Interplay between fungicides and parasites: Tebuconazole, but not copper, suppresses infection in a Daphnia-Metschnikowia experimental model

Abstract

Natural populations are commonly exposed to complex stress scenarios, including anthropogenic contamination and their biological enemies (e.g., parasites). The study of the pollutant-parasite interplay is especially important, given the need for adequate regulations to promote improved ecosystem protection. In this study, a host-parasite model system (Daphnia spp. and the microparasitic yeast Metschnikowia bicuspidata) was used to explore the reciprocal effects of contamination by common agrochemical fungicides (copper sulphate and tebuconazole) and parasite challenge. We conducted 21-day life history experiments with two host clones exposed to copper (0.00, 25.0, 28.8 and 33.1 μg L-1) or tebuconazole (0.00, 154, 192 and 240 μg L-1), in the absence or presence of the parasite. For each contaminant, the experimental design consisted of 2 Daphnia clones × 4 contaminant concentrations × 2 parasite treatments × 20 replicates = 320 experimental units. Copper and tebuconazole decreased Daphnia survival or reproduction, respectively, whilst the parasite strongly reduced host survival. Most importantly, while copper and parasite effects were mostly independent, tebuconazole suppressed infection. In a follow-up experiment, we tested the effect of a lower range of tebuconazole concentrations (0.00, 6.25, 12.5, 25.0, 50.0 and 100 μg L-1) crossed with increasing parasite challenge (2 Daphnia clones × 6 contaminant concentrations × 2 parasite levels × 20 replicates = 480 experimental units). Suppression of infection was confirmed at environmentally relevant concentrations (> 6.25 μg L-1), irrespective of the numbers of parasite challenge. The ecological consequences of such a suppression of infection include interferences in host population dynamics and diversity, as well as community structure and energy flow across the food web, which could upscale to ecosystem level given the important role of parasites.

Temperature modulates the interaction between fungicide pollution and disease: evidence from a Daphnia-microparasitic yeast model

“…The studied parasite was a single isolate of the endoparasitic yeast M. bicuspidata. Host genotypes and parasite strain were isolated from Lake Ammersee (Germany) and have been used in other studies (Yin et al 2011; Buser et al 2012 b ; Cuco et al 2017).…”

“…Daphnia genotypes (Clone 12 and Clone 47) were reared as parthenogenetic lineages in moderately hard reconstituted water (123 mg L −1 MgSO 4 ·7H 2 O, 96 mg L −1 NaHCO 3 , 60 mg L −1 CaSO 4 ·2H 2 O, 4 mg L −1 KCl) supplemented with a standard organic additive (algal extract) and vitamins (Cuco et al 2016, 2017). Cultures were maintained with a 16h L :8h D photoperiod and the medium was renewed three times a week.…”

“…Lake epidemics of M. bicuspidata can reach a prevalence up to 40% (Caceres et al 2006; Duffy et al 2009; Hall et al 2011; Wolinska et al 2011), and they are important in the ecological dynamics of Daphnia natural populations (Duffy and Sivars-Becker, 2007; Duffy et al 2009, 2011). This host–parasite model allows experimental manipulation of spore load and parasite transmission (Lohr et al 2010; Yin et al 2011), as well as the discrimination of the interactive effects of parasite and other stressors (Duffy et al 2011; Civitello et al 2012; Cuco et al 2017).…”

“…Copper sulphate and tebuconazole were selected based on their contrasting effects on the host–parasite system described (i.e. Daphnia infected with M. bicuspidata , Cuco et al 2017). We hypothesize that temperature will affect the outcome of the contaminant × disease interaction in the case of tebuconazole (which causes a suppression of infection), but this may be less important in the case of copper sulphate because of the lack of interaction between parasite and toxicant effects (Cuco et al 2017).…”

Magnetic iron(III)‐based framework composites for the magnetic solid‐phase extraction of fungicides from environmental water samples

“…Herein, we adopted a facile hydrofluoric acid‐free hydro‐/solvothermal method for the preparation of four magnetic iron(III)‐based framework composites, MIL‐101@Fe 3 O 4 ‐COOH, MIL‐101‐NH 2 @Fe 3 O 4 ‐COOH, MIL‐53@Fe 3 O 4 ‐COOH, and MIL‐53‐NH 2 @Fe 3 O 4 ‐COOH (Figure ). The obtained four magnetic iron(III)‐based framework composites were applied to magnetic separation and enrichment of the fungicides (prochloraz, myclobutanil, tebuconazole, and iprodione) from environmental samples, and MIL‐101‐NH 2 @Fe 3 O 4 ‐COOH showed more remarkable pre‐concentration ability for them as compared to the other three magnetic iron(III)‐based framework composites. The potential factors affecting the performance of the MIL‐101‐NH 2 @Fe 3 O 4 ‐COOH on the MSPE of the fungicides were investigated and optimized.…”