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Journal of Veterinary Internal Medicine Mar 2020There are limited data on potential dysbiosis of the airway microbiota in horses with asthma.
BACKGROUND
There are limited data on potential dysbiosis of the airway microbiota in horses with asthma.
HYPOTHESIS/OBJECTIVES
We hypothesized that the respiratory microbiota of horses with moderate asthma is altered. Our objectives were (a) to quantify tracheal bacterial populations using culture and qPCR, (2) to compare aerobic culture and qPCR, and (c) to correlate bacterial populations with bronchoalveolar lavage fluid (BALF) cytology.
ANIMALS
Eighteen horses with moderate asthma from a hospital population and 10 controls.
METHODS
Prospective case-control study. Aerobic culture was performed on tracheal aspirates, and streptococci, Pasteurella multocida, Chlamydophila spp., Mycoplasma spp., as well as 16S (bacterial) and 18S (fungal) rRNA subunits were quantified by qPCR.
RESULTS
Potential pathogens such as Streptococcus spp., Actinobacillus spp., and Pasteurellaceae were isolated from 8, 5, and 6 horses with asthma and 3, 0, and 2 controls, respectively. There was a positive correlation between Streptococcus spp. DNA and 16S rRNA gene (r ≥ 0.7, P ≤ 0.02 in both groups), but the overall bacterial load (16S) was lower in asthma (1.5 ± 1.3 versus 2.5 ± 0.8 × 10 copy/μL, P < 0.05). There was no association between microbial populations and clinical signs, tracheal mucus or BALF inflammation.
CONCLUSIONS AND CLINICAL IMPORTANCE
This study does not support that bacterial overgrowth is a common feature of chronic moderate asthma in horses. Lower bacterial load could suggest dysbiosis of the lower airways, either as a consequence of chronic inflammation or previous treatments, or as a perpetuating factor of inflammation.
Topics: Actinobacillus; Animals; Asthma; Bronchoalveolar Lavage Fluid; Case-Control Studies; Female; Horse Diseases; Horses; Male; Pasteurellaceae; Prospective Studies; Streptococcus; Trachea
PubMed: 31985115
DOI: 10.1111/jvim.15707 -
Animals : An Open Access Journal From... Apr 2023Porcine Respiratory Diseases Complex (PRDC) is a multifactorial disease that involves several bacterial pathogens, including , , , , and In pigs, the infection may...
Porcine Respiratory Diseases Complex (PRDC) is a multifactorial disease that involves several bacterial pathogens, including , , , , and In pigs, the infection may cause lesions such pleurisy, which can lead to carcass condemnation. Hence, 1015 carcasses were selected from three different commercial pig farms, where the respiratory conditions were evaluated using slaughterhouse pleurisy evaluation system (SPES) and classified into five groups. In total, 106 pleural and lung fragments were collected for qPCR testing to identify the five abovementioned pathogens. A moderate correlation between the severity of the lesions and the presence of (R = 0.38) and (R = 0.28) was observed. Concerning the lung samples, the severity of the lesions was moderately correlated with the presence of (R = 0.43) and (R = 0.35). Moreover, there was a strong correlation between the presence of and in the pleura (R = 0.82). Finally, this approach may be a useful tool to identify and quantify causative agents of PRDC using qPCR, providing a comprehensive evaluation of its relevance, strength, and potential application in the field as a surveillance tool for veterinarians.
PubMed: 37174529
DOI: 10.3390/ani13091493 -
The Canadian Veterinary Journal = La... Dec 2020Medical records of 20 horses with a confirmed diagnosis of valvular endocarditis at the Ontario Veterinary College between January 1, 1993 and February 3, 2020 were...
Medical records of 20 horses with a confirmed diagnosis of valvular endocarditis at the Ontario Veterinary College between January 1, 1993 and February 3, 2020 were reviewed. The diagnosis was based on physical examination findings, complete blood (cell) count (CBC), serum biochemistry, echocardiography, blood culture, and post-mortem findings. Common presenting signs included tachycardia, pyrexia, weight loss, lameness/joint distension, and a heart murmur. Clinicopathological findings included leukocytosis, anemia, hypoalbuminemia, hyperglobulinemia, and elevated inflammatory markers. Culture from 5 horses yielded in 2 cases and in 1 case. Of the 20 horses included in this study, 17 were euthanized and 3 were treated. Only 1 case had follow-up more than 1 year after discharge.
Topics: Animals; Echocardiography; Endocarditis; Euthanasia, Animal; Horse Diseases; Horses; Ontario
PubMed: 33299245
DOI: No ID Found -
The Journal of Biological Chemistry Aug 2014N-Linked protein glycosylation is a very common post-translational modification that can be found in all kingdoms of life. The classical, highly conserved pathway...
