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Smut fungi, such as Ustilago maydis, have been studied extensively as a model for plant- pathogenic basidiomycetes. However, little attention has been paid to smut diseases of agronomic importance that are caused by species of the fungus Thecaphora spp., probably due to their more localized distribution. Peanut smut by T. frezii has been reported only in South America, with Argentina being the only country where this disease has been noted in commercial species. In this work, important advances in deciphering T. frezii specific biology/pathobiology in relation to the agronomically relevant potato (T. solani), wheat (U. tritici) and barley (U. nuda) smuts are presented. The state of knowledge of fungal effectors, functionally characterized to date in U. maydis and most recently in T. thlaspeos, as well as the potential to be present in other Thecaphora species involved in dicot-host interactions like T. frezii-peanut, is summarized. We also discuss the applicability and limitations of current available methods for the identification of smut fungi in different matrices, and the management strategies to reduce their impact on the agri-food quality. To conclude, we describe some of the challenges in elucidating T. frezii strategies which allow it to successfully infect the host, and tolerate or evade plant immune defense mechanisms, as well as analysis of other aspects related to pest control and their implications for human health.

To evaluate the natural occurrence of the plant growth-promoting bacterium Azospirillum brasilense and petunia plants, local strains were isolated and characterized by biochemical and molecular methods. Three strains were assessed in greenhouse conditions using Petunia × hybrida Ultra™. Treatments: Plants without bacterial inoculation or chemical fertilization; fertilized with NPK and KNO3 ; and independently inoculated with the strains 2A1, 2A2, and 2E1 by submerging their roots in a bacterial suspension (~106 CFU·ml-1 ). Root length, dry weight of roots and shoots, leaf area, leaf greenness, and nutrient content were evaluated. The number of days from transplanting to the opening of the first flower and the number of flowers per plant were also determined. As a result, five isolates were characterized as A. brasilense, showing the capacity to produce indoles and siderophores, to solubilize phosphate, nitrogenase activity, and nifH-PCR amplification. In general, all the parameters of the plant assay were improved in plants inoculated with A. brasilense, with variations among the strains, as well as the onset of flowering and the number of flowers per plant, compared with uninoculated or fertilized plants. This is the first report on the natural occurrence of A. brasilense in petunia with the capacity to improve plant growth and flowering.

Microsporidia are obligate intracellular fungi with a remarkable ability to infect a wide range of invertebrate and vertebrate hosts. Namely, Enterocytozoon bieneusi is the most frequently microsporidia reported worldwide, and mainly associated with chronic diarrhea and wasting syndrome in AIDS patients. Microscopy and PCR-based detection techniques are effective for diagnosis and identification of species and genotypes; however, these methods should be standardized in each laboratory. In this study, we performed microscopy and nested PCR techniques with PCR product sequencing to detect E. bieneusi in human stool samples. These techniques, if applied together, might prove useful for diagnosis and future epidemiological studies of intestinal microsporidiosis in Argentina.

Mercury and selenium concentrations and Se:Hg molar ratio in edible muscle and hepatopancreas of the crab Callinectes arcuatus from coastal lagoons of northwest Mexico were determined using atomic absorption spectrophotometry. The three coastal lagoons were Santa Maria La Reforma (SMLR), Urias (UR), and Huizache-Caimanero (HC); samplings were carried out from December 2016 to October 2017. The mercury ranges in the muscle of C. arcuatus in SMLR, UR, and HC lagoons were 0.31–0.52, 0.15–0.45, and 0.22–0.55 μg g−1, respectively. In hepatopancreas, the values ranged from 0.08 to 0.15, 0.06 to 0.15, and 0.05 to 0.12 μg g−1 in SMLR, UR, and HC lagoons, in that order. For selenium concentrations in C. arcuatus muscle, the ranges 11.64–20.14, 14.88–19.71, and 15.27–29.51 μg g−1 were determined in SMLR, UR, and HC lagoons, respectively. While for hepatopancreas, the ranges were 34.34–44.13, 27.77–40.45, and 15.16–49.80 μg g−1, in that order. No significant relationships (p > 0.05) between mercury and selenium concentrations (in white meat and hepatopancreas) were observed in C. arcuatus carapace width and length. Se:Hg molar ratio values were 98.1 ± 20.8, 171.4 ± 81.6, and 176.8 ± 51.2 for SMLR, UR, and HC lagoons, in that order. This high ratio (> 1) in C. arcuatus edible muscle indicated that selenium concentration was sufficient to neutralize possible mercury toxicity, so it does not represent danger to humans when it is consumed.

Raptors as top predators have been used as effective sentinels of environmental stressors in agricultural areas worldwide. Pollutants in agricultural areas have negative effects on top predator populations. Biomarkers such as erythrocyte nuclear abnormalities have been used as an effective measure of genotoxicity caused by exposure—particularly short-term exposure—to pollutants. We took blood samples from 54 wild specimens of American kestrel (Falco sparverius) captured in an agricultural area in Valle de Santo Domingo, Baja California Sur, Mexico in the autumns of 2018 and 2019 (n = 25) and the winters of 2019 and 2020 (n = 29). We prepared and examined blood smears to look for erythrocyte abnormalities as a means to evaluate genotoxicity. The number of abnormality types and the total frequency of abnormalities (MNs and NAs: notched, symmetrically or asymmetrically constricted, displaced, or indented nuclei) per 10,000 erythrocytes were calculated for all the specimens. We found a high frequency of abnormalities in numerous individuals, similar to those found in raptors from highly polluted areas. The best-fit generalized linear model for the number of abnormality types included season-of-the-year as the main significant predictor; the model for the total frequency of abnormalities included season and wing chord, an indicator of body size and health condition, as significant predictors. MNs frequencies were significantly related to season; NAs frequencies were related to season, wing chord length, and coverage of native vegetation around the area where the birds were captured. Abnormalities observed in the autumn closely coincide with the time when agrochemicals are applied in the area, mainly after the rains and during hot spells in late summer and early autumn. Small-sized kestrels showed higher frequencies of NAs, with an additional impact if native vegetation had been cleared for agriculture; this suggests both that resident birds are more exposed, and the observed genotoxicity has a local origin. These results, together with the ecological and physiological characteristics of the American kestrel suggest that this charismatic and widely distributed species might constitute a suitable biomonitor of genotoxicity in rural landscapes.

The objective of this review is to synthetize knowledge of the relationship between metals and oxidative stress in aquatic crustaceans (mainly shrimp and crabs) to analyze antioxidant responses when organisms are exposed to metals because the direct metal binding to the active site of enzymes inactivates most of the antioxidant systems. This study reviewed over 150 works, which evidenced that: (i) antioxidant defense strategies used by aquatic decapod crustaceans vary among species; (ii) antioxidant enzymes could be induced or inhibited by metals depending on species, concentration, and exposure time; and (iii) some antioxidant enzymes, as superoxide dismutase increase their activity in low metal levels and time exposures, but their activities are inhibited with higher metal concentrations and exposure time.

