Assessment of waterborne parasites in Irish river basin districts – use of zebra mussels (Dreissena polymorpha) as bioindicators (original) (raw)
Related papers
Parasitology Research, 2004
Zebra mussels (Dreissena polymorpha) from throughout the Shannon River drainage area in Ireland were tested for the anthropozoonotic waterborne parasites Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, E. hellem, and Enterocytozoon bieneusi, by the multiplexed combined direct immunofluorescent antibody and fluorescent in situ hybridization method, and PCR. Parasite transmission stages were found at 75% of sites, with the highest mean concentration of 16, nine, and eight C. parvum oocysts, G. lamblia cysts, and Encephalitozoon intestinalis spores/mussel, respectively. On average eight Enterocytozoon bieneusi spores/mussel were recovered at any selected site. Approximately 80% of all parasites were viable and thus capable of initiating human infection. The Shannon River is polluted with serious emerging human waterborne pathogens including C. parvum, against which no therapy exists. Zebra mussels can recover and concentrate environmentally derived pathogens and can be used for the sanitary assessment of water quality.
Dreissenid mussels as sentinel biomonitors for human and zoonotic pathogens
2014
Zebra mussels (Dreissena polymorpha) are recognised biomonitors in determining the presence and viability of the human waterborne pathogens Cryptosporidium parvum, C. hominis, Giardia intestinalis and microsporidia in surface waters. This study investigated whether the size of zebra mussels is a significant factor in the concentration of protozoan Cryptosporidium oocysts, Giardia cysts and microsporidian spores. Zebra mussels were collected in Lough Arrow, a small Irish lake, which is utilized for drinking water abstraction and is subject to agricultural and human wastewater pollution drivers, both recognised risk factors for human waterborne pathogens. Zebra mussels were cleaned, divided into size (5 mm) interval classes based on their shell length and made up to 150 g samples (wet weight with shell). Combined fluorescence in situ hybridization (FISH) and immunofluorescent antibody (IFA) techniques were utilized as biomolecular techniques to assess the presence and concentration of the pathogens. PCR analysis provided source-tracking information on human and animal pollution sources. There was no significant relationship between the size of D. polymorpha and pathogen loads in similar sized samples, indicating that different sites in the same or different waterbody can be compared in terms of relative concentrations of human waterborne parasites irrespective of the zebra mussels' size. Cryptosporidium was the most abundant species, with lower counts of Giardia and the microsporidian Encephalitozoon hellem, respectively. Cryptosporidium oocysts and Giardia cysts were detected in zebra mussel samples at all three lake water abstraction points. A lake transect showed a decline in Cryptosporidium with increasing distance from a stream discharging sewage. Samples from agricultural sites indicated faecal inputs contaminated with these pathogens. Species identification implicated both human and animal faecal inputs to the lake from treated effluent, septic tanks, and agriculture. The research demonstrates the efficacy of zebra mussels as sentinels of water quality i rrespective of their size.
Zebra mussels (Dreissena polymorpha) and Asian freshwater clams (Corbicula fluminea) are nonindigenous invasive bivalves present in North American fresh waters that are frequently contaminated with human enteric parasites, Cryptosporidium parvum and Giardia lamblia. Six-week laboratory exposure of D. polymorpha and Corbicula fluminea to both parasites seeded daily at concentrations reported from surface waters demonstrated efficient removal of Cryptosporidium parvum oocysts and G. lamblia cysts by both bivalve species. The number of parasites in mollusk tissue progressively increased in relation to the concentration of waterborne contamination, and decreased after cessation of the contamination. Oocysts outnumbered cysts in the tissue of both bivalves, and more parasites were identified in D. polymorpha than in Corbicula fluminea; overall 35.0% and 16.3% of the parasites seeded, respectively. Because C. fluminea and D. polymorpha can accumulate human waterborne parasites in proportion to ambient concentrations, these species of bivalves can be effective bioindicators of contamination of freshwater habitats with Cryptosporidium and Giardia.
Asian Freshwater clams (Corbicula fluminea) and zebra mussels (Dreissena polymorpha), accidentally introduced into North America, became established in many freshwater habitats. Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis are human enteric parasites with the infectious stage transmitted via water. C. parvum (Genotype 1) were identified in D. polymorpha from the St. Lawrence River, Quebec. Approximately 67 C. parvum oocysts per ml of D. polymorpha hemolymph and 129 per gram of soft tissue were recovered. The pathogen retention rates per C. fluminea clam measured under laboratory conditions were 1.9 x 10 5 C. parvum oocysts/24 hr, 5.0 x 10 2 G. lamblia cysts/24 h, and 4.6 x 10 2 C. cayetanensis oocysts/24 h. C. fluminea clams and zebra mussels can recover and concentrate environmentally-derived waterborne parasites and therefore can be used for sanitary assessment of water quality.
