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1.
J Environ Manage ; 261: 110220, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148290

RESUMEN

Faecal pollution modelling is a valuable tool to evaluate and improve water management strategies, especially in a context of water scarcity. The reduction dynamics of five faecal indicator organisms (E. coli, spores of sulphite-reducing clostridia, somatic coliphages, GA17 bacteriophages and a human-specific Bifidobacterium molecular marker) were assessed in an intermittent Mediterranean stream affected by a wastewater treatment plant (WWTP). Using Bayesian inverse modelling, the decay rates of each indicator were correlated with two environmental drivers (temperature and streamflow downstream of the WWTP) and the generated model was used to evaluate the self-depuration distance (SDD) of the stream. A consistent increase of 1-2 log10 in the concentration of all indicators was detected after the discharge of the WWTP effluent. The decay rates showed seasonal variation, reaching a maximum in the dry season, when SDDs were also shorter and the stream had a higher capacity to self-depurate. High seasonality was observed for all faecal indicators except for the spores of sulphite-reducing clostridia. The maximum SDD ranged from 3 km for the spores of sulphite-reducing clostridia during the dry season and 15 km for the human-specific Bifidobacterium molecular marker during the wet season. The SDD provides a single standardized metric that integrates and compares different contamination indicators. It could be extended to other Mediterranean drainage basins and has the potential to integrate changes in land use and catchment water balance, a feature that will be especially useful in the transient climate conditions expected in the coming years.


Asunto(s)
Aguas Residuales , Calidad del Agua , Teorema de Bayes , Monitoreo del Ambiente , Escherichia coli , Heces , Humanos , Estaciones del Año , Microbiología del Agua
2.
J Appl Microbiol ; 126(3): 701-717, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30244503

RESUMEN

The objective of this review is to assess the current state of knowledge of pathogens, general faecal indicators and human-specific microbial source tracking markers in sewage. Most of the microbes present in sewage are from the microbiota of the human gut, including pathogens. Bacteria and viruses are the most abundant groups of microbes in the human gut microbiota. Most reports on this topic show that raw sewage microbiological profiles reflect the human gut microbiota. Human and animal faeces share many commensal microbes as well as pathogens. Faecal-orally transmitted pathogens constitute a serious public health problem that can be minimized through sanitation. Assessing both the sanitation processes and the contribution of sewage to the faecal contamination of water bodies requires knowledge of the content of pathogens in sewage, microbes indicating general faecal contamination and microbes that are only present in human faecal remains, which are known as the human-specific microbial source-tracking (MST) markers. Detection of pathogens would be the ideal option for managing sanitation and determining the microbiological quality of waters contaminated by sewage; but at present, this is neither practical nor feasible in routine testing. Traditionally, faecal indicator bacteria have been used as surrogate indicators of general faecal residues. However, in many water management circumstances, it becomes necessary to detect both the origin of faecal contamination, for which MST is paramount, and live micro-organisms, for which molecular methods are not suitable. The presence and concentrations of pathogens, general faecal indicators and human-specific MST markers most frequently reported in different areas of the world are summarized in this review.


Asunto(s)
Bacterias/aislamiento & purificación , Heces/microbiología , Heces/virología , Virus/aislamiento & purificación , Animales , Bacterias/clasificación , Bacterias/genética , Humanos , Virus/clasificación , Virus/genética , Microbiología del Agua
3.
J Water Health ; 16(5): 762-772, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30285957

RESUMEN

A study was conducted of the occurrence of Cryptosporidium in indoor heated public swimming pools and of three bacterial indicators (Escherichia coli, faecal enterococci and Clostridium perfringens) on pool surrounds. Although all examined pools adhered strictly to the Spanish regulations, the influence of several parameters related to water conditions, pool structure, users and location on the presence of protozoa and bacteria was analysed. Cryptosporidium was detected in 18.8% of pools in 60% of the five towns studied. The maximum concentration was 13 oocysts/L in one swimming pool and one Jacuzzi. The bacterial indicators' prevalence on pool surrounds was higher than 50%, being present in all of the towns. Plastic surfaces presented the lowest bacterial prevalence, whereas painted surfaces were 100% positive. No differences were observed for pool surrounds with autonomous or disabled users. Risk of cryptosporidiosis in pool vessels indicated that concentrations over 1 oocyst/10 L enhance the risk of infection, even in one exposure. Guidelines for managing faecal accidents and public information on the importance of good hygiene behaviours in and around swimming pools are recommended to limit oocysts' presence.