Adult sharpnose sharks (Rhizoprionodon longurio) with a mean total length of 110.93 ± 5.30 cm were obtained from a local fishery in Mazatlan (Southeast Gulf of California, Mexico). The total mercury content in muscle was analyzed by cold vapor atomic absorption spectrophotometry. The minimum and maximum total mercury content were 0.77 ± 0.23 and 2.33 ± 0.57 µg/g (dry weight), respectively. Only 6.6 % of the organisms did show mercury content higher than the permissible limit. No significant relationship was observed between weight and total mercury content in edible muscle of the sharks (r = 0.364, p > 0.05). The Hazard Quotient values for total mercury (0.005–0.015) and methyl mercury (0.022–0.065) indicated no risk by edible muscle consumption of the shark Rhizoprionodon longurio.

This study investigated acute arsenic toxicity and bioconcentration capacity in Litopenaeus vannamei because it has been frequently exposed to lower salinities than its isosmotic point (25 g L−1). Juveniles (9.9 ± 0.4 g) were exposed to low (5–10 g L−1) and isosmotic salinity (25 g L−1) levels; As values were 30.8, 20.2, 16.8 and 13.9 mg L−1 at 5 g L−1; 30.4, 19.1, 16.8 and 14.8 mg L−1 at 10 g L−1; 31.5, 19.0, 15.0 and 11.9 mg L−1 at 25 g L−1 at 24, 48, 72 and 96 h LC50, respectively. No significant differences were found among As LC50 values calculated for different salinity levels and same exposure times, concluding that low salinity did not affect shrimp sensitivity to As. Likewise, no significant differences were observed in As bioconcentration in shrimp exposed to the same waterborne As and distinct salinity, supporting the results of acute toxicity. Bioconcentration factors of As maintained a relatively stable tendency where all values (0.8 ± 0.2 to 1.7 ± 0.4) were statistically comparable to 1, indicating that As was accumulated in a similar proportion to waterborne As concentration at three salinity levels. This study proposed 135.3 ± 12.1 μg L−1 for salinities from 5 to 25 g L−1 as provisional safe As concentration. According to these results, the hypothesis that sustains an effect of low salinity on As acute toxicity and its bioconcentration capacity cannot be acceptable. Therefore, the information provided allows knowing the threshold levels of As in water to avoid ecological and economic losses.

The aim of this work was to determine the best conditions for biomass production of the bacterium Enterobacter cloacae and for Cd and Pb retention by adsorption on the cell walls or by absorption and accumulation in the bacterial biomass. Suspended and immobilized cultures of this bacterium, acclimated to both metals, were grown for 24 h at pH 6, 7 and 9, in trypticase soy (TS) medium added with 2.73 mg/L of Cd or 16.8 mg/L of Pb. Immobilized cultures at pH 7 and 9 had the highest biomass production. Percentages of Cd retention by adsorption and absorption increased with increasing pH, but adsorption was higher in suspended while absorption was higher in immobilized cultures. Possibly because of different affinity of bacterial cells for these metals, the percentages of Pb retention were higher than those of Cd. In percentage, the highest Pb adsorption on cell walls was at pH 9, while retention by biomass decreased with increasing pH. The amount of metal retained by one g of bacterial biomass, efficiency was higher at pH 6, possibly because of the presence of dead or dying bacterial cells.

Litopenaeus vannamei juveniles were exposed to sublethal levels (2.33-18.03 µg/L) of inorganic mercury. Time of exposure (0, 24 and 168 h) was a source of DNA damage. Mean comet tail length not changed significantly with mercury concentrations and exposure time, and this parameter cannot be used to assess DNA damage in this shrimp. Total hemocyte count showed a trend to decrease according to the increase of mercury concentrations, although no significant difference between treatments with mercury was observed. The phenoloxidase (PO) activity was not influenced by the time of exposure. At the end of the experiment, the PO in organisms exposed to 18.03 µg/L was different from the control. The time of exposure has a more important influence in superoxide dismutase than the concentration of mercury. According to these results, a suitable criterion of water quality for long-term exposure of L. vannamei should be lower than 2 µg/L of mercury.

Frixione, Martín G., Rodríguez-Estrella, Ricardo (2021): Trophic segregation of the Burrowing Owl and the American Kestrel in fragmented desert in Mexico. Journal of Natural History 54 (41-42): 2713-2732, DOI: 10.1080/00222933.2020.1865470, URL: http://dx.doi.org/10.1080/00222933.2020.1865470

Some Plant Growth-Promoting Rhizobacteria (PGPR) can induce protection against pathogens, increasing plant tolerance to various diseases. This so-called biocontrol activity is replacing harmful practices in agriculture caused by the use of agrochemicals. Azospirillum brasilense is one of the PGPR already effectively used as a resistance inducer in several crops. The aim of this study was to evaluate the protective effect of PGPR A. brasilense strains isolated from strawberry and petunia plants (REC3, 2A1, 2A2, and 2E1) against the fungal pathogen Macrophomina phaseolina, which is the causal agent of the strawberry charcoal rot disease. In vitro antagonism assays and enzymatic tests on Petri dishes revealed no direct inhibition on M. phaseolina growth by any of the A. brasilense strains. However, strawberry plants treated with REC3 and 2A1 strains increased callose and lignin deposition and stomatal closure compared to untreated plants. In addition, treatments with either bacterial strains induced a defense response in strawberry plants against virulent isolates of M. phaseolina evidenced by an increased tolerance to the charcoal rot disease. These results suggest that A. brasilense REC3 and 2A1 strains can be used for the activation of innate immunity in strawberry plants as a strategy for managing charcoal rot in a sustainable and environmentally friendly way. EEA Famaillá Fil: Viejobueno, Josefina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina Fil: Albornoz, Patricia Liliana. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; Argentina Fil: Albornoz, Patricia Liliana. Fundación Miguel Lillo; Argentina Fil: Camacho, María. Instituto de Investigación y Formación Agraria y Pesquera; España Fil: Santos, Berta de los. Instituto de Investigación y Formación Agraria y Pesquera; España Fil: Martinez Zamora, Martin Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Martinez Zamora, Martin Gustavo. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Salazar, Sergio Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina Fil: Salazar, Sergio Miguel. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina

