Reduction of selenite and tellurite by a highly metal-tolerant marine bacterium / Reducción de selenita y telurito por una bacteria marina altamente tolerante a los metales

Selenium (Se) and tellurium (Te) contaminations in soils and water bodies have been widely reported in recent years. Se(IV) and Te(IV) were regarded as their most dangerous forms. Microbial treatments of Se(IV)- and Te(IV)-containing wastes are promising approaches because of their environmentally friendly and sustainable advantages. However, the salt-tolerant microbial resources that can be used for selenium/tellurium pollution control are still limited since industrial wastewaters usually contain a large number of salts. In this study, a marine Shewanella sp. FDA-1 (FDA-1) was reported for efficient Se(IV) and Te(IV) reduction under saline conditions. Process and product analyses were performed to investigate the bioreduction processes of Se(IV) and Te(IV). The results showed that FDA-1 can effectively reduce Se(IV) and Te(IV) to Se0 and Te0 Se(IV)/Te(IV) to Se0/Te0 in 72 h, which were further confirmed by XRD and XPS analyses. In addition, enzymatic and RT‒qPCR assays showed that flavin-related proteins, reductases, dehydrogenases, etc., could be involved in the bioreduction of Se(IV)/Te(IV). Overall, our results demonstrate the ability of FDA-1 to reduce high concentrations of Se(IV)/or Te(IV) to Se0/or Te0 under saline conditions and thus provide efficient microbial candidate for controlling Se and Te pollution.(AU)

Microbial communities in the deep-sea sediments of the South São Paulo Plateau, Southwestern Atlantic Ocean / Comunidades microbianas en los sedimentos de aguas profundas de la meseta sur de São Paulo, océano Atlántico sudoccidental

Microbial communities play a key role in the ocean, acting as primary producers, nutrient recyclers, and energy providers. The São Paulo Plateau is a region located on the southeastern coast of Brazil within economic importance, due to its oil and gas reservoirs. With this focus, this study examined the diversity and composition of microbial communities in marine sediments located at three oceanographic stations in the southern region of São Paulo Plateau using the HOV Shinkai 6500 in 2013. The 16S rRNA gene was sequenced using the universal primers (515F and 926R) by the Illumina Miseq platform. The taxonomic compositions of samples recovered from SP3 station were markedly distinct from those obtained from SP1 and SP2. Although all three stations exhibited a high abundance of Gammaproteobacteria (> 15%), this taxon dominated more than 90% of composition of the A and C sediment layers at SP3. The highest abundance of the archaeal class Nitrososphaeria was presented at SP1, mainly at layer C (~ 21%), being absent at SP3 station. The prediction of chemoheterotrophy and fermentation as important microbial functions was supported by the data. Additionally, other metabolic pathways related to the cycles of nitrogen, carbon and sulfur were also predicted. The core microbiome analysis comprised only two ASVs. Our study contributes to a better understanding of microbial communities in an economically important little-explored region. This is the third microbiological survey in plateau sediments and the first focused on the southern region.(AU)

Biosorption of heavy metals from phosphate-processing effluent by Serratia rubidaea NCTC12971 immobilized in Ca-alginate beads / Biosorción de metales pesados a partir de efluentes de procesamiento de fosfatos por Serratia rubidaea NCTC12971 inmovilizados en cuentas de Ca-alginato

In this study, the biosorption ability of various potentially toxic elements from phosphate-processing effluent (PPE) using the indigenous bacterium Serratia rubidaea NCTC12971 immobilized in Ca-alginate beads was investigated. The experimental data analyzed by the Langmuir isotherm revealed that the optimum dose of 2 g·100 ml−1 of immobilized S. rubidaea NCTC12971 at pH 7 and a contact time of 48 h allowed the removal of 92.07%, 98.05%, 95.57%, and 88.39% of lead (Pb (II)), cadmium (Cd (II)), copper (Cu (II)), and zinc (Zn (II)), respectively. Moreover, under the Langmuir isotherm, the maximum single-layer adsorption capacity (qmax) of the biosorbent was estimated to 32.14 mg g−1, 45.87 mg g−1, 0.06 mg g−1, and 3.01 mg g−1 for Pb (II), Cd (II), Cu (II), and Zn (II), respectively, under the stated conditions. Alternatively, the regeneration and reuse of the Ca-alginate beads was evaluated. Indeed, after four consecutive adsorption–desorption cycles, there was no significant loss in the biosorption capacity. The effectiveness of the bacterial biosorption as treatment process was evaluated by assessing the phytotoxicity of the treated effluent (TE) on Medicago sativa and Lactuca sativa seed germination and their root elongation. Results exhibited a significant toxicity removal expressed by a notable increase in the germination indices (GI), which reach 80% and 70%, respectively, for Medicago sativa and Lactuca sativa compared to the GI values of 46.6% and 16.6% of the same species in presence of the untreated effluent (PPE).(AU)

SSThe coexistence and diversity of Candidatus methylomirabilis oxyfera-like and anammox bacteria in sediments of an urban eutrophic lake / SLa coexistencia y diversidad de bacterias Candidatus methylomirabilis oxyfera y anammox en sedimentos de un lago urbano eutrófico

