ABSTRACT
Footpad lesions are an important factor in evaluation of animal welfare in broilers regulated by law; however, no legal requirements have been set for the parent birds. Nevertheless, the present study confirms that foot health in broiler breeders declines significantly with increasing age, thus potentially impairing the animal welfare due to pain and discomfort from footpad dermatitis. Furthermore, this is the first report demonstrating a correlation between the presence of footpad lesions and systemic bacterial infections with Gram-positive cocci in broiler breeder birds.
Subject(s)
Bacterial Infections/veterinary , Foot/pathology , Poultry Diseases/microbiology , Age Factors , Animals , Bacterial Infections/microbiology , Bacterial Infections/pathology , Chickens/microbiology , Foot/microbiology , Poultry Diseases/pathologyABSTRACT
Several types of Escherichia coli have been associated with extra-intestinal infections in poultry, however, they may vary significantly in their virulence potential. The aim of the present study was to investigate the virulence of five strains of E. coli obtained from different disease manifestations or from the cloacae of a healthy chicken. The virulence potential of the strains were evaluated in an avian experimental model for ascending infections, and experiments were conducted in both layers and broiler breeders. The clinical outcome of infection was highly depending on the challenge strain, however, not significantly reflecting the origin of the strain. In general, broiler breeders had a more severe clinical outcomes of infection compared to layers, but major with-in group diversity was observed for all challenge strains of clinical origin. A single strain of ST95 (phylogroup B2) had a distinct ability to cause disease. Results of the study shows major differences in virulence of different strains of E. coli in ascending infections; however, there was no indication of tissue-specific adaptation, since strains obtained from lesions unrelated to the reproductive system were fully capable of causing experimental infection. In conclusion, the study provides evidence for the clinical outcome of infection with E. coli in poultry is largely influenced by the specific strain as well as individual host factors.
Subject(s)
Escherichia coli Infections/veterinary , Escherichia coli/physiology , Escherichia coli/pathogenicity , Host-Pathogen Interactions , Poultry Diseases/microbiology , Salpingitis/veterinary , Animals , Chickens , Escherichia coli/classification , Escherichia coli/genetics , Escherichia coli Infections/microbiology , Escherichia coli Infections/pathology , Female , Genetic Variation , Poultry Diseases/pathology , Salpingitis/microbiology , Salpingitis/pathology , Species SpecificityABSTRACT
Here, we present three draft genome sequences of Escherichia coli strains that experimentally were proven to possess low (strain D2-2), intermediate (Chronic_salp), or high virulence (Cp6salp3) in an avian (ascending) infection model of the oviduct.