Mycoviruses appear to be widespread in Fusarium species worldwide. The aim of this work was to identify mycoviral infections in Fusarium spp., isolated from maize and sorghum grown in Argentina, and to estimate their potential effects on the pathogenicity and toxigenesis of the host fungus towards maize. Mycoviruses were identified in 2 out of 105 isolates analyzed, Fusarium verticillioides strain Sec505 and Fusarium andiyazi strain 162. They were characterized as members of the genus Mitovirus by high-throughput sequencing and sequence analysis. The F. verticillioides mitovirus was a novel mycovirus whereas the F. andiyazi mitovirus was found to be a new strain of a previously identified mitovirus. We have named these mitoviruses, Fusarium verticillioides mitovirus 1 (FvMV1) and Fusarium andiyazi mitovirus 1 strain 162 (FaMV1-162). To our knowledge, FvMV1 is the first mycovirus reported as naturally infecting F. verticillioides, the major causal agent of ear rot and fumonisin producer in corn. Both mitoviruses exhibited 100% vertical transmission rate to microconidia. The Fa162 strain infected with FaMV1-162 did not show phenotypic alterations. In contract, F. verticillioides Sec505 infected with FvMV1 showed increased virulence as well as microconidia and fumonisin-B1 production, compared with two uninfected strains. These results suggest that FvMV1 could have a role in modulating F. verticillioides pathogenicity and toxin production worth further exploring.

Antibacterial coatings have currently gained great importance in biomedical technology investigations. Because of the spatial arrangement of the film coatings, evaluation of antibacterial activity presents a new challenge regarding traditional bacterial counting methods. In this protocol, four clinically relevant pathogens, Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were incubated on titania mesostructured thin film coatings for 24 h. Then, cell viability was studied considering three methods: counting of the number of colony forming units (CFU), live/dead staining, and quantification of extracellular DNA in suspension. Firstly, bacterial count was determined by the standard plate-count technique. Secondly, bacteria membrane integrity was evaluated by utilization of two fluorescent dyes, which allow distinction between live (membrane intact) and dead (membrane disrupted) bacteria. Lastly, extracellular DNA was quantified by spectrophotometry. In this manner, the three aforementioned techniques enabled the study of bacterial viability by qualitative and quantitative analyses.

Juveniles of the shrimp Litopenaeus vannamei (3.3 ± 0.4 g) were exposed separately to nitrite (0.0, 1.1, 2.6, and 5.3 mg/L nitrogen as nitrite [NO2−-N]) and nitrate (0, 90, 225 and 400 mg/L nitrogen as nitrate [NO3−-N]) concentrations equivalent to 0, 10, 25, and 50% of the LC50-96 h value of NO2−-N and NO3−-N in low salinity water (3 g/L). Shrimps responded to nitrite and nitrate according to changes in oxyhemocyanin, glucose, lactate and ion levels in the hemolymph after 6, 12, 24, and 48 h of exposure. Oxyhemocyanin levels decreased with increasing nitrite and nitrate levels and were higher at 50% exposure to the contaminants. Compared to the control, glucose and lactate increased significantly at 50% exposure to nitrite and nitrate, particularly at 12 and 24 h. Na+ in the hemolymph changed with nitrite and nitrate, while K+ only changed ˜with nitrite.

Moon phases influence the molting process of shrimp, which affect other physiological processes as immune response. This study analyzed some parameters of immune response: total hemocytes counts (THC), hemolymph clotting time and superoxide anion (O2−) production, total protein concentration, superoxide dismutase activity, and the presence of Vibrio spp. in Litopenaeus vannamei at different moon phases. The highest percentage of organisms in intermolt stage was observed in the first quarter moon phase (95%). The highest THC was observed at new moon phase, which was significantly different (p 0.05) between different moon phases. The higher (p

Background and aimFungal and plant secondary metabolites modulate the plant-pathogen interactions. However, the participation of fumonisins in the Fusarium verticillioides-maize pathosystem is unclear. In this work was studied the cell death, and the reactive oxygen species (ROS) - phytohormone imbalance interplay underlying the phytotoxicity of fumonisin B1 (FB1) in maize germplasms with contrasting resistance to Fusarium ear rot in the field.MethodsResistant (RH) and susceptible hybrid (SH) maize seedlings, grown from uninoculated seeds irrigated with FB1 (1 and 20 ppm), were harvested at 7, 14 and 21 days after planting, and were examined for electrolyte leakage (aerial parts); and for oxidative stress biomarkers (aerial parts and roots). The phytohormone (salicylic and jasmonic acids) imbalance interplay underlying the FB1-induced cell death were further explored in seedlings exposed 24 h to the mycotoxin (1 ppm) in hydroponics.ResultsCell death increased in RH and SH watered with 1 and 20 ppm of mycotoxin, respectively. Both toxin concentrations were pro-oxidant, and the major perturbations were found in roots. An Integrated Biomarker Response index was calculated suggesting that phytotoxicity occurs in a redox context more efficiently controlled by RH.ConclusionThe pre-treatment with the antioxidant ascorbic acid led to the conclusion that cell death in RH was related to a salicylic acid increase mediated by ROS. Nevertheless, FB1 induced two different phytohormonal regulatory mechanisms mediated by oxidative stress in both maize hybrids.

Experiments were carried out to verify the existing information on the LC50 of waterborne Hg for L. vannamei postlarvae and determine that of juveniles. Additionally, the structure of different tissues of the organisms which survived the acute toxicity test was examined. The experiment with juveniles was performed after addition of 1.00, 0.75, 0.50, 0.25 and 0.10 mg/L of Hg (using HgCl2). For postlarvae, additions were 0.5, 0.4, 0.3, 0.2, 0.1 and 0.01 mg/L. Acute toxicity tests determined that, after 96 h of exposure to Hg, the respective LC50 values for juveniles and postlarvae of Litopenaeus vannamei were 0.50 and 0.25 mg/L. Although lower that the only value of LC50 known for L. vannamei postlarvae, these lethal concentrations are one order of magnitude higher than those known for larval and juvenile stages of other crustaceans, suggesting that L. vannamei has a high resistance to the toxic effects of waterborne Hg. The only histological damages in survivors to 96 h of exposure were observed in nervous tissues and consisted in the presence of necrotic cells. The degree of damage severity was related to the concentration of dissolved Hg, and the numbers of necrotic cells decreased progressively with increasing distance from the nerve ganglia. A safe level of mercury exposure for L. vannamei postlarvae would be 2.5 μg/L.

