Scientific Research Commission CIC

La Plata, Argentina

Scientific Research Commission CIC

La Plata, Argentina
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Dunn J.R.,U.S. Department of Agriculture | Auten K.,U.S. Department of Agriculture | Auten K.,Michigan State University | Heidari M.,U.S. Department of Agriculture | And 2 more authors.
Avian Diseases | Year: 2014

Marek's disease (MD) virus (MDV) is an alphaherpesvirus that causes MD, a lymphoproliferative disease in chickens. Pathotyping has become an increasingly important assay for monitoring shifts in virulence of field strains; however, it is time-consuming and expensive, and alternatives are needed to provide fast answers in the face of current outbreaks. The purpose of this study was to determine whether differences in virus replication between pathotypes that have been reported using a small number of virulent (v) and very virulent plus (vv+) MDV strains could be confirmed with a large collection of MD viruses. Based on pilot study data, bursa, brain, and lung samples were collected at 9 and 11 days postinoculation (dpi) from birds challenged with 1 of 15 MDV strains. The correlation between virus replication and virulence was confirmed between vMDV strains and higher virulent strains, but in most cases, there was no significant difference between very virulent (vv) and vv+MDV groups. At both 9 and 11 dpi, chickens infected with vv and vv+MDV had significantly lower body weights and relative thymus and bursa weights compared with chickens challenged with vMDV. However, similar to virus quantity, there was no significant difference between weights in birds challenged with vv or vv+MDV. The significant differences observed in maternal antibody negative (ab-) chickens were not significant in maternal antibody positive (ab+) chickens, demonstrating the requirement of ab- birds for this type of comparison. These data do not support the use of virus replication or organ weights as an alternative to pathotyping for discrimination between all three virulent MDV pathotypes but may be useful for determining a virus replication threshold to choose which field strains meet a minimum virulence to be pathotyped by traditional methods. © American Association of Avian Pathologists.


Garcia M.E.,Aquatic Ecology Program | Garcia M.E.,CONICET | Garcia M.E.,National University of Luján | Rodrigues Capitulo A.,CONICET | And 2 more authors.
Ecotoxicology and Environmental Safety | Year: 2010

The standardization of toxicity tests requires the selection of the most suitable test species and their developmental stages, as well as the selection of the appropriate assay matrix and the evaluation of the sensitivity of the test species to the reference toxicants. International protocols recommend the use of the amphipod Hyalella azteca from the Northern Hemisphere for sediment toxicity tests. We selected the widely distributed amphipod Hyalella curvispina, representative of pleustonic, epiphitic and zoobenthic assemblages in austral South America, as test species to be used in regional studies. Our goals were to evaluate the sensitivity of three developmental stages of H. curvispina to cadmium as a reference toxicant and to select the most suitable age and exposure time for aquatic ecotoxicity assessment. The three ages were highly susceptible to cadmium, with sensitivities: neonates > adults > juveniles. Our results validate the use of the native H. curvispina as a standard species for ecotoxicological assessment studies. © 2009.


Giusto A.,National University of Luján | Salibian A.,National University of Luján | Ferrari L.,National University of Luján | Ferrari L.,Scientific Research Commission CIC
Ecotoxicology | Year: 2014

The utility of early effect endpoints as biomarkers of ecotoxicity of natural sediments in water-sediment static system was investigated. The particular goal was to evaluate the ecotoxicity of the sediment samples from La Choza stream, located in upper basin of the Reconquista river, the second most polluted river of Argentina. Native juveniles Hyalella curvispina were used as test organisms evaluating survival, growth, oxidative stress parameters (SOD; CAT, TBARS) and the electron transport system (ETS) activity as early toxic effect. This study used methodologies and techniques that allow the assessment of sediment pollution with a native species as test organism and provided data to discuss the viability of sublethal endpoints as tools for freshwater sediment assessment. In spring and in summer two ten-day series of whole-sediment assays were conducted simultaneously: (a) standard assays and (b) biomarkers assays. A control sediment was ran simultaneously in which no - effect on survival was measured. In summer there was a significant increase in length and biomass in both exposed and control groups. In spring an inhibitory effect on growth and an increase in oxidative damage with a concomitant rise in antioxidant defenses, was observed in animals exposed to La Choza sediment. ETS measurement indicated a significant depression of metabolic activity of amphipods exposed to contaminated sediments. The measured biomarkers represent the first record for juvenile H. curvispina exposed to polluted natural sediments under standardized laboratory conditions. The used bioanalytical tools demonstrated higher sensitivity and a more accurate assessment of the effects than those obtained by the standard tests of survival and growth. We propose their adoption in biomonitoring of freshwater sediment toxicity. © 2014 Springer Science+Business Media New York.


