scholarly journals Streptococcus pluranimalium 2N12 Exerts an Antagonistic Effect Against the Swine Pathogen Actinobacillus pleuropneumoniae by Producing Hydrogen Peroxide

2021 ◽  
Vol 8 ◽  
Author(s):  
Katy Vaillancourt ◽  
Michel Frenette ◽  
Marcelo Gottschalk ◽  
Daniel Grenier
Keyword(s):  
Hydrogen Peroxide ◽  
Culture Supernatant ◽  
Actinobacillus Pleuropneumoniae ◽  
Antagonistic Effect ◽  
Economic Losses ◽  
Protective Mechanism ◽  
Upper Respiratory Tract ◽  
Lactate Oxidase ◽  
Swine Industry

Actinobacillus pleuropneumoniae is the causal agent of porcine pleuropneumonia, a highly contagious and often deadly respiratory disease that causes major economic losses in the swine industry worldwide. The aim of the present study was to investigate the hydrogen peroxide (H2O2)-dependent antagonistic activity of Streptococcus pluranimalium 2N12 (pig nasal isolate) against A. pleuropneumoniae. A fluorimetric assay showed that S. pluranimalium produces H2O2 dose- and time-dependently. The production of H2O2 increased in the presence of exogenous lactate, suggesting the involvement of lactate oxidase. All 20 strains of A. pleuropneumoniae tested, belonging to 18 different serovars, were susceptible to H2O2, with minimal inhibitory concentrations and minimal bactericidal concentrations ranging from 0.57 to 2.3 mM. H2O2, as well as a culture supernatant of S. pluranimalium, killed planktonic cells of A. pleuropneumoniae. Treating the culture supernatant with catalase abolished its bactericidal property. H2O2 was also active against a pre-formed biofilm-like structure of A. pleuropneumoniae albeit to a lesser extent. A checkerboard assay was used to show that there were antibacterial synergistic interactions between H2O2 and conventional antibiotics, more particularly ceftiofur. Based on our results and within the limitations of this in vitro study, the production of H2O2 by S. pluranimalium could be regarded as a potential protective mechanism of the upper respiratory tract against H2O2-sensitive pathogens such as A. pleuropneumoniae.

ISOLATION, IDENTIFICATION AND CHARACTERIZATION OF BACTERIAL ANTAGONISTS OF THE DRAGON FRUIT FUNGAL PATHOGEN Neoscytalidium dimidiatum

2021 ◽  
Vol 44 (02) ◽  
Author(s):  
NGUYEN NGOC AN ◽  
HUA HUYNH MINH THAO ◽  
HO NGUYEN HOANG YEN ◽  
NGUYEN THI DIEU HANH ◽  
NGUYEN LE HIEN HOA ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Pathogenic Fungi ◽  
Fungal Spore ◽  
Stem Canker ◽  
Antagonistic Effect ◽  
Fruit Rot ◽  
Economic Losses ◽  
Neoscytalidium Dimidiatum ◽  
Dragon Fruit

Dragon fruit or pitahaya (Hylocereus spp.) are famous for their nutrient-rich favourable taste, which brings high economic value to subtropical and tropical countries. However, dragon fruit cultivation all over the world is threatened by fungal pathogens and among them, Neoscytalidium dimidiatum has recently been shown to be responsible for stem canker and fruit rot which cause big economic losses. In order to find an environmentally friendly way to control this pathogen, five out of sixty-nine bacterial isolates used in a screening test for antifungal activity were selected. All five strains appeared to be aerobic Gram positive spore forming bacteria suggesting that they all belong to the Bacillus genus. Cell-free culture supernatants of these strains were found to strongly inhibit both fungal spore germination and mycelia growth in vitro for at least 5 days. The strain D19 which possessed the highest antagonistic effect was further identified to be Bacillus amyloliquefaciens, a well-known species shown to have antifungal effect against several other pathogenic fungi. Thus, the results of this study opened a new promising perspective to prevent Neoscytalidium dimidiatum infection during cultivation of dragon fruit.

