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Journal of Veterinary Science Mar 2020(APP) causes a form of porcine pleuropneumonia that leads to significant economic losses in the swine industry worldwide. The gene is responsible for the secretion of...
(APP) causes a form of porcine pleuropneumonia that leads to significant economic losses in the swine industry worldwide. The gene is responsible for the secretion of the ApxI and ApxII toxins and the gene is responsible for the adaptation of bacteria to cold temperature and a virulence factor. The and genes were deleted successfully from APP serotype 1 and 5 by transconjugation and sucrose counter-selection. The APP1ΔΔ and APP5ΔΔ mutants lost hemolytic activity and could not secrete ApxI and ApxII toxins outside the bacteria because both mutants lost the ApxI- and ApxII-secreting proteins by deletion of the gene. Besides, the growth of these mutants was defective at low temperatures resulting from the deletion of . The APP1ΔΔ and APP5ΔΔ mutants were significantly attenuated compared with wild-type ones. However, mice vaccinated intraperitoneally with APP5ΔΔ did not provide any protection when challenged with a 10-times 50% lethal dose of virulent homologous (APP5) and heterologous (APP1) bacterial strains, while mice vaccinated with APP1ΔΔ offered 75% protection against a homologous challenge. The ΔΔ mutants were significantly attenuated and gave different protection rate against homologous virulent wild-type APP challenging.
Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Female; Gene Deletion; Genes, Bacterial; Mice; Mice, Inbred BALB C; Serogroup; Vaccination
PubMed: 32233129
DOI: 10.4142/jvs.2020.21.e20 -
Journal of Veterinary Diagnostic... Jul 2020Two isolates from clinical cases of porcine pleuropneumonia in Japan were positive in the capsular serovar 15-specific PCR assay, but nontypeable (NT) in the agar gel...
Two isolates from clinical cases of porcine pleuropneumonia in Japan were positive in the capsular serovar 15-specific PCR assay, but nontypeable (NT) in the agar gel precipitation (AGP) test. Nucleotide sequence analysis of gene clusters involved in the biosynthesis of capsular polysaccharide (CPS) and lipopolysaccharide O-polysaccharide (O-PS) revealed that both clusters contained transposable element IS of belonging to the IS30 family. Immunoblot analysis revealed that these 2 isolates could not produce O-PS. We conclude that the IS of can interfere in the biosynthesis of both CPS and O-PS.
Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; DNA Transposable Elements; Genes, Bacterial; Immunoblotting; Multigene Family; Pleuropneumonia; Polymerase Chain Reaction; Polysaccharides; Swine; Swine Diseases
PubMed: 32517629
DOI: 10.1177/1040638720931469 -
Viruses Dec 2019and are two novel members of the family. These phages were isolated on cultures of the plant pathogen , known for its worldwide economic impact on potato crops....
and are two novel members of the family. These phages were isolated on cultures of the plant pathogen , known for its worldwide economic impact on potato crops. Transmission electron microscopy showed viral particles with double-layered icosahedral capsids, and frequent instances of protruding nanotubes harboring a collar-like structure. Mass-spectrometry confirmed the presence of lipids in the virion, and serial purification of colonies from turbid plaques and immunity testing revealed that both phages are temperate. and have linear dsDNA chromosomes (18,266 bp and 18,251 bp long, respectively) with the characteristic two-segment architecture of the . Both genomes encode homologs of the canonical tectiviral proteins (major capsid protein, packaging ATPase and DNA polymerase), as well as PRD1-type virion-associated transglycosylase and membrane DNA delivery proteins. Comparative genomics and phylogenetic analyses firmly establish that these two phages, together with , form a new genus within the , which we have tentatively named . The identification of a cohesive clade of Actinobacteria-infecting tectiviruses with conserved genome structure but with scant sequence similarity to members of other tectiviral genera confirms that the are an ancient lineage infecting a broad range of bacterial hosts.
Topics: Actinobacillus; Bacteriolysis; Computational Biology; DNA, Viral; Genome, Viral; Genomics; Host Specificity; Molecular Sequence Annotation; Phylogeny; Streptomyces; Tectiviridae
PubMed: 31817897
DOI: 10.3390/v11121134 -
Journal of Global Antimicrobial... Dec 2023The aim of this study was to characterize the floR-carrying plasmids originating from Glaesserella parasuis and Actinobacillus indolicus isolated from pigs with...
OBJECTIVES
The aim of this study was to characterize the floR-carrying plasmids originating from Glaesserella parasuis and Actinobacillus indolicus isolated from pigs with respiratory disease in China.
METHODS
A total of 125 G. parasuis and 28 A. indolicus strains collected between 2009 and 2022 were screened for florfenicol resistance. Characterization of floR-positive isolates and plasmids were determined by antimicrobial susceptibility testing, serotyping, multilocus sequence typing (MLST), conjugation and transformation assays, whole-genome sequencing (WGS), and phylogenetic analysis.