Asunto(s)
Cryptosporidium , Piscinas/estadística & datos numéricos , Microbiología del Agua , Animales , Bacterias , Criptosporidiosis/epidemiología , Monitoreo del Ambiente , España
4.
Curr Microbiol ; 72(1): 12-8, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26362161

RESUMEN

Human enteric viruses are a major causative agent of emerging waterborne diseases and constitute a serious public health concern. Environmental contamination occurs through discharge of waste materials from infected persons. Methods for viral detection should be developed to detect low infective dose of enteric viruses in environment. In this study, we aimed at comparing two concentration methods for the detection of naturally occurring enteroviruses in raw and treated sewage. In the first method, polyethylene glycol is used to concentrate viral particles from the collected samples. The second method is based on ultracentrifugation of viral particles at high speed (110,000×g). Genomes of enteroviruses were quantified by the quantitative real-time PCR method in raw and treated sewage samples. PEG-based method yielded higher genomic copies of enteric viruses (with an average of 5.9 log10 genomic copies/100 mL) when applied to raw sewage samples. While the ultracentrifugation assay in the second method decreases genomic copies number (with an average of 5.4 log10 genomic copies/100 mL). The recovery differences between the two methods were not significant when applied to clean samples (treated sewage). This could be explained by the presence of inhibitors, which interfere with qRT-PCR, in less quantity comparatively to raw sewage. PEG-based method would be more accurate for samples with high-organic matter load. This report emphasizes the importance of matrices nature on the recovery of enteroviruses from sewage samples. This should be taken into consideration for establishing standardized virological assays to ensure the virological quality control of discharged water in environment.


Asunto(s)
Enterovirus/aislamiento & purificación , Aguas del Alcantarillado/virología , Virología/métodos , Precipitación Química , Humanos , Reacción en Cadena en Tiempo Real de la Polimerasa , Ultracentrifugación/métodos , Carga Viral
5.
J Appl Microbiol ; 118(2): 412-8, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25443658

RESUMEN

AIMS: Escherichia coli (EC) is the primary indicator micro-organism in regulations for sewage sludge reuse. The aim of this work was to assess the ability of EC to enter and recover from a viable-but-not-culturable state (VBNC) after sludge hygienization treatments. METHODS AND RESULTS: The persistence of EC, somatic coliphages (SOMCPH), spores of sulphite-reducing clostridia (SRC) and Salmonella spp. was assessed in digested sludge after different pasteurization treatments and storage conditions. Pasteurization at 55°C produced EC-injured cells that were resuscitated during the first 24 h. Different sludge treatments altered the inactivation kinetics of EC, while SOMCPH and SRC did not resuscitate and showed lower die-off than EC. No regrowth was observed in stored sludge for up to 60 days. CONCLUSIONS: EC monitoring by culturable methods is not by itself a suitable method for assessing the hygienization achieved in sludge as EC can enter into VBNC from which it can recover during the first hours of storage. SIGNIFICANCE AND IMPACT OF THE STUDY: The regulations should indicate the time when monitoring of EC should be performed to avoid the period when EC can resuscitate from VBNC or add alternative microbial indicators, such as SOMCPH, which do not have a VBNC state.


Asunto(s)
Escherichia coli/aislamiento & purificación , Aguas del Alcantarillado/microbiología , Clostridium/aislamiento & purificación , Colifagos/aislamiento & purificación , Escherichia coli/crecimiento & desarrollo , Pasteurización , Salmonella/aislamiento & purificación
6.
Lett Appl Microbiol ; 58(1): 70-8, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24024645