scholarly journals An enzyme-based protocol for cell-free synthesis of nature-identical capsular oligosaccharides from Actinobacillus pleuropneumoniae serotype 1

2020 ◽  
Vol 295 (17) ◽  
pp. 5771-5784 ◽  
Author(s):  
Insa Budde ◽  
Christa Litschko ◽  
Jana I Führing ◽  
Rita Gerardy-Schahn ◽  
Mario Schubert ◽  
...  
Keyword(s):  
Animal Health ◽  
Health Sector ◽  
Actinobacillus Pleuropneumoniae ◽  
Economic Losses ◽  
Tetratricopeptide Repeats ◽  
Single Action ◽  
Serotype 1 ◽  
Glycoconjugate Vaccines ◽  
Culture Supernatants

Actinobacillus pleuropneumoniae (App) is the etiological agent of acute porcine pneumonia and responsible for severe economic losses worldwide. The capsule polymer of App serotype 1 (App1) consists of [4)-GlcNAc-β(1,6)-Gal-α-1-(PO4-] repeating units that are O-acetylated at O-6 of the GlcNAc. It is a major virulence factor and was used in previous studies in the successful generation of an experimental glycoconjugate vaccine. However, the application of glycoconjugate vaccines in the animal health sector is limited, presumably because of the high costs associated with harvesting the polymer from pathogen culture. Consequently, here we exploited the capsule polymerase Cps1B of App1 as an in vitro synthesis tool and an alternative for capsule polymer provision. Cps1B consists of two catalytic domains, as well as a domain rich in tetratricopeptide repeats (TPRs). We compared the elongation mechanism of Cps1B with that of a ΔTPR truncation (Cps1B-ΔTPR). Interestingly, the product profiles displayed by Cps1B suggested processive elongation of the nascent polymer, whereas Cps1B-ΔTPR appeared to work in a more distributive manner. The dispersity of the synthesized products could be reduced by generating single-action transferases and immobilizing them on individual columns, separating the two catalytic activities. Furthermore, we identified the O-acetyltransferase Cps1D of App1 and used it to modify the polymers produced by Cps1B. Two-dimensional NMR analyses of the products revealed O-acetylation levels identical to those of polymer harvested from App1 culture supernatants. In conclusion, we have established a protocol for the pathogen-free in vitro synthesis of tailored, nature-identical App1 capsule polymers.

scholarly journals Selection and Characterization of CSFV-Specific Single-Domain Antibodies and Their Application along with Immunomagnetic Nanobeads and Quantum Dots

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shunli Yang ◽  
Li Yuan ◽  
Youjun Shang ◽  
Jinyan Wu ◽  
Xiangtao Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Magnetic Beads ◽  
Molecular Probes ◽  
Single Domain ◽  
Molecular Probe ◽  
Economic Losses ◽  
Single Domain Antibody ◽  
Swine Industry ◽  
E2 Protein

Outbreak of classical swine fever (CSF) results in high mortality and thus causes severe economic losses in the swine industry. Single-domain antibody (sdAb) is the smallest antigen-binding molecule derived from camelid heavy-chain antibodies and has the potential to be used as a molecular probe for detection of CSF virus (CSFV). In this study, two sdAb fragments against the E2 antigen of CSFV were obtained, expressed in vitro. The functional characteristics analysis indicated that the recombinant sdAbE2-1 and sdAbE2-2 have excellent binding activity, specificity, and high affinity with equilibrium constant value of 3.34 × 10−7 and 1.35 × 10−8 M to E2 protein. Then, sdAbE2s were conjugated with quantum dots (QD)/AF488 to synthesize two molecular probes for imaging CSFV distribution in cells. The sdAbE2-1 was also labeled with carboxyl-magnetic beads to construct immunomagnetic nanobeads (IMNBs) able to capture CSFV virions and recombinant E2 protein. QD/AF455-sdAbE2s probes colocalised with CSFV virions in swine testis cells, and IMNBs were used as a detection template and proved to bind specifically with CSFV virions and E2 protein. The selected sdAb fragments and sdAb-based molecular probes may be used for the rapid identification of CSFV during field outbreaks and for research on CSFV and host interactions.

