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 Categorization of Orthologous Gene Clusters in 92 Ascomycota Genomes Reveals Functions Important for Phytopathogenicity

2021 ◽  
Vol 7 (5) ◽  
pp. 337
Author(s):  
Daniel Peterson ◽  
Tang Li ◽  
Ana M. Calvo ◽  
Yanbin Yin
Keyword(s):  
Comparative Genomics ◽  
Orthologous Gene ◽  
Gene Clusters ◽  
Phytopathogenic Fungi ◽  
Secreted Proteins ◽  
Economic Losses ◽  
Comparative Genomic ◽  
Signal Peptides ◽  
Comparative Genomics Analysis

Phytopathogenic Ascomycota are responsible for substantial economic losses each year, destroying valuable crops. The present study aims to provide new insights into phytopathogenicity in Ascomycota from a comparative genomic perspective. This has been achieved by categorizing orthologous gene groups (orthogroups) from 68 phytopathogenic and 24 non-phytopathogenic Ascomycota genomes into three classes: Core, (pathogen or non-pathogen) group-specific, and genome-specific accessory orthogroups. We found that (i) ~20% orthogroups are group-specific and accessory in the 92 Ascomycota genomes, (ii) phytopathogenicity is not phylogenetically determined, (iii) group-specific orthogroups have more enriched functional terms than accessory orthogroups and this trend is particularly evident in phytopathogenic fungi, (iv) secreted proteins with signal peptides and horizontal gene transfers (HGTs) are the two functional terms that show the highest occurrence and significance in group-specific orthogroups, (v) a number of other functional terms are also identified to have higher significance and occurrence in group-specific orthogroups. Overall, our comparative genomics analysis determined positive enrichment existing between orthogroup classes and revealed a prediction of what genomic characteristics make an Ascomycete phytopathogenic. We conclude that genes shared by multiple phytopathogenic genomes are more important for phytopathogenicity than those that are unique in each genome.

scholarly journals Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae

BMC Genomics ◽  
2009 ◽  
Vol 10 (1) ◽  
pp. 88 ◽  
Author(s):  
Julien Gouré ◽  
Wendy A Findlay ◽  
Vincent Deslandes ◽  
Anne Bouevitch ◽  
Simon J Foote ◽  
...  
Keyword(s):  
Actinobacillus Pleuropneumoniae ◽  
Comparative Genomic ◽  
Genomic Profiling ◽  
Field Isolates ◽  
Reference Strains

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.

scholarly journals Genomic characterization of asymptomatic Escherichia coli isolated from the neobladder

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 1088-1102 ◽  
Author(s):  
Jason W. Sahl ◽  
Amanda L. Lloyd ◽  
Julia C. Redman ◽  
Thomas A. Cebula ◽  
David P. Wood ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Severe Disease ◽  
Comparative Genomic ◽  
Trauma Studies ◽  
Ileal Neobladder ◽  
E Coli ◽  
Genomic Characterization ◽  
Tract Infections ◽  
Ileal Tissue

The replacement of the bladder with a neobladder made from ileal tissue is the prescribed treatment in some cases of bladder cancer or trauma. Studies have demonstrated that individuals with an ileal neobladder have recurrent colonization by Escherichia coli and other species that are commonly associated with urinary tract infections; however, pyelonephritis and complicated symptomatic infections with ileal neobladders are relatively rare. This study examines the genomic content of two E. coli isolates from individuals with neobladders using comparative genomic hybridization (CGH) with a pan-E. coli/Shigella microarray. Comparisons of the neobladder genome hybridization patterns with reference genomes demonstrate that the neobladder isolates are more similar to the commensal, laboratory-adapted E. coli and a subset of enteroaggregative E. coli than they are to uropathogenic E. coli isolates. Genes identified by CGH as exclusively present in the neobladder isolates among the 30 examined isolates were primarily from large enteric isolate plasmids. Isolations identified a large plasmid in each isolate, and sequencing confirmed similarity to previously identified plasmids of enteric species. Screening, via PCR, of more than 100 isolates of E. coli from environmental, diarrhoeagenic and urinary tract sources did not identify neobladder-specific genes that were widely distributed in these populations. These results taken together demonstrate that the neobladder isolates, while distinct, are genomically more similar to gastrointestinal or commensal E. coli, suggesting why they can colonize the transplanted intestinal tissue but rarely progress to acute pyelonephritis or more severe disease.

scholarly journals Genetic loci of the R. anatipestifer serotype discovered by Pan-GWAS and its application for the development of a multiplex PCR serotyping method

2021 ◽  
Author(s):  
Zhishuang Yang ◽  
Xueqin Yang ◽  
Mingshu Wang ◽  
Renyong Jia ◽  
Shun Chen ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Capsular Polysaccharide ◽  
Association Studies ◽  
Gene Clusters ◽  
Genomic Variation ◽  
Economic Losses ◽  
Genome Wide Association Studies ◽  
Genetic Loci ◽  
Genome Wide ◽  
Pcr Method

