Parasite --Bacteria Co-Infection in the Egyptian Common Sole (Solea solea ) by Livoneca redmanii and Aeromonas veronii.

In the present research, samples of Solea solea (Linnaeus) were randomly collected from Qarun Lake, Egypt, for routine parasitological, microbiological, and histopathological examinations. The parasitological analysis revealed that 6.70% of the examined samples were infested with the cymothoid isopod Livoneca redmanii. This parasite was isolated as females from the branchial cavity and as juveniles from the skin of the affected fish. Bacteriological examination identified Aeromonas species isolated from the gills, kidney, and liver of S. solea. Morphological, biochemical characterization, and molecular analysis confirmed the isolate as Aeromonas veronii. The isolated strain produced brown colonies on tryptic soy agar (TSA) supplemented with 3% NaCl. The drug susceptibility test indicated that Aeromonas veronii was sensitive to gentamicin, erythromycin, and trimethoprim/sulfamethoxazole, while exhibiting resistance to nalidixic acid, ampicillin, oxolinic acid, and tetracycline. Histopathological examination of the affected gills revealed edema, leukocyte infiltration, and hyperplasia of mucous cells. The infested skin exhibited sloughing and detachment of the lining epithelium, along with edema and degeneration of the muscles at the site of isopod attachment. [ABSTRACT FROM AUTHOR]