scholarly journals Amentoflavone AmelioratesStreptococcus suis-Induced InfectionIn VitroandIn Vivo

2018 ◽  
Vol 84 (24) ◽  
Author(s):  
Xue Shen ◽  
Xiaodi Niu ◽  
Gen Li ◽  
Xuming Deng ◽  
Jianfeng Wang
Keyword(s):  
Bacterial Resistance ◽  
Cell Model ◽  
Streptococcus Suis ◽  
Chinese Herbs ◽  
Economic Losses ◽  
Swine Industry ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Anti Inflammatory

ABSTRACTStreptococcus suis, an important zoonotic pathogen, has caused considerable economic losses in the swine industry and severe public health issues worldwide. The development of a novel effective strategy for the prevention and therapy ofS. suisis urgently needed. Here, amentoflavone, a natural biflavonoid compound isolated from Chinese herbs that has negligible anti-S. suisactivity, was identified as a potent antagonist of suilysin (SLY)-mediated hemolysis without interfering with the expression of SLY. Amentoflavone effectively inhibited SLY oligomerization, which is critical for its pore-forming activity. The treatment with amentoflavone reducedS. suis-induced cytotoxicity in macrophages (J774 cells). Furthermore,S. suis-infected mice that received amentoflavone exhibited lower mortality and bacterial burden. Additionally, amentoflavone significantly decreased the production of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 in anS. suis-infected cell model. Analyses of signaling pathways demonstrated that amentoflavone reducedS. suis-induced inflammation inS. suisserotype 2 (SS2)-infected cells by regulating the p38, Jun N-terminal protein kinase 1 and 2 (JNK1/2), and NF-κB pathways. The antivirulence and anti-inflammatory properties of amentoflavone againstS. suisinfection provide the possibility for future pharmaceutical application of amentoflavone in the treatment ofS. suisinfection.IMPORTANCEThe widespread use of antibiotics in therapy and in the prevention ofStreptococcus suisinfection in the swine industry raises concerns for the emergence of a resistant strain. The use of antivirulence agents has potential benefits, mainly because of the reduced selective pressure for the development of bacterial resistance. In this study, we found that amentoflavone is an effective agent againstS. suisserotype 2 (SS2) infection bothin vitroandin vivo. Our results demonstrated that amentoflavone is a promising anti-infective therapeutic forS. suisinfections, due to its antivirulence and anti-inflammatory effects without antibacterial activity, with fewer side effects than conventional antibacterial agents.

scholarly journals Draft Genome Sequence of Actinobacillus pleuropneumoniae Serotype 7 Strain S-8

2012 ◽  
Vol 194 (23) ◽  
pp. 6606-6607 ◽  
Author(s):  
Gang Li ◽  
Fang Xie ◽  
Yanhe Zhang ◽  
Chunlai Wang
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Actinobacillus Pleuropneumoniae ◽  
Draft Genome Sequence ◽  
Economic Losses ◽  
Negative Bacterium ◽  
Swine Industry ◽  
Gram Negative ◽  
Content Type ◽  
Porcine Pleuropneumonia

ABSTRACTThe Gram-negative bacteriumActinobacillus pleuropneumoniaeis the etiological agent of porcine pleuropneumonia, a respiratory disease that leads to severe economic losses in the swine industry. For years, scientists working with it have lacked a reliable genome sequence for comparison with otherActinobacillusspecies. Here, we report the draft genome sequence ofA. pleuropneumoniaeserotype 7 (strain S-8), isolated from swine lung in China in 1992.

scholarly journals Impact of Trichoderma sp. on the Development of Heterobasidion Annosum in Decayed Understory Picea Abies Stumps

2017 ◽  
Vol 71 (1-2) ◽  
pp. 52-56
Author(s):  
Kristīne Kenigsvalde ◽  
Dina Nitiša ◽  
Dace Saulīte ◽  
Kari Korhonen ◽  
Līvija Vulfa ◽  
...  
Keyword(s):  
Biological Control ◽  
Field Studies ◽  
Antagonistic Effect ◽  
Heterobasidion Annosum ◽  
Economic Losses ◽  
Biological Control Agents ◽  
Trichoderma Sp ◽  
The Impact ◽  
Trichoderma Isolates