Distincts methods are used to evaluate acute toxicity and generate different values of LC50. However, the static with renewal (100% renewal every 24 h) and feeding method is the more utilized. This study was developed to determine the differences between the LC50 obtained and define which method is most adequate for testing acute toxicity of nitrite in shrimp. Litopenaeus vannamei postlarvae (PL18) were exposed to different concentrations of nitrite-N (nitrite as nitrogen) at 3 g/L of salinity, using two different strategies of renewal solution and feeding trials: treatment Ts/nf/1 (static (no water renewal) + not feed), Tsr/f/2 (static with renewal + feed), Tsr/nf/3 (static with renewal + not feed) and Ts/f/4 (static + feed). Different values of LC50 nitrite-N for 96 h values were generated for the four distinct treatments (Tsr/f/2 > Tsr/nf/3 > Ts/nf/1, Ts/f/4). However, significant differences (p Tsr/nf/3). Considering the magnitude and variation of the LC50 values, it is recommended the static with renewal method and feeding method which generates higher values of LC50 and lowest variation, results suggesting that this method is more adequate to evaluate in shrimps nitrite and other nitrogen compounds acute toxicity.

Induced systemic resistance (ISR) is one of the indirect mechanisms of growth promotion exerted by plant growth-promoting bacteria, and can be mediated by ethylene (ET). We assessed ET production and the expression of related genes in the Azospirillum?strawberry plant interaction. Ethylene production was evaluated by gas chromatography in plants inoculated or not with A. brasilense REC3. Also, plants were treated with AgNO3, an inhibitor of ET biosynthesis; with 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ET biosynthesis; and with indole acetic acid (IAA). Plant dry biomass and the growth index were determined to assess the growth-promoting effect of A. brasilense REC3 in strawberry plants. Quantitative real time PCR (qRT-PCR) was performed to analyse relative expression of the genes Faetr1, Faers1 and Faein4, which encode ET receptors; Factr1 and Faein2, involved in the ET signalling pathway; Faacs1 encoding ACC synthase; Faaco1 encoding ACC oxidase; and Faaux1 and Faami1 for IAA synthesis enzymes. Results showed that ET acts as a rapid and transient signal in the first 12 h post-treatment. A. brasilense REC3-inoculated plants had a significantly higher growth index compared to control plants. Modulation of the genes Faetr1, Faers1, Faein4, Factr1, Faein2 and Faaco1 indicated activation of ET synthesis and signalling pathways. The up-regulation of Faaux1 and Faami1 involved in IAA synthesis suggested that inoculation with A. brasilense REC3 induces production of this auxin, modulating ET signalling. Ethylene production and up-regulation of genes associated with ET signalling in strawberry plants inoculated with A. brasilense REC3 support the priming activation characteristic of ISR. This type of resistance and the activation of systemic acquired resistance previously observed in this interaction indicate that both are present in strawberry plants, could act synergistically and increase protection against pathogens. Fil: Elías, Juliana María. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Guerrero Molina, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Martinez Zamora, Martin Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Diaz Ricci, Juan Carlos. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Pedraza, Raúl Osvaldo. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina

Shrimp aquaculture has been the fastest growing and diversifying food production industry in the world. On the other hand, basil is an important herb moderately salt-tolerant, which is among the most main crops which essential oils stand out for the quality and chemical diversity. This paper evaluates the performance of an aquaponic shrimp (Litopenaeus vannamei)-basil (Ocimum basilicum) system in terms of water quality, water use, and nutrient removal. This aquaponic system consists of three units (aquaculture; water conditioning; and hydroponic) coupled in a recirculation system using low-salinity water: well water (WW) and diluted seawater (DSW). The experiment was conducted over 78 days to characterize the performance of the proposed system, which reduces ~73% and 76% of the organic suspended solids, 23% and 18% of the total phosphorous (TP), and 24% and 21% of total nitrogen (TN) for WW and DSW, respectively. The reduction of TN and TP in the system implies a great efficiency in the use of nutrients, and consequently a low environmental impact. The water use by the shrimp biomass was 2.7 and 3.0 m3 kg−1 for WW and DSW, respectively, while by the total biomass (shrimp + basil) was 0.5 and 0.8 m3 kg−1 for WW and DSW, respectively. These results evidence that aquaponic shrimp-basil system remove N and P from water, improve water quality, enable efficient use of water and nutrients, reduce effluent discharge to the environment, as well as increase production.

Procyrnea choique n. sp. is described from the lesser rhea, Rhea pennata d'Orbigny (Aves: Rheidae), from the Protected Natural Area Península Valdés, Chubut province, Argentina. The new species resembles P. ficheuri, P. murrayi, P. excisiformis, P. dollfusi, P. haliasturi, P. anterovulvata, P. graculae, P. brevicaudata, P. uncinipenis, P. javaensis, P. ameerae, P. ornata, P. aegotheles, P. spiralis, P. ruschii and P. aptera, mainly in the absence of lateral alae; but differs from its congeners by having a left spicule without barbs, the position of the vulva which is post-equatorial, the absence of lateral ridges, absent median precloacal papilla, asymmetrical caudal alae, males more than 6 mm long, left spicule 1 mm long and spicule ratio 1:3. Our results extend the taxonomy of Procyrnea Chabaud, 1958 and comprise the first report of a habronematid from R. pennata. A key to species of Procyrnea is presented. Fil: Bagnato, Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Frixione, M.. Centro de Investigaciones Biológicas del Noroeste; México Fil: Digiani, Maria Celina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cremonte, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina

The antiparasitic activity of 3-hydroxykynurenine (3-HK), one of the major tryptophan catabolites of the kynurenine pathway, against both Trypanosoma cruzi evolutive forms that are important for human infection, trypomastigotes (Tps) and amastigotes (Am), possible targets in the parasite and the drug toxicity to mammalian cells have been investigated. 3-HK showed a potent activity against Am with IC50 values in the μM concentration range while the IC50 values to cause Tps death was ∼6000-times higher, indicating that the replicative form present in the vertebrate hosts is much more susceptible to 3-HK than bloodstream Tps. In addition, 3-HK showed activity against Tps and Am, at concentrations which did not exhibit toxicity to mammalian cells. Ultrastructural analysis and flow cytometry studies indicated that Am and Tps mitochondrion and nuclei contain 3-HK targets. The potency and selectivity of 3-HK, which is generated during T. cruzi infection in human and mice, suggest that 3-HK may be a suitable candidate for drug research and development for Chagas disease. Fil: Knubel, Carolina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Insfran, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Martinez, Fernando Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Díaz Luján, Cintia María. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Biologia Celular; Argentina Fil: Fretes, Ricardo Emilio. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Biologia Celular; Argentina Fil: Theumer, Martín Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Cervi, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Motran, Claudia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina

Cholinesterases (ChE) have been suggested as biomarkers of the presence of organophosphorus insecticides (OP). The activities of these enzymes were determined in abductor muscle, gills and labial palps of oysters collected during the rainy and the dry seasons at eight points of the coastal zone of Nayarit state (NW Mexico), aiming to determine if their variability is related to geographic and seasonal differences in the use of OP. At all stations, ChE mean activity was lower in the dry than in the rainy season, and the muscle had consistently lower values than gills and labial palps. Lower activities were found in Bahia de Banderas, in the southern part of the state, than in the northern stations. This may be explained by the year-round use of OP insecticides in the southern part of the state, whereas herbicides are the most common pesticides used in agricultural areas draining into the northern stations during the rainy season.