Tangxun Lake is the largest urban lake in China, which is polluted by multiple wastewaters, and now is severely eutrophic. We detected diversity, abundance, and the coexistence of Candidatus Methylomirabilis oxyfera-like and anammox bacteria in different horizontal and vertical directions of the lake sediments through qPCR and clone library. Phylogenetic tree analysis showed that the Ca. Methylomirabilis oxyfera-like and anammox bacteria exhibited high diversity, and they belonged to group B—E and Ca. Brocadia genus, respectively. These two bacteria displayed higher diversity in polluted area than in other areas. Furthermore, they had great spatial variation of abundance both horizontally and vertically. The abundance of anammox bacteria was significantly higher than that of Ca. Methylomirabilis oxyfera-like bacteria. The stronger the human interference were, the higher abundances these two bacteria exhibited horizontally, whereas both their abundances and the ratio of anammox to Ca. Methylomirabilis oxyfera-like bacteria decreased with the increasing depth. Redundancy analysis indicated that nitrate was the most influential environmental factor to the abundance of these two bacteria. Ammonia, nitrite, total nitrogen, and organic matters were in positive correlation with the abundance of these two bacteria. Nitrate was slightly negatively correlated with the abundance of Ca. Methylomirabilis oxyfera-like bacteria, while it was positively correlated with that of anammox bacteria. Our results provided an insight into the effects of environmental factors such as ammonia, nitrite, and nitrate on the diversity and abundances of these two bacteria and theoretical basis for restoration of water.(AU)

Perfiles de susceptibilidad a los antibióticos en cepas del género Bacillus aisladas de ambientes acuáticos extremos del Ecuador / Susceptibility profiles to antibiotics in strains of the genus Bacillus isolated from extreme aquatic environments of Ecuador

INTRODUCCIÓN: En el agua de los ecosistemas acuáticos considerados extremos, debido a los valores de sus parámetros fisicoquímicos y químicos, tales como altas concentraciones de sales, ambientes oligotróficos, pH extremos, alta radiación y temperaturas extremas, existe una población bacteriana que se ha adaptado a esas condiciones y que pueden ser un reservorio importante de resistomas naturales. OBJETIVO: Conocer los perfiles de susceptibilidad a diversos antibióticos en cepas del género Bacillus aisladas de balnearios de aguas mineromedicinales y de agua de un lago cratérico volcánico del Ecuador. MATERIALES Y MÉTODOS. Se analizaron un total de 16 muestras de agua mineromedicinal y 32 muestras de agua de lago cratérico volcánico. El aislamiento de Bacillus se realizó por la técnica de filtración en membrana, utilizando filtros Millipore de 0,45 μm de poro, un volumen de muestra de 100 mL y el agar R2A. Las cepas aisladas se identificaron siguiendo los esquemas de MacFaddin (2004), complementadas con las pruebas bioquímicas de las galerías Microgen para Bacillus. El perfil de resistencia a los antibióticos se determinó por el método de difusión en placas de Kirby y Bauer (1966) interpretándose según el CLSI (2019). RESULTADOS: Se identificaron 19 cepas de Bacillus. La mayoría de las cepas fueron resistentes y multiresistentes a los antibióticos clindamicina, eritromicina, gentamicina, oxacilina y penicilina. CONCLUSIONES: Los resultados señalan la presencia de especies de Bacillus y de resistomas asociados a este género en el agua de ambientes naturales extremos en el Ecuador, lo cual sugiere que estos ambientes pueden ser un reservorio importante de bacterias resistentes a los antibióticos

INTRODUCTION: The water of aquatic ecosystems considered extreme, given the values of its physicochemical and chemical parameters, such as high concentrations of salts, oligotrophic environments, extreme pH, high radiation and extreme temperatures, there is a bacterial population that has adapted to these conditions and that they can be an important reservoir of natural resistomes. OBJECTIVE: The objective of the present work was to know the profiles of susceptibility to various antibiotics in strains of the Bacillus genus isolated from mineromedicinal water spas and water from a volcanic crater lake in Ecuador. MATERIALS AND METHODS: A total of 16 mineromedicinal water samples and 32 samples of crater volcanic lake water were analyzed. The isolation of the Bacillus colonies was carried out by the membrane filtration technique, using Millipore filters of 0.45 μm pore, a sample volume of 100 mL and R2A agar. The isolated strains were identified following the schemes of MacFaddin (2004), complemented with the biochemical tests of the Microgen galleries for Bacillus. The antibiotic resistance profile was determined by the plate diffusion method of Kirby and Bauer (1966), interpreted according to the CLSI (2019). RESULTS: 19 Bacillus strains were identified. Most of the strains were resistant and multi-resistant to the antibiotic clindamycin, erythromycin, gentamicin, oxacillin, and penicillin. CONCLUSIONS: The results indicate the presence of Bacillus species and resistomes associated with this genus in the water of extreme natural environments in Ecuador, which suggests that these environments may be an important reservoir of bacteria resistant to antibiotics

Análisis de parámetros de función pulmonar en nadadores de piscinas cubiertas / Lung functional parameters in users of indoor swimming pools

