floors. This study also investigated the effect of CO on the expression of virulence genes in and . Specifically, the study revealed that the application of CO resulted in a downregulation trend in virulence genes, including , , , , and , in both and , implying that CO may alter the pathogenicity of these bacterial pathogens. Overall, this study reveals that CO has the potential to be used as a natural antimicrobial in the prevention and management of -related infections in chicken production, offering a viable alternative to control these re-emerging diseases.
PubMed: 38200754
DOI: 10.3390/ani14010023 -
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 -
BMC Veterinary Research Dec 2023The objective of this study was to evaluate the effects of glutamine on the growth performance and systemic innate immune response in broiler chickens challenged with...
BACKGROUND
The objective of this study was to evaluate the effects of glutamine on the growth performance and systemic innate immune response in broiler chickens challenged with Salmonella pullorum. A total of 600 one-day-old Arbor Acres broiler chickens were assigned randomly to 6 dietary treatments with 10 replicates for a 21-day feeding experiment. The experimental treatments were as follows: the control treatment (birds fed the basal diet), the Gln1 treatment, and the Gln 2 treatment (birds fed the basal diet supplemented with 0.5%, and 1.0% Glutamine, respectively). At 3 d of age, half of the birds from each treatment were challenged oral gavage with 2.0 × 10 CFU/mL of S. pullorum suspension (1.0 mL per bird) or an equivalent amount of sterile saline alone, which served as a control.
RESULTS
The results showed that S. pullorum infection had adverse effects on the average daily feed intake, average daily gain, and feed conversion ratio of broiler chickens compared with those of the CON treatment on d 7, decreased the spleen and bursa of fabricius relative weights (except on d 21), serum immunoglobulin A (IgA),immunoglobulin G (IgG), and immunoglobulin M (IgM) concentrations, and spleen melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology gene 2 (LGP2) mRNA expression levels, and increased the mRNA expression levels of spleen Nodinitib-1 (NOD1), Toll-like receptors 2,4 (TLR2, TLR4), DNA-dependent activator of IFN-regulatory factors (DAI), mitochondrial antiviral-signaling protein (MAVS), P50, P65, and RelB on d 4, 7, 14, and 21. Supplementation with Gln improved the relative weights of the spleen and bursa of Fabricius (except on d 21), increased the serum IgA, IgG, and IgM concentrations and the mRNA expression levels of spleen MDA5 and LGP2, and decreased the mRNA expression levels of spleen NOD1, TLR2, TLR4, DAI, MAVS, P50, P65, and RelB of S. pullorum-challenged broiler chickens.
CONCLUSION
These results indicate that Gln might stimulate the systemic innate immune responses of the spleen in broiler chickens challenged with S. pullorum.
Topics: Animals; Chickens; Toll-Like Receptor 2; Glutamine; Toll-Like Receptor 4; Dietary Supplements; Diet; Immunity, Innate; Salmonella; Immunoglobulin G; Immunoglobulin M; RNA, Messenger; Immunoglobulin A; Animal Feed
PubMed: 38102601
DOI: 10.1186/s12917-023-03836-5 -
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