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1.
Eur J Nutr ; 62(5): 2245-2256, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37079158

RESUMO

PURPOSE: Iodine deficiency disorder (IDD) is an ongoing worldwide recognized problem with over two billion individuals having insufficient iodine intake. School-aged children and pregnant women are often target groups for epidemiological studies, but there is a lack of knowledge on the general adult population. The aim of this study was to assess the iodine status among a Portuguese public university staff as a proxy for the adult working population. METHODS: The population study covered 103 adults within the iMC Salt randomized clinical trial, aged 24-69 years. Urinary iodine concentration was measured spectrophotometrically using the Sandell-Kolthoff reaction. Iodine food intake was assessed using a 24-h dietary recall. The contribution of discretionary salt to the iodine daily intake was assessed through 24-h urinary sodium excretion (UIE) and potentiometric iodine determination of household salt. RESULTS: The mean urine volume in 24 h was 1.5 L. The median daily iodine intake estimated from 24-h UIE was 113 µg/day, being lower among women (p < 0.05). Only 22% of participants showed iodine intake above the WHO-recommended cutoff (150 µg/day). The median daily iodine intake estimated from the 24-h dietary recall was 58 µg/day (51 and 68 µg/day in women and men, respectively). Dairy, including yoghurt and milk products, were the primary dietary iodine source (55%). Iodine intake estimated from 24-h UIE and 24-h dietary recall was moderately correlated (Spearman rank correlation coefficient r = 0.34, p < 0.05). The average iodine concentration in household salt was 14 mg I/kg, with 45% of the samples below the minimum threshold preconized by WHO (15 mg I/kg). The contribution of discretionary salt to the daily iodine intake was around 38%. CONCLUSION: This study contributes new knowledge about iodine status in Portuguese working adults. The results revealed moderate iodine deficiency, particularly in women. Public health strategies and monitoring programs are needed to ensure iodine adequacy in all population groups.


Assuntos
Iodo , Desnutrição , Masculino , Adulto , Criança , Humanos , Feminino , Gravidez , Animais , Portugal/epidemiologia , Universidades , Estado Nutricional , Cloreto de Sódio na Dieta , Leite/química
2.
Int J Food Sci Nutr ; 70(3): 349-354, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30160547

RESUMO

Iodine deficiency remains a worldwide problem with two billion individuals having insufficient iodine intake. Universal salt iodisation was declared by UNICEF and WHO as a safe, cost-effective, and sustainable way to tackle iodine deficiency. In Portugal, the few studies available unravel an iodine status below the WHO guidelines for pregnant women and school-aged children. In the present study, the iodine levels of household salt consumed in Portugal was assessed, for the first time. Non-iodised (median 14 ppm) and fortified (median 48 ppm) marine salt samples showed iodine levels lower than the minimum and above the maximum threshold recommended by non-mandatory Portuguese law and WHO recommendations, respectively. This study calls attention to the fact that marine salt per se, in spite of containing a natural high amount of iodine, requires further fortification in order to be used as an effective tool to deal with iodine insufficiency.


Assuntos
Iodo/administração & dosagem , Água do Mar/química , Cloreto de Sódio na Dieta/administração & dosagem , Humanos , Iodo/deficiência , Portugal
3.
J Water Health ; 16(6): 991-1006, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30540273

RESUMO

The Ave River in northern Portugal has a history of riverbanks and water quality degradation. The river water quality was assessed by physicochemical, biological (macroinvertebrates) and microbiological (Enterococcus spp. and Escherichia coli) parameters in six locations (A-F, point A being the nearest to the source) throughout its course during a year. Epilithic biofilms were studied through polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Antimicrobial susceptibility testing helped with selecting isolates (n = 149 E. coli and n = 86 enterococci) for further genetic characterization. Pursuant to physicochemical and macroinvertebrates-based parameters, the river water was of reasonable quality according to European legislation (Directive 2000/60/EC). However, the microbiological analysis showed increased fecal contamination downstream from point C. At point D, four carbapenem-resistant E. coli isolates were recovered. Paradoxically, point D was classified as a point of 'Good Water Quality' according to macroinvertebrates results. Point F presented the highest contamination level and incidence of multidrug-resistant (MDR) isolates in the water column (13 MDR enterococci out of 39 and 33 MDR E. coli out of 97). Epilithic biofilms showed higher diversity in pristine points (A and B). Thus, biological and microbiological parameters used to assess the water quality led to divergent results; an outcome that reinforces the need for a holistic evaluation.