OBJETIVO: Es controvertido el efecto que la natación en piscinas cubiertas puede tener sobre la función pulmonar y sobre los parámetros de inflamación bronquial. El objetivo del estudio fue estudiar la evolución de parámetros funcionales y de inflamación antes y después del baño en usuarios de piscinas cubiertas y sin patología respiratoria conocida. METODOLOGÍA: Estudio observacional prospectivo en el que se incluyeron nadadores habituales de piscinas cubiertas. Los individuos incluidos en el estudio no presentaban antecedentes de asma ni alteraciones funcionales o de inflamación bronquial en el momento de la inclusión. Se realizaron pruebas funcionales (espirometría) y medida de inflamación (FeNO) minutos antes y tras el baño en diferentes piscinas públicas. Se analizaron de forma paralela los parámetros físico-químicos del agua de dichas piscinas en el momento de la natación y que fueron proporcionados por la Inspección de Sanidad adscrita a dicha piscina pública. RESULTADOS: Fueron incluidos 50 nadadores, 26 hombres y 24 mujeres, de edad media 40,8 ± 10,8 años. El tiempo de inmersión fue de 32 minutos. Encontramos diferencias antes y tras la inmersión. En los nadadores incluidos mejoraron tras la inmersión de forma significativa la FVC (p < 0,05), y el FEV1 (p < 0,04) así como disminuyó el FENO (p < 0,01) Las características del agua de las piscinas, medidas según los protocolos habituales de sanidad, se encontraron en todos los casos dentro del rango habitual determinados en el Real Decreto 742/2013, de 27 de septiembre (BOE, Viernes 11 de octubre de 2013), por el que se establecen los criterios técnico-sanitarios de las piscinas. Tras el análisis estadístico, no se obtuvieron diferencias en parámetros de función e inflamación bronquial en relación con los datos físicos y químicos del agua de las piscinas y recogidos en el momento de la inclusión de los pacientes en el estudio. CONCLUSIONES: Hemos objetivado una mejoría significativa de los parámetros funcionales respiratorios en nadadores de piscinas cubiertas

INTRODUCTION: it is controversial the effect that swimming in indoor swimming pool can have on lung function and parameters of inflammation. The objective of the study was to study the evolution of functional parameters and inflammation before and after swimming in users of indoor swimming pools and without known respiratory pathology. MATERIAL AND METHODS: this was an observational prospective study in which regular swimmers were included. Individuals included in the study had no history of asthma or functional or inflammatory diseases at the time of inclusion. Functional tests (spirometry) and inflammation measurement (FENO) were performed minutes before and after bathing in different public swimming pools. The physical-chemical parameters of the water of these swimming pools were analyzed in parallel at the time of swimming and were provided by the sanitary inspection attached to said public swimming pool. RESULTS: were included 50 swimmers, 26 men and 24 women, mean age 40.8 ± 10.8 years. The immersion time was 32 minutes. In the swimmers included, FVC significantly improved after dipping (p < 0.05), FEV1 (p < 0.04) as did FENO (p < 0.01). The water characteristics of the swimming pools, measured according to the usual health protocols, were found in all cases within the usual range determined in Royal Decree 742/2013, de 27th September (BOE 11th October 2013). After statistical analysis, no differences were found in parameters of bronchial function and inflammation in relation to the physical and chemical data of the swimming pools included in the study. CONCLUSIONS: we have observed a significant improvement in respiratory functional parameters in indoor swimming pool swimmer

Diversidad bacteriana en aguas mineromedicinales del balneario "Urauco". Pichincha. Ecuador / Bacterial biodiversity in mineromedicinal waters of spa "Urauco". Pichincha. Ecuador

La presencia de manantiales de aguas mineromedicinales en Ecuador se encuentra en relación con el gran número de volcanes que existen en el país, los cuales se han venido utilizando desde épocas remotas como medicamentos por la población. Sin embargo, se desconoce cuál es la biodiversidad bacteriana presente. Por ello, el objetivo del trabajo fue determinar la biodiversidad bacteriana de las aguas mineromedicinales del balneario "Urauco" ubicado en la Provincia de Pichincha. Ecuador. Se tomaron muestras de agua de un volumen de 1 litro en dos punto del balneario. Los muestreos se realizaron en 2 ocasiones durante un periodo de dos año. Para la toma y transporte de las muestras se siguieron las normas ecuatorianas INEN 2 176-98 y INEN 2 169-98. Para la determinación de la biodiversidad bacteriana se utilizó las técnicas de siembra, selección e identificación de bacterias indicados por Barrow y Feltan (2004) y MacFfadin (2004), complementadas con las pruebas bioquímicas contenidas en las galerías API (BioMérieux) y galería Microgen (Microgen corp.). Los resultados señalan un población de bacterias heterótrofas en las aguas del balneario de 3,1 x 102 UFC/mL, con la prevalencia de las bacterias Gram negativa de la clase Gamma Proteobacterias. Se pudo aislar e identificar 64 colonias de bacterias. Los géneros de bacterias encontrados fueron Acidovorax, Aeromonas, Bacillus, Brevundimonas, Budvicia, Citrobacter, Corynebacterium, Ed- wardsiella, Enterococcus, Ewingella, Flavobacterium, Kurthia, Micrococcus, Proteus, Pseudomonas, Psychrobacter, Ralstonia, Staphylococcus, Vibrio y Yokonella. La biodiversidad bacteriana observada fue alta, aunque escasa en número de individuos

The presence of mineromedicinal water springs in Ecuador is related to the large number of volcanoes that exist in the country, which have been used since ancient times as medicines by the population. However, it is unknown what bacterial biodiversity is present. Therefore, the objective of these work was to determine the bacterial biodi- versity of the mineromedicinal waters of “Urauco” spa located in Pichincha Provinces of Ecuador. Water samples of a volume of 1 liter were taken at two points in each spa studied. Sampling was done 2 times over a period of two year. To take and transport the samples, the Ecuadorian standards INEN 2 176-98 and INEN 2 169-98 were followed. For the determination of bacterial biodiversity, the techniques of planting, selection and identification of bacteria indicated by Barrow and Feltan (2004) and MacFfadin (2004) were used, complemented with the bio- chemical tests contained in the API (BioMérieux) galleries and Microgen (Microgen corp.). The results indicate a population of heterotrophic bacteria in the spa waters of 3.1 x 102 CFU / mL, with the prevalence of Gram negative bacteria of the Gamma Proteobacteria class. It was possible to isolate and identify 64 colonies of bacteria. The genera of bacteria were Acidovorax, Aeromonas, Bacillus, Brevundimonas, Budvicia, Citrobacter, Corynebacterium, Edwardsiella, Enterococcus, Ewingella, Flavobacterium, Kurthia, Micrococcus, Proteus, Pseudomonas, Psychrobacter, Ralstonia, Staphylococcus, Vibrio and Yokonella. The bacterial biodiversity observed was high, although low in number