This research was to evaluate the load and mobility of Cu in juvenile Litopenaeus vannamei after exposure (48 h) to sublethal concentration of nitrite (5.3 mg/L NO2−-N) at a salinity of 3.0 g/L. The hypothesis is that such exposure causes a Cu mobility in the tissues of shrimp. The Cu concentration in exoskeleton, hepatopancreas, muscle and hemolymph in the control group were 38.9 ± 3.0, 2478 ± 256, 11.9 ± 0.2 µg/g (dw) and 95.4 ± 19.1 µg/mL, while in the nitrite exposure, were 46.0 ± 0.1, 1546 ± 173, 11.3 ± 0.3 µg/g (dw) and 118.2 ± 10.5 µg/mL, respectively. Only hepatopancreas exhibited a significant (p

Mercury and selenium were assessed in Mustelus henlei, which is a carnivorous predatory shark that is important for the coastal communities of the northern Mexican Pacific (NMP). Sixty-two individuals were sampled; muscle and liver were isolated and analyzed by atomic absorption spectrophotometry. The mean Hg concentrations (wet weight) obtained for muscle (0.08 ± 0.10 μg g−1) and liver (0.09 ± 0.26 μg g−1) were below the allowed limits (

With the aim of determining the benefit from consumption of dolphinfish Coryphaena hippurus from La Paz and Cabo San Lucas in the southern area of the Gulf of California, mercury (Hg) and selenium (Se) were measured in liver and muscle of specimens (n = 362) collected between 2006 and 2013. Mean levels of Hg in muscle (0.61 μg g-1) and liver (0.42 μg g-1) of all individuals from La Paz were significantly higher (p < 0.05) than in fish from Cabo San Lucas; in the case of Se, mean concentrations in liver (1.54 μg g-1) of all individuals from La Paz were significantly higher (p < 0.05) than in fish from Cabo San Lucas. Hg levels in muscle were positively and significantly (p < 0.05) correlated with fork length and weight of fish; in liver, Hg and Se were significantly (p < 0.05) correlated with fork length and weight of specimens. Levels of Hg and Se in muscle and liver among years varied significantly (p < 0.05); although there was not a defined pattern of temporal fluctuations for both elements, the lowest Hg levels occurred in 2009 when surface water temperatures were the highest for the sampled years. With respect to the Se health benefit value (HBVSe), results were positive and above the unit in all cases; it implies that consumption of dolphinfish in the southern Gulf of California is beneficial.

Information on toxicity of nitrogen compounds for Litopenaeus vannamei in coastal ecosystems and culture under low salinity is scarce. Acute toxicity trials were conducted in L. vannamei to determine the single and combined effects of ammonia, nitrite and nitrate at a salinity of 3 g/L. The 96 h-LC50 was 29.0 mg/L for total ammonia nitrogen (TAN); 10.6 mg/L for nitrogen as nitrite (NO2−-N); and 900 mg/L for nitrogen as nitrate (NO3−-N). The joint effects of ammonia, nitrite and nitrate exposure were antagonistic at 24–72 h; and additive from 72 to 96 h. The proposed safety levels of single exposure to TAN, NO2−-N and NO3−-N for L. vannamei are 1.45, 0.53 and 45.0 mg/L, respectively. When in mixture, the proposed level of TAN/NO2−-N/NO3−-N is 0.05 TU (Toxicity Unit) corresponding to 0.48, 0.08 and 14.6 mg/L of TAN, NO2−-N and NO3−-N, respectively.

Poloxamer block copolymers (also known as Pluronic®) are particularly useful for drug delivery and self-assembly techniques. These nanopolymers are generally considered to be biologically inert and they were used to generate only bacteria repellent surfaces but keeps bacteria alive and as a latent threat. However, the inherent capabilities of these nanopolymers to kill bacteria have been largely overlooked. Here, we report that Pluronic shaped as superstructures (self-organized array of micelles) in fact possess a broad-spectrum bactericidal activity (capability of killing bacteria) similar to that shown for some antibiotics. This further represents the first report that shows that appropriate control of superstructured mesophase architecture is a key parameter for bactericidal efficacy. Based on this finding, we have developed a highly bactericidal coating (>99.9 % kill) against all tested Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Salmonella typhimurium LT2, Escherichia coli K12 and Pseudomonas aeruginosa PAO1) bacteria which moreover allows the adhesion and proliferation of mammalian cells. The inexpensiveness and ease of production make these versatile nanopolymer structures a powerful tool for the development of a new generation of highly effective antimicrobial coatings. Fil: Scilletta, Natalia Antonela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes.; Argentina Fil: Pezzoni, Magdalena. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Catalano, Paolo Nicolás. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes.; Argentina Fil: Bellino, Gabriel Martín. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Constituyentes.; Argentina

The use of drones has expanded the boundaries of several activities, which is expected to be utilized intensively in the near future. Interactions between urbanity and naturalness have been increasing while urban expansion amplifies the proximity between urban and natural areas. In this scenario, the interactions between drones and fauna could be augmented. Therefore, the aim of this study was to depict and evaluate the responses of the opportunistic and territorial seagull Larus livens to a small-sized drone during the non-breeding stage in urban areas and natural surroundings. The results evidenced that gulls do not react to drone sounds, coloration, or distance between them and the drone take-off spot. Clearly, the take-off vertical movement triggers an agonistic behavior that is more frequent in groups conformed by two adults, evidencing some kind of territorial response against the device, expressed as characteristic mobbing behavior. Thus, adult settled gulls in touristic and non-urbanized areas displayed agonistic behavior more frequently against the drone. Despite the coastal urban area being a free interaction environment, it evidences a low risk between drone management and territorial seabirds.

