actinobacillus pleuropneumoniae

Actinobacillus pleuropneumoniae (App) is a globally distributed Gram-negative bacterium that produces porcine pleuropneumonia. This highly contagious disease produces high morbidity and mortality in the swine industry. However, no effective vaccine exists to prevent it. The infection caused by App provokes characteristic lesions, such as edema, inflammation, hemorrhage, and necrosis, that involve different virulence factors. The colonization and invasion of host surfaces involved structures and proteins such as outer membrane vesicles (OMVs), pili, flagella, adhesins, outer membrane proteins (OMPs), also participates proteases, autotransporters, and lipoproteins...

BACKGROUND: Emerging infectious diseases pose a significant threat to both human and animal populations. Rapid de novo identification of protective antigens from a clinical isolate and development of an antigen-matched vaccine is a golden strategy to prevent the spread of emerging novel pathogens. METHODS: Here, we focused on Actinobacillus pleuropneumoniae , which poses a serious threat to the pig industry, and developed a general workflow by integrating proteosurfaceomics, secretomics, and BacScan technologies for the rapid de novo identification of bacterial protective proteins from a clinical isolate...

AIMS: Structural cells play an important role in regulating immune cells during infection. Our aim was to determine whether structural porcine tracheal epithelial cells (PTECs) can regulate alveolar macrophages (AMs) to prevent bacterial pneumonia, explore the underlying mechanism(s) and therapeutic target. MATERIALS AND METHODS: Actinobacillus pleuropneumoniae (APP) was used as the model strain for infection studies. Small RNA sequencing was used to identify differentially abundant exosome-derived miRNAs...

Extracellular vesicle (EV) production by bacteria is an important mechanism for microbial communication and host-pathogen interaction. EVs of some bacterial species have been reported to contain nucleic acids. However, the role of small RNAs (sRNAs) packaged in EVs is poorly understood. Here, we report on the RNA cargo of EVs produced by the pig pathogen Actinobacillus pleuropneumoniae , the causal agent of porcine pleuropneumonia, a disease which causes substantial economic losses to the swine industry worldwide...

Monitoring the antimicrobial susceptibility of last-resource antimicrobials for veterinary pathogens is urgently needed from a one-health perspective. The objective of this study was to analyze the antimicrobial susceptibility trends of Spanish porcine bacteria to quinolones, cephalosporins, and polymyxins. Isolates of Actinobacillus pleuropneumoniae , Pasteurella multocida , and Escherichia coli were isolated from sick pigs from 2019 to 2022. An antimicrobial susceptibility test was determined based on the minimal inhibitory concentration (MIC) following an internationally accepted methodology...

Haemophilus parasuis ( H. parasuis, HPS) is a prominent pathogenic bacterium in pig production. Its infection leads to widespread fibrinous inflammation in various pig tissues and organs, often in conjunction with various respiratory virus infections, and leads to substantial economic losses in the pig industry. Therefore, the rapid diagnosis of this pathogen is of utmost importance. In this study, we used recombinase polymerase amplification (RPA) and clustered regularly interspaced short palindromic repeats (CRISPR) technology to establish a convenient detection and analysis system for H...

Actinobacillus pleuropneumoniae is an important swine respiratory pathogen causing substantial economic losses to the global pig industry. The Apx toxins of A. pleuropneumoniae belong to the RTX toxin family and are major virulence factors. In addition to hemolysis and/or cytotoxicity via pore-forming activity, RTX toxins, such as ApxIA of A. pleuropneumoniae, have been reported to cause other effects on target cells, e.g., apoptosis. A. pleuropneumoniae ApxIIA is expressed by most serotypes and has moderate hemolytic and cytotoxic activities...

AIMS: Swine respiratory disease (SRD) is a major disease complex in pigs that causes severe economic losses. SRD is associated with several intrinsic and extrinsic factors such as host health status, viruses, bacteria, and environmental factors. Particularly, it is known that many pathogens are associated with SRD to date, but most of test to detect those pathogens can be normally investigated only one pathogen while taking time and labor. Therefore, it is desirable to develop rapidly and efficiently detectable methods those pathogens to minimize the damage caused by SRD...

Antimicrobial resistance is an important health issue in human and veterinary medicine. The aim of this study was to monitor the antimicrobial resistance of three of the most important bacteria involved in porcine respiratory disease. A total of 465 isolates were tested during the 2017-2022 period for antimicrobial susceptibility for Actinobacillus pleuropneumoniae (n = 137), Streptococcus suis (n = 207), and Pasteurella multocida (n = 121) by disk diffusion method. The results were interpreted by CLSI breakpoints, where available...

The diagnostic workup of respiratory disease in pigs is complex due to coinfections and non-infectious causes. The detection of pathogens associated with respiratory disease is a pivotal part of the diagnostic workup for respiratory disease. We aimed to report how frequently certain viruses and bacteria were detected in samples from pigs with respiratory symptoms in the course of routine diagnostic procedures. Altogether, 1975 routine diagnostic samples from pigs in Austrian swine stocks between 2016 and 2021 were analysed...