Calidad microbiológica de las aguas termales del balneario "El Tingo". Pichincha. Ecuador / Microbial Quality of the Thermal Waters of the Spa "El Tingo". Pichincha. Ecuador

OBJETIVO: El propósito del trabajo fue determinar la calidad microbiológica del agua termal del Balneario "El Tingo", situado a 2500 msnm, Provincia de Pichincha, Ecuador. Materiales y MÉTODOS: Se realizaron cuatro muestreos en diferentes épocas del año y en dos zonas del Balneario. Se determinaron "in situ" los parámetros fisicoquímicos (conductividad, dureza, oxígeno disuelto, pH y temperatura). La cuantificación de bacterias heterótrofas, coliformes y hongos se hizo en medios de cultivos específicos para cada grupo microbiano. La identificación de las cepas bacterianas aisladas se realizó de acuerdo con lo indicado por MacFaddin (2004). RESULTADOS: Los resultados indican que el agua termal del Tingo se clasifica como de conductividad muy fuerte, mineralización excesiva, aguas muy duras, con muy poco oxígeno disuelto, pH neutro e hipertermales. El contaje promedio de bacterias heterótrofas en el agua contenida en la cisterna del balneario fue de 2,10 X 102 UFC/mL, coliformes totales de 0,30 X 10 UFC/mL y hongos 1,00 X 10 UFC/mL. Para las duchas de agua termal los valores promedios fueron de 2,42 X 102 UFC/mL de bacterias heterótrofas, 0,85 X 10 UFC/mL coliformes totales y 0,68 X 10 UFC/mL de hongos. No se detectó la presencia de Escherichia coli en ninguna de las muestras analizadas. Se identificaron 14 cepas Gram negativas de los géneros Aeromonas, Burkholderia, Citrobacter y Pseudomonas, 5 Gram positivas de los géneros Bacillus y Staphylococcus y 2 cepas fúngicas del género Aspergillus. CONCLUSIONES: Los resultados obtenidos demuestran una población microbiana escasa y poco diversa, lo que implica una buena calidad del agua y de los acuíferos

OBJECTIVE: The purpose of research was determining the microbiological quality of the thermal water of the "El Tingo" Spa, located at 2500 mamsl, Pichincha Province, Ecuador. METHODS: Four samplings were carried out at different times of the year and in two areas of the Spa. The physicochemical parameters (conductivity, hardness, dissolved oxygen, pH, dissolved solids and temperature) were determined "in situ". The heterotrophic bacteria, coliforms and molds was determined, as well as the identification of the isolated strains according to the indicated by MacFaddin (2004). RESULTS: The Tingo thermal water is classified as very strong conductivity, excessive mineralization, very hard water, with very little dissolved oxygen, neutral pH and hyperthermal. The average count of heterotrophic bacteria in the water contained in the cistern of the spa were 2.10 X 102 CFU / mL, coliforms 0.30 X 10 CFU / mL and fungi1,00 X 10 CFU / mL. For the thermal water showers, the average values were 2.42 X 102 CFU/ mL of heterotrophic bacteria, 0.85 X 10 CFU / mL coliforms and 0.68 X 10 CFU/ mLfungi. Escherichia coli were not detectedin any of the samples. It was possible to identify 14 Gram negative strains of the genus Aeromonas, Burkholderia, Citrobacter and Pseudomonas, 5 Gram positive of the genera Bacillus and Staphylococcus and 2 fungal strains of the genus Aspergillus

Contaminación microbiológica en humidificadores de sistemas de oxigenoterapia de alto y bajo flujo: una revisión sistemática / Microbiological contamination in high and low flow oxygen humidifiers: A systematic review

Objetivo: Determinar el riesgo de contaminación microbiológica de los humidificadores de burbujeo para oxigenoterapia de alto o bajo flujo de uso hospitalario. Métodos: Revisión sistemática de la literatura a través de 6 bases de datos bibliográficas. Se seleccionaron estudios observacionales o experimentales publicados entre 1990 y 2016, en inglés o español, que analizaban la contaminación microbiana de los humidificadores de burbujeo de los dispositivos de oxigenoterapia hospitalaria de alto y bajo flujo. Resultados: Se incluyeron 12 artículos: 4 analizaron el agua de humidificadores reutilizables, 4 de desechables y otros 4 compararon muestras procedentes de ambos modelos. Se observó la presencia de contaminación microbiana en todos los estudios que evaluaron humidificadores reutilizables (generalmente bacterias habituales de la flora cutánea). En 2 de ellos se notificaron aislamientos de especies potencialmente patogénicas. No se aisló contaminación microbiana en las muestras procedentes de modelos desechables, independientemente de si fueron utilizados por un único paciente o por varios de forma consecutiva a lo largo del tiempo. Conclusión: Parece existir bajo riesgo de contaminación en humidificadores desechables durante las primeras semanas de uso, pudiendo reutilizarse entre pacientes distintos sin riesgo de contaminación cruzada. Por otro lado, cabe destacar que la manipulación de los humidificadores reutilizables de forma no aséptica puede aumentar la probabilidad de contaminación, por lo que la sustitución de humidificadores reutilizables por modelos desechables podría ser la opción más segura