This study evaluated low salinity effect on acute Hg toxicity and bioconcentration capacity in L. vannamei juveniles (8.4 ± 0.7 g), because this species is frequently exposed to hypo-osmotic environments in its natural habitat, and in farming ponds. Hg LC50 values were 1723, 1272, 983 and 536 μg L−1 at salinity of 5 ppt (parts per thousand); 2203, 1740, 1340 and 873 μg L−1 at 10 ppt; and 7013, 5693, 1759 and 1534 μg L−1 at 25 ppt for 24, 48, 72 and 96 h, respectively. After 96 h, acute Hg toxicity in shrimp was significantly higher in salinity of 5 ppt than in 25 ppt; likewise, Hg bioconcentration in shrimp exposed to different Hg treatments was statistically greater in salinity of 5 ppt than in 25 ppt. The chemical speciation calculated in experimental waters suggested that neutral chemical Hg species (HgCl2 and HgClOH) were the most bioavailable because their fractions (51–62%) increased when salinity decreased. Therefore, the inverse relationship between Hg toxicity and salinity was due to osmotic stress and the neutral chemical Hg species fractions that increased at lower salinities. Hg bioconcentration factors indicated that the higher Hg waterborne concentrations were the most saturated uptake and storage mechanisms in shrimp. Thus, Hg concentrations in organisms did not increase in proportion to waterborne Hg concentrations in the three salinities. These results support the hypothesis of an effect of low salinity on Hg toxicity and bioconcentration capacity in L. vannamei. The safe Hg concentrations 5.4, 8.7 and 15.3 μg L−1 were proposed for shrimp exposed to salinity of 5, 10 and 25 ppt, respectively. This information allows recognizing risky environments for both wild and cultured healthy growth of these shrimp, which can help decision makers on coastal management and shrimp pond managers to have better water quality.

With the aim of knowing annual variations of Hg concentrations in muscle and liver of blue marlin (Makaira nigricans) from the southern Gulf of California, fish were collected between 2005 and 2012 in three areas. In general, Hg levels were more elevated in liver than in muscle. Variations of Hg concentrations in muscle and liver among the studied years were not significant. Hg levels in muscle and liver increased significantly with length and weight of fish. In comparison to other studies, Hg levels in muscle and liver were lower. With respect to maximum permissible limits (1.0 µg g−1 wet weight) of Hg in Mexico, the average concentration (1.91 µg g−1 wet weight) in the edible portion (muscle) of blue marlin was over the legal limit; this issue is worth research efforts in relation to the rate of ingestion of this species and the co-occurrence of selenium in the edible portion.

The mercury content of mullets and black mojarras of Urías lagoon (NW Mexico) were determined every second month from November 2012 to September 2013, to determine differences related to season or to trophic levels. The Hg contents of the muscle were significantly higher in mojarras, confirming that Hg contents tend to increase along the food chain, while the levels in liver were higher in mullets, suggesting different Hg storage strategies of these species. In mullets, the content of muscles did not vary seasonally and was significantly lower than in the liver. In black mojarras there were no significant differences between muscle and liver, and the lowest mean values were in May in both tissues. Given the low Hg contents, both species are safe for human consumption, but care should be taken in traditional fishing communities.

The nitrite toxicity was estimated in juveniles of L. vannamei. The 24, 48, 72 and 96 h LC50 of nitrite-N on juveniles were 8.1, 7.9, 6.8 and 5.7 mg L−1 at 0.6 g L−1; 14.4, 9.6 8.3 and 7.0 mg L−1 at 1.0 g L−1; 19.4, 15.4, 13.4 and 12.4 mg L−1 at 2.0 g L−1 of salinity respectively. The tolerance of juveniles to nitrite decreased at 96 h of exposure by 18.6% and 54.0%, when salinity declined from 1.0 to 0.6 g L−1 and from 2.0 to 0.6 g L−1 respectively. The safe concentrations at salinities of 0.6, 1.0 and 2.0 g L−1 were 0.28, 0.35 and 0.62 mg L−1 nitrite-N respectively. The relationship between LC50 (mg L−1), salinity (S) (g L−1) and exposure time (T) (h) was LC50 = 8.4688 + 5.6764S – 0.0762T for salinities from 0.6 to 2.0 g L−1 and for exposure times from 24 to 96 h; the relationship between survival (%) and nitrite-N concentration (C) for salinity of 0.6–2.0 g L−1, nitrite-N concentrations of 0–40 mg L−1 and exposure times from 0 to 96 h was as follows: survival (%) = 0.8442 + 0.1909S – 0.0038T – 0.0277C + 0.0008ST + 0.0001CT–0.0029SC, and the tentative equation for predicting the 96-h LC50 to salinities from 0.6 to 35 g L−1 in L. vannamei juveniles (3.9–4.4 g) was 96-h LC50 = 0.2127 S2 + 1.558S + 5.9868. For nitrite toxicity, it is shown that a small change in salinity of waters from 2.0 to 0.6 g L−1 is more critical for L. vannamei than when wider differences in salinity occur in brackish and marine waters (15–35 g L−1).

The golden cownose ray (Rhinoptera steindachneri) and the whale shark (Rhincodon typus) are two elasmobranch species commonly found in Bahia de La Paz, Baja California Sur, Mexico. There are no records of the species sharing the same sites, as their prey, ecology and migration sites normally deviate. Both are listed as endangered and vulnerable species, respectively, under Mexican and international regulations. We took images by a quad-copter near Mogote Beach and recorded whale sharks during late July, alongside a group of golden cownose rays, although earlier research suggests that the main whale shark feeding season starts in late August or September. These recordings showed for the first time, the co-occurrence of these two vulnerable elasmobranch species while feeding possibly simultaneously. This indicates that there might be a relation between the presence of the two species and the interannual variability in zooplankton abundance. The latter may have implications for possible resource overlapping, a current topic in elasmobranch research. Furthermore, these findings highlight the usefulness of drones when capturing biological data. This information is important in the understanding of the ecology and trophic interactions of threatened species and is a step forward towards their understanding and conservation.

Damaged cells release the pro-inflammatory signal ATP, which is degraded by the ectonucleotidases CD39 and CD73 to the anti-inflammatory mediator adenosine (ADO). The balance between ATP/ADO is known to determine the outcome of inflammation/infection. However, modulation of the local immune response in different tissues due to changes in the balance of purinergic metabolites has yet to be investigated. Here, we explored the contribution of CD73-derived ADO on the acute immune response against Trypanosoma cruzi parasite, which invades and proliferates within different target tissues. Deficiency of CD73 activity led to an enhanced cardiac microbicidal immune response with an augmented frequency of macrophages with inflammatory phenotype and increased CD8+ T cell effector functions. The increment of local inducible nitric oxide (NO) synthase (iNOS)+ macrophages and the consequent rise of myocardial NO production in association with reduced ADO levels induced protection against T. cruzi infection as observed by the diminished cardiac parasite burden compared to their wild-type (WT) counterpart. Unexpectedly, parasitemia was substantially raised in CD73KO mice in comparison with WT mice, suggesting the existence of tissue reservoir/s outside myocardium. Indeed, CD73KO liver and visceral adipose tissue (VAT) showed increased parasite burden associated with a reduced ATP/ADO ratio and the lack of substantial microbicidal immune response. These data reveal that the purinergic system has a tissue-dependent impact on the host immune response against T. cruzi infection.