RESULTS
One A. indolicus and six G. parasuis were identified as positive for floR. The six G. parasuis were assigned to four different serovars, including serovars 6, 7, 9, and unknown. In addition to strain XP11, six floR genes were located on plasmids. The six floR-bearing plasmids could be transformed into Pasteurella multocida and divided into two different types, including ∼5000 bp and ∼6000 bp plasmids. The ∼5000 bp plasmids consisting of rep, lysR, mobB, and floR genes, exhibited high similarity among Pasteurellaceae bacteria. Furthermore, the ∼6000 bp plasmids, consisting of rep, lysR, mobC, mobA/L, and floR genes, showed high similarity between G. parasuis and Actinobacillus Spp. Notably, WGS results showed that the floR modules of the two types of plasmids could be transferred and integrated into the diverse Pasteurellaceae- origined plasmids.
CONCLUSION
This study firstly reported the characterization of floR-carrying plasmids from A. indolicus and a non-virulent serovar of G. parasuis in pigs in China and elucidated the transmission mechanism of the floR resistance gene among the Pasteurellaceae family.
Topics: Animals; Swine; Anti-Bacterial Agents; Multilocus Sequence Typing; Phylogeny; Plasmids; Actinobacillus
PubMed: 37726088
DOI: 10.1016/j.jgar.2023.09.009 -
Genomics Jan 2019Actinobacillus spp. are Gram-negative bacteria associated with mucosal membranes. While some are commensals, others can cause important human and animal diseases. A....
Actinobacillus spp. are Gram-negative bacteria associated with mucosal membranes. While some are commensals, others can cause important human and animal diseases. A. pleuropneumoniae causes severe fibrinous hemorrhagic pneumonia in swine but not systemic disease whereas other species invade resulting in septicemia and death. To understand the invasive phenotype of Actinobacillus spp., complete genomes of eight isolates were obtained and pseudogenomes of five isolates were assembled and annotated. Phylogenetically, A. suis isolates clustered by surface antigen type and were more closely related to the invasive A. ureae, A. equuli equuli, and A. capsulatus than to the other swine pathogen, A. pleuropneumoniae. Using the LS-BSR pipeline, 251 putative virulence genes associated with serum resistance and invasion were detected. To our knowledge, this is the first genome-wide study of the genus Actinobacillus and should contribute to a better understanding of host tropism and mechanisms of invasion of pathogenic Actinobacillus and related genera.
Topics: Actinobacillus; Animals; Gene Rearrangement; Genetic Variation; Genome-Wide Association Study; Genomics; Host Specificity; N-Acetylneuraminic Acid; Neuraminidase; Phenotype; Phylogeny; Pseudogenes; Sequence Inversion; Serine Endopeptidases; Swine; Type V Secretion Systems; Virulence; Whole Genome Sequencing
PubMed: 29317305
DOI: 10.1016/j.ygeno.2018.01.001 -
Microbial Genomics Apr 2022is a causative agent of pleuropneumonia in pigs of all ages. . is divided into 19 serovars based on capsular polysaccharides (CPSs) and lipopolysaccharides. The...
is a causative agent of pleuropneumonia in pigs of all ages. . is divided into 19 serovars based on capsular polysaccharides (CPSs) and lipopolysaccharides. The serovars of isolates are commonly determined by serological tests and multiplex PCR. This study aimed to develop a genomic approach for typing by screening for the presence of the species-specific gene in whole-genome sequencing (WGS) reads and identifying capsule locus (KL) types in genome assemblies. A database of the . KL, including CPS synthesis and CPS export genes, was established and optimized for Kaptive. To test the developed genomic approach, WGS reads of 189 . isolates and those of 66 samples from 14 other bacterial species were analysed. ariba analysis showed that was detected in all 189 . samples. These -positive WGS reads were assembled into genome assemblies and assessed. A total of 105 . genome assemblies that passed the quality assessment were analysed by Kaptive analysis against the . KL database. The results showed that 97 assemblies were classified and predicted as 13 serovars, which matched the serovar information obtained from the literature. The six genome assemblies from previously nontypable isolates were typed and predicted as serovars 17 and 18. Notably, one of the two “” samples was positive, and its genome assembly was typed as KL03 with high identity and predicted as . serovar 3. Collectively, a genomic approach was established and could accurately determine the KL type of . isolates using WGS reads. This approach can be used with high-quality genome assemblies for predicting . serovars and for retrospective analysis.
Topics: Actinobacillus pleuropneumoniae; Animals; Serogroup; Serotyping; Swine; Swine Diseases
PubMed: 35404221
DOI: 10.1099/mgen.0.000780 -
International Journal of Molecular... Sep 2021is a pathogen that infects pigs and poses a serious threat to the pig industry. The emergence of quinolone-resistant strains of further limits the choice of treatment....
is a pathogen that infects pigs and poses a serious threat to the pig industry. The emergence of quinolone-resistant strains of further limits the choice of treatment. However, the mechanisms behind quinolone resistance in remain unclear. The genomes of a ciprofloxacin-resistant strain, SC1810 and its isogenic drug-sensitive counterpart were sequenced and analyzed using various bioinformatics tools, revealing 559 differentially expressed genes. The biological membrane, plasmid-mediated quinolone resistance genes and quinolone resistance-determining region were detected. Upregulated expression of efflux pump genes led to ciprofloxacin resistance. The expression of two porins, OmpP2B and LamB, was significantly downregulated in the mutant. Three nonsynonymous mutations in the mutant strain disrupted the water-metal ion bridge, subsequently reducing the affinity of the quinolone-enzyme complex for metal ions and leading to cross-resistance to multiple quinolones. The mechanism of quinolone resistance in may involve inhibition of expression of the outer membrane protein genes and to decrease drug influx, overexpression of AcrB in the efflux pump to enhance its drug-pumping ability, and mutation in the quinolone resistance-determining region to weaken the binding of the remaining drugs. These findings will provide new potential targets for treatment.