Aim: To determine the risk of microbiological contamination with hospital use high- and low-flow bubbling humidifiers. Methods: A systematic literature review was carried out in 6 databases. Observational or experimental studies published between 1990 and 2016 were selected, written in English or Spanish, and in which microbiological contamination with hospital use high- and low-flow bubbling humidifiers was investigated. Results: A total of 12 articles were included: 4 analyzed the water from reusable humidifiers, 4 analyzed the water from prefilled system humidifiers, and the rest compared samples from both models. Microbial contamination was observed in all studies in which reusable humidifiers were evaluated, usually involving common bacteria from the skin flora, while potential pathogenic species were notified in 2 studies. No microbial contamination was isolated from reusable humidifiers, regardless of whether they had been consecutively used over time by a single patient or by several patients. Conclusion: On one hand, there seems to be a low risk of contamination during the first weeks of use of prefilled humidifiers, which allows multiple use in different patients, without a risk of cross-contamination. On the other hand, it should be underscored that handling reusable humidifiers without correct aseptic measures can increase the risk of contamination; replacing reusable humidifiers with prefilled models therefore could be the safest option

Effect of water activity and temperature on the growth of Eurotium species isolated from animal feeds / Efecto de la actividad del agua y la temperatura en el crecimiento de especies de Eurotium aisladas de alimentos para animales

Background. Xerophilic fungi represent a serious problem due to their ability to grow at low water activities causing the spoiling of low and intermediate moisture foods, stored goods and animal feeds, with the consequent economic losses. Aims. The combined effect of water activity and temperature of four Eurotium species isolated from animal feeds was investigated. Methods. Eurotium amstelodami, Eurotium chevalieri, Eurotium repens and Eurotium rubrum were grown at 5, 15, 25, 37 and 45°C on malt extract agar adjusted with glycerol in the range 0.710-0.993 of water activities. Results. The cardinal model proposed by Rosso and Robinson (2001) was applied to fit growth data, with the variable water activity at fixed temperatures, obtaining three cardinal water activities (awmin, awmax, awopt) and the specific growth rate at the optimum aw (μopt). A probabilistic model was also applied to define the interface between growth and no-growth. The cardinal model provided an adequate estimation of the optimal aw to grow and the maximum growth rate. The probabilistic model showed a good performance to fit growth/no-growth cases in the predicted range. Conclusions. The results presented here could be applied to predict Eurotium species growth in animal feeds (AU)

Antecedentes. Los hongos xerófilos son un problema importante debido a su capacidad de crecer a bajas actividades del agua, lo que causa el deterioro de alimentos a humedades bajas e intermedias, de materias primas almacenadas y de piensos para animales, con las consecuentes pérdidas económicas. Objetivos. Se llevó a cabo un estudio sobre el efecto de los factores ambientales (temperatura y actividad del agua) sobre el crecimiento de cuatro especies pertenecientes al género Eurotium aisladas de piensos para animales. Métodos. Se estudió el crecimiento de Eurotium amstelodami, Eurotium chevalieri, Eurotium repens y Eurotium rubrum a valores de actividad de agua en el rango 0,710-0,993 en el medio de cultivo agar extracto de malta modificado con glicerol, y valores de temperatura de 5, 15, 25, 37 y 45°C. Resultados. El modelo cardinal propuesto por Rosso y Robinson (2001) se aplicó para realizar el ajuste de datos con la actividad del agua como variable a una temperatura fija; se obtuvieron tres valores cardinales de actividad del agua (awmin, awmax, awopt) y la tasa de crecimiento específico en el valor óptimo de aw (μopt). También se aplicó un modelo probabilístico para definir la interfase entre crecimiento y no crecimiento. El modelo cardinal presentó una adecuada estimación del awopt y la máxima velocidad de crecimiento. El modelo probabilístico fue adecuado para el ajuste de los casos de crecimiento/falta de crecimiento en el rango previsto. Conclusiones. Los resultados presentados en este artículo pueden aplicarse para pronosticar el crecimiento de especies de Eurotium en piensos para animales (AU)

Genetic diversity reflects geographical origin of Ralstonia solanacearum strains isolated from plant and water sources in Spain

The characterization and intraspecific diversity of a collection of 45 Ralstonia solanacearum strains isolated in Spain from different sources and geographical origins is reported. To test the influence of the site and the host on strain diversity, phenotypic and genotypic analysis were performed by a polyphasic approach. Biochemical and metabolic profiles were compared. Serological relationship was evaluated by Indirect-ELISA using polyclonal and monoclonal antibodies. For genotypic analysis, hrpB and egl DNA sequence analysis, repetitive sequences (rep-PCR), amplified fragment length polymorphism (AFLP) profiles and macrorestriction with XbaI followed by pulsed field gel electrophoresis (PFGE) were performed. The biochemical and metabolic characterization, serological tests, rep-PCR typing and phylogenetic analysis showed that all analysed strains belonged to phylotype II sequevar 1 and shared homogeneous profiles. However, interesting differences among strains were found by AFLP and macrorestriction with XbaI followed by PFGE techniques, some profiles being related to the geographical origin of the strains. Diversity results obtained offer new insights into the biogeography of this quarantine organism and its possible sources and reservoirs in Spain and Mediterranean countries