A farm in North-West Germany experienced a high morbidity and mortality in their sow herd. Sows showed fever, lethargy, oedema, mucosal discharge and dyspnoea. Necropsy revealed a severe fibrinous and purulent polyserositis. Haematological and histological examinations confirmed septicaemia. Streptococcus equi subspecies zooepidemicus was isolated in high yields from major organs. Sequence typing of this isolate (21/455) revealed a new sequence type showing a significantly higher proliferation rate in comparison to two other isolates...

BACKGROUND: Antimicrobial resistance is one of the most important health challenges in humans and animals. Antibiotic susceptibility determination is used to select the most suitable drug to treat animals according to its success probability following the European legislation in force for these drugs. We have studied the antibiotic susceptibility pattern (ASP) of Actinobacillus pleuropneumoniae (APP) and Pasteurella multocida (PM) isolates, collected during the period 2019-2022 in Spain...

INTRODUCTION: Actinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on...

Formulating a therapeutic strategy that can effectively combat concurrent infections of Actinobacillus pleuropneumoniae ( A. pleuropneumoniae ) and Pasteurella multocida ( P. multocida ) can be challenging. This study aimed to 1) establish minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time kill curve, and post-antibiotic effect (PAE) of tylosin against A. pleuropneumoniae and P. multocida pig isolates and employ the MIC data for the development of epidemiological cutoff (ECOFF) values; 2) estimate the pharmacokinetics (PKs) of tylosin following its intramuscular (IM) administration (20 mg/kg) in healthy and infected pigs; and 3) establish a PK-pharmacodynamic (PD) integrated model and predict optimal dosing regimens and PK/PD cutoff values for tylosin in healthy and infected pigs...

N-Glycosyltransferase (NGT) is an inverting glycosyltransferase for an unusual pathway of N-linked protein glycosylation and glycosylates polypeptides in the consensus sequon (N-(X≠P)-T/S) with hexose monosaccharides. Here, we expressed and characterized a novel N-glycosyltransferase from Mannheimia haemolytica (named MhNGT). RP-HPLC and Mass Spectrometry were used to assay and quantify glycopeptide formation by MhNGT and determine its substrate specificities. MhNGT could utilize a variety of nucleotide-activated sugar donors, including UDP-Glc, UDP-Gal and UDP-Xyl, to glycosylate the tested peptides DANYTK, GGNWTT and PAVGNCSSALR with higher efficiency than ApNGT which was comprehensive studied...

We conducted whole-genome sequencing to investigate the serotypes, the presence of virulence and antimicrobial resistance genes, and the genetic relationships among isolates of Actinobacillus. pleuropneumoniae derived from diseased pigs. Serotype 2 (71.2%) was the most common, but the prevalence of serotypes 6 (13.6%) and 15 (6.8%) increased. Existing vaccines are considered ineffective on the isolates belonging to serotypes 6 and 15. The phylogenetic tree based on core genome single nucleotide polymorphisms showed that the isolates were clustered by serotype...

Due to the increase in bacterial resistance, improving the anti-infectious immunity of the host is rapidly becoming a new strategy for the prevention and treatment of bacterial pneumonia. However, the specific lung immune responses and key immune cell subsets involved in bacterial infection are obscure. Actinobacillus pleuropneumoniae (APP) can cause porcine pleuropneumonia, a highly contagious respiratory disease that has caused severe economic losses in the swine industry. Here, using high-dimensional mass cytometry, the major immune cell repertoire in the lungs of mice with APP infection was profiled...

The soluble N-glycosyltransferase from Actinobacillus pleuropneumoniae (ApNGT) can establish an N-glycosidic bond at the asparagine residue in the Asn-Xaa-Ser/Thr consensus sequon and is one of the most promising tools for N-glycoprotein production. Here, by integrating computational and experimental strategies, we revealed the molecular mechanism of the substrate recognition and following catalysis of ApNGT. These findings allowed us to pinpoint a key structural motif (215 DVYM218 ) in ApNGT responsible for the peptide substrate recognition...

Porcine respiratory disease complex (PRDC) has been a major animal health, welfare, and economic problem in Hungary; therefore, great emphasis should be put on both the prevention and control of this complex disease. As antibacterial agents are effective tools for control, antibiotic susceptibility testing is indispensable for the proper implementation of antibacterial therapy and to prevent the spread of resistance. The best method for this is to determine the minimum inhibitory concentration (MIC) by the broth microdilution method...

This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples were collected from 85 pig farms in Zhejiang Province and surrounding areas. In this study, samples were analyzed using bacterial isolation and purification, Gram staining, PCR amplification, and antimicrobial susceptibility testing. A total of 36 Pasteurella multocida ( Pm ) isolates were detected, with an isolation rate of 6.84%; 37 Bordetella bronchiseptica ( Bb ) isolates were detected, with an isolation rate of 7...