First Record of Aeromonas Sobria in Yellow Tail Cichlid, Pseudotropheus Acei

Abstract

In this study, Aeromonas sobria was isolated in yellow tail cichlid (mean weight 6 g) in an aquarium. The disease occurred in June 2017. The cumulative mortality was calculated as 74.6 % at 26 degrees C. Infected fish exhibited lethargy, abdominal swelling, lack of appetite and erosion of the caudal fins. Internal findings included accumulation of ascidic fluid in the abdominal cavity, enlarged and necrotic kidney, enlarged and anaemic liver, which in some fish showed congestion and hyperemia. Isolates (n=6) were obtained from samples of kidney, liver and brain following incubation at 22 degrees C for 24 h on tryptic soy agar medium. The biochemical characteristics of all isolates were studied by conventional bacteriological tests and following API 20NE, API 20 E and API 50 CH Strip tests (BIoMe'rieux). In addition, the 16S rRNA and gryB gene region of representative isolate SM07 were sequenced to verify isolate identification. According to the identification scheme the causative agent of disease was identified as A. sobria. This is the first case report of A. sobria as a pathogenic agent of tail-rot disease in yellow tail cichlid.