No disponible

A six-month Serratia marcescens outbreak in a Neonatal Intensive Care Unit / Brote epidémico por Serratia marcescens en una Unidad de Cuidados Intensivos Neonatales

OBJECTIVE: To investigate a Serratia marcescens (S. marcescens) outbreak in a Neonatal Unit in a tertiary university hospital. METHODS: Descriptive study of children admitted to the Unit with S. marcescens infection from November 2012 to March 2013. Conventional microbiological methods for clinical and environmental samples were used. The clonal relationship between all available isolates was established by molecular methods. A multidisciplinary team was formed, and preventive measures were taken. RESULTS: S. marcescens was isolated from 18 children. The overall attack rate was 12%, and the case fatality rate in the Intensive Care Unit was 23.5%. The most prevalent types of infections were pneumonia (6), conjunctivitis (6), and bloodstream infection (5). Clinical isolates and environmental isolates obtained from an incubator belonged to a unique clone. The clonal relationship between all S. marcescens strains helped us to identify the possible source of the outbreak. CONCLUSION: Isolation of S. marcescens from stored water in a container, and from the surface of an incubator after cleaning, suggests a possible environmental source as the outbreak origin, which has been perpetuated due to a failure of cleaning methods in the Unit. The strict hygiene and cleaning measures were the main factors that contributed to the end of the outbreak

OBJETIVO: Investigar un brote por Serratia marcescens (S. marcescens) en una unidad de neonatología en un hospital universitario de tercer nivel. MÉTODO: Estudio descriptivo de los pacientes ingresados en la Unidad de noviembre de 2012 a marzo de 2013. Se usaron métodos microbiológicos convencionales de muestras clínicas y ambientales. La relación clonal de los aislados disponibles se llevó a cabo mediante estudio molecular. Se formó un equipo multidisciplinar a partir del cual se tomaron las medidas preventivas. RESULTADOS: Se aisló S. marcescens en 18 niños. La tasa global de ataque fue del 12% y la letalidad en la Unidad de Cuidados Intensivos llegó al 23,5%. Los tipos de infección más frecuentes fueron la neumonía (6), conjuntivitis (6) y bacteriemia (5). Tanto las muestras clínicas como las ambientales obtenidas de una incubadora pertenecían a un único clon. La relación clonal entre todas las cepas de S. marcescens permitió identificar la posible fuente de infección del brote. CONCLUSIÓN: El aislamiento de S. marcescens en agua almacenada en un contenedor y en la superficie de una incubadora tras su limpieza sugiere una posible fuente ambiental como el origen del brote, perpetuado por fallos en los métodos de limpieza en la Unidad. El cumplimiento estricto de la higiene de manos y mejora en la limpieza fueron los principales factores que contribuyeron a la finalización del brote

Microbiological quality of pediatric oral liquid formulations / Calidad microbiológica de las formulaciones orales líquidas pediátricas

The oral administration of drugs to the pediatric population involves the extemporaneous preparation of liquid formulations. These formulations have studies on their physicochemical stability, but they often lack microbiological studies. The objective of this study is to check the microbiological quality of five oral liquid formulations prepared with different excipients, which represent five major combinations, in two conditions: kept unopened until the day of the test, and in a multi-dose vial opened daily. The formulations were prepared according to standard operating procedures. Half of each batch was packaged in vials that remained closed until the day of testing, and the other half in a single container which was opened daily. Both the vials and the containers had been previously sterilized. Microbiological tests were performed weekly during the first month of the study, and then every two weeks, until the expiration date. The microbiological quality of oral liquid formulations is determined by the Royal Spanish Pharmacopoeia. The conclusion was that none of the formulations prepared that were packaged in sterilized containers became contaminated, either in unopened vials or in multi-dose containers when they were opened daily (AU)

La administración oral de fármacos a la población pediátrica implica la preparación de fórmulas líquidas extemporáneas. Estas fórmulas tienen estudios de estabilidad fisicoquímica pero en muchas ocasiones carecen de estudios microbiológicos. El objetivo del estudio es comprobar la calidad microbiológica de cinco fórmulas orales líquidas, preparadas con diferentes excipientes, que representan mayoritariamente cinco combinaciones, en dos condiciones: conservadas sin abrir hasta el día del análisis y abriendo diariamente el envase multidosis. Se prepararon las fórmulas según los procedimientos normalizados de trabajo. La mitad del lote de cada fórmula se envasó en viales que estuvieron cerrados hasta el día del análisis y la otra mitad en un solo frasco que se abría diariamente. Tanto los viales como los frascos para el envasado estaban esterilizados previamente. El análisis microbiológico se realizó cada semana durante el primer mes de estudio y después cada dos semanas hasta llegar al periodo de caducidad. La calidad microbiológica de las fórmulas orales líquidas viene marcada por la Real Farmacopea Española. Se concluye que ninguna de las fórmulas elaboradas envasadas en contenedores esterilizados se contaminó ni en los viales cerrados ni en los frascos multidosis cuando se abrieron diariamente (AU)

Control microbiológico ambiental / Environmental microbiological control

El control microbiológico ambiental es necesario para evitar infecciones relacionadas con determinados procedimientos que se llevan a cabo en el hospital. En esta revisión se abordan los procedimientos de control del agua y líquidos en las unidades de diálisis y de aire en quirófano y unidades de inmunodeprimidos. Las guías de gestión de calidad del líquido de diálisis definen los niveles máximos de contaminación química, microbiológica y de endotoxinas tanto del agua purificada como del líquido de diálisis. El control microbiológico del agua y del líquido de diálisis debe incluir la detección de microorganismos y de los niveles de endotoxinas. Respecto al control microbiológico del aire de los quirófanos y unidades de inmunodeprimidos, en esta revisión se definen los tipos de salas limpias en los que hay que realizar controles microbiológicos del aire; los métodos de recogida de muestras; los medios de cultivo y las condiciones de incubación; los microorganismos más frecuentes, y los niveles admisibles según el tipo de quirófano