RESUMEN

UNLABELLED: The fast analysis of relative proportions of live and dead cells can be of great value whether for comparing inactivation efficiencies of different biocidal treatments or for monitoring organisms of interest in environmental samples. We introduce here a straightforward method to determine the percentage of intact cells based on treatment of samples with the viability dye propidium monoazide (PMA). PMA selectively enters membrane-damaged cells and suppresses their PCR detection through modification of their DNA. The study was performed using Cryptosporidium parvum oocysts as a model although the principle should be applicable to other organisms. Validation was performed with defined mixtures of live and heat-killed oocysts and by exposing oocysts to a heat stress gradient. The method correctly indicated increasingly lower proportions of intact cells with increasing temperatures. When comparing the loss of membrane integrity of UV-killed (40 mJ cm(-2) ) oocysts during storage in nonsterile tap water, results suggested that integrity declines slowly (over weeks) and at a rate comparable to non-UV-exposed oocysts. For all experiments, the amplification of longer DNA sequences was found beneficial. In the UV experiment, longer amplicons revealed not only higher sensitivity in excluding membrane-damaged oocysts, but also in excluding DNA with UV-induced damage. SIGNIFICANCE AND IMPACT OF THE STUDY: Whether in the context of microbial ecology or in an industrial context, many questions in microbiology are linked to microbial viability. As cultivation of micro-organisms can be long or may not be possible, fast methods to assess the numbers of live cells are in great demand. We present here a straightforward strategy to determine the relative proportions of intact cells. The PCR-based rapid method is expected to be useful where relative information is sufficient (e.g. for comparing the effect of different antimicrobial treatments on known numbers of micro-organisms) or when the presence of PCR inhibitors does not allow absolute quantification.


Asunto(s)
Azidas , Cryptosporidium parvum/fisiología , Oocistos/fisiología , Reacción en Cadena de la Polimerasa/métodos , Propidio/análogos & derivados , Cryptosporidium parvum/genética , ADN Protozoario/análisis , ADN Protozoario/genética , Calor , Viabilidad Microbiana , Rayos Ultravioleta
7.
Water Res ; 249: 120981, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38091698

RESUMEN

Rapid population growth and coastal development has led to increased fecal contamination of coastal surface waters worldwide, enhancing the potential risk of waterborne human pathogens in bathing areas. More frequent heavy rainfall events, attributed to global warming, have further exacerbated the problem by causing sometimes sewer overflows into recreational waters. As traditional bacterial indicators have limited accuracy for predicting health risks associated with waterborne viruses, the additional use of viral indicators such as coliphages is recommended. In this study, we compared the behavior of bacterial and viral indicators of water quality at 10 Barcelona beaches during three bathing seasons, in dry conditions, and after four rainstorms that caused specific pollution events due to rain runoff with combined sewer overflows (CSO). Levels of all target indicators increased after the rainstorms, but compared to Escherichia coli and intestinal enterococci, somatic coliphages exhibited a slower decline and higher environmental persistence following a rain event. Daily continuous sampling carried out during the days following a rainstorm allowed not only the determination of the decay kinetics of each target indicator but also the day when the water quality recovered the values established in the current European regulation in approximately 2 -3 days after each CSO. These observations indicate that the combined use of bacterial and viral indicators can enhance the surveillance of microbial quality of bathing waters. Moreover, coliphages can swiftly provide insights into transient fecal pollution linked to rainfall episodes, thanks to available analytical techniques that enable same-day recommendations. The management of urban wastewater and recreational water regulations should consistently employ microbial indicators to address rainwater runoff or sewer overflows resulting from heavy rainfall.


Asunto(s)
Monitoreo del Ambiente , Calidad del Agua , Humanos , Monitoreo del Ambiente/métodos , Enterococcus , Bacterias , Colifagos , Lluvia , Escherichia coli , Heces/microbiología , Microbiología del Agua
8.
J Water Health ; 10(4): 539-48, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23165711

RESUMEN

Water scarcity leads to an increased use of reclaimed water, which in turn calls for an improvement in water reclamation procedures to ensure adequate quality of the final effluent. The presence of infectious Cryptosporidium oocysts (IOO) in reclaimed water is a health hazard for users of this resource. Here, we gathered information on Cryptosporidium (concentrations, infectivity and genotype) in order to perform quantitative microbial risk assessment (QMRA). Moreover, data concerning the spores of sulphite-reducing clostridia (SRC) were used to undertake QMRA at a screening level. Our results show that the probability of infection (PI) by Cryptosporidium depends on the tertiary treatment type. The mean PI using the exponential dose-response model was 3.69 × 10(-6) in tertiary effluents (TE) treated with UV light, whereas it was 3 log(10) units higher, 1.89 × 10(-3), in TE not treated with this disinfection method. With the ß-Poisson model, the mean PI was 1.56 × 10(-4) in UV-treated TE and 2 log(10) units higher, 4.37 × 10(-2), in TE not treated with UV. The use of SRC to perform QMRA of Cryptosporidium showed higher PI than when using directly IOO data. This observation suggests the former technique is a conservative method of QMRA.