Cellular and humoral responses were evaluated in Litopenaeus vannamei juveniles when exposed to malathion, endosulfan, and their mixture. Each experiment was performed in the hemolymph collected at each exposure time (5 and 96 h) in duplicate; total hemocyte count, coagulation time, hemocyanin concentration, phenoloxidase (PO) and superoxide dismutase (SOD) activities were quantified. Survival was not affected by pesticides applied individually and mixed. Clotting time did not show significant differences concerning increase of concentration percentage of the pesticides tested. In organisms exposed to the pesticide mixture, hemocyanin decreased at 5 h of exposure as the concentration increased. Only in the malathion experiment did exposed shrimp to 10 and 50% of the LC50-96 h show significantly (p

Activation of photocatalytic titania by ultraviolet-A (UVA) radiation has been proposed as a good approach for combating bacteria. Titania powder, in solution or immobilized on a surface, has excellent UVA-assisted killing properties on several microorganisms. However, these properties could not be demonstrated in biofilms of Pseudomonas aeruginosa, a resistant opportunistic human pathogen that can cause severe complications in patients who are immunocompromised or have burn wounds or cystic fibrosis. P. aeruginosa biofilms have detrimental effects on health and industry, causing serious economic damage. In this study, the effect of titania photocatalysis for controlling P. aeruginosa biofilms was investigated by employing different coatings obtained through sol-gel and evaporation-induced self-assembly. Biofilms were grown on non-mesoporous and mesoporous titania surfaces with different pore sizes, which were achieved based on the use of surfactants Brij-58 and Pluronics-F127. In addition, two structural forms of titania were assayed: amorphous and anatase. As well as inhibiting biofilm formation, these coatings significantly enhanced the bactericidal effect of UVA on P. aeruginosa biofilms. The most efficient surface with regard to total antibacterial effect was the mesoporous Brij-58-templated anatase film, which, compared to control biofilms, decreased the number of viable bacteria by about 5 orders, demonstrating the efficacy of this methodology as a disinfection system.

Shrimp of Farfantepenaeus californiensis (78 groups) and Litopenaeus stylirostris (14 groups) were caught in the northwestern fishing zones in Mexico during the 2014–2015 fishing season (September–February); both shrimp species have high commercial value. Muscle, hepatopancreas and exoskeleton were analyzed to determine their metal contents. For F. californiensis, the highest Cd, Pb and Zn contents were determined in specimens caught off the State of Baja California Sur (BCS) with 22.4 ± 8.9 (hepatopancreas), 2.83 ± 4.63 (muscle), and 748.5 ± 1567 (muscle) µg/g, in the regions off Mulege, Los Cabos and Los Cabos, respectively. For L. stylirostris, the fishing zone of Comundu (BCS) showed higher Cd (12.3 ± 11.5 µg/g), Cu (569.1 ± 646.5 µg/g) and Zn (549.7 ± 400.7 µg/g) contents; all values were determined in the hepatopancreas. Regarding the hazard quotient and total hazard quotient calculated in this study, the consumption of marine shrimp caught off NW Mexico does not represent a risk to human health (both

Shrimp farming in low salinities waters is an alternative to increasing production, and counteracting disease problems in brackish and marine waters. However, in low-salinity waters, toxicity of nitrogen compounds increases, and there is no available data of its acute toxicity in shrimp postlarvae. This study determined the acute toxicity of ammonia, nitrite and nitrate in Litopenaeus vannamei postlarvae in 1 and 3 g/L salinity, as well as the safety levels. The LC50 confirms that nitrite is more toxic than ammonia and nitrate in low salinity waters, and that its toxicity increases with a decrease in salinity. The safe levels estimated for salinities of 1 and 3 g/L were 0.54 and 0.81 mg/L for total ammonia–N, 0.17 and 0.25 mg/L for NO2–N, and 5.6 and 21.5 mg/L for NO3–N, respectively.

The reproductive cycle in oysters has been the subject of several studies in temperate zones. However, little information is available for tropical and subtropical species. This study describes the seasonal changes in the gonadic index (GI) of two species of oysters, Crassostrea iridescens and Crassostrea corteziensis, which differ markedly in their hàbitad and time of reproduction. Both oysters were sampled at 45 days intervals in the Northwest coast of Mexico between November 1989 and October 1990. Gonadal and somatic tissue per individual were dried for three days at 90°C, weighed and recorded. The gonadic index (GI) applied in this work was calculated from: GI = Wg/ws. Were WG is the average gonadal tissue dry weight, and Ws is the average somatic tissue dry weight. Seasonal variations in the gonadal state were evident for the two species. C.iridescens exhibited only a single maximum in the year, while C. corteziensis two peaks. This situation is presumably related to the contrastable environmental conditions that prevail in the sites where each species inhabit. El ciclo reproductivo en ostras ha sido objeto de varios estudios en zonas templada. Si embargo, poca información está disponible para especies tropicales y subtropicales. Este estudio describe los cambios estacionales en el ídice gonádico (GI) de dos especies de ostras, Crassostrea iridescens y Crassostrea corteziensis, la cuaes diferen signifcativamnte en su hábitat y tiempo de reproducción. Abas ostras fueron muestradas a intervalos de 45 días cada uno en la costa noroeste de México entre noviembre de 1989 y octubre de 1990. El tejido gonádico y somático por organismo fue secado por tes días a 90·c, pesados y registrados. El índice gonádico (GI) usado en este trabao fue calculado de: Gl= Wg/ws. Donde Wg es el peso seco promedio del tejido gonáico, y Ws el peso seco promedio del tejido somáico. Las varaciones estacionaes en el estado gonádico feron evidentes para las dos especies. C iridescens presentó sólo un máximo en el año, mientra que C. corteziensis presentó dos máximos. Posiblemente esta situación es relacionada con las contrastables condicones ambíentales que prevalecen donde cada especie habita.

Dos poblaciones de Crassostrea iridescens fueron muestreadas en la zona coster¡l de la ciudad de Mazatlan y en una zona libre de actividad antropogénica. Los bivalvos fueron colectados de febrero de 1992 a febrero de 1993. Concentraciones de Cd, Co, Cr, Cu, Fe, Mn, Ni y Zn fueron 4etenninados por espectrofotome!ria de absorción atóIJrica. Los valores medios anuales en la estación de muestreo de la ciudad de Mazatlán fueron mayores en Co, Cu, Fe, Mn, Ni y Zn que los determinados en la zona libre de actividad antropogénica; sin embargo, las diferencias no fueron significativas a! nivel de confianza del 95%. Una conclusión es que las descargas urbanas en la zona costera en frente de Mazatlán no tiene, o tiene, bajas concentraciones de metales pesados disueltos o particulados.