Assuntos
Monitoramento Ambiental/métodos , Poluição da Água/análise , Escherichia coli/crescimento & desenvolvimento , Portugal , Rios , Poluição da Água/estatística & dados numéricos
4.
J Environ Sci (China) ; 45: 131-42, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27372127

RESUMO

Estuarine ecosystems in SE Asia have been poorly studied when compared to other tropical environments. Important gaps exist particularly in the understanding of their biogeochemical function and contribution to global change. In this work we looked into N-turnover in the water column and sediments of the Bangpakong estuary (13°N). A seasonal sampling program was performed along the salinity gradient covering different stretches of the estuary (68km). Key physical and chemical characteristics were also monitored in order to unravel possible environmental controls. Results showed the occurrence of active denitrification in sediments (5.7-50.9nmol N-N2/(cm(3)·hr)), and water column (3.5-1044pmol N-N2/(cm(3)·hr)). No seasonal or spatial variability was detected for denitrification potential in sediment samples. However, in the water column, the denitrification activity peaked during the transition season in the downstream sites coinciding with high turbidity levels. Therefore, in that period of the year, the water column compartment may be an important contributor to nitrate reduction within the estuary. The rather low nitrification rates detected were not always measurable, probably due to the reduced oxygen content and high siltation. This study is one of the few dealing simultaneously with sediments and water column processes in a highly turbid tropical estuary. Therefore, it emerges as a valuable contribution for the understanding of the dynamics of the nitrogen cycle in tropical environments by exploring the role of estuarine N microbial activity in reducing the effects of increased nitrogen loads.


Assuntos
Monitoramento Ambiental , Estuários , Ciclo do Nitrogênio , Nitrogênio/análise , Poluentes Químicos da Água/análise , Desnitrificação , Ecossistema , Tailândia
5.
J Environ Manage ; 137: 10-5, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24584003

RESUMO

Degradation of petroleum hydrocarbons in colonized and un-colonized sediments by salt marsh plants Juncus maritimus and Phragmites australis collected in a temperate estuary was investigated during a 5-month greenhouse experiment. The efficiency of two bioremediation treatments namely biostimulation (BS) by the addition of nutrients, and bioaugmentation (BA) by addition of indigenous microorganisms was tested in comparison with hydrocarbon natural attenuation in un-colonized and with rhizoremediation in colonized sediments. Hydrocarbon degrading microorganisms and root biomass were assessed as well as hydrocarbon degradation levels. During the study, hydrocarbon degradation in un-colonized sediments was negligible regardless of treatments. Rhizoremediation proved to be an effective strategy for hydrocarbon removal, yielding high rates in most experiments. However, BS treatments showed a negative effect on the J. maritimus potential for hydrocarbon degradation by decreasing the root system development that lead to lower degradation rates. Although both plants and their associated microorganisms presented a potential for rhizoremediation of petroleum hydrocarbons in contaminated salt marsh sediments, results highlighted that nutrient requirements may be distinct among plant species, which should be accounted for when designing cleanup strategies.


Assuntos
Hidrocarbonetos/metabolismo , Magnoliopsida/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Estuários , Sedimentos Geológicos/microbiologia , Magnoliopsida/microbiologia , Petróleo , Poluição por Petróleo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Áreas Alagadas
6.
J Environ Sci (China) ; 26(8): 1605-14, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25108716

RESUMO

Potable water is a resource out of reach for millions worldwide, and the available water may be chemically and microbiologically compromised. This is particularly acute in Africa, where water-networks may be non-existent or restricted to a small fraction of the urban population, as in the case of Guinea-Bissau, West Africa. This study was carried out seasonally in Bolama (11°N), where unprotected hand-dug wells with acidic water are the sole source of water for the population. We inspected the free-living bacterial community dynamics by automated rRNA intergenic spacer analyses, quantitative polymerase chain reaction and cloning approaches. The results revealed a clear seasonal shift in bacterial assemblage composition and microbial abundance within the same sampling site. Temperature, pH and turbidity, together with the infiltration and percolation of surface water, which takes place in the wet season, seemed to be the driving factors in the shaping and selection of the bacterial community and deterioration of water quality. Analysis of 16S rDNA sequences revealed several potential pathogenic bacteria and uncultured bacteria associated with water and sediments, corroborating the importance of a culture-independent approach in drinking water monitoring.


