Abstract
Ichthyophthirius multifiliis is a widespread, ciliated protozoan ectoparasite of fish. In the present study, we investigated the effects of metal nanoparticles on the reproduction and infectivity of free-living stages of I. multifiliis. We determined that ~50% of theronts could be killed within 30 min of exposure to either 20 ng mL-1 gold, 10 ng mL-1 silver or 5 ng mL-1 zinc oxide nanoparticles. Silver and zinc oxide nanoparticles at concentration of 10 and 5 ng mL-1 killed 100 and 97% of theronts, respectively and inhibited reproduction of tomonts after 2 h exposure. Gold nanoparticles at 20 ng mL killed 80 and 78% of tomonts and theronts 2 h post exposure, respectively. In vivo exposure studies using rainbow trout (Oncoryhnchus mykiss) demonstrated that theronts, which survived zinc oxide nanoparticles exposure, showed reduced infectivity compared with control theronts. No mortalities were recorded in the fish groups cohabited with theronts exposed to either nanoparticles compared with 100% mortality in the control group. On the basis of the results obtained from this study, metal nanoparticles particularly silver nanoparticles hold the best promise for the development of effective antiprotozoal agents useful in the management of ichthyophthiriosis in aquaculture.
Highlights
Ichthyophthirius multifiliis is a ciliated protozoan parasite with a worldwide distribution
We investigated the effects of gold, silver and zinc oxide nanoparticles on survival and reproduction of I. multifiliis free-living stages, and assessed the infectivity of surviving theronts to rainbow trout in vivo
Protomonts: Exposures to 20, 10, 5 ng mL−1 gold, silver or zinc oxide nanoparticles for 30 min resulted in ∼50% mortality (Table 1)
Summary
Ichthyophthirius multifiliis is a ciliated protozoan parasite with a worldwide distribution. It causes ‘white spot disease’ of freshwater fish, and is responsible for severe epizootics in aquaria, hatcheries, and ponds. The parasite has low host and tissue specificity, infecting body surfaces including gills, skin, eyes, and fins. The parasite has worldwide distribution, which is primary correlated to human mediated introductions of alien host species (non-naive) into new environments (Hoffman, 1970), and has been reported in feral fishes in tropical and temperate regions (Nigrelli et al 1976). Factors leading to epizootic include thermal triggers, the temperature tolerance of the host fish, and degree of resistance of the host (Nigrelli et al 1976). Despite the widespread and costly impacts of the parasite, few successful management strategies have been developed to control
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