Asunto(s)
Criptosporidiosis/prevención & control , Cryptosporidium/efectos de la radiación , Desinfección/métodos , Oocistos/efectos de la radiación , Medición de Riesgo/métodos , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Clostridium/aislamiento & purificación , Cryptosporidium/clasificación , Cryptosporidium/genética , Cryptosporidium/aislamiento & purificación , ADN Protozoario/análisis , Agua Potable/microbiología , Agua Potable/parasitología , Genotipo , Citometría de Barrido por Láser , Oocistos/clasificación , Oocistos/fisiología , Oxidación-Reducción , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , España , Sulfitos/metabolismo , Rayos Ultravioleta
9.
J Dent Res ; 101(6): 647-654, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35001681

RESUMEN

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey's test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios , Acrilamidas , Resinas Compuestas/química , Cementos Dentales/química , Dentina , Recubrimientos Dentinarios/química , Humanos , Ensayo de Materiales , Metacrilatos/química , Cementos de Resina/química , Resistencia a la Tracción , Agua
10.
J Appl Microbiol ; 107(4): 1178-85, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19486397

RESUMEN

AIMS: To determine relative to faecal coliforms (FC) and sulfite-reducing clostridia (SRC), the environmental persistence of natural populations of Bifidobacterium spp. enumerated by culturing and quantitative polymerase chain reaction (q-PCR). METHODS AND RESULTS: Dialysis tubing containing river supplemented with overnight cultures of Bifidobacterium adolescentis (BA) and Bifidobacterium dentium (BD) or urban wastewater were suspended in a river for up to 10 days. At intervals, the contents of each dialysis tube were assayed using q-PCR assays for BA and BD, and selective culture media for FC, SRC, total bifidobacteria (TB), sorbitol-fermenting bifidobacteria (SFB) and cultivable BA. Mean summer T(90) values were 251 h for SRC, 92 h for FC, 48 h for BA and BD by q-PCR, and 9 h for TB. CONCLUSIONS: Bifidobacterium spp. was the population with the lowest persistence, showing seasonal differences in T(90) when measured by culture techniques or by q-PCR. This difference in relative persistence is because of a longer persistence of molecular targets than cultivable cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The persistence of a viable bifidobacteria cells is shorter, but the longest persistence of molecular targets. This factor could be used for origin the faecal pollution in water for the development of microbial source tracking (MST).


Asunto(s)
Bifidobacterium/aislamiento & purificación , Ríos/microbiología , Microbiología del Agua , Técnicas Bacteriológicas , Bifidobacterium/genética , Bifidobacterium/crecimiento & desarrollo , Recuento de Colonia Microbiana , Cartilla de ADN/genética , Reacción en Cadena de la Polimerasa/métodos , Estaciones del Año , Sensibilidad y Especificidad , Factores de Tiempo
11.
Hepatogastroenterology ; 56(93): 1133-6, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19760956

RESUMEN

BACKGROUND/AIMS: This study aim was to investigate an association between donor age and lower recipient survival in liver transplantation. METHODOLOGY: A total of 178 consecutive patients underwent liver transplantation between 1999 and 2007. Among these patients, 172 liver transplants (donor age: 32.04 +/- 16.66) and 167 recipients were included in the analysis. Mean recipient age was 39.16 +/- 21.61 years (range: 6 mo-71 years) and 90 (53.89%) were males. RESULTS: Among 172 transplants, 32.9% recipients died during follow-up. Mean follow-up time was 34.37 +/- 20.50 mo. A lower mean recipient survival prevailed from donors older than 50 years (p = .01) at 7-year patient survival. At 6-month and 1-year recipient survival, cut-offs were 50 and 55 years, respectively (p < .05). A significant difference was observed in graft survival from donors older than 30 years (p = .02) and at 6-month and 1-year, cutoffs were 35 and 50 years, respectively (p < .05). CONCLUSIONS: Although the utilization of donors with increased age in liver transplantation offers a new option to increase the number of liver transplants it presents lower survivals. Other factors related to graft loss such as MELD score > 15 and longer CIT (cold ischemia time) should be avoided to reduce the risk of using elderly donor grafts.


