Avian Pathogenic Escherichia Coli
Mostrando 25-36 de 43 artigos, teses e dissertações.
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25. Role of Virulence Factors in Resistance of Avian Pathogenic Escherichia coli to Serum and in Pathogenicity
In chickens, colibacillosis is caused by avian pathogenic Escherichia coli (APEC) via respiratory tract infection. Many virulence factors, including type 1 (F1A) and P (F11) fimbriae, curli, aerobactin, K1 capsule, and temperature-sensitive hemagglutinin (Tsh) and plasmid DNA regions have been associated with APEC. A strong correlation between serum resistan
American Society for Microbiology.
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26. Functional Analysis of the Tsh Autotransporter from an Avian Pathogenic Escherichia coli Strain
The temperature-sensitive hemagglutinin (Tsh) is an autotransporter protein secreted by avian-pathogenic Escherichia coli strains that colonize the respiratory tract and lead to airsacculitis, pericarditis, and colisepticemia. It is synthesized as a 140-kDa precursor protein, whose processing results in a 106-kDa passenger domain (Tshs) and a 33-kDa β-domai
American Society for Microbiology.
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27. Genetic relationships among pathogenic strains of avian Escherichia coli.
Genetic relationships among 79 strains of Escherichia coli, isolated mostly from diseased chickens, were estimated on the basis of allelic variation at 15 enzyme-encoding loci, determined by multilocus enzyme electrophoresis. All 15 loci were polymorphic, with an average of 4.1 allelic states per locus. Comparisons of the observed combinations of alleles amo
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28. Production of toxins (enterotoxins, verotoxins, and necrotoxins) and colicins by Escherichia coli strains isolated from septicemic and healthy chickens: relationship with in vivo pathogenicity.
Since the mechanism of virulence of Escherichia coli strains pathogenic to birds is not fully understood, the prevalence of toxic factors produced by E. coli strains pathogenic to other animals was investigated. A total of 625 E. coli strains isolated from visceral organs of chickens with colisepticemia and from feces of healthy chickens in Spain were tested
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29. Incidence and Characterization of Integrons, Genetic Elements Mediating Multiple-Drug Resistance, in Avian Escherichia coli
Antibiotic resistance among avian bacterial isolates is common and is of great concern to the poultry industry. Approximately 36% (n = 100) of avian, pathogenic Escherichia coli isolates obtained from diseased poultry exhibited multiple-antibiotic resistance to tetracycline, oxytetracycline, streptomycin, sulfonamides, and gentamicin. Clinical avian E. coli
American Society for Microbiology.
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30. Role of Avian Pathogenic Escherichia coli Virulence Factors in Bacterial Interaction with Chicken Heterophils and Macrophages
Avian pathogenic Escherichia coli (APEC) cause extraintestinal disease in avian species via respiratory tract infection. Virulence factors associated with APEC include type 1 and P fimbriae, curli, aerobactin, lipopolysaccharide (LPS), K1 capsular antigen, temperature-sensitive hemagglutinin (Tsh), and an uncharacterized pathogen-specific chromosomal region
American Society for Microbiology.
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31. Escherichia coli Hemoglobin Protease Autotransporter Contributes to Synergistic Abscess Formation and Heme-Dependent Growth of Bacteroides fragilis
Intra-abdominal infections (IAI) continue to be a serious clinical problem. Bacterial synergism is an important factor that influences the shift from contamination to IAI, leading to the development of lesions and abscess formation. Escherichia coli and Bacteroides fragilis are particularly abundant in IAI. The underlying molecular mechanisms of this pathoge
American Society for Microbiology.
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32. Association of iss and iucA, but Not tsh, with Plasmid-Mediated Virulence of Avian Pathogenic Escherichia coli
Avian pathogenic Escherichia coli (APEC) is an economically important respiratory pathogen of chickens worldwide. Factors previously associated with the virulence of APEC include adhesins, iron-scavenging mechanisms, the production of colicin V (ColV), serum resistance, and temperature-sensitive hemagglutination, but virulence has generally been assessed by
American Society for Microbiology.
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33. A carAB mutant of avian pathogenic Escherichia coli serogroup O2 is attenuated and effective as a live oral vaccine against colibacillosis in turkeys.
Colibacillosis is a serious and economically important disease of the respiratory tract of chickens and turkeys. The serogroups of Escherichia coli commonly associated with colibacillosis in poultry are O1, O2, and O78. Although previous attempts to develop a vaccine have not been very successful, vaccination is still considered the most effective way of con
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34. Isolation and Molecular Characterization of Nalidixic Acid-Resistant Extraintestinal Pathogenic Escherichia coli from Retail Chicken Products
Fluoroquinolone use in poultry production may select for resistant Escherichia coli that can be transmitted to humans. To define the prevalence and virulence potential of poultry-associated, quinolone-resistant E. coli in the United States, 169 retail chicken products from the Minneapolis-St. Paul area (1999 to 2000) were screened for nalidixic acid (Nal)-re
American Society for Microbiology.
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35. Role of crl in avian pathogenic Escherichia coli: a knockout mutation of crl does not affect hemagglutination activity, fibronectin binding, or Curli production.
This study determined the role of crl in the production of curli by, the hemagglutination activity of, and fibronectin binding by avian pathogenic Escherichia coli chi 7122. Curli, an extracellular structure that binds fibronectin, was recently described (A. Olsén, A. Jonsson, and S. Normark, Nature [London] 338:652-655, 1989). The crl gene product was hypo
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36. Characterization of the Avian Pathogenic Escherichia coli Hemagglutinin Tsh, a Member of the Immunoglobulin A Protease-Type Family of Autotransporters
We reported earlier that a single gene, tsh, isolated from a strain of avian pathogenic Escherichia coli (APEC) was sufficient to confer on E. coli K-12 a hemagglutinin-positive phenotype and that the deduced sequence of the Tsh protein shared homology to the serine-type immunoglobulin A (IgA) proteases of Neisseria gonorrhoeae and Haemophilus influenzae. In
American Society for Microbiology.