Marine fish parasite, lernanthropus kroyeri (Copepoda) is a repository of vibrio anguillarum as evidenced by loop-mediated isothermal amplification method

Abstract

Fish parasites act as a vector of other pathogenic diseases such as bacteria and virus in fish. Although it has been long known that fish parasites can act as a vector for bacterial pathogens, their role in the transmission of specific bacterial pathogens via particular parasites in the off-host stage has been neglected. The aim of the present study was to disclose that if the copepod parasite, Lernanthropus kroyeri in the off-host stage, can store up the aquatic bacterial pathogens: Aeromonas hydrophila, Photobacterium damsela subsp. piscicida, Vibrio (Listonella) anguillarum, V. harveyi, V. vulnificus, and V. alginolyticus. Our results using the Loop-mediated Isothermal Amplification (LAMP) method demonstrated that the bacteria, V. anguillarum is internally present in the off-host copepod parasites, L. kroyeri. It was also found that the parasite, L. kroyeri could survive in the off-host stage for a given time with its potential of vectoring ability in terms of transmission of the bacterium to the fish. This study demonstrates evidence that the copepod parasite in the off-host stage on the gills of sea bass is a reservoir of pathogen bacteria, Vibrio anguillarum.