Abstract Heterobasidion annosum (Fr.) Bref. s.l. causes significant economic losses in conifer forests. Therefore, to reduce the spread of the infection surfaces of freshly cut conifer, stumps are commonly treated with biological control agents. Trichoderma sp. shows very strong antagonistic effect against H. annosum in vitro, but relatively few field studies have been conducted. Moreover, most of previous studies examined the impact of Trichoderma sp. on H. annosum in healthy conifer stumps. The aim of our work was to evaluate the effect of Trichoderma sp. against H. annosum in already decayed understory spruce stumps. In total, 75 decayed spruce stumps were surveyed. Part of the spruce stumps were left as a control, and the others were treated with one of two Trichoderma isolates (T472 and T945) belonging to two different species: T. viridescens and T. viride. The occurrence of H. annosum was evaluated 3 and 12 months after treatment. The main results were that the area of previously healthy wood occupied by H. annosum was larger in control stumps in comparison with treated stumps, but the differences were not statistically significant.

scholarly journals Comparative Genomic Characterization of Actinobacillus pleuropneumoniae

2010 ◽  
Vol 192 (21) ◽  
pp. 5625-5636 ◽  
Author(s):  
Zhuofei Xu ◽  
Xiabing Chen ◽  
Lu Li ◽  
Tingting Li ◽  
Shengyue Wang ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Severe Disease ◽  
Gene Clusters ◽  
Actinobacillus Pleuropneumoniae ◽  
Etiologic Agent ◽  
Economic Losses ◽  
Comparative Genomic ◽  
Swine Industry ◽  
Genomic Characterization ◽  
Reference Strains

ABSTRACT The Gram-negative bacterium Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumoniae, a lethal respiratory infectious disease causing great economic losses in the swine industry worldwide. In order to better interpret the genetic background of serotypic diversity, nine genomes of A. pleuropneumoniae reference strains of serovars 1, 2, 4, 6, 9, 10, 11, 12, and 13 were sequenced by using rapid high-throughput approach. Based on 12 genomes of corresponding serovar reference strains including three publicly available complete genomes (serovars 3, 5b, and 7) of this bacterium, we performed a comprehensive analysis of comparative genomics and first reported a global genomic characterization for this pathogen. Clustering of 26,012 predicted protein-coding genes showed that the pan genome of A. pleuropneumoniae consists of 3,303 gene clusters, which contain 1,709 core genome genes, 822 distributed genes, and 772 strain-specific genes. The genome components involved in the biogenesis of capsular polysaccharide and lipopolysaccharide O antigen relative to serovar diversity were compared, and their genetic diversity was depicted. Our findings shed more light on genomic features associated with serovar diversity of A. pleuropneumoniae and provide broader insight into both pathogenesis research and clinical/epidemiological application against the severe disease caused by this swine pathogen.

scholarly journals Weaning-associated feed deprivation stress causes microbiota disruptions in a novel mucin-containing in vitro model of the piglet colon (MPigut-IVM)

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Raphaële Gresse ◽  
Frédérique Chaucheyras-Durand ◽  
Sylvain Denis ◽  
Martin Beaumont ◽  
Tom Van de Wiele ◽  
...  
Keyword(s):  
Animal Experiments ◽  
Taxonomic Composition ◽  
Economic Losses ◽  
Strong Increase ◽  
Swine Industry ◽  
Feed Deprivation ◽  
And Function ◽  
The Impact

