Cellulitis lesions in broiler chickens are induced by Escherichia coli Vacuolating Factor (ECVF).

Nov 2012

Quel NG, Aragão AZ, Salvadori MR, Farias AS, Joazeiro PP, Santos LM, Sá LR, Ferreira AJ, Yano T.

Source

Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Rua Monteiro Lobato, 255, Campinas, SP, CEP 13083-862, Brazil.

Abstract

Keywords

• APEC; 
• Avian cellulitis; 
• Escherichia coli Vacuolating Factor (ECVF); 
• Purification; 
• Cytokines; 
• Inflammatory response; 
• Dermatopathology

Escherichia coli Vacuolating Factor (ECVF) is a heat-labile, vacuolating cytotoxin produced by avian pathogenic E. coli (APEC) isolated from avian cellulitis lesions. In this report, we intend to demonstrate that purified ECVF induces the inflammatory process of cellulitis. Our group is the first to demonstrate the effect of ECVF in a histological analysis by in situ inoculation of broiler chickens with purified ECVF. The animals were inoculated with the APEC AC53 and with purified ECVF subcutaneously on their ventral surface (in the sternum region). The histological analysis showed different grades of an acute inflammatory response in the epidermis, dermis and panniculus. An increase in mRNA expression of the proinflammatory cytokine TNF-α was also demonstrated in the inflamed tissue. When ECVF was systemically administered, increased levels of TNF-α and IL-10 were observed in the serum. These results suggest that ECVF plays a key role in the inflammatory process associated with cellulitis that is mainly mediated by TNF-α. In addition, this inflammation can be down regulated by the anti-inflammatory. 

cytokine IL-10.

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