The environmental microbiological control is necessary to prevent infections associated with certain procedures that are performed at the hospital. In this review the procedures for control of water and dialysis fluids, and air in operating rooms and immunocompromised units are addressed. The dialysis quality management guidelines define the highest levels of chemical, microbiological and endotoxin in purified water and dialysis fluids based on the recommendations of scientific societies. The microbiological control of water and dialysis fluids should include detection of microorganisms and endotoxin levels. Regarding the microbiological air sampling of operating rooms and immunocompromised units the types of clean rooms in which is recommended to perform microbiological air monitoring; the sample collection methods; culture media; incubation conditions; the most common microorganisms, and permissible levels depending on the type of surgery are described

Guía de gestión de calidad del líquido de diálisis (LD) (segunda edición, 2015) / Guideline for dialysate quality of Spanish Society of Nephrology (second edition, 2015)

La Sociedad Española de Nefrología elaboró en 2004 una Guía de Gestión de Calidad del Líquido de Diálisis. La segunda edición revisada de la guía ha tenido en cuenta nuevas evidencias y la normativa internacional. En la guía se hacen algunas recomendaciones sobre normas para preparar el líquido de diálisis: agua, concentrados y sistemas de dosificación de la hemodiálisis. Esta guía se basa en la norma ISO13959, la Farmacopea Europea, la Real Farmacopea Española, las normas y prácticas recomendadas de la AAMI, la Guía Europea de Buena Práctica en Hemodiálisis, revisiones de la bibliografía, según su nivel de evidencia, y la opinión del grupo español de expertos. Se definieron 2 niveles de calidad del agua: agua purificada y agua purificada de alta calidad (ultra pura), y para el líquido de diálisis: líquido de diálisis ultra puro. El uso habitual de líquido de diálisis ultra puro se recomienda en todo tipo de hemodiálisis para prevenir y retrasar la aparición de complicaciones: inflamación, desnutrición, anemia y amiloidosis. Los requisitos de la calidad del agua, de los concentrados y del líquido de diálisis se definen como los niveles máximos admisibles de contaminantes: sustancias químicas (4.1.2), conductividad, microbiana y endotoxinas (4.1.1): Se especificaron la frecuencia de control, el mantenimiento y las medidas correctivas. Los métodos de muestreo y análisis se describieron en los anexos. Para el control microbiológico es recomendable el medio de cultivo R2A, incubado durante 7-14días a una temperatura de 17-23°C. El proceso de garantía de la calidad del líquido de diálisis implica a todos los miembros del personal de diálisis y exige protocolos estrictos. El médico a cargo de la hemodiálisis tiene la responsabilidad final de la calidad del líquido de diálisis. Pueden dirigir sus sugerencias y preguntas acerca de esta guía a www.senefro.org (AU)

A Best Practice Guideline about Dialysis fluid purity was developed under the leadership of the Spanish Society of Nephrology in 2004. The second edition revised Guideline considered new evidences and International Standard. The Guideline has established recommendations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. This Guideline is based on the ISO13959, European Pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, European Best Practice Guidelines for Haemodialysis, literature reviews, according to their level of evidence, and the opinion of the expert Spanish group. Two levels of quality of water were defined: purified water and high purified water (ultra pure) and for dialysate: ultra pure dialysate. Regular use of ultra pure dialysate is recommended for all type of hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anaemia and amiloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowable contaminant levels: chemicals (4.1.2), conductivity, microbial and endotoxins (4.1.1): Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (anexos). For microbiological monitoring, R2A medium is recommended, incubated during 7-14 days at a temperature of 17-23°C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality. All suggestions and questions about this Guideline are wellcome to www.senefro.org (AU)

Spatial homogeneity of bacterial and archaeal communities in the deep eastern Mediterranean Sea surface sediments

The diversity of microorganisms inhabiting the deep sea surface sediments was investigated in 9 stations (700-1900 m depth) in the Levantine basin by 454 massive tag sequencing of the 16S rDNA V4 region using universal primers. In total, 108,811 reads (an average of 10,088 per sample) were assigned to 5014 bacterial and 966 archaeal operational taxonomic units (OTUs; at 97% cut off). The 55% of the reads were of archaea, indicating dominance of archaea over bacteria at eight of the stations. The diversity and estimated richness values were high (e.g., H´ ranged from 5.66 to 7.41 for bacteria). The compositions of the microorganisms at all stations were remarkably similar, with Bray-Curtis similarities of 0.53-0.91 and 0.74-0.99 for bacterial and archaeal orders respectively. At two stations, very high abundances of only a few genera (Marinobacterium, Bacillus, Vibrio, Photobacterium) were accountable for the dissimilarities documented compared to the other deep sea stations. Half of the bacterial reads (51%) belonged to the phylum Proteobacteria, comprising mainly Gammaproteobacteria (41-72% of the proteobacterial reads per sample), Deltaproteobacteria (12-29%), Alphaproteobacteria (7-18%) and Betaproteobacteria (3-14%). The most abundant bacterial family was Sinobacteraceae (order Xanthomonadales) with 5-10% of total bacterial reads per sample. Most abundant reads (15.4% of all microbial reads) were affiliated with Marine Group 1 archaea, putatively capable of ammonia oxidation (213 OTUs), and bacteria involved in nitrification were found in all samples. The data point to the significant role that chemolithotrophic carbon assimilation and nitrification fill in the oligotrophic deep sea Levant sediments (AU)

