Occurrence and genetic diversity of Cryptosporidium and Giardia in urban wastewater treatment plants in north-eastern Spain

This study was designed to investigate the presence and removal efficiency of Cryptosporidium and Giardia in wastewater treatment plants at the 20 most populated towns in Aragón (north-eastern Spain). Samples of influent and effluent wastewater and dewatered sewage sludge were collected seasonally from 23 plants and processed according to USEPA Method 1623. All samples from raw and treated wastewater tested positive for Giardia, at an average concentration of 3247 ± 2039 cysts/l and 50 ± 28 cysts/l, respectively. Cryptosporidium was identified in most samples from both raw (85/92) and treated (78/92) wastewaters in a concentration significantly lower than Giardia, at both influent (96 ± 105 oocysts/l) and effluent samples (31 ± 70 oocysts/l) (P < 0.001). The (oo)cyst counts peaked in summer in most plants. The removal efficiency was higher for Giardia (1.06-log to 2.34-log) than Cryptosporidium (0.35-log to 1.8-log). Overall, high removal efficiency values were found for Giardia after secondary treatment based on activated sludge, while tertiary treatment (microfiltration, chlorination and/or ultraviolet irradiation) was needed to achieve the greatest removal or inactivation of Cryptosporidium. Most samples of treated sludge were positive for Giardia (92/92) and Cryptosporidium (45/92), at an average concentration of 20–593 cysts/g and 2–44 oocyst/g, respectively. The molecular characterization of Cryptosporidium oocysts and Giardia cysts were attempted at the SSU rRNA/GP60 and bg/tpi loci, respectively. G. duodenalis sub-assemblage AII was identified in all plants, with a large proportion of samples (15/47) harboring mixed assemblages (AII + B). Nine Cryptosporidium species and six subtypes were identified, with C. parvum IIaA15G2R1 being the most prevalent. The presence of significant numbers of (oo)cysts in samples of final effluents and treated sludge reveals the limited efficacy of conventional treatments in removing (oo)cysts and highlights the potential environmental impact and public health risks associated with disposal and reclamation of wastewater

Occurrence of Cryptosporidium and Giardia in raw and finished drinking water in north-eastern Spain

This paper collects the first large-sample-size study on the presence of Cryptosporidium oocysts and Giardia cysts in drinking water plants at the 20 most populated towns in Aragón (north-eastern Spain). Samples of influent raw water and effluent finished water were collected from each plant during different seasons and processed according to USEPA Method 1623. Cryptosporidium oocysts and Giardia cysts were detected in samples collected from 55% and 70% plants, respectively, with nine plants being positive for both protozoa and only four plants being negative over the study period. Both parasites were identified in the raw water throughout the year, with a lower frequency in autumn and a peak in winter, at a mean concentration of 67 ± 38 oocysts per 100 l and 125 ± 241 cysts per 100 l. The turbidity of raw water was not related to the presence or concentration of (oo)cysts, and the (oo)cyst removal efficiency was not related to the type of water treatment. One or both pathogens were identified in the finished water in 7 out of 11 plants with a conventional treatment process (coagulation, flocculation, sedimentation, filtration, and disinfection processes) compared to 4 out of 9 plants that did not apply one of the pre-chlorination treatment steps. Protozoa were detected in the finished water of positive plants at a mean concentration of 88 ± 55 oocysts per 100 l and 37 ± 41 cysts per 100 l, and most of them excluded propidium iodide so were considered potentially viable. The ubiquity of these parasites in the drinking water sources and the inefficiency of conventional water treatment in reducing/inactivating them may present a serious public health issue in this geographical area

Caveolin-1 Modulates Mechanotransduction Responses to Substrate Stiffness through Actin-Dependent Control of YAP

The transcriptional regulator YAP orchestrates many cellular functions, including tissue homeostasis, organ growth control, and tumorigenesis. Mechanical stimuli are a key input to YAP activity, but the mechanisms controlling this regulation remain largely uncharacterized. We show that CAV1 positively modulates the YAP mechanoresponse to substrate stiffness through actin-cytoskeleton-dependent and Hippo-kinase-independent mechanisms. RHO activity is necessary, but not sufficient, for CAV1-dependent mechanoregulation of YAP activity. Systematic quantitative interactomic studies and image-based small interfering RNA (siRNA) screens provide evidence that this actin-dependent regulation is determined by YAP interaction with the 14-3-3 protein YWHAH. Constitutive YAP activation rescued phenotypes associated with CAV1 loss, including defective extracellular matrix (ECM) remodeling. CAV1-mediated control of YAP activity was validated in vivo in a model of pancreatitis-driven acinar-to-ductal metaplasia. We propose that this CAV1-YAP mechanotransduction system controls a significant share of cell programs linked to these two pivotal regulators, with potentially broad physiological and pathological implications. Moreno-Vicente et al. report that CAV1, a key component of PM mechanosensing caveolae, mediates adaptation to ECM rigidity by modulating YAP activity through the control of actin dynamics and phosphorylation-dependent interaction of YAP with the 14-3-3-domain protein YWHAH. Cav1-dependent YAP regulation drives two pathophysiological processes: ECM remodeling and pancreatic ADM. © 2018 The Author