The disease caused by Riemerella anatipestifer (R. anatipestifer) causes large economic losses to the global duck industry every year. Serotype-related genomic variation (such as in O-antigen and capsular polysaccharide gene clusters) has been widely used for the serotyping in many gram-negative bacteria. To date, there have been few studies focused on genetic basis of serotypes in R. anatipestifer. Here, we used pan-genome-wide association studies (Pan-GWAS) to identify the serotype-specific genetic loci of 38 R. anatipestifers strain. Analyses of the loci of 11 serotypes showed that the loci could be well mapped with the serotypes of the corresponding strains. We constructed the knockout strain for the wzy gene at the locus, and the results showed that the mutant lost the agglutination characteristics to positive antisera. Based on the of Pan-GWAS results, we developed a multiple PCR method to identify serotypes 1, 2, and 11 of R. anatipestifer. Our study provides a precedent for systematically analysing the genetic basis of the R anatipestifer serotypes and establishing a complete serotyping system in the future.

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 Genome Sequencing and Comparative Analysis of Klebsiella pneumoniae NTUH-K2044, a Strain Causing Liver Abscess and Meningitis

2009 ◽  
Vol 191 (14) ◽  
pp. 4492-4501 ◽  
Author(s):  
Keh-Ming Wu ◽  
Ling-Hui Li ◽  
Jing-Jou Yan ◽  
Nina Tsao ◽  
Tsai-Lien Liao ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Liver Abscess ◽  
Nosocomial Infections ◽  
Capsular Polysaccharide ◽  
Gene Clusters ◽  
Genomic Diversity ◽  
Whole Genome Sequence ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Major Health Problem

ABSTRACT Nosocomial infections caused by antibiotic-resistant Klebsiella pneumoniae are emerging as a major health problem worldwide, while community-acquired K. pneumoniae infections present with a range of diverse clinical pictures in different geographic areas. In particular, an invasive form of K. pneumoniae that causes liver abscesses was first observed in Asia and then was found worldwide. We are interested in how differences in gene content of the same species result in different diseases. Thus, we sequenced the whole genome of K. pneumoniae NTUH-K2044, which was isolated from a patient with liver abscess and meningitis, and analyzed differences compared to strain MGH 78578, which was isolated from a patient with pneumonia. Six major types of differences were found in gene clusters that included an integrative and conjugative element, clusters involved in citrate fermentation, lipopolysaccharide synthesis, and capsular polysaccharide synthesis, phage-related insertions, and a cluster containing fimbria-related genes. We also conducted comparative genomic hybridization with 15 K. pneumoniae isolates obtained from community-acquired or nosocomial infections using tiling probes for the NTUH-K2044 genome. Hierarchical clustering revealed three major groups of genomic insertion-deletion patterns that correlate with the strains' clinical features, antimicrobial susceptibilities, and virulence phenotypes with mice. Here we report the whole-genome sequence of K. pneumoniae NTUH-K2044 and describe evidence showing significant genomic diversity and sequence acquisition among K. pneumoniae pathogenic strains. Our findings support the hypothesis that these factors are responsible for the changes that have occurred in the disease profile over time.

scholarly journals Adhesion Protein ApfA of Actinobacillus pleuropneumoniae Is Required for Pathogenesis and Is a Potential Target for Vaccine Development

2012 ◽  
Vol 20 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Yang Zhou ◽  
Lu Li ◽  
Zhaohui Chen ◽  
Hong Yuan ◽  
Huanchun Chen ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Actinobacillus Pleuropneumoniae ◽  
Etiologic Agent ◽  
Host Cells ◽  
Economic Losses ◽  
Mouse Lung ◽  
Content Type ◽  
Humoral Immune ◽  
Fimbrial Subunit ◽  
Type Iv

ABSTRACTActinobacillus pleuropneumoniaeis the etiologic agent of porcine pleuropneumonia, which causes serious economic losses in the pig farming industry worldwide. Due to a lack of knowledge of its virulence factors and a lack of effective vaccines able to confer cross-serotype protection, it is difficult to place this disease under control. By analyzing its genome sequences, we found that type IV fimbrial subunit protein ApfA is highly conserved among different serotypes ofA. pleuropneumoniae. Our study shows that ApfA is an adhesin since its expression was greatly upregulated (135-fold) upon contact with host cells, while its deletion mutant attenuated its capability of adhesion. The inactivation ofapfAdramatically reduced the ability ofA. pleuropneumoniaeto colonize mouse lung, suggesting thatapfAis a virulence factor. Purified recombinant ApfA elicited an elevated humoral immune response and conferred robust protection against challenges withA. pleuropneumoniaeserovar 1 strain 4074 and serovar 7 strain WF83 in mice. Importantly, the anti-ApfA serum conferred significant protection against both serovar 1 and serovar 7 in mice. These studies indicate that ApfA promotes virulence through attachment to host cells, and its immunogenicity renders it a promising novel subunit vaccine candidate against infection withA. pleuropneumoniae.