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De novo synthesis and functional analysis of the phosphatase-encoding gene acI-B of uncultured Actinobacteria from Lake Stechlin (NE Germany)

The National Center for Biotechnology Information [http://www.ncbi.nlm.nih.gov/guide/taxonomy/] database enlists more than 15,500 bacterial species. But this also includes a plethora of uncultured bacterial representations. Owing to their metabolism, they directly influence biogeochemical cycles, which underscores the important status of bacteria on our planet. To study the function of a gene from an uncultured bacterium, we have undertaken a de novo gene synthesis approach. Actinobacteria of the acI-B subcluster are important but yet uncultured members of the bacterioplankton in temperate lakes of the northern hemisphere such as oligotrophic Lake Stechlin (NE Germany). This lake is relatively poor in phosphate (P) and harbors on average ~1.3 x 106 bacterial cells/ml, whereby Actinobacteria of the ac-I lineage can contribute to almost half of the entire bacterial community depending on seasonal variability. Single cell genome analysis of Actinobacterium SCGC AB141-P03, a member of the acI-B tribe in Lake Stechlin has revealed several phosphate-metabolizing genes. The genome of acI-B Actinobacteria indicates potential to degrade polyphosphate compound. To test for this genetic potential, we targeted the exoP-annotated gene potentially encoding polyphosphatase and synthesized it artificially to examine its biochemical role. Heterologous overexpression of the gene in Escherichia coli and protein purification revealed phosphatase activity. Comparative genome analysis suggested that homologs of this gene should be also present in other Actinobacteria of the acI lineages. This strategic retention of specialized genes in their genome provides a metabolic advantage over other members of the aquatic food web in a P-limited ecosystem (AU)

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El Balneario de Villavieja (Castellón) / No disponible

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Microbiología del agua mineromedicinal del Balneario de Villavieja / Microbiology of the natural mineral water of Villavieja Spa

Se ha estudiado la microbiota autóctona y alóctona del agua mineromedicinal del Balneario de Villavieja (Castellón). El número total de microorganismos en el agua ha sido de 4,7 x104/mL y el número de bacterias viables heterótrofas y oligotrofas de 103 ufc/mL. No se han encontrado indicadores fecales ni microorganismos patógenos en 250 mL de agua. La microbiota autóctona está constituida, principalmente, por bacilos Gram negativos no fermentadores del Phylum Proteobacteria (64,4%) y, en menor proporción, por bacilos Gram positivos (24,4 %) y cocos Gram positivos (6,7 %). Las especies más frecuentes han sido Pseudomonas pseudoalcaligenes (15,5 %) y Leifsonia aquatica (13,3 %). Se han detectado bacterias con actividades amonificantes, proteolíticas, amilolíticas y sulfato‐reductoras en 100 mL de agua que contribuyen a la autodepuración del agua (AU)

The autochthonous and alocthonous microbiota of the natural mineral water of Villavieja Spa have been studied. The total number of microorganisms in the water was of 4.7 x104 /mL and the number of heterotrophic and oligotrophic viable bacteria was 103 cfu/mL. Neither faecal indicators nor pathogenic microorganisms were found in 250 mL of water. The autochthonous microbiota mostly belongs to Gram‐negative bacilli, from the Phylum Proteobacteria (64.4%) and in smaller percentage to the Gram‐positive bacilli (24.4%) and cocci (6.7%). The most frequently found species were Pseudomonas pseudoalcaligenes (15.5%) and Leifsonia aquatica (13.3%). Moreover ammonifying, proteolytic, amylolytic and sulphato‐reducted bacteria have been detected in 100 mL of water, all of them involved in self‐purification process of water (AU)

Solar water disinfection (SODIS): impact on hepatitis A virus and on a human Norovirus surrogate under natural solar conditions

This study evaluates the effectiveness of solar water disinfection (SODIS) in the reduction and inactivation of hepatitis A virus (HAV) and of the human Norovirus surrogate, murine Norovirus (MNV-1), under natural solar conditions. Experiments were performed in 330 ml polyethylene terephthalate (PET) bottles containing HAV or MNV-1 contaminated waters (103 PFU/ml) that were exposed to natural sunlight for 2 to 8 h. Parallel experiments under controlled temperature and/or in darkness conditions were also included. Samples were concentrated by electropositive charged filters and analysed by RT-real time PCR (RT-qPCR) and infectivity assays. Temperature reached in bottles throughout the exposure period ranged from 22 to 40ºC. After 8 h of solar exposure (cumulative UV dose of ~828 kJ/m2 and UV irradiance of ~20 kJ/l), the results showed significant (P < 0.05) reductions from 4.0 (±0.56) ×104 to 3.15 (±0.69) × 103 RNA copies/100 ml (92.1%, 1.1 log) for HAV and from 5.91 (±0.59) × 104 to 9.24 (±3.91) × 103 RNA copies/100 ml (84.4%, 0.81 log) for MNV-1. SODIS conditions induced a loss of infectivity between 33.4% and 83.4% after 4 to 8 h in HAV trials, and between 33.4% and 66.7% after 6 h to 8 h in MNV-1 trials. The results obtained indicated a greater importance of sunlight radiation over the temperature as the main factor for viral reduction (AU)

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