histology of the inflammatory response of carp (cyprinus carpio l.) to aeromonas hydrophila infection

The inflammatory response is the basic mechanism protecting tissue from damage from whatever cause. it can be considered as a fundamental aspect of pathology because of its frequent occurrence in many diseases and also its protective role. the present investigation was carried out to study the inflammatory response of carp (cyprinus carpio l.) to a biological stimulus, aeromonas hydrophila infection at 27.5± 1°c. the treated fish were sacrificed over a while, and sequential tissue samples were processed for histopathological examinations. fish challenged with a. hydrophila exhibited an acute inflammatory response which was lethal for some fish within 48 hours post-injection.polymorphonuclear cells (pmns) were infiltrated in the lesions 1 h post-challenge, and revealed a remarkable response to the infection. polymorphonuclear cells remained up to 7 days post-injection, and participated in myophagia and contributed in micro-abscess formation. the acute inflammation progressed into a chronic inflammation characterized by fibroplasia which was active 5 days post-infection. the wound healing progress initiated and developed in 5-10 days and was completed by scar formation on 28 days post-challenge. in addition, the regeneration of muscle bundles increased and filled the defect area.