Environmental Pollution, 2012
Biological responses measured in aquatic organisms to monitor environmental pollution could be also affected by different biotic and abiotic factors. Among these environmental factors, parasitism has often been neglected even if infection by parasites is very frequent. In the present field investigation, the parasite infra-communities and zebra mussel biological responses were studied up-and downstream a waste water treatment plant in northeast France. In both sites, mussels were infected by ciliates and/or intracellular bacteria, but prevalence rates and infection intensities were different according to the habitat. Concerning the biological responses differences were observed related to the site quality and the infection status. Parasitism affects both systems but seemed to depend mainly on environmental conditions. The influence of parasites is not constant, but remains important to consider it as a potential confounding factor in ecotoxicological studies. This study also emphasizes the interesting use of integrative indexes to synthesize data set.
Environmental Toxicology, 2010
It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro-pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008. For two months, mussels and water samples were collected from two sites every two weeks and analyzed for metal and PAH content as well as water physicochemical parameters. Diffusive gradients in thin film (DGT) were also used to assess levels of labile metals. Exposure of mussels to contaminants and potential impact were evaluated using physiological indices and various biomarkers including condition index (CI), defense mechanisms (glutathione-S-transferase: GST), digestive enzymes (amylase and cellulase) and genotoxicity (micronucleus test: MN and comet assay: CA). For most contaminants, the water contamination was significantly higher downstream. Bioaccumulation in zebra mussels was related to water contamination in the framework of the biodynamic model, which allowed us to take into account the biological dilution that was caused by the growth of soft tissue downstream. Thus, metal influxes were on average two times higher downstream than upstream in particular for Zn, Cr, Cu and Cd. Significant differences in condition index were observed (final CI was 0.42 6 0.03 downstream and 0.31 6 0.03 upstream) reflecting a better food availability downstream. Moreover a significant decrease of GST activity and digestive enzymes activity in the cristalline style was observed downstream. Interpreting this decrease requires considering not only micro-pollution but also the trophic status related to the water's physicochemistry. The MN test and the CA on gill cells highlighted genotoxicity in mussels transplanted downstream compared to upstream. # 2010 Wiley Periodicals, Inc. Environ Toxicol 25: 468-478, 2010.
Multiresistant Bacteria: Invisible Enemies of Freshwater Mussels
SSRN Electronic Journal, 2021
Freshwater mussels are among the most endangered groups of fauna anywhere in world. The indiscriminate use of antibiotics has led to the emergence of resistant strains. These antibiotic-resistant bacteria play a key role in increasing the risk allied with the use of surface water and in spread of resistance genes. Two endangered freshwater mussel species, Margaritifera margaritifera and Potomida littoralis, were sampled at 4 sampling sites along a 50 km stretch of River Tua. Water samples were taken at same sites. Of the total of 135 isolates, 64.44% (39.26% from water and 25.19% from mussels) were coliform bacteria. Site T1, with the lowest concentration of coliform bacteria, and site T2 were the only ones where M. margaritifera was found. No E. coli isolates were found in this species and the pattern between water and mussels was similar. P. littoralis, which was present at T3/T4 sites, is the one that faces the highest concentration of bacterial toxins, which are found in treated wastewater effluents and around population centers. Sites T3/T4 have the isolates (water and mussels) with the highest resistance pattern, mainly to β-lactams. Water and P. littoralis isolates (T3/T4) showed resistance to penicillins and their combination with clavulanic acid, and to cephalosporins, precisely to a fourth generation of cephalosporin antibiotics. The analysis provides important information on the risk to water systems, as well as the need to investigate possible management measures. It is suggested that future studies on the health status of freshwater bivalves should incorporate measures to indicate bacteriological water quality.
Parasitology Research, 2008
Surface inland and coastal waters in Ireland were surveyed for the human waterborne enteropathogens; Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, Encephalitozoon hellem, and Enterocytozoon bieneusi by utilizing bivalve mussel species, i.e., Mytilus edulis (blue mussel), Anodonta anatina (duck 'mussel', actually a unionid clam), and the invasive Dreissena polymorpha (zebra mussel) as biomonitors at twelve sites located in three Irish river-basin districts with various waterquality pressures. Biomolecular techniques were utilized to assess the presence and concentration of these pathogens. At least one pathogen species was detected in shellfish at each site. Cryptosporidium, implicated in several recent Irish gastrointestinal epidemics, was recorded at all sites subjected to agricultural runoff and at one sewage discharge site, linking source-track directly to human and animal fecal wastes. G. lamblia was present at eleven of the twelve sites in a range of concentrations. A coastal bay with raw urban sewage discharge was 100% positive for all analyzed enteropathogens. Overall, the results demonstrate long-term human enteropathogen contamination of Irish waters with consequent public-health risk factors for drinking-water abstraction and water-based activities.
Water Research, 2014
Dreissena polymorpha a b s t r a c t Cryptosporidium parvum, Giardia duodenalis and Toxoplasma gondii are ubiquitous pathogens, which waterborne transmission has been largely demonstrated. Since they can be found in various watercourses, interactions with aquatic organisms are possible. Protozoan detection for watercourses biomonitoring is currently based on large water filtration. The zebra mussel, Dreissena polymorpha, is a choice biological model in ecotoxicological studies which are already in use to detect chemical contaminations in watercourses. In the present study, the zebra mussel was tested as a new tool for detecting water contamination by protozoa.