Fungal and Bacterial Co-Infection of Sea Bass (Dicentrarchus labrax, Linnaeus 1758) in a Recirculating Aquaculture System: Saprolegnia parasitica and Aeromonas hydrophila

DOI: 10.26650/ASE201811 Aeromonas hydrophila causes symptoms of hemorrhagic septicemia in acute cases and can cause death in freshwater fish, whereas Saprolegnia parasitica is the cause of ulcers complicated by fungal mycelia located on skin that has lost its scales for various reasons. Both pathogens co-infect recirculating aquaculture systems at the ？zmir Katip ？elebi University Fisheries Research and Training Center. Clinical, bacteriological, parasitological, and mycological studies were carried out on 25 fish samples during the infestation. Sabouraud glucose agar and malt extract agar were used to isolate the fungus, and the bacterial isolates were streaked on tryptic soy agar (Oxoid) with 5% defibrinated sheep blood. Gray-white cotton-like patches, erosions on the skin, and hemorrhaging were detected on the infected fish samples. The analytical profile index test and molecular identification showed that the bacterial agent was A. hydrophila and a fungal examination and amplification by polymerase chain reaction confirmed that the mycotic agent was S. parasitica