23 research outputs found
Bioaccumulation of inorganic elements in dreissena polymorpha from the Ebro river, Spain: could zebra mussels be used as a bioindicator of the impact of human activities?
Dreissena polymorpha is among the top 100 most harmful invasive species in aquatic habitats. European Directive 2013/39/UE establishes Environmental Quality Standards for biota because it has been demonstrated that pollutants bioaccumulate in aquatic organisms. This study evaluated bioaccumulation of inorganic elements in the soft tissues of D. polymorpha in order to assess the usefulness of zebra mussels as a bioindicator of contaminant presence in super fi cial waters. Concentrations of 66 elements were measured in order to evaluate their relation- ship with nearby anthropogenic activity and to the values recommended by Environmental Quality Standards for biota. Bivalves were col- lected from four sample points along the Ebro River Basin (Spain), where diverse human activities are carried out. Zebra mussels accumulate toxins in soft tissue during their life cycle, including Al, Cr, Fe, Hg, Pb, Th, Cd and U. The highest levels of accumulation corresponded to elements associated with human activity in the area, showing the impact of anthropogenic actions on biota. D. polymorpha not only supplies information about current water quality but also acts as a witness of past water quality by bioconcentrating toxic elements present in the environment and providing relevant results about historical water contamination. In conclusion, D. polymorpha is a harmful and dangerous invasive species, but its pervasiveness means that it can be used as a bioindicator to assess current and past presence of elements in water
Amebas de vida libre en aguas residuales y fangos: Su papel como reservorio natural de bacterias potencialmente pat贸genas
Las amebas de vida libre (AVL) son protozoos ubicuos, presentes en suelos y en ecosistemas acu谩ticos naturales y artificiales. Participan en los procesos de depuraci贸n desarrollados en las Estaciones Depuradoras de Aguas Residuales (EDAR), convirti茅ndolas en un nicho ecol贸gico id贸neo para la proliferaci贸n de AVL, que las colonizan e instauran en ellas su h谩bitat, ya que se alimentan de bacterias presentes en el medio. Los procesos de depuraci贸n biol贸gica no est谩n dise帽ados con el fin de eliminar la contaminaci贸n microbiol贸gica, aunque ayudan a reducir algunas poblaciones bacterianas.
Hasta la fecha, s贸lo algunas especies y g茅neros de AVL han sido descritos como pat贸genos, pero todas ellas suponen un riesgo como reservorio de bacterias pat贸genas. Su forma qu铆stica, les confiere resistencia frente a las condiciones adversas y desinfectantes comunes, permiti茅ndoles superar los procesos de depuraci贸n y potabilizaci贸n y colonizar sistemas artificiales de agua. En este trabajo, se estudi贸 la presencia de AVL en aguas y fangos de 5 EDAR que vierten sus aguas a la cuenca del Ebro, analizando un total de 20 puntos de muestreo. Para ello, se llev贸 a cabo el aislamiento AVL y la posterior identificaci贸n de g茅nero y especie, as铆 como de las bacterias endosimbiontes, mediante la reacci贸n en cadena de la polimerasa (PCR).
De las 41 amebas aisladas en el 85 % de las muestras, 21 fueron identificadas gen茅ticamente. Trece de ellas, pertenecieron al g茅nero Acanthamoeba spp., 6 a Naegleria spp. y 2 se identificaron como Vermamoeba vermiformis. El 53,66 % de las AVL albergaba en su interior Mycobacterium spp., el 29,27 % Legionella pneumophila y el 14,63 % Pseudomonas spp.
Free-living amoebae (FLA) are ubiquitous protozoa, present in soils and in natural and artificial aquatic ecosystems. They take part in the purification processes that take place in Wastewater Treatment Plants (WWTPs), thereby turning these plants into ecological niches suitable for proliferation of FLAs, which they colonize and in which they establish their habitat, since they feed on bacteria present in the environment. Biological purification processes are not designed to remove microbiological contamination, although they help to reduce some microbial populations. At present only some genera and species of FLAs have been described as pathogenic, but all of them pose a risk as reservoirs of pathogenic bacteria. Their cystic stage gives them resistance to adverse conditions and common disinfectants, allowing them to withstand water purification processes and colonize artificial water systems. The presence of FLAs in waters and sludges from 5 WWTPs that discharge their waters into the Ebro river basin has been studied in this work. To this end, a total of 20 sample points were analysed by isolating the FLAs and subsequently identifying their genus and species. The same was done for endosymbiotic bacteria, by Polymerase Chain Reaction (PCR). Out of 41 FLAs that were isolated in 85 % of the samples, 21 were genetically identified. Thirteen belonged to the genus Acanthamoeba spp., 6 to Naegleria spp. and 2 were identified as Vermamoeba vermiformis. 53.66 % of FLAs hosted Mycobacterium spp., 29.27 % Legionella pneumophila, and 14.63 % Pseudomonas spp
El gen tpi como herramienta en los estudios epidemiolo麓gicos de la giardiosis
Giardia duodenalis es un protozoo que causa infecci贸n en humanos y animales, que se puede transmitir por v铆a h铆drica, de persona a persona o por contacto con animales, siendo una de las infecciones intestinales m谩s frecuentes en nuestro pa铆s, por lo que supone una preocupaci贸n de Salud P煤blica. Su estudio epidemiol贸gico, requiere la caracterizaci贸n molecular de los par谩sitos, utilizando genes con gran variabilidad como el que codifica la triosafosfatoisomerasa (tpi) y analizando la homolog铆a entre aislamientos.