Assuntos
Bactérias/isolamento & purificação , Água Potável/química , Água Potável/microbiologia , Microbiologia da Água , Bactérias/classificação , Bactérias/genética , Clonagem Molecular , Guiné-Bissau , Concentração de Íons de Hidrogênio , Ilhas
7.
Artigo em Inglês | MEDLINE | ID: mdl-38266309

RESUMO

CONTEXT: Iodine is necessary for the proper brain development. The prevalence of iodine deficiency in Portuguese pregnant women led the health authorities, in 2013, to recommend iodine supplementation for women in preconception, throughout pregnancy and during lactation. OBJECTIVE: To assess the impact of iodine supplementation initiated in the preconception or the first trimester of pregnancy on the prevalence of iodine deficiency and maternal thyroid status. METHODS: An observational prospective cohort study that follows thyroid function and iodine status of women recruited in preconception or in the first trimester of pregnancy. RESULTS: The median urinary iodine concentration (UIC) was significantly higher among women taking iodine supplements (no-supplement group UIC=63µg/L; supplement group UIC =100µg/L, p = 0.002) but still below the levels recommended by the World Health Organization. Only 15% of pregnant women had adequate iodine status and 17% showed UIC < 50 µg/l. There was no influence of whether iodine supplementation started in preconception or in the 1st trimester of gestation (UIC preconception group: 112µg/L vs UIC pregnancy group: 91µg/L, p = 0.569). In the 1st trimester of pregnancy, total thyroxine levels were lower and free triiodothyronine levels were higher in non-supplemented women. Thyroglobulin levels were lower in women who started iodine supplementation in preconception compared to non-supplemented women and women who started iodine supplementation during gestation. CONCLUSION: In the Minho region of Portugal, fertile women have insufficient iodine intake. Additional public health measures are needed since the current recommendations for iodine supplementation for pregnancy are unsatisfactory to achieve an adequate iodine status.

8.
Biodegradation ; 24(1): 111-23, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22692293

RESUMO

In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.


Assuntos
Bactérias/metabolismo , Cádmio/análise , Cobre/análise , Sedimentos Geológicos/química , Hidrocarbonetos/metabolismo , Chumbo/análise , Petróleo/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Cádmio/metabolismo , Cobre/metabolismo , Sedimentos Geológicos/microbiologia , Hidrocarbonetos/análise , Chumbo/metabolismo , Petróleo/análise , Filogenia
9.
Nutrients ; 15(6)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36986054

RESUMO

Salt iodization programs are considered the most cost-effective measures to ensure adequate iodine intake in iodine-deficient populations. Portuguese women of childbearing age and pregnant women were reported to be iodine-deficient, which led the health authorities, in 2013, to issue a recommendation for iodine supplementation during preconception, pregnancy and lactation. In the same year, iodized salt became mandatory in school canteens. Of note, no regulation or specific programs targeting the general population, or the impact of iodized salt availability in retailers, are known. The present study analyzed iodized salt supermarket sales from 2010 to 2021 from a major retailer, identifying the proportion of iodized salt in total salt sales and its distribution in mainland Portugal. Data on iodine content were collected through the nutritional label information. Of a total of 33 salt products identified, 3 were iodized (9%). From 2010 to 2021, the weighted sales of iodized salt presented a growing tendency, reaching the maximum of 10.9% of total sales (coarse plus fine salt) in 2021. Iodized salt reached a maximum of 11.6% of total coarse salt in 2021, a maximum of 2.4% of the total fine salt in 2018. The overall sales of iodized salt and their contribution to iodine intake are extremely low, prompting additional studies to understand the consumer's choice and awareness of the benefits of iodized salt.


