Isolation of Alcaligenes faecalis in fish Betta splendens Regan, 1910 in Brazil

Abstract

This paper aimed to describe one case of infection by Alcaligenes faecalis in an ornamental fish Betta splendens, including clinical, pathological, and bacteriological evaluation. A female fish weighing 16 g initially showed discrete ulcerative lesions in the integument, inappetence, progressive weight loss, lethargy, dyspnea, and increased volume in the left lateral region. Necropsy revealed bilateral exophthalmia, corneal opacity, ascites, and subcutaneous abscess causing distension of the celomatic cavity. Histological changes of the skin were characterized by abscess, necrosis, hemorrhage, and inflammatory infiltrate consisting mainly of heterophils. Microbiological assays using the exudates and venous blood isolated exclusively A. faecalis.