N-Linked protein glycosylation is a very common post-translational modification that can be found in all kingdoms of life. The classical, highly conserved pathway entails the assembly of a lipid-linked oligosaccharide and its transfer to an asparagine residue in the sequon NX(S/T) of a secreted protein by the integral membrane protein oligosaccharyltransferase. A few species in the class of γ-proteobacteria encode a cytoplasmic N-glycosylation system mediated by a soluble N-glycosyltransferase (NGT). This enzyme uses nucleotide-activated sugars to modify asparagine residues with single monosaccharides. As these enzymes are not related to oligosaccharyltransferase, NGTs constitute a novel class of N-glycosylation catalyzing enzymes. To characterize the NGT-catalyzed reaction, we developed a sensitive and quantitative in vitro assay based on HPLC separation and quantification of fluorescently labeled substrate peptides. With this assay we were able to directly quantify glycopeptide formation by Actinobacillus pleuropneumoniae NGT and determine its substrate specificities: NGT turns over a number of different sugar donor substrates and allows for activation by both UDP and GDP. Quantitative analysis of peptide substrate turnover demonstrated a strikingly similar specificity as the classical, oligosaccharyltransferase-catalyzed N-glycosylation, with NX(S/T) sequons being the optimal NGT substrates.
Topics: Amino Acid Sequence; Bacterial Proteins; Cytoplasm; Glucosyltransferases; Glycosylation; Hydrolysis; Kinetics; Molecular Sequence Data; Nuclear Magnetic Resonance, Biomolecular; Proton Magnetic Resonance Spectroscopy; Sequence Homology, Amino Acid; Substrate Specificity
PubMed: 24962585
DOI: 10.1074/jbc.M114.579326 -
Toxins Oct 2014The cytolethal distending toxin (Cdt) is a heterotrimeric holotoxin produced by a diverse group of Gram-negative pathogenic bacteria. The Cdts expressed by the members... (Review)
Review
The cytolethal distending toxin (Cdt) is a heterotrimeric holotoxin produced by a diverse group of Gram-negative pathogenic bacteria. The Cdts expressed by the members of this group comprise a subclass of the AB toxin superfamily. Some AB toxins have hijacked the retrograde transport pathway, carried out by the Golgi apparatus and endoplasmic reticulum (ER), to translocate to cytosolic targets. Those toxins have been used as tools to decipher the roles of the Golgi and ER in intracellular transport and to develop medically useful delivery reagents. In comparison to the other AB toxins, the Cdt exhibits unique properties, such as translocation to the nucleus, that present specific challenges in understanding the precise molecular details of the trafficking pathway in mammalian cells. The purpose of this review is to present current information about the mechanisms of uptake and translocation of the Cdt in relation to standard concepts of endocytosis and retrograde transport. Studies of the Cdt intoxication process to date have led to the discovery of new translocation pathways and components and most likely will continue to reveal unknown features about the mechanisms by which bacterial proteins target the mammalian cell nucleus. Insight gained from these studies has the potential to contribute to the development of novel therapeutic strategies.
Topics: Aggregatibacter actinomycetemcomitans; Animals; Bacterial Proteins; Bacterial Toxins; Cell Nucleus; Cell Survival; Endocytosis; Endoplasmic Reticulum; Golgi Apparatus; Humans; Mammals; Models, Biological; Protein Subunits; Protein Transport; Species Specificity
PubMed: 25365527
DOI: 10.3390/toxins6113098 -
Microbiology Spectrum Oct 2022Outer membrane vesicles (OMVs) are spontaneously released by Gram-negative bacteria, including Actinobacillus pleuropneumoniae, which causes contagious pleuropneumonia...
Outer membrane vesicles (OMVs) are spontaneously released by Gram-negative bacteria, including Actinobacillus pleuropneumoniae, which causes contagious pleuropneumonia in pigs and leads to considerable economic losses in the swine industry worldwide. A. pleuropneumoniae OMVs have previously been demonstrated to contain Apx toxins and proteases, as well as antigenic proteins. Nevertheless, comprehensive characterizations of their contents and interactions with host immune cells have not been made. Understanding the protein compositions and immunomodulating ability of A. pleuropneumoniae OMVs could help illuminate their biological functions and facilitate the development of OMV-based applications. In the current investigation, we comprehensively characterized the proteome of native A. pleuropneumoniae OMVs. Moreover, we qualitatively and quantitatively compared the OMV proteomes of a wild-type strain and three mutant strains, in which relevant genes were disrupted to increase OMV production and/or produce OMVs devoid of superantigen PalA. Furthermore, the interaction between A. pleuropneumoniae OMVs and porcine alveolar macrophages was also characterized. Our results indicate that native OMVs spontaneously released by A. pleuropneumoniae MIDG2331 appeared to dampen the innate immune responses by porcine alveolar macrophages stimulated by either inactivated or live parent cells. The findings suggest that OMVs may play a role in manipulating the porcine defense during the initial phases of the A. pleuropneumoniae infection. Owing to their built-in adjuvanticity and antigenicity, bacterial outer membrane vesicles (OMVs) are gaining increasing attention as potential vaccines for both human and animal use. OMVs released by Actinobacillus pleuropneumoniae, an important respiratory pathogen in pigs, have also been investigated for vaccine development. Our previous studies have shown that A. pleuropneumoniae secretes OMVs containing multiple immunogenic proteins. However, immunization of pigs with these vesicles was not able to relieve the pig lung lesions induced by the challenge with A. pleuropneumoniae, implying the elusive roles that A. pleuropneumoniae OMVs play in host-pathogen interaction. Here, we showed that A. pleuropneumoniae secretes OMVs whose yield and protein content can be altered by the deletion of the and genes. Furthermore, we demonstrate that A. pleuropneumoniae OMVs dampen the immune responses in porcine alveolar macrophages stimulated by A. pleuropneumoniae cells, suggesting a novel mechanism that A. pleuropneumoniae might use to evade host defense.