Intra-Species Diversity and Panmictic Structure of Cryptosporidium parvum Populations in Cattle Farms in Northern Spain

The intra-herd and intra-host genetic variability of 123 Cryptosporidium parvum isolates was investigated using a multilocus fragment typing approach with eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene. Isolates were collected from intensively farmed diarrheic pre-weaned calves originating from 31 dairy farms in three adjoining regions in northern Spain (País Vasco, Cantabria and Asturias). The multilocus tool demonstrated an acceptable typeability, with 104/123 samples amplifying at all twelve loci. The ML2, TP14, GP60 and the previously un-described minisatellite at locus cgd2_3850 were the most discriminatory markers, while others may be dismissed as monomorphic (MSB) or less informative (CP47, ML1 and the novel minisatellites at loci Cgd1_3670 and Cgd6_3940). The 12-satellite typing tool provided a Hunter-Gaston index (HGDI) of 0.987 (95% CI, 0.982–0.992), and differentiated a total of 70 multilocus subtypes (MLTs). The inclusion of only the four most discriminatory markers dramatically reduced the number of MLTs (n: 44) but hardly reduced the HGDI value. A total of 54 MLTs were distinctive for individual farms, indicating that cryptosporidiosis is an endemic condition on most cattle farms. However, a high rate of mixed infections was detected, suggesting frequent meiotic recombination. Namely, multiple MLTs were seen in most farms where several specimens were analyzed (90.5%), with up to 9 MLTs being found on one farm, and individual specimens with mixed populations being reported on 11/29 farms. Bayesian Structure analysis showed that over 35% of isolates had mixed ancestry and analysis of evolutionary descent using the eBURST algorithm detected a high rate (21.4%) of MLTs appearing as singletons, indicating a high degree of genetic divergence. Linkage analysis found evidence of linkage equilibrium and an overall panmictic structure within the C. parvum population in this discrete geographical area

Genetic uniqueness of Cryptosporidium parvum from dairy calves in Colombia

Fecal specimens from 432 pre-weaned calves younger than 35 days were collected over a 2-year period (2010–2012) from 74 dairy cattle farms in the central area of Colombia. These samples were microscopically examined for the presence of Cryptosporidium oocysts, and positive specimens were selected for molecular examination. Microscopy revealed that 115 calves (26.6%) from 44 farms (59.5%) tested positive. Oocyst shedding was recorded in calves aged 3-day-old onwards, although the infection rate peaked at 8–14 days (40.7%). Infection rates were higher in diarrheic (52.2%) than in non-diarrheic calves (19.9%) (p &lt; 0.0001, ¿2), and infected calves had up to seven times more probability of having diarrhea than non-infected calves. Cryptosporidium species and subtypes were successfully identified in 73 samples from 32 farms. Restriction and sequence analyses of the SSU rRNA gene revealed C. parvum in all but two isolates identified as Cryptosporidium bovis. Sequence analyses of the 60-KDa glycoprotein (gp60) gene revealed eight subtypes within the IIa family. An unusual subtype (IIaA18G5R1) was the most prevalent and widely distributed (more than 66% specimens and 68% farms) while the subtype most frequently reported in cattle worldwide (IIaA15G2R1) was found in less than 13% of specimens and 16% farms. The remaining subtypes (IIaA16G2R1, IIaA17G4R1, IIaA20G5R1, IIaA19G6R1, IIaA20G6R1, and IIaA20G7R1) were restricted to 1–3 farms. This is the first large-sample size study of Cryptosporidium species and subtypes in Colombia and demonstrates the genetic uniqueness of this protozoan in cattle farms in this geographical area

Phytotoxicity of sewage sludge biochars prepared at different pyrolysis conditions

6 Pags.- 8 Figs.- 3 Tabls. Creative Commons License Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).Pyrolysis of sewage sludge was carried out at three different lab-scale reactors and conditions: an Auger reactor for sewage sludge pyrolysis at low temperature (300ºC), a stirred batch reactor (530ºC) and a fluidised bed reactor (530ºC). The starting material is anaerobically digested and thermally dried sewage sludge from a wastewater treatment plant located in Spain. A preliminary study to assess the feasibility of application to soil of the three biochars was performed using two germination tests and a greenhouse experiment. Water soluble compounds from biochar did not affect seed germination, but volatile compounds reduced germination of more sensitive seeds. Biochar applied to soil at agricultural rates (20 t/ha) reduced growth and development of a corn crop. No differential effects of the three pyrolysis conditions were found.The Authors are grateful to the Spanish Ministry of Economy and Competitiveness (MINECO) for the Project CTQ2013-47260-R.Peer reviewe