Achiorno C.L.,CONICET | De Villalobos C.,Scientific Research Commission CIC | De Villalobos C.,National University of La Plata | Ferrari L.,Scientific Research Commission CIC | Ferrari L.,National University of Luján
Journal of Helminthology | Year: 2014

We evaluated the effect of carbendazim on non-target organisms using the parasite Chordodes nobilii as a test organism. The Gordiida act as a link between freshwater and terrestrial ecosystems; and C. nobilii, a neotropical representative species of this group, has been shown to be sensitive to other contaminants even at environmentally acceptable concentrations. The taxa susceptible to carbendazim, however, may not be adequately represented among the standard aquatic test species used in ecotoxicological risk assessment. Moreover, the autochthonous organisms in this area that could be used as bioindicators still need to be found. The aim of the present work was therefore to assess the susceptibility of the preparasitic stages of C. nobilii to noxious effects by carbendazim. The assay protocol consisted in 96- and 48-h acute exposures of early embryonic stages and larvae, respectively, to concentrations ranging from 10 to 360 μg/l. Embryonic development was not inhibited by carbendazim at any of the evaluated concentrations, but the infectivity of larvae emerging from the exposed eggs was significantly diminished. Larval survival rate was also affected at the lowest concentration assayed. Values of the mean inhibition concentration (IC50) were 7 and 11 μg/l for embryos and larvae, respectively. Compared to other freshwater organisms, C. nobilii can be considered a species moderately to highly susceptible to carbendazim. As the expected environmental concentrations of carbendazim range from 6.25 to 41.3 μg/l, C. nobilii could well be a species in danger when exposed to this fungicide. Copyright © Cambridge University Press 2014


Achiorno C.L.,CONICET | De Villalobos C.,Scientific Research Commission CIC | Ferrari L.,Scientific Research Commission CIC
Journal of helminthology | Year: 2015

We evaluated the effect of carbendazim on non-target organisms using the parasite Chordodes nobilii as a test organism. The Gordiida act as a link between freshwater and terrestrial ecosystems; and C. nobilii, a neotropical representative species of this group, has been shown to be sensitive to other contaminants even at environmentally acceptable concentrations. The taxa susceptible to carbendazim, however, may not be adequately represented among the standard aquatic test species used in ecotoxicological risk assessment. Moreover, the autochthonous organisms in this area that could be used as bioindicators still need to be found. The aim of the present work was therefore to assess the susceptibility of the preparasitic stages of C. nobilii to noxious effects by carbendazim. The assay protocol consisted in 96- and 48-h acute exposures of early embryonic stages and larvae, respectively, to concentrations ranging from 10 to 360 μg/l. Embryonic development was not inhibited by carbendazim at any of the evaluated concentrations, but the infectivity of larvae emerging from the exposed eggs was significantly diminished. Larval survival rate was also affected at the lowest concentration assayed. Values of the mean inhibition concentration (IC50) were 7 and 11 μg/l for embryos and larvae, respectively. Compared to other freshwater organisms, C. nobilii can be considered a species moderately to highly susceptible to carbendazim. As the expected environmental concentrations of carbendazim range from 6.25 to 41.3 μg/l, C. nobilii could well be a species in danger when exposed to this fungicide.


Ferrari L.,National University of Luján | Ferrari L.,Scientific Research Commission CIC | Eissa B.L.,National University of Luján | Salibian A.,National University of Luján | Salibian A.,Scientific Research Commission CIC
Fish Physiology and Biochemistry | Year: 2011

Stress in fish can be assessed by means of a bioenergetic approach, based on the evaluation of changes in their physiological parameters. The objective of this study was to determine the impact of sublethal water-borne cadmium (Cd) on the energetic balance of juvenile Cyprinus carpio under laboratory conditions after a short-term exposure. Fish were exposed to a concentration of Cd (0. 15 mg Cd l -1) for 2 weeks. This concentration is environmentally realistic since it is usually found, even at higher values, in heavily polluted periurban water bodies of Argentina. No mortality was recorded among the animals used in the experiments. Food intake, food assimilation and assimilation efficiency, fecal production, liver glycogen content, oxygen consumption, oxygen extraction efficiency, specific metabolic rate, ammonia excretion and ammonia quotient (AQ), condition factor, and liver somatic index were determined. The overall balance was expressed as the scope for growth (SFG). The morphological indices and the liver glycogen content of Cd-exposed fish showed no significant differences when compared to those of controls. There was a significant decrease in the food intake, fecal production, and food assimilation rates as well as in AQ; the SFG exhibited a highly significant decrease. The remaining parameters (assimilation efficiency, oxygen consumption, oxygen extraction efficiency, specific metabolic rate, and ammonia excretion) increased after the exposure to Cd. We concluded that the sub-chronic exposure of Cyprinus carpio to a sublethal concentration of Cd causes important alterations in the energy-related homeostasis of fish. Most of the responses are indicative of physiological adaptations to compensate an increased energy requirement due to the impairments caused by the metal. © 2011 Springer Science+Business Media B.V.