Topics: Animals; Actinobacillus Infections; Actinobacillus pleuropneumoniae; Bacterial Outer Membrane Proteins; Bacterial Vaccines; Immunity; Macrophages, Alveolar; Peptide Hydrolases; Pleuropneumonia; Proteome; Superantigens; Swine
PubMed: 36040198
DOI: 10.1128/spectrum.01819-22 -
ACS Omega May 2021Glycoproteins are post-translationally modified proteins that take part in nearly every biological process and make up a large percent of the proteome. N-Linked...
Glycoproteins are post-translationally modified proteins that take part in nearly every biological process and make up a large percent of the proteome. N-Linked glycosylation can be performed by -glycosyltransferase (NGT), which recognizes the consensus amino acid sequence, -Asn-X-Ser/Thr- (NXT), within the protein. The enzyme catalyzes glycosidic bond formation between the oligosaccharide donor, containing nucleoside phosphatase, and the amide nitrogen of the asparagine residue. The attachment of the sugar moiety can influence physiological and biological properties of the protein by affecting their folding, modulating interactions with other biomolecules, and modifying their functions at the cellular level. We are specifically interested in the properties of membrane glycoproteins, which are key components in a number of different disease states. Therefore, the use of protein glycosylation can help further evaluate the effects of the properties for these important macromolecules. studies of N-linked glycosylation were done in a stepwise fashion in a membrane-mimetic environment to confirm that the methods for glycosylating soluble proteins could be applicable to membrane proteins. Detergent and lipid systems were used since hydrophobic peptides and membrane proteins are insoluble in aqueous solvents. The stepwise method consisted of the glycosylation of a soluble 7-residue peptide, a hydrophobic WALP-NVT peptide, and a γ-sarcoglycan membrane protein, all of which contained the glycosylation site Asn-Val-Thr (NVT). Glycosylation of the samples was performed using -expressed NGT from the genome, and a single sugar moiety of glucose, provided from a nucleotide-linked donor, was added to the glycosylation site. Gel electrophoresis, mass spectrometry, and NMR studies were used for the detection of glycosyltransferase activity and to show the attachment of a single glucose molecule. Our experiments demonstrated that small or large membrane proteins that contain an N-glycosylation consensus sequence can be glycosylated by NGT in membrane-mimetic environments.
PubMed: 34056367
DOI: 10.1021/acsomega.1c00835 -
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 -
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 -
International Journal of Molecular... Jul 2023(APP) is the causative pathogen of porcine pleuropneumonia, a highly contagious respiratory disease in the pig industry. The increasingly severe antimicrobial...
(APP) is the causative pathogen of porcine pleuropneumonia, a highly contagious respiratory disease in the pig industry. The increasingly severe antimicrobial resistance in APP urgently requires novel antibacterial alternatives for the treatment of APP infection. In this study, we investigated the effect of tea polyphenols (TP) against APP. MIC and MBC of TP showed significant inhibitory effects on bacteria growth and caused cellular damage to APP. Furthermore, TP decreased adherent activity of APP to the newborn pig tracheal epithelial cells (NPTr) and the destruction of the tight adherence junction proteins β-catenin and occludin. Moreover, TP improved the survival rate of APP infected mice but also attenuated the release of the inflammation-related cytokines IL-6, IL-8, and TNF-α. TP inhibited activation of the TLR/MAPK/PKC-MLCK signaling for down-regulated TLR-2, TLR4, p-JNK, p-p38, p-PKC-α, and MLCK in cells triggered by APP. Collectively, our data suggest that TP represents a promising therapeutic agent in the treatment of APP infection.
Topics: Animals; Swine; Mice; Pleuropneumonia; Actinobacillus pleuropneumoniae; Toll-Like Receptor 4; Actinobacillus; Tight Junctions; Lung; Actinobacillus Infections; Mycoplasma Infections; Tea; Swine Diseases
PubMed: 37511601
DOI: 10.3390/ijms241411842