Causal agents of mycobacterial diseases in freshwater ornamental fish and their importance for human health in the Czech Republic

In the period from 1995 to 2004, the following mycobacterial species were isolated during the examination of the state of health of aquarium fish from the Moravian-Silesian region of the Czech Republic: Mycobacterium fortuitum (Paracheirodon axelrodi, Poecilia sphenops, Hemigrammus rhodostomus, Hyphessobrycon flammeus), M. chelonae (P. axelrodi, Berta splendens, Xiphophorus helleri, Puntius tetrazona), M. kansasii (P. axelrodi, B. splendens), M. simiae (Hyphessobrycon ecuadoriensis), and M. gordonae (P. axelrodi, Colisa lalia, B. splendens, Symphysodon discus). The first isolation from aquarium fish was recorded in the case of M. kansasii and the second isolation in the case of M. simiae; both should also be taken into account as aetiological agents of mycobacterial infections in humans. The measures to reduce mycobacterial infections in both fish and humans should include monitoring water mains as possible sources of M. kansasii infections, compliance with the sanitation principles in handling fish suspected of being infected and the content of tanks (molluscs, water, plants), and the introduction of strict veterinary inspection of imported fish, fish from aquarist shops and from large-scale distributors.