Topics: Actinobacillus pleuropneumoniae; Biofilms; Porins; Quinolones; Transcriptome
PubMed: 34576206
DOI: 10.3390/ijms221810036 -
Journal of Veterinary Pharmacology and... Oct 2017Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules of oxytetracycline for two pig pneumonia pathogens,...
Pharmacokinetic/pharmacodynamic integration and modelling of oxytetracycline for the porcine pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida.
Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules of oxytetracycline for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) were determined in broth and porcine serum. PK/PD integration established ratios of average concentration over 48 h (C )/MIC of 5.87 and 0.27 μg/mL (P. multocida) and 0.70 and 0.85 μg/mL (A. pleuropneumoniae) for broth and serum MICs, respectively. PK/PD modelling of in vitro time-kill curves established broth and serum breakpoint values for area under curve (AUC )/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4 log reductions in bacterial count. Doses were then predicted for each pathogen, based on Monte Carlo simulations, for: (i) bacteriostatic and bactericidal levels of kill; (ii) 50% and 90% target attainment rates (TAR); and (iii) single dosing and daily dosing at steady-state. For 90% TAR, predicted daily doses at steady-state for bactericidal actions were 1123 mg/kg (P. multocida) and 43 mg/kg (A. pleuropneumoniae) based on serum MICs. Lower TARs were predicted from broth MIC data; corresponding dose estimates were 95 mg/kg (P. multocida) and 34 mg/kg (A. pleuropneumoniae).
Topics: Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Dose-Response Relationship, Drug; Microbial Sensitivity Tests; Oxytetracycline; Pasteurella multocida; Pneumonia; Swine
PubMed: 28090673
DOI: 10.1111/jvp.12385 -
The Journal of Veterinary Medical... May 2022The species of the genus Actinobacillus have so far been associated with specific animal hosts, and A. suis sensu stricto, an opportunistic pathogen of swine, is rarely...
The species of the genus Actinobacillus have so far been associated with specific animal hosts, and A. suis sensu stricto, an opportunistic pathogen of swine, is rarely isolated from ruminants. We describe here the isolation of A. suis sensu stricto from a newborn calf that died on a dairy farm in Japan. Identification of the isolate was performed by phenotypic and genotypic characterization, with the latter consisting of nucleotide sequence analyses of the 16S rRNA gene plus three housekeeping genes, rpoB, infB and recN.
Topics: Actinobacillus; Actinobacillus Infections; Actinobacillus suis; Animals; Phylogeny; RNA, Ribosomal, 16S; Swine; Swine Diseases
PubMed: 35387957
DOI: 10.1292/jvms.22-0044 -
Microbial Pathogenesis Nov 2022Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite the extensive number of studies...
Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, a thorough analysis of the A. pleuropneumoniae exoproteome is still missing. Using a complementary approach of quantitative proteomics and immunoproteomics we gained an in-depth insight into the A. pleuropneumoniae serotype 2 exoproteome, which provides the basis for future functional studies. Label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed 593 exoproteins, of which 104 were predicted to be virulence factors. The RTX toxins ApxIIA and ApxIIIA -were found to be the most abundant proteins in the A. pleuropneumoniae serotype 2 exoproteome. Furthermore, the ApxIVA toxin was one of the proteins showing the highest abundance, although ApxIVA is commonly assumed to be expressed exclusively in vivo. Our study revealed several antigens, including proteins with moonlight functions, such as the elongation factor (EF)-Tu, and proteins linked to specific metabolic traits, such as the maltodextrin-binding protein MalE, that warrant future functional characterization and might present potential targets for novel therapeutics and vaccines. Our Ig-classes specific serological proteome analysis (SERPA) approach allowed us to explore the development of the host humoral immune response over the course of the infection. These SERPAs pinpointed proteins that might play a key role in virulence and persistence and showed that the immune response to the different Apx toxins is distinct. For instance, our results indicate that the ApxIIIA toxin has properties of a thymus-independent antigen, which should be studied in more detail.
Topics: Swine; Animals; Actinobacillus pleuropneumoniae; Pleuropneumonia; Actinobacillus Infections; Proteomics; Proteome; Antigens, T-Independent; Chromatography, Liquid; Swine Diseases; Bacterial Proteins; Tandem Mass Spectrometry; Mycoplasma; Virulence Factors; Peptide Elongation Factors
PubMed: 36087692
DOI: 10.1016/j.micpath.2022.105759