scholarly journals Burkholderia pseudomallei Capsular Polysaccharide Conjugates Provide Protection against Acute Melioidosis

2014 ◽  
Vol 82 (8) ◽  
pp. 3206-3213 ◽  
Author(s):  
Andrew E. Scott ◽  
Mary N. Burtnick ◽  
Margaret G. M. Stokes ◽  
Adam O. Whelan ◽  
E. Diane Williamson ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Capsular Polysaccharide ◽  
High Titer ◽  
Severe Disease ◽  
Lethal Dose ◽  
Survival Rates ◽  
Etiologic Agent ◽  
Content Type ◽  
Covalently Linked ◽  
Study Type

ABSTRACTBurkholderia pseudomallei, the etiologic agent of melioidosis, is a CDC tier 1 select agent that causes severe disease in both humans and animals. Diagnosis and treatment of melioidosis can be challenging, and in the absence of optimal chemotherapeutic intervention, acute disease is frequently fatal. Melioidosis is an emerging infectious disease for which there are currently no licensed vaccines. Due to the potential malicious use ofB. pseudomalleias well as its impact on public health in regions where the disease is endemic, there is significant interest in developing vaccines for immunization against this disease. In the present study, type A O-polysaccharide (OPS) andmanno-heptose capsular polysaccharide (CPS) antigens were isolated from nonpathogenic, select-agent-excluded strains ofB. pseudomalleiand covalently linked to carrier proteins. By using these conjugates (OPS2B1 and CPS2B1, respectively), it was shown that although high-titer IgG responses against the OPS or CPS component of the glycoconjugates could be raised in BALB/c mice, only those animals immunized with CPS2B1 were protected against intraperitoneal challenge withB. pseudomallei. Extending upon these studies, it was also demonstrated that when the mice were immunized with a combination of CPS2B1 and recombinantB. pseudomalleiLolC, rather than with CPS2B1 or LolC individually, they exhibited higher survival rates when challenged with a lethal dose ofB. pseudomallei. Collectively, these results suggest that CPS-based glycoconjugates are promising candidates for the development of subunit vaccines for immunization against melioidosis.

scholarly journals Binding of Actinobacillus pleuropneumoniae to Phosphatidylethanolamine

2003 ◽  
Vol 71 (8) ◽  
pp. 4657-4663 ◽  
Author(s):  
Marie-Eve Jeannotte ◽  
Maan Abul-Milh ◽  
J. Daniel Dubreuil ◽  
Mario Jacques
Keyword(s):  
Bacterial Colonization ◽  
Actinobacillus Pleuropneumoniae ◽  
Host Cells ◽  
Mass Spectrometry Analysis ◽  
Economic Losses ◽  
Respiratory Pathogens ◽  
Swine Industry ◽  
Molybdenum Blue ◽  
O Antigen ◽  
Serotype 1

ABSTRACT The gram-negative bacterium Actinobacillus pleuropneumoniae is the causative agent of porcine fibrinohemorrhagic necrotizing pleuropneumonia, a disease that causes important economic losses to the swine industry worldwide. In general, the initial step of bacterial colonization is attachment to host cells. The purpose of the present study was to evaluate the binding of A. pleuropneumoniae serotype 1 to phospholipids, which are the major constituents of biological membranes. Phospholipids serve as receptors for several bacteria, including respiratory pathogens. To study this effect, we used thin-layer chromatography overlay binding assays to test commercial phospholipids such as phosphatidic acid, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, and phosphatidylethanolamine (PE). Our results indicate that A. pleuropneumoniae serotype 1 binds to PE but not to the other phospholipids tested. Serotypes 5b and 7, which, along with serotype 1, are the most prevalent serotypes of A. pleuropneumoniae in North America, share the ability to bind PE. Inhibition of binding with a monoclonal antibody against A. pleuropneumoniae serotype 1 O antigen and the use of isogenic lipopolysaccharide (LPS) mutants of A. pleuropneumoniae serotype 1 showed that the O antigen seems to be implicated in the binding to PE, at least for A. pleuropneumoniae serotype 1. A. pleuropneumoniae was also shown to bind to a phospholipid extracted from swine lungs by using the method of Folch. Chemical staining with molybdenum blue and ninhydrin, migration with neutral, acidic, and basic solvent systems, and mass spectrometry analysis all indicated that this lipid is PE. This study is, to the best of our knowledge, the first description of A. pleuropneumoniae binding to phospholipids. Our data also suggest that LPS O antigens could be involved in binding to PE.

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