Differences in the in vitro susceptibility to resveratrol and other chemical compounds among several Philasterides dicentrarchi isolates from turbot

Abstract

Philasterides dicentrarchi is a histophagous scuticociliate that causes important losses in aquaculture. Several strains that differ in morphological, genetic and serological characteristics and virulence have been isolated from outbreaks of turbot scuticociliatosis. In the present study, seven isolates of the ciliate were exposed in vitro to formalin, hydrogen peroxide and resveratrol (a phytoalexin produced by plants) in order to evaluate the susceptibility of the isolates to the different compounds. The LD50 values for the three compounds tested varied widely among the isolates. The LD100 values were similar among isolates for formalin (25-30 ppm) and resveratrol (60-70 ppm) but were very different for hydrogen peroxide (25->80 ppm). The results indicate that there are many physiological differences among isolates and even among specimens of the same isolates, which must be taken into account in designing control programmes. The naturally occurring resveratrol may be a good alternative to other compounds for reducing the amounts of viable ciliates in water.

Combined antiparasitic and anti‐inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis

“…; Budiño et al . ). However, because of the restrictions on the use of chemicals in aquaculture and also the rapid development of the disease at present, there are no effective treatments for systemic infections in fish.…”

Preventive and therapeutic effects of auxotrophic Edwardsiella tarda mutant harboring CpG 1668 motif-enriched plasmids against scuticociliatosis in olive flounder (Paralichthys olivaceus)

“…In Korea, epizootics of scuticociliatosis caused by Miamiensis avidus (= Philasterides dicentrarchi) have led to mass mortalities in cultured olive flounder every year (Kim et al, 2004;Jung et al, 2007). Many chemotherapeutics for treatment of scuticociliatosis have been attempted (Iglesias et al, 2002;Quintela et al, 2003;Paramá et al, 2004Paramá et al, , 2007Budiño et al, 2012), but finding effective in vivo therapeutics has failed. Although a high treatment efficacy of feeding doxycycline or bath with freshwater containing doxycycline against scuticociliatosis in olive flounder was demonstrated by our recent study (Kang et al, 2013b), development of immunological control measures is still required not only to enhance survival of fish but also to solve problems related to chemotherapeutics' side-effects.…”

Alternative oxidase inhibitors as antiparasitic agents against scuticociliatosis

“…Possible strategies for the control of turbot scuticociliatosis necessarily include erradication from the external environment and destruction of the endoparasitic stage of the parasite (Leiro et al 2004). The elimination of scuticociliates from water is feasible, via the application of chemical disinfectants such as formalin and hydrogen peroxide (Iglesias et al 2002;Paramá et al 2003;Budiño et al 2012;Harikrishnan et al 2010;Jin et al 2010); however, at present there are no drugs available to treat systemic infections in fish. There are also numerous legal restrictions regarding the use of drugs in fish in relation to food safety and environmental impacts (Hedley and Huntington, 2009).…”