Prevalencia y grado de parasitación por flagelados entéricos en ratones NMRI, C57Bl/6 y Balb/c

In order to analyze the prevalence and parasitation degree by enteric flagellates in NMRI, C57Bl/6 and Balb/c mice, discriminating on the basis of strain, age and sex of animals produced conventionally in animal facilities of the Universidad Centroccidental Lisandro Alvarado (Venezuela), 50 mice were selected by strain and sex, and 10 by age (3, 5, 7, 9 and 14 weeks) (N = 300). They were sampled both fresh feces and intestinal contents at three differents sections (duodenum, yeyuno-ileon and cecum), for direct observation and smears stained with Giemsa. The data was analyzed with Chi-square, Mann-Whitney, Kruskal-Wallis test, correlation of Spearman and factor analysis. Giardia muris was located at cecum of NMRI mice (100%) and 99% of C57Bl/6 and Balb/c. At yeyuno-ileon in 89% of C57Bl/6, 84% of NMRI and 46% of Balb/c; and at duodenum, in male C57Bl/6 (73%), which increases the prevalence with age. Trichomonas muris was identified in 58-76% of the three strains with the highest prevalence in males NMRI and C57B1/6. Spironucleus muris, only 70% of the six-weeks-old NMRI were identified. The less parasitized strain is the Balb/c. There are significant differences in the prevalence of three parasitic diseases among the strains studied, about Giardia there are differences between the ages in the NMRI and C57Bl/6 and about Trichomonas between both sex. It is recommended to consider animals strain produced and/or used in research, their sex and age in order to establish the sanitary controls aimed to enteric flagellates.Con el objetivo de analizar la prevalencia y grado de parasitación por flagelados entéricos en ratones NMRI, C57Bl/6 y Balb/c, discriminando en base a la cepa, edad y sexo de los animales producidos convencionalmente en el Bioterio de la Universidad Centroccidental Lisandro Alvarado (Venezuela), se seleccionaron 50 ratones por cada cepa y sexo, 10 por edad (3, 5, 7, 9 y 14 semanas) (N=300). Se recogieron por duplicado muestras de heces frescas y de contenido intestinal en tres tramos diferentes (duodeno, yeyuno-íleon y ciego), para observación directa y frotis teñido con Giemsa. Los datos fueron analizados con Chi-cuadrado, U de Mann-Whitney, Prueba de Kruskal-Wallis, correlación de Spearman y análisis factorial. Giardia muris se localizó en ciego de los ratones NMRI (100%) y en 99% de los C57Bl/6 y Balb/c. En yeyuno-íleon en 89% de los C57Bl/6, 84% de NMRI y 46% de Balb/c; y en duodeno, en los machos C57Bl/6 (73%), en los que aumenta la prevalencia con la edad. Se identificó Trichomonas muris en 58-76% de las tres cepas con la máxima prevalencia en machos NMRI y C57Bl/6. Spironucleus muris, solo se identificó en 70% de los NMRI de 6 semanas. La cepa menos parasitada es la Balb/c. Existen diferencias significativas en la prevalencia de las tres parasitosis entre las cepas estudiadas, en Giardia diferencias entre las edades en NMRI y C57Bl/6 y en Trichomonas entre ambos sexos. Existen diferencias significativas en la prevalencia de las tres parasitosis entre las cepas estudiadas, en Giardia diferencias entre las edades en NMRI y C57Bl/6 y en Trichomonas entre ambos sexos. Se recomienda tomar en cuenta la cepa de los animales producidos y/o empleados en investigación, su sexo y edad para establecer los controles sanitarios dirigidos a flagelados entéricos

Conceptos de Química

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¿Qué opinan los futuros maestros sobre el aprendizaje de las ciencias a través de la indagación y sobre sus necesidades formativas?

The application of an open-ended questionnaire allows us to detect some ideas about inquiry in preservice Primary teachers. A first analysis allows us to categorize the type of answers. In general, the majority of students ask for more theoretical contents about science, since they are not confidence in being involved in science teaching without this background. A great scattering of answers appears when students are asked for inquiry in the Primary classrooms. Finally, no coherent answers are detected when students declare that they want to learn “more scientific contents” (90%), whereas less than 50% of them would like to be taught about this issue