Microsporidia parasites disrupt the responses to cadmium exposure in a gammarid

Abstract

a b s t r a c tMicrosporidia parasites are commonly found in amphipods, where they are often asymptomatic, vertically-transmitted and have several effects on host sexuality and behaviour. As amphipods are often used as models in ecotoxicological studies, we investigated the effect of microsporidian infections on energy reserves and defence capacities of Gammarus roeseli under cadmium stress. Only females were infected by two microsporidia parasites: Dictyocoela roeselum or Dictyocoela muelleri. In physiological conditions, microsporidia had no major effect on energy reserves and defence capacities of G. roeseli, while under cadmium exposure, energy reserves and antioxidant defence were weaker in infected females. Moreover, higher malondialdehyde levels detected in infected females revealed that they suffered more cellular damages. Our results suggest that microsporidia may affect gammarid fitness in stressful conditions, when parasitic stress cannot be compensated by the host. Consequently, microsporidia parasites should be a factor necessary to take into account in ecotoxicology studies involving amphipods.

Acanthocephalan parasites: help or burden in gammarid amphipods exposed to cadmium?

“…This higher mortality could be explained by the presence of other parasites as vertically-transmitted microsporidia parasites which are found in many arthropod species (Terry et al 1999;Ironside et al 2003;Weedall et al 2006;Haine et al 2007), especially in females (Haine et al 2004). In a previous study, we demonstrated that these microsporidia parasites accentuated oxidative stress in G. roeseli females exposed to cadmium (Gismondi et al 2012). Results obtained in the present study suggested that the potential presence of two parasites (i.e.…”

“…exposed to a multistress environment (Minguez et al 2009). This decrease of antitoxic defence compounds could lead to an increase of host damage as it was the case in Gammarus roeseli infected by verticallytransmitted microsporidia parasites exposed to cadmium (Gismondi et al 2012). …”

Microsporidian Parasites Found in the Hemolymph of Four Baikalian Endemic Amphipods

“…verrucosus (GenBank data). It is known that some species of Dictyocoela stimulate feminization and change the sex ratio in their host populations [25]. There is hypothesis that this genus of microsporidia has a high degree of genetic diversity in populations of Eurasian amphipods and shows horizontal transmission [26].…”

Gammarus fossarum (Crustacea, Amphipoda) as a model organism to study the effects of silver nanoparticles

“…Other individuals were sexed based on sexual dimorphism such as gnathopode sizes (males present bigger gnathopodes compared to females). As parasitism is known to interfere with the studied responses (Gismondi et al, 2012a(Gismondi et al, , 2012b(Gismondi et al, , 2012c, Acanthocephala sp. parasitized organisms (parasites appear as orange spots visible through the cuticle) were excluded from sampling.…”