Asunto(s)
Supervivencia de Injerto , Trasplante de Hígado/mortalidad , Donantes de Tejidos , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Tasa de Supervivencia
12.
Water Res ; 155: 233-244, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30851594

RESUMEN

Recent studies have shown that crAssphage is abundant in human faecal samples worldwide. It has thus been postulated as a potential microbial source tracking (MST) marker to detect human faecal pollution in water. However, an effective implementation of crAssphage in water management strategies will depend on an understanding of its environmental dynamics. In this work, the abundance and temporal distribution of crAssphage was analysed in the effluent of wastewater treatment plants using different sewage treatments, and in two rivers (water and sediments) that differ in pollution impact and flow regime. Additionally, the influence of environmental conditions (temperature and rainfall) on the removal of the marker was studied along a river section, and natural inactivation was assessed by a mesocosms approach. Molecular and culture-based tools were used to compare crAssphage abundance and dynamics with those of bacteria and bacteriophages currently applied as global indicators (E. coli, somatic coliphages, Bacteroides GA17 bacteriophages, and the human-associated MST markers HF183 and HMBif). CrAssphage concentrations in sewage effluent and river samples were similar to those of HF183 and HMBif and higher than other general and/or culture-based indicators (by 2-3 orders of magnitude). Measurement of crAssphage abundance revealed no temporal variability in the effluent, although rainfall events affected the dynamics, possibly through the mobilisation of sediments, where the marker was detected in high concentrations, and an increase in diffuse and point pollution. Another factor affecting crAssphage inactivation was temperature. Its persistence was longer compared with other bacterial markers analysed by qPCR but lower than culturable markers. The results of this study support the use of crAssphage as a human source tracking marker of faecal pollution in water, since it has similar abundances to other molecular human MST markers, yet with a longer persistence in the environment. Nevertheless, its use in combination with infectious bacteriophages is probably advisable.


Asunto(s)
Escherichia coli , Microbiología del Agua , Bacteroides , Colifagos , Heces , Humanos , Aguas del Alcantarillado
13.
J Appl Microbiol ; 105(6): 1945-55, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19120641

RESUMEN

AIMS: Update information regarding occurrence and levels of culturable enteroviruses in several types of surface polluted waters in north-eastern Spain and determine the proportion of the different species and serotypes. METHODS AND RESULTS: The best procedures on hand in our laboratory for concentrating and quantifying culturable enteroviruses from different water sample types were used. Sequencing was used for typing the virus isolates. Geometric means of enteroviruses densities expressed in plaque forming units per litre were 968 in raw sewage, 12.51 in secondary effluents, 0.017 in tertiary effluents, 0.4 in river water and 0.36 in seawater. Enterovirus densities in wastewater revealed certain seasonality with a maximum at the end of spring - beginning of the summer. Coxsackievirus B, and amid them serotype CB4, were the most abundant species and serotypes detected. CONCLUSIONS: Densities of enteroviruses in different north-eastern Spain surface waters are similar to those present in industrialized countries with temperate climate. No wild polioviruses were detected. Distribution of species showed a clear prevalence of coxsackieviruses. SIGNIFICANCE AND IMPACT OF THE STUDY: Information regarding enteroviruses in this geographical area provides valuable information to estimate the risk of enteroviruses transmission through water and for complementing clinical epidemiological data.


Asunto(s)
Enterovirus/aislamiento & purificación , Microbiología del Agua , Contaminación del Agua , Animales , Recuento de Colonia Microbiana , Enterovirus/clasificación , Monitoreo del Ambiente/métodos , Agua Dulce , Estaciones del Año , Agua de Mar , Serotipificación , Aguas del Alcantarillado , España , Eliminación de Residuos Líquidos
14.
Water Sci Technol ; 57(6): 935-40, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18413956

RESUMEN

The combined effects of disinfectant agents on the microbiological quality of reclaimed water produced by two full-scale water reclamation plants in Catalonia, Spain, were examined in this work. All the disinfectant treatments tested led to the absence, or near absence, of E. coli in 100 mL samples of water, with log reductions of more than 3 log u. Hypochlorite reduced the bacterial concentrations. However, ultraviolet light was more effective than hypochlorite at reducing the concentrations of bacteriophages, viruses and pathogenic protozoa such as Cryptosporidium spp. We conclude that a combination of these two disinfectant agents is effective in protecting public health, as each agent acts to a different degree against the different groups of microorganisms studied. Further studies should investigate the combined action of disinfectant agents at water reclamation plants with ultraviolet light equipment in more favourable working conditions in order to assess their capacity to inactivate microorganisms.