El objetivo del trabajo es establecer el criterio de identidad que permita la comparaci贸n epidemiol贸gica de los aislamientos de Giardia.
Se recogieron 2-3 muestras de heces en d铆as alternos, de 26 pacientes con giardiosis. Tras la extracci贸n de ADN, se amplificaron por t茅cnicas de PCR, un fragmento del gen tpi y un fragmento del gen de la beta-giardina (bg), que se utiliz贸 como comparaci贸n. Los fragmentos obtenidos fueron secuenciados y las secuencias analizadas con los programas BioEdit y DnaSP v.5.0. Las secuencias del gen tpi mostraron una elevada divergencia, con valores de diversidad 驴 entre 0 y 0, 21219. La aparici贸n de picos m煤ltiples en el cromatograma, indicaron la presencia de varios clones en la misma muestra. Las diferencias entre aislamientos del mismo paciente fueron iguales o mayores que las encontradas para el conjunto de todas las muestras.
La variabilidad del gen tpi no permite establecer unos criterios de identidad, necesarios para la identificaci贸n de aislamientos.
Las infecciones mixtas intragenotipo ocurren de una forma muy frecuente, sugiriendo una implicaci贸n de la v铆a ambiental como principal fuente de transmisi贸n o una variaci贸n gen茅tica muy elevada.
Giardia duodenalis is a protozoon that causes infection in humans and animals. It can be transmitted by contaminated water, from person to person or by contact with animals; it being the cause one of the most common intestinal infections in our country, so it is a public health concern. The epidemiological study thereof requires the molecular characterization of parasites, using genes with great variability, such as the one that codes triosephosphate isomerase (tpi), and analizing the homology between isolates. The purpose of this work is to establish the identity criterion for epidemiological comparison of Giardia isolates. 2-3 stool samples were collected in alternate days from 26 patients with giardiasis. After DNA extraction, a fragment of the tpi gene and a fragment of the beta-giardin (bg) gene-used for comparison purposes-were amplified by means of PCR techniques. The obtained fragments were sequenced and the sequences analyzed with the BioEdit and DnaSP v.5.0 software. The tpi gene sequences showed a high divergence, with values of diversity 驴 ranging from 0 to 0.21219. The appearance of multiple peaks in the chromatogram points to the presence of various clones in the same sample. The differences between isolates from the same patient where equal or higher than those found for the collection of all samples. The variability of the tpi gene does not allow identity criteria to be established, which are necessary for isolate identification. Mixed intragenotype infections occur very frequently, which suggests the environmental path is the principal path of transmission and/or there is very high genetic variability
Quality and readability of English-language internet information for adults with hearing impairment and their significant others
La ricerca in Psicologia Clinica Perinatale : fattori di rischio e protezione per la tutela della salute mentale
Standardizing the influenza neuraminidase inhibition assay among United States public health laboratories conducting virological surveillance
Standardizing the influenza neuraminidase inhibition assay among United States public health laboratories conducting virological surveillance
Background: Monitoring influenza virus susceptibility to neuraminidase (NA) inhibitors (NAIs) is vital for detecting drug-resistant variants, and is primarily assessed using NA inhibition (NI) assays, supplemented by NA sequence analysis. However, differences in NI testing methodologies between surveillance laboratories results in variability of 50% inhibitory concentration (IC50) values, which impacts data sharing, reporting and interpretation. In 2011, the Centers for Disease Control and Prevention (CDC), in collaboration with the Association for Public Health Laboratories (APHL) spearheaded efforts to standardize fluorescence-based NI assay testing in the United States (U.S.), with the goal of achieving consistency of IC50 data.
Methods: For the standardization process, three participating state public health laboratories (PHLs), designated as National Surveillance Reference Centers for Influenza (NSRC-Is), assessed the NAI susceptibility of the 2011-12 CDC reference virus panel using stepwise procedures, with support from the CDC reference laboratory. Next, the NSRC-Is assessed the NAI susceptibility of season 2011-12 U.S. influenza surveillance isolates (n = 940), with a large subset (n = 742) tested in parallel by CDC. Subsequently, U.S. influenza surveillance isolates (n = 9629) circulating during the next three influenza seasons (2012-15), were independently tested by the three NSRC-Is (n = 7331) and CDC (n = 2298).
Results: The NI assay IC50s generated by respective NSRC-Is using viruses and drugs prepared by CDC were similar to those obtained with viruses and drugs prepared in-house, and were uniform between laboratories. IC50s for U.S. surveillance isolates tested during four consecutive influenza seasons (2011-15) were consistent from season to season, within and between laboratories.
Conclusion: These results show that the NI assay is robust enough to be standardized, marking the first time IC50 data have been normalized across multiple laboratories, and used for U.S. national NAI susceptibility surveillance