Abstract Background Risk factors for the etiology of post-weaning diarrhea, a major problem in swine industry associated with enormous economic losses, remain to be fully elucidated. In concordance with the ethical concerns raised by animal experiments, we developed a new in vitro model of the weaning piglet colon (MPigut-IVM) including a mucin bead compartment to reproduce the mucus surface from the gut to which gut microbes can adhere. Results Our results indicated that the MPigut-IVM is able to establish a representative piglet archaeal and bacterial colon microbiota in terms of taxonomic composition and function. The MPigut-IVM was consequently used to investigate the potential effects of feed deprivation, a common consequence of weaning in piglets, on the microbiota. The lack of nutrients in the MPigut-IVM led to an increased abundance of Prevotellaceae and Escherichia-Shigella and a decrease in Bacteroidiaceae and confirms previous in vivo findings. On top of a strong increase in redox potential, the feed deprivation stress induced modifications of microbial metabolite production such as a decrease in acetate and an increase in proportional valerate, isovalerate and isobutyrate production. Conclusions The MPigut-IVM is able to simulate luminal and mucosal piglet microbiota and represent an innovative tool for comparative studies to investigate the impact of weaning stressors on piglet microbiota. Besides, weaning-associated feed deprivation in piglets provokes disruptions of MPigut-IVM microbiota composition and functionality and could be implicated in the onset of post-weaning dysbiosis in piglets.

scholarly journals Development and In Vivo Evaluation of a MGF110-1L Deletion Mutant in African Swine Fever Strain Georgia

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 286
Author(s):  
Elizabeth Ramirez-Medina ◽  
Elizabeth Vuono ◽  
Sarah Pruitt ◽  
Ayushi Rai ◽  
Ediane Silva ◽  
...  
Keyword(s):  
Deletion Mutant ◽  
African Swine Fever Virus ◽  
Field Isolate ◽  
African Swine Fever ◽  
Economic Losses ◽  
Swine Industry ◽  
In Vivo Evaluation ◽  
Viral Virulence

African swine fever (ASF) is currently causing an epizootic, affecting pigs throughout Eurasia, and causing significant economic losses in the swine industry. ASF is caused by African swine fever virus (ASFV) that consists of a large dsDNA genome that encodes for more than 160 genes; few of these genes have been studied in detail. ASFV contains four multi-gene family (MGF) groups of genes that have been implicated in regulating the immune response and host specificity; however, the individual roles of most of these genes have not been well studied. Here, we describe the evaluation of the previously uncharacterized ASFV MGF110-1L open reading frame (ORF) using a deletion mutant of the ASFV currently circulating throughout Eurasia. The recombinant ASFV lacking the MGF110-1L gene (ASFV-G-ΔMGF110-1L) demonstrated in vitro that the MGF110-1L gene is non-essential, since ASFV-G-ΔMGF110-1L had similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-ΔMGF110-1L produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the MGF110-1L gene from the ASFV genome does not affect viral virulence.

scholarly journals Emodin from Aloe Inhibits Porcine Reproductive and Respiratory Syndrome Virus via Toll-Like Receptor 3 Activation

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1243
Author(s):  
Zhichao Xu ◽  
Meiyan Huang ◽  
Yongbo Xia ◽  
Peng Peng ◽  
Yun Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Antiviral Agents ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Finishing Pigs ◽  
Toll Like Receptor ◽  
Swine Industry ◽  
Infectious Cycle

Porcine reproductive and respiratory syndrome virus (PRRSV) causes severe reproductive failure in sows and respiratory diseases in growing and finishing pigs and results in great economic losses to the swine industry. Although vaccines are available, PRRSV remains a major threat to the pig farms. Thus, there is an urgent need to develop antiviral drugs to compensate for vaccines. In this study, we report that Aloe extract (Ae) can strongly inhibit PRRSV in Marc-145 cells and porcine alveolar macrophages lines (iPAMs) in vitro. Furthermore, we identified a novel anti-PRRSV molecule, Emodin, from Ae by high-performance liquid chromatography (HPLC). Emodin exerted its inhibitory effect through targeting the whole stages of PRRSV infectious cycle. Moreover, we also found that Emodin can inactivate PRRSV particles directly. Notably, we confirmed that Emodin was able to significantly induce Toll-like receptor 3 (TLR3) (p < 0.01), IFN-α (p < 0.05) and IFN-β expression in iPAMs, indicating that induction of antiviral agents via TLR3 activation by Emodin might contribute to its anti-PRRSV effect. These findings imply that the Emodin from Aloe could hamper the proliferation of PRRSV in vitro and might constitute a new approach for treating PRRSV infection.

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