Survival, clotting time, hemocyanin concentrations, total hemocyte counts, phenoloxidase activity (PO), and superoxide dismutase (SOD) of Litopenaeus vannamei juveniles (11.7 g) exposed for periods of 5, 48, and 96 h to copper (Cu) concentrations equivalent to 0.008, 1, 10, and 50% of the LC50–96 h for L. vannamei postlarvae showed that survival was similar in all treatments, but clotting time was significantly higher with the two highest Cu concentrations. Hemocyanin had lower values after 5 h with the two highest Cu concentrations, but this difference disappeared with longer times of exposure. The mean number of hemocytes varied widely but with no clear relation to Cu concentration or period of exposure. Differences in PO were related to period of exposure but not to Cu concentrations. SOD mean values did not show significant variation throughout the experiment. Apart from an increase in clotting time, the overall mean values of the stress indicators used in this study show that this particular shrimp s...

The main objective of this study was to evaluate the total mercury content in hepatopancreas and edible muscle of the whiteleg shrimp Litopenaeus vannamei cultured along the NW coast of Mexico, and to evaluate the potential human health risk due to their consumption. Samples were obtained between May and June 2010 in 26 shrimp farms from the three most important shrimp-producing states of NW Mexico, and total Hg was analyzed after reduction with SnCl 2 in a mercury analyzer. The ranges of Hg concentrations of the hepatopancreas were 0.101 ± 0.03–0.184 ± 0.13 μg g −1 in Sonora, 0.077 ± 0.055–0.813 ± 0.363 μg g −1 in Sinaloa and 0.139 ± 0.037–0.791 ± 0.33 μg g −1 in Nayarit. In the muscle, values were from 0.078 ± 0.02 to 0.539 ± 0.09 μg g −1 in Sonora, 0.154 ± 0.03–0.861 ± 0.423 μg g −1 in Sinaloa and 0.121 ± 0.041–1.48 ± 0.44 μg g −1 in Nayarit. Considering the concentrations of Hg in the muscle and the national consumption rate, shrimp farmed in NW Mexico does not represent a risk for human health (HQ

Total mercury (Hg) concentrations were determined by atomic absorption spectrophotometry in muscles and liver of composite samples of Mugil cephalus and M. curema collected during November 2013 and in January, April, and July 2014 from the coastal lagoons Altata-Ensenada del Pabellón (AEP), Ceuta (CEU), and Teacapán-Agua Brava (TAG) of Sinaloa State. The mean Hg contents and information on local consumption were used to assess the possible risk caused by fish ingestion. Mean total mercury levels in the muscles ranged from 0.11 to 0.39 μg/g, while the range for liver was 0.12-3.91 μg/g. The mean Hg content of the liver was significantly (p 0.001) higher than that of the muscles only in samples collected from AEP. Although total Hg levels in the muscles were lower than the official permissible limit, the HQ values for methyl mercury calculated for the younger age classes of one fishing community were1, indicating a possible risk for some fishing communities of the Mexican Pacific coast.

Despite worldwide prevalence of superficial mycoses, the immune response in dermatophytosis has scarcely been investigated. In this study, we developed a model of superficial skin infection in C57BL/6 mice with Microsporum canis, a highly prevalent human pathogen. This model mimics mild inflammatory human dermatophytosis, characterized by neutrophil recruitment and fungal invasion limited to the epidermis and exhibits the establishment of a specific T helper type 17 immune response during infection. By using IL-17RA- or IL-17A/F-deficient mice we showed that, in the absence of a functional IL-17 pathway, M. canis extensively colonizes the epidermis and promotes an exaggerated skin inflammation and a shift to an IFN-γ-mediated (T helper type 1) response. IL-17 signaling was not involved in neutrophil influx to skin or fungal invasion to deeper tissues. Finally, this study shows that skin langerin-expressing cells contribute to the antifungal T helper type 17 response in vivo. In conclusion, these data directly show a dual function of IL-17 cytokines in dermatophytosis by controlling superficial infection and down-modulating a T helper type 1 antifungal response. Fil: Burstein, Verónica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Guasconi, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Beccacece, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Theumer, Martín Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Mena, Cristian Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Prinz, Immo. Hannover Medical School; Alemania Fil: Cervi, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Herrero, Mónica. Hospital Córdoba; Argentina Fil: Masih, Diana Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina Fil: Chiapello, Laura Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina

In this work we compared the cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) contents of muscle, liver and placenta of gestating females of the viviparous shark Rhizoprionodon longurio and of muscle, liver and umbilical cord of their respective embryos. The higher values of the essential Cu and Zn were in embryonic or embryo-related tissues (placenta and umbilical cord). Maternal muscle and liver had the highest values of Pb and Cd, respectively. There were significant direct correlations between the Zn and Cd concentrations of placenta and umbilical cord, as well as between maternal muscle and embryonic livers for Pb and Cd, but the relation between these tissues was inverse in the case of Zn. All correlations between the metal content of embryonic tissues and size of the embryos were negative, suggesting an inverse relation between the rate of mother-to-embryo metal transfer and embryonic growth.

In this work, the purification and characterization of an extracellular elicitor protein, designated AsES, produced by an avirulent isolate of the strawberry pathogen Acremonium strictum, are reported. The defense eliciting activity present in culture filtrates was recovered and purified by ultrafiltration (cutoff, 30 kDa), anionic exchange (Q-Sepharose, pH 7.5), and hydrophobic interaction (phenyl-Sepharose) chromatographies. Two-dimensional SDS-PAGE of the purified active fraction revealed a single spot of 34 kDa and pI 8.8. HPLC (C2/C18) and MS/MS analysis confirmed purification to homogeneity. Foliar spray with AsES provided a total systemic protection against anthracnose disease in strawberry, accompanied by the expression of defense-related genes (i.e. PR1 and Chi2-1). Accumulation of reactive oxygen species (e.g. H2O2 and O2) and callose was also observed in Arabidopsis. By using degenerate primers designed from the partial amino acid sequences and rapid amplification reactions of cDNA ends, the complete AsES-coding cDNA of 1167 nucleotides was obtained. The deduced amino acid sequence showed significant identity with fungal serine proteinases of the subtilisin family, indicating that AsES is synthesized as a larger precursor containing a 15-residue secretory signal peptide and a 90-residue peptidase inhibitor I9 domain in addition to the 283-residue mature protein. AsES exhibited proteolytic activity in vitro, and its resistance eliciting activity was eliminated when inhibited with PMSF, suggesting that its proteolytic activity is required to induce the defense response. This is, to our knowledge, the first report of a fungal subtilisin that shows eliciting activity in plants. This finding could contribute to develop disease biocontrol strategies in plants by activating its innate immunity.