Giusto A.,National University of Luján | Somma L.A.,National University of Luján | Ferrari L.,National University of Luján | Ferrari L.,Scientific Research Commission CIC
Ecotoxicology and Environmental Safety | Year: 2012

Hyalella curvispina is representative of zoobenthic communities in Austral South America. It is taxonomically close to Hyalella azteca and abundant in fresh water bodies of the pampasic region of Argentina. It is usually used as test organism in ecotoxicological studies at a regional level, and there is a strong concern to increase the knowledge of both their biology and their sensitivity to different toxic agents. The aim of the present work was to assess the effects of cadmium on H. curvispina juveniles exposed to concentrations expected in the water bodies of the distribution area of the species. Survival, growth and cadmium body burden were evaluated in aqueous and solid matrices under fixed experimental conditions. Animals were exposed in ten-day static toxicity bioassays to 2.5, 5.25 and 11.25 μg Cd/L for the aqueous-phase bioassays, and to 0.85, 2.8 and 5.6. mg Cd/Kg dry sediment for the solid-phase bioassays. In water only assays, the animals exposed to 11.25 μg Cd/L showed a significant decrease in survival and growth. In the sediment bioassays, no effect was observed on survival, and weight was significantly reduced at the highest concentration. Cadmium uptake was concentration dependent for both assay matrices and one order of magnitude higher in the aqueous medium than in the solid matrix. Results indicate that juveniles of H. curvispina are sensitive to cadmium concentrations expected in their environment and thus confirm their importance as test organisms for ecotoxicity assessment in water bodies within the distribution area of the species. © 2012 Elsevier Inc.


Giusto A.,National University of Luján | Ferrari L.,National University of Luján | Ferrari L.,Scientific Research Commission CIC
Ecotoxicology and Environmental Safety | Year: 2014

The use of physiological parameters as sensitive indicators of toxic stress from exposure to different pollutants is an important issue to be studied. Hyalella curvispina is a Neotropical amphipod often used in ecotoxicological evaluations. This work aimed to quantify biochemical responses of ecological importance in H. curvispina males under stress exposure to sublethal concentrations of waterborne copper (Cu) and cadmium (Cd); in order to obtain basic physiological data as indicators of early effect on this species, on track to its standardization. In order to evaluate the physiological, biochemical and energetic status of the exposed animals, the following endpoints were selected: content of glycogen, total proteins, total lipids, triglycerides, glycerol, arginine, arginine phosphate, levels of lipid peroxidation (TBARS), and Na+/K+ATPase, catalase (CAT) and superoxide dismutase (SOD) activities. Our results show that the concentrations of Cu (135 and 175μg/L) and Cd (6.5 and 10.5μg/L) tested altered most of the biochemical variables measured (glycogen, total proteins, total lipids, triglycerides, arginine phosphate, TBARS, and SOD and Na+/K+ATPase activities). In addition, neither the levels of glycerol and arginine nor CAT activity were affected by exposure to either metal. Energy metabolism was similarly affected both by exposure to Cu and exposure to Cd. The results obtained show the existence of an energy imbalance associated with oxidative damage, suggesting a comprehensive response. This work represents a first contribution of the evaluation of the effect of two heavy metals in some parameters of oxidative stress and energy metabolism of H. curvispina males. The results indicate these parameters can provide a sensitive criterion for the assessment of early ecotoxicological effects of Cu and Cd in laboratory assays, on a native species representative of the zoobenthic and epiphytic communities of South America. © 2013 Elsevier Inc.


PubMed | CONICET and Scientific Research Commission CIC
Type: Journal Article | Journal: Journal of helminthology | Year: 2015

We evaluated the effect of carbendazim on non-target organisms using the parasite Chordodes nobilii as a test organism. The Gordiida act as a link between freshwater and terrestrial ecosystems; and C. nobilii, a neotropical representative species of this group, has been shown to be sensitive to other contaminants even at environmentally acceptable concentrations. The taxa susceptible to carbendazim, however, may not be adequately represented among the standard aquatic test species used in ecotoxicological risk assessment. Moreover, the autochthonous organisms in this area that could be used as bioindicators still need to be found. The aim of the present work was therefore to assess the susceptibility of the preparasitic stages of C. nobilii to noxious effects by carbendazim. The assay protocol consisted in 96- and 48-h acute exposures of early embryonic stages and larvae, respectively, to concentrations ranging from 10 to 360g/l. Embryonic development was not inhibited by carbendazim at any of the evaluated concentrations, but the infectivity of larvae emerging from the exposed eggs was significantly diminished. Larval survival rate was also affected at the lowest concentration assayed. Values of the mean inhibition concentration (IC50) were 7 and 11g/l for embryos and larvae, respectively. Compared to other freshwater organisms, C. nobilii can be considered a species moderately to highly susceptible to carbendazim. As the expected environmental concentrations of carbendazim range from 6.25 to 41.3g/l, C. nobilii could well be a species in danger when exposed to this fungicide.

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