Critical assessment of commercially available microtitre panels for antimicrobial susceptibility testing of veterinary pathogens.

Antimicrobial susceptibility testing (AST) in the veterinary sector by broth microdilution is mainly based on commercially available microtitre plates with specific panels. A critical review of commercially available microtitre panels identified AST panels that fulfil the requirements for obtaining reliable AST results by covering the necessary antimicrobial concentrations for both clinical breakpoints as well as quality control (QC) ranges for approved QC strains. However, there are AST panels in which these prerequisites are only in part fulfilled, and some AST panels that do not fulfil the aforementioned criteria at all.

Characterization of class-switched B cells in chickens.

While B cell development in the birds' primary B cell organ, the bursa Fabricius, is relatively well understood, very little is known about post bursal B cell differentiation into plasma and memory cells though these cells are essential for a protecting antibody response and so far, no specific markers for these cells were available. Since immunoglobulin class switch is one part of the B cell differentiation process, our objective was to conduct a first detailed investigation of class-switched chicken B cells. As only very few IgY and IgA expressing cells were detected in lymphoid organs of young chickens, we used CD40L and IL-10 to establish a prolonged culture system, which induces B cell proliferation, class switch to IgY and IgA and enhanced antibody secretion.

Vaccination strategies to protect chickens from fowl adenovirus (FAdV)-induced diseases: A comprehensive review.

In recent years, fowl adenovirus (FAdV)-induced diseases became a global problem with considerable impact on chicken health and welfare. This has prompted numerous studies to focus on experimental immunization strategies using whole virus formulations (live or killed vaccines), some of them modified as recombinantly constructed vector vaccines. In addition, FAdV capsid proteins were frequently reported as immunizing antigens (subunit vaccines), with fiber proteins being amongst the most successful candidates.

Diametral influence of deoxynivalenol (DON) and deepoxy-deoxynivalenol (DOM-1) on the growth of Campylobacter jejuni with consequences on the bacterial transcriptome.

Background: Deoxynivalenol (DON) is a type B trichothecene mycotoxin that is commonly found in cereals and grains worldwide. The presence of this fungal secondary-metabolite raises public-health concerns at both the agriculture and food industry level. Recently, we have shown that DON has a negative impact on gut integrity, a feature also noticed for Campylobacter (C.

Influence of biosecurity on the occurrence of various enteric viruses in broiler flocks.

Detection timepoints and patterns indicate horizontal introduction of various enteric viruses.Flock infection profiles were very heterogeneous; no dominating virus profile.Broiler production was negatively affected by the number of enteric viruses detected.

A systematic review on the role of biosecurity to prevent or control colibacillosis in broiler production.

This systematic review aimed at investigating the role that biosecurity can have in preventing or controlling colibacillosis in broiler production. Primary studies with natural or experimental exposure to avian pathogenic Escherichia coli, evaluating any biosecurity measure to prevent or control colibacillosis in broiler chickens with at least one of the following outcomes: feed conversion ratio (FCR), condemnations at slaughter, and mortality due to colibacillosis, were included. A systematic search was carried out in 4 databases according to the Cochrane handbook and reported following the PRISMA 2020 directions.

In vitro investigations on interference of selected probiotic candidates with Campylobacter jejuni adhesion and invasion of primary chicken derived cecal and Caco-2 cells.

Background: Campylobacter (C.) jejuni is one of the most important bacterial foodborne pathogens worldwide. Probiotics such as Lactobacillus or Bacillus species are considered one option for reducing the colonization rate and magnitude in poultry, the most frequent source of human infections.

The Evolution of Transglutaminases Underlies the Origin and Loss of Cornified Skin Appendages in Vertebrates.

Transglutaminases (TGMs) cross-link proteins by introducing covalent bonds between glutamine and lysine residues. These cross-links are essential for epithelial cornification which enables tetrapods to live on land. Here, we investigated which evolutionary adaptations of vertebrates were associated with specific changes in the family of TGM genes.

A comprehensive study of colisepticaemia progression in layer chickens applying novel tools elucidates pathogenesis and transmission of Escherichia coli into eggs.

Colisepticaemia caused by avian pathogenic Escherichia coli (APEC) is a challenging disease due to its high economic importance in poultry, dubious pathogenesis and potential link with zoonosis and food safety. The existing in vitro studies can't define hallmark traits of APEC isolates, suggesting a paradigm shift towards host response to understand pathogenesis. This study investigated the comprehensive pathological and microbial progression of colisepticaemia, and transmission of E.

Factors associated with keel bone damage - a longitudinal study of commercial layer flocks during the laying period.

1. Keel bone damage, such as deformations and fractures, is a severe problem regarding animal welfare in layers. To identify risk factors under commercial conditions, 33 layer flocks (22 barn, 11 free range) with white ( = 18), brown ( = 11) and mixed ( = 4) genotypes were examined.

Detection of to identify persistently contaminated locations using faecal and environmental samples in broiler houses of clinically healthy flocks.

Worldwide outbreaks make infections with pathogenic strains of (EC) one of the most important diseases in the broiler industry. Although research has increased knowledge about the pathogen, the transmission is not fully understood. Samples from different locations were collected from two broiler farms in Germany over a total of six production cycles.

A systematic review and meta-analysis on the efficacy of vaccination against colibacillosis in broiler production.