Asunto(s)
Cloro/farmacología , Desinfección/métodos , Rayos Ultravioleta , Purificación del Agua/métodos , Abastecimiento de Agua/normas , Animales , Conservación de los Recursos Naturales/métodos , Desinfectantes/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/efectos de la radiación , Eucariontes/efectos de los fármacos , Eucariontes/efectos de la radiación , Ácido Hipocloroso/farmacología , Reproducibilidad de los Resultados , España , Virus/efectos de los fármacos , Virus/efectos de la radiación , Microbiología del Agua , Abastecimiento de Agua/análisis
15.
Water Res ; 128: 10-19, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29078067

RESUMEN

The use of somatic coliphages as indicators of fecal and viral pollution in water and food has great potential due to the reliability, reproducibility, speed and cost effectiveness of methods for their detection. Indeed, several countries already use this approach in their water management policies. Although standardized protocols for somatic coliphage detection are available, user-friendly commercial kits would facilitate their routine implementation in laboratories. The new method presented here allows detection of up to 1 somatic coliphage in under 3.5 h, well within one working day. The method is based on a modified Escherichia coli strain with knocked-out uidB and uidC genes, which encode the transport of glucuronic acid inside cells, and overexpressing uidA, which encodes the enzyme ß-glucuronidase. The enzyme accumulated in the bacterial cells only has contact with its substrate after cell lysis, such as that caused by phages, since the strain cannot internalize the substrate. When the enzyme is released into the medium, which contains a chromogen analogous to glucuronic acid, it produces a change of color from yellow to dark blue. This microbiological method for the determination of fecal pollution via the detection of culturable microorganisms can be applied to diverse sample types and volumes for qualitative (presence/absence) and quantitative analysis and is the fastest reported to date.


Asunto(s)
Colifagos/aislamiento & purificación , Heces/microbiología , Microbiología del Agua , Contaminación del Agua/análisis , Calidad del Agua , Escherichia coli/aislamiento & purificación , Reproducibilidad de los Resultados
16.
Rev Esp Quimioter ; 30(3): 195-200, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28361525

RESUMEN

OBJECTIVE: A rapid, simple and sensitive high-performance liquid chromatography (HPLC) method with ultraviolet detection has been developed for quantification of darunavir and raltegravir in their pharmaceutical dosage form. METHODS: The assay enables the measurement of both drugs with a linear calibration curve (R2= 0.999) over the concentration range 5-100 mg/L. The determination was performed on an analytical Tracer Excel 120 ODSB (15x0.4.6 cm) column at 35ºC. The selected wavelength was 254 nm. The mobile phase was a mixture of 0.037 M sodium dihydrogen phosphate buffer, acetonitrile and methanol (40:50:10, v/v/v) at a flow rate of 2.0 mL/min Nevirapine (50 mg/L) was used as internal standard. RESULTS: Accuracy, intra-day repeatability (n = 5), and inter-day precision (n = 3) were found to be satisfactory, being the accuracy from -4.33 to 3.88% and precisions were intra-day and inter-day, 0.25% and 4.42% respectively in case of darunavir. Raltegravir intra-day and inter-day precisions lower of 1.01 and 2.36%, respectively and accuracy values bet from -4.02 to 1.06%. CONCLUSIONS: Determination of the darunavir and raltegravir in their dosage form was done with a maximum deviation of 4%. This analytical method is rapid, easily implantable and offers good results.


Asunto(s)
Fármacos Anti-VIH/análisis , Darunavir/análisis , Raltegravir Potásico/análisis , Calibración , Cromatografía Líquida de Alta Presión , Formas de Dosificación , Combinación de Medicamentos , Límite de Detección , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrofotometría Ultravioleta
17.
Environ Sci Pollut Res Int ; 22(10): 7361-74, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-24946701