Assuntos
Iodo , Humanos , Feminino , Gravidez , Portugal , Gestantes , Cloreto de Sódio na Dieta
11.
Biodegradation ; 22(4): 729-39, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21188477

RESUMO

Estuaries are often considered sinks for contaminants and the cleanup of salt marshes, sensitive ecosystems with a major ecological role, should be carried out by means of least intrusive approaches, such as bioremediation. This study was designed to evaluate the influence of plant-microorganisms associations on petroleum hydrocarbons fate in salt marshes of a temperate estuary (Lima River, NW Portugal). Sediments un-colonized and colonized (rhizosediments) by different plants (Juncus maritimus, Phragmites australis, Triglochin striata and Spartina patens) were sampled in four sites of the lower and middle estuary for hydrocarbon degrading microorganisms (HD), total cell counts (TCC) and total petroleum hydrocarbons (TPHs) assessment. In general, TPHs, HD and TCC were significantly higher (P < 0.05) in rhizosediments than in un-colonized sediments. Also recorded were differences on the abundance of hydrocarbon degraders among the rhizosediment of the different plants collected at the same site (J. maritimus < P. australis < T. striata), with statistically significant differences (P < 0.05) between J. maritimus and T. striata. Moreover, strong positive correlations-0.81 and 0.84 (P < 0.05), between biotic (HD) and abiotic (organic matter content) parameters and TPHs concentrations were also found. Our data clearly suggest that salt marsh plants can influence the microbial community, by fostering the development of hydrocarbon-degrading microbial populations in its rhizosphere, an effect observed for all plants. This effect, combined with the plant capability to retain hydrocarbons around the roots, points out that salt marsh plant-microorganisms associations may actively contribute to hydrocarbon removal and degradation in estuarine environments.


Assuntos
Bactérias/metabolismo , Poluição Ambiental/prevenção & controle , Sedimentos Geológicos/análise , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Raízes de Plantas/microbiologia , Plantas/microbiologia , Áreas Alagadas , Biodegradação Ambiental , Contagem de Colônia Microbiana , Sedimentos Geológicos/microbiologia , Hidrocarbonetos/análise , Indóis , Consórcios Microbianos , Petróleo/análise , Portugal , Rizosfera , Rios , Sais/metabolismo
12.
Environ Monit Assess ; 174(1-4): 493-508, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20449650

RESUMO

The objective of this study was to use an integrative approach to assess the ecological status of a small river impacted by multiple sources of disturbance. The River Febros (NW Portugal) is a small and highly impacted non-regulated river; approximately 44% of the watershed area is dedicated to agriculture, but there is also some urbanization. Environmental status was evaluated using a new multi-index approach, combining quality indices for water (Water Quality Index (WQI)), benthic macroinvertebrates (Iberian Biological Monitoring Working Party Index (IBMWP)), and human modification (Riparian Forest Quality Index (QBR)); Ecological Status River Mediterranean Index (ECOSTRIMED); River Habitat Survey (RHS)). Surveys were carried out between October 2002 and 2003, along four stretches of the main course of the river for physicochemical characteristics, as well as water microbiology and macroinvertebrates. Water quality was poor at all sites (WQI averaged 30.4%) and decreased downstream. The RHS (assessment of instream habitats and the river corridor) and the QBR quantification displayed the same trend. Macroinvertebrates diversity was permanently low with only the most tolerant insects taxa present; oligochaetes dominated. The ecological status of River Febros was well represented using the experimental assessment system, where a downstream decrease in condition was noticeable (in spite of a lower water quality upstream). Our results emphasize the importance of assessing several components of disturbed ecosystems in order to ascertain overall quality and the importance of promoting improvement of the riparian gallery as a buffer against multiple agents of disturbance.


Assuntos
Ecologia , Monitoramento Ambiental/métodos , Água Doce , Portugal
13.
Artigo em Inglês | MEDLINE | ID: mdl-34769812

RESUMO

Cholera remains a heavy burden worldwide, especially in Sub-Saharan African countries, which account for the majority of the reported cases on the continent. In this study, a 27-year retrospective analysis of cholera epidemics in Guinea-Bissau was performed in order to highlight major stressors fueling the trigger and dissemination of the disease. Although the role of environmental factors did not always have the same degree of importance for the onset of epidemics, a cholera seasonal pattern was clearly perceived, with most of the reported cases occurring during the wet season. The generated theoretical hypothesis indicated rainfall above climatological average, associated with a lack of WASH (water, sanitation and hygiene) infrastructure, and the occurrence of concomitant epidemics in neighboring countries as the key indicators for optimal conditions for cholera to thrive in Guinea-Bissau. Warmer air temperature, the increase in sea surface temperature, and the decrease in salinity in the coastal areas may also contribute to the emergence and/or aggravation of cholera events. Prediction of the conditions favorable for cholera growth and identification of risk pathways will allow the timely allocation of resources, and support the development of alert tools and mitigation strategies.


