Exemplifying ‘pathobiome’ concept through case study: Co-infection with Vibrio harveyi, Photobacterium damsela and Cryptocaryon irritans in Salema (Sarpa salpa)

A pathobiome approach has been revealed as a set of organisms (i.e. prokaryotic, eukaryotic, and virus associations) in the aquatic environment that interact with the host (fish) to cause disease. The approach of the one pathogen–one disease is not wholly satisfactory to comment on the impairment of health status and disease process in fish. To exemplify the pathobiome concept, we present a fish disease in which more than one pathogen and possible synergistic interaction of inadequate water quality. In this case, the heavy mortalities were observed in Salema (Sarpa salpa) from an exhibition aquaria. Bacterial identification with matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS) showed the pathogen bacteria species of vibrio and photobacterium. In the parasitic examination, the invasion of marine ciliata, Cryptocaryon irritans was observed in the diseased fish. Moreover, poor water quality was considered as contributing factor to disease emergence in this case. The co-existence of pathogen Vibrio species (Vibrio harveyi) and Photobacterium damsela with its subspecies (subsp. damsela and subsp. piscicida) as well as marine ciliata, C. irritans for a description of a disease picture in a marine fish species are reported for the first time, providing an example of a pathobiome paradigm.