RESUMEN

This paper presents the current sewage sludge legislation in Europe and expected developments regarding the coming directives on the application of the "End-of-waste" criteria and on fertilizers. Discussion on sludge production and processing is also included. The Directive 86/278 has regulated the use in agriculture of residual sludge from domestic and urban wastewater. After 1986, this directive was transposed in the different member state legislation and currently the national limit values on heavy metals, some organic micropollutants and pathogens are placed in a rather wide range. This seems the inevitable consequence of different attitudes towards sludge management practices in the member states. The discussion by the European Joint Research Center (JRC) in Seville regarding application of end-of-waste criteria for compost and digestate has produced a final document (IPTS 2014) where sludge was excluded from the organic wastes admitted for producing an end-of-waste compost. Sludge processing in Europe seems addressed to different goals: sludge minimization, full stabilization and hygienization by thermal hydrolysis processes before anaerobic digestion, and on-site incineration by fluidized bed furnace. Thermophilic anaerobic digestion was applied with success on the Prague WWTP with a preliminary lysimeter centrifugation. Coming techniques, like wet oxidation and pyrolysis, are applied only on very few plants.


Asunto(s)
Aguas del Alcantarillado/legislación & jurisprudencia , Eliminación de Residuos Líquidos/legislación & jurisprudencia , Eliminación de Residuos Líquidos/normas , Agricultura , Unión Europea , Fertilizantes/análisis , Hidrólisis , Metales Pesados/análisis , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos
18.
Environ Sci Pollut Res Int ; 22(10): 7237-47, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25233915

RESUMEN

The present research aims at the evaluation of the hygienization performances of innovative sludge treatment processes applied for the separated treatment of secondary sludge. Namely, two digestion pretreatments (sonication and thermal hydrolysis) and two sequential biological processes (mesophilic/thermophilic and anaerobic/aerobic digestion) were compared to the mesophilic (MAD) and thermophilic anaerobic digestion (TAD). Microbial indicators (Escherichia coli, somatic coliphages and Clostridium perfringens spores) and pathogens (Salmonella and enteroviruses), which show different resistances to treatment processes, were monitored in untreated and treated sludge. Overall, microbial load in secondary sludge was shown to be similar or lower than previously reported in literature for mixed sludge. Notably, the anaerobic/aerobic digestion process increased the removal of E. coli and somatic coliphages compared to the simple MAD and always achieved the hygienization requirement (2-log-unit removal of E. coli) proposed by EU Commission in the 3rd Working Document on sludge (April 2000) for the use of treated sludges in agriculture with restriction on their application. The microbial quality limits for the unrestricted use of sludge in agriculture (no Salmonella in 50 g wet weight (WW) and E. coli <500 CFU/g) were always met when thermal digestion or pretreatment was applied; however, the required removal level (6-log-unit removal of E. coli) could not be assessed due to the low level of this microorganism in raw sludge. Observed levels of indicator removal showed a higher resistance of viral particles to thermal treatment compared with bacterial cells and confirmed the suitability of somatic coliphages as indicators in thermal treatment processes.


Asunto(s)
Bacterias/aislamiento & purificación , Enterovirus/aislamiento & purificación , Fertilizantes/análisis , Aguas del Alcantarillado/análisis , Aguas del Alcantarillado/microbiología , Calor , Hidrólisis , Aguas del Alcantarillado/virología , Sonicación
19.
Water Res ; 83: 121-31, 2015 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-26141428

RESUMEN

The feasibility of substituting a conventional pre-treatment, consisting of dioxi-chlorination, coagulation/flocculation, settling and sand filtration, of a drinking water treatment plant (DWTP) by direct ultrafiltration (UF) has been assessed from a microbiological standpoint. Bacterial indicators, viral indicators and human viruses have been monitored in raw river, ultrafiltered and conventionally pre-treated water samples during two years. Direct UF has proven to remove bacterial indicators quite efficiently and to a greater extent than the conventional process does. Nevertheless, the removal of small viruses such as some small bacteriophages and human viruses (e.g. enteroviruses and noroviruses) is lower than the current conventional pre-treatment. Membrane integrity has been assessed during two years by means of tailored tests based on bacteriophages with different properties (MS-2, GA and PDR-1) and bacterial spores (Bacillus spores). Membrane integrity has not been compromised despite the challenging conditions faced by directly treating raw river water. Bacteriophage PDR-1 appears as a suitable microbe to test membrane integrity, as its size is slightly larger than the considered membrane pore size. However, its implementation at full scale plant is still challenging due to difficulties in obtaining enough phages for its seeding.