Colibacillosis, a disease caused by Escherichia coli in broiler chickens has serious implications on food safety, security, and economic sustainability. Antibiotics are required for treating the disease, while vaccination and biosecurity are used for its prevention. This systematic review and meta-analysis, conducted under the COST Action CA18217-European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), aimed to assess the efficacy of E.

Recommendation of a standardized broth microdilution method for antimicrobial susceptibility testing of and resistance monitoring.

Unlabelled: This study aimed to develop a method for standardized broth microdilution antimicrobial susceptibility testing (AST) of (.) , the causative agent of infectious coryza in chickens. For this, a total of 83 isolates and strains were collected from 15 countries.

GWAS and comparative genomics reveal candidate antibiotic resistance genes in the avian pathogen Gallibacterium anatis for six widespread antibiotics.

Gallibacterium anatis is a Gram-negative bacterium found in the respiratory and genital tracts of various animals, primarily poultry. Its association with septicemia and high mortality in poultry, along with the rise in multidrug-resistant strains, has amplified concerns. Recent research uncovered significant variability in antibiotic resistance profiles among G.

Vaccination Technology in Poultry: Principles of Vaccine Administration.

Poultry vaccines are very important tools for disease prevention and may be administered collectively by drinking water or spray or individually by injection or oculonasal drop, whereas inactivated vaccines are administered by injection only. Poultry vaccines are increasingly delivered at the hatchery to day-old chicks or , because mass vaccination is much more efficiently implemented and controlled at the hatchery than on the farm. Mass administration on the farm by drinking water or spray requires strict compliance with guidelines regarding water quality, preparation of vaccines, and application, so as to cover the whole flock.

The Immunological Basis for Vaccination.

Vaccination is crucial for health protection of poultry and therefore important to maintaining high production standards. Proper vaccination requires knowledge of the key players of the well-orchestrated immune system of birds, their interdependence and delicate regulation, and, subsequently, possible modes of stimulation through vaccine antigens and adjuvants. The knowledge about the innate and acquired immune systems of birds has increased significantly during the recent years but open questions remain and have to be elucidated further.

Association Between Load in the Gut and Body Weight Gain in Broiler Chickens: A Systematic Review and Meta-Analysis.

is one of the first commensal bacteria to colonize the chicken gut, where it predominates at an early stage of broiler chick life can potentially cause colibacillosis in chickens, spreading to extraintestinal systemic organs, which results in high economic losses in poultry industry, as well as a potential risk to public health. Many studies conducted to investigate the effectiveness of natural products as alternatives to antibiotics and to enhance the production performance in broiler chickens have assessed load in the chicken gut, but it is still unknown how the count is linked to broiler growth performance. A systematic search of published research articles, including key terms of interest such as broiler chickens, growth performance, and count, was conducted using two main databases (PubMed and the Web of Science).

Serological monitoring of Enterococcus cecorum specific antibodies in chickens.

Pathogenic Enterococcus cecorum (EC) has gained increasing importance as the cause of skeletal infections in meat-type chicken production. Since effective intervention strategies are scarce, it must be focused on preventive measures. Vaccination of meat-type breeder chicken flocks is common practice to protect the progeny against infection with EC.

Research Note: Preliminary results, first detection of Enterococcus cecorum from environmental samples by streaking on X-Gluc containing selective media.

The isolation of cultivable E. cecorum from the environment of poultry houses remains a challenge. Environmental samples (dust wipes, equipment swabs, pooled feces) and samples from culled bird vertebras were collected from an infected broiler flock on d 37 posthatching.

H-NMR based-metabolomics reveals alterations in the metabolite profiles of chickens infected with ascarids and concurrent histomonosis infection.

Background: Gut infections of chickens caused by Ascaridia galli and Heterakis gallinarum are associated with impaired host performance, particularly in high-performing genotypes. Heterakis gallinarum is also a vector of Histomonas meleagridis that is often co-involved with ascarid infections. Here, we provide a first insight into the alteration of the chicken plasma and liver metabolome as a result of gastrointestinal nematode infections with concomitant histomonosis.

Antimicrobial Peptides (AMP) in the Cell-Free Culture Media of and Exert Anti-Protist Activity against Eukaryotic Vertebrate Pathogens including and Species.

Anti-microbial peptides provide a powerful toolkit for combating multidrug resistance. Combating eukaryotic pathogens is complicated because the intracellular drug targets in the eukaryotic pathogen are frequently homologs of cellular structures of vital importance in the host organism. The entomopathogenic bacteria (EPB), symbionts of entomopathogenic-nematode species, release a series of non-ribosomal templated anti-microbial peptides.

Distribution of importin-α isoforms in poultry species and their tissue- and age-related differences.

While importin-α is well studied in mammals, the knowledge in avian species is still limited. In this study, we compared the mRNA expression patterns of five importin-α isoforms in the respiratory tract, liver, and spleen of chickens, turkeys, and pekin ducks in two different age-groups. In addition, we determined the distribution of importin-α in selected tissue of conchae, trachea, and lung of post-hatch chickens at all cellular levels by immunohistochemical staining.

Investigation of Spotty Liver Disease and in Layer Flocks-A Field Study.

() was recently discovered as the causative agent of Spotty Liver Disease (SLD). SLD affects laying hens and causes significant economic losses in egg production in several countries throughout the world. Field observations reveal that cases of SLD appear with a high risk of reoccurrence, specifically in free-range and organic brown-feathered layer lines.