Assuntos
Cólera , Epidemias , África Ocidental , Cólera/epidemiologia , Guiné-Bissau/epidemiologia , Humanos , Estudos Retrospectivos
14.
Eur J Clin Nutr ; 72(11): 1576-1582, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29284787

RESUMO

BACKGROUND/OBJECTIVES: Iodine deficiency disorders are estimated to affect 25% of all school-age children around the world. Current policies concerning iodine deficiency disorders in many countries are not based on robust or recent national data. Our objective was to evaluate the current status of iodine nutrition in Guinea-Bissau (West Africa). SUBJECT/METHODS: A cross-sectional survey including 299 school-age children, aged 6-14 years old, from four distinct regions of Guinea-Bissau across a coast-hinterland gradient (Bolama, Bissau, Cambaju-Bafatá, and Gabú) was performed. Several iodine deficiency disorders indicators were used: total goiter rate, median urinary iodine concentration (UIC) and regional iodine content in household salt and drinking water samples. Data on the total goiter rate were obtained by thyroid ultrasound. RESULTS: Goiter was found in 73.5% (CI 95%, 68.5-78.2%) of the school-age children. We observed a median urinary iodine concentration of 110 mcg/l, with 7.3% of the studied population presenting urinary iodine concentration < 50 mcg/l. Only 12.5% of the household salt samples revealed iodine content ≥ 15 mg/kg. Median well water iodine concentration was 11.7 mcg/l. CONCLUSIONS: Guinea-Bissau presents high rates of goiter in school-age children despite satisfactory median urinary iodine concentration population levels. Salt and drinking water iodine median content cannot explain these findings. Further studies following the progress in iodine deficiency status and the presence of potential goitrogens in diet of this vulnerable population are in needed.


Assuntos
Deficiências Nutricionais/epidemiologia , Bócio Endêmico/epidemiologia , Iodo/deficiência , Estado Nutricional , Adolescente , Criança , Estudos Transversais , Deficiências Nutricionais/complicações , Dieta , Água Potável/química , Características da Família , Feminino , Bócio Endêmico/etiologia , Guiné-Bissau/epidemiologia , Humanos , Iodo/urina , Masculino , Prevalência , Cloreto de Sódio na Dieta/análise
15.
Talanta ; 186: 192-199, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29784349

RESUMO

The use of saliva for diagnose and surveillance of systemic illnesses, and general health has been arousing great interest worldwide, emerging as a highly desirable goal in healthcare. The collection is non-invasive, stress-free, inexpensive, and simple representing a major asset. Glucose, calcium, and magnesium concentration are three major parameters evaluated in clinical context due to their essential role in a wide range of biochemical reactions, and consequently many health disorders. In this work, a spectrophotometric sequential injection method is described for the fast screening of glucose, calcium, and magnesium in saliva samples. The glucose determination reaction involves the oxidation of the aldehyde functional group present in glucose with simultaneous reduction of 3,5-dinitrosalicylic acid (DNS) to 3-amino, 5-nitrosalicylic acid under alkaline conditions, followed by the development of colour. The determination of both metals is based on their reaction with cresolphtalein complexone (CPC), and the interference of calcium in the magnesium determination minimized by ethylene glycol-bis[ß-aminoethyl ether]-N,N,N',N'-tetraacetic acid (EGTA). The developed multi-parametric method enabled dynamic ranges of 50 - 300 mg/dL for glucose, 0.1 - 2 mg/dL for calcium, and 0.1 - 0.5 mg/dL for magnesium. Determination rates of 28, 60, 52 h-1 were achieved for glucose, calcium, and magnesium, respectively. Less than 300 µL of saliva is required for the multi-parametric determination due to saliva viscosity and inherent necessity of dilution prior to analysis. RSDs lower than 5% were obtained, and the results agreed with those obtained by reference methods, while recovery tests confirmed its accuracy.


Assuntos
Cálcio/análise , Colorimetria , Glucose/análise , Magnésio/análise , Saliva/química , Ácido Egtázico/química , Salicilatos/química
16.
Talanta ; 167: 688-694, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28340780

RESUMO

In this work, a potentiometric flow injection method is described for the fast bi-parametric determination of iodide and iodate in urine and salt samples. The developed methodology aimed for iodine speciation with a potentially portable system (running on batteries). The iodate reduction to iodide was effectively attained in line within the same manifold. The iodide determination was accomplished in the dynamic range of 2.50×10-6-1.00×10-3M and the total iodine dynamic range, resulted from iodide plus iodate, was 3.50×10-6-2.00×10-3M. The calculated limits of detection were 1.39×10-6M and 1.77×10-6M for iodide and iodate, respectively. A determination rate of 21h-1 for the bi-parametric iodide and iodate determination was obtained for sample injection. The urine samples (RSD <5.8% for iodide and RSD <7.0% for iodate) results were in agreement with those obtained by the classic Sandell-Kolthoff reaction colorimetric reference procedure (RD <7.0%) and standard samples from Centers for Disease Control and Prevention, Atlanta, USA (CDC) international inter-laboratory EQUIP program. The developed flow method was also successfully applied to the iodide and iodate determination in salt samples (RSD <3.1% for iodate and iodide), with comparable results to conventional procedures. No significant interferences were observed interference percentage <9% for both determinations.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Iodetos/análise , Potenciometria/métodos , Cloreto de Sódio/química , Urinálise/métodos , Humanos
17.
Ecohealth ; 13(2): 339-49, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26940502

RESUMO

V. cholerae, V. parahaemolyticus, and V. vulnificus are recognized human pathogens. Although several studies are available worldwide, both on environmental and clinical contexts, little is known about the ecology of these vibrios in African coastal waters. In this study, their co-occurrence and relationships to key environmental constraints in the coastal waters of Guinea-Bissau were examined using the most probable number-polymerase chain reaction (MPN-PCR) approach. All Vibrio species were universally detected showing higher concentrations by the end of the wet season. The abundance of V. cholerae (ISR 16S-23S rRNA) ranged 0-1.2 × 10(4) MPN/L, whereas V. parahaemolyticus (toxR) varied from 47.9 to 1.2 × 10(5) MPN/L. Although the presence of genotypes associated with virulence was found in environmental V. cholerae isolates, ctxA+ V. cholerae was detected, by MPN-PCR, only on two occasions. Enteropathogenic (tdh+ and trh+) V. parahaemolyticus were detected at concentrations up to 1.2 × 10(3) MPN/L. V. vulnificus (vvhA) was detected simultaneously in all surveyed sites only at the end of the wet season, with maximum concentrations of 1.2 × 10(5) MPN/L. Our results suggest that sea surface water temperature and salinity were the major environmental controls to all Vibrio species. This study represents the first detection and quantification of co-occurring Vibrio species in West African coastal waters, highlighting the potential health risk associated with the persistence of human pathogenic Vibrio species.


Assuntos
Vibrio cholerae/isolamento & purificação , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/isolamento & purificação , África Ocidental , Guiné-Bissau , Humanos , Microbiologia da Água
18.
Water Res ; 39(9): 1783-94, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15899276

RESUMO

The regulatory effects of salinity and inorganic nitrogen compounds on nitrification and denitrification were studied in intertidal sandy sediments and rocky biofilms in the Douro River estuary, Portugal, over a 12-month period. Nitrification and denitrification rates were measured in slurries of field samples and enrichment experiments using the difluoromethane and the acetylene inhibition techniques, respectively. Salinity did not regulate denitrification in either environment, suggesting that halotolerant bacteria dominated the denitrifier communities. However, nitrification rates were stimulated when salinity increased from 0 to 15 practical salinity units. NO3- addition experiments revealed that NO3- availability stimulates denitrification rates in sandy sediments, but not in rocky biofilms; however, in rocky biofilms a positive and linear relationship was observed between denitrification rates and water column NO3- concentrations (r=0.92) during the monthly surveys. The N2O:N2 ratios increased rapidly when NO3- increased from 63 to 363 microM; however, results from monthly surveys showed that environmental parameters other than NO3- availability may be important in controlling the variation in N2O production via denitrification. Ammonium additions to sandy sediments stimulated nitrification rates by 35% for the 20 microM NH4+ addition, but NH4+ appeared to inhibit nitrification at high concentration addition (200 microM NH4+). In contrast