Asunto(s)
Agua Potable/microbiología , Ríos/microbiología , Ultrafiltración/métodos , Purificación del Agua/métodos , Bacillus/aislamiento & purificación , Bacteriófagos/aislamiento & purificación , Agua Potable/virología , Monitoreo del Ambiente , Ríos/virología , Esporas Bacterianas/aislamiento & purificación
20.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1705-1712, Sept.-Oct. 2020. tab, graf, mapas
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-1131561

RESUMEN

Seiscentos primatas neotropicais foram submetidos a exames post mortem para avaliação da prevalência parasitária de helmintos gastrointestinais. Foram examinados 556 calitriquídeos (Callithrix spp.), 23 bugios (Alouatta guariba), 19 macacos-pregos (Sapajus nigritus), um mico-leão-dourado (Leontopithecus rosalia) e um mico-leão-da-cara-dourada (Leontopithecus chrysomelas). Do total de 600 animais, foram encontrados espécimes parasitos pertencentes aos filos Acanthocephala, Nemathelmintes e Platyhelminthes (classes Trematoda e Cestoda) em 110 primatas. A prevalência de primatas positivos para, pelo menos, uma espécie de helminto foi de 18,3% (110/600), sendo destes 83,6% (92/110) calitriquídeos, 8,2% (9/110) bugios, 6,4% (7/110) macacos-pregos, 0,9% (1/110) mico-leão-dourado e 0,9% (1/110) mico-leão-da-cara dourada. Em 80,4% (74/92) dos calitriquídeos foram encontrados nematoides Primasubulura sp. e em 1,1% (1/92) nematoides Trypanoxyuris callithrix, em 26,1% (24/92) acantocéfalos (Pachysentis sp.) e em 5,4% (5/92) digenéticos (Platynosomum sp.); em 77,8% (7/9) dos bugios foram encontrados nematoides (Trypanoxyuris minutus), em 11,1% (1/9) acantocéfalos (Pachysentis sp.) e em 11,1% (1/9) cestoides (Bertiella sp.); em 14,3% (1/7) dos macacos-pregos foram encontrados nematoides (Physaloptera sp.), em 28,6% (2/7) acantocéfalos (Prostenorchis sp.) e em 14,3% (1/7) digenéticos (Platynosomum sp.) e no mico-leão-da-cara-dourada foram encontrados acantocéfalos (Prostenorchis sp.). Foi realizado o georreferenciamento dos pontos de encontro dos cadáveres para pontuar a distribuição dos helmintos por região.(AU)


Six hundred neotropical primates underwent postmortem examinations to evaluate the parasitic prevalence of gastrointestinal helminths. Fifty-five callitrichids tamarins (Callithrix spp.), 23 howlers (Alouatta guariba), 19 nail monkeys (Sapajus nigritus), a golden lion tamarin (Leontopithecus rosalia) and a golden-faced lion tamarin (Leontopithecus chrysomelas) were examined. Parasitic specimens belonging to phylums Acantocephala, Nemathelmintes and Platyhelmintes (Trematoda and Cestoda Classes) were found. The prevalence of primates positive for at least one species of helminth was 18.3% (110/600), of which 83.6% (92/110) callitrichids, 8.2% (9/110) howler monkeys, 6.4% (7/110) capuchin monkeys, 0.9% (1/110) golden lion tamarin and 0.9% (1/110) golden faced lion tamarin. In 80.4% (74/92) of callitrichids nematodes (Primasubulura sp.) were found, and in 1.1% (1/92) nematodes (Trypanoxyuris callithricis), in 26.1% (24/92) acanthocephalus (Pachysentis sp.) and 5.4% (5/92) digenetics (Platynosomum sp.); in 77.8% (7/9) of howler monkeys presented nematodes (Trypanoxyuris minutus), 11.1% (1/9) acanthocephalus (Pachysentis sp.) and 11.1% (1/9) cestoids (Bertiella sp.); in 14.3% (1/7) of capuchin monkeys presented nematodes (Physaloptera sp.), 28.6% (2/7) acanthocephalus (Prostenorchis sp.) and 14.3% (1/7) digenetics (Platynosomum sp.) and in the golden-faced lion tamarin acanthocephalus (Prostenorchis sp.) were found. Georreferencing of the meeting points of the cadavers was performed in order to punctuate the distribution of helminths by region.(AU)


Asunto(s)
Animales , Primates/parasitología , Tracto Gastrointestinal/parasitología , Mapeo Geográfico , Helmintiasis Animal/epidemiología , Helmintos/aislamiento & purificación , Platelmintos , Brasil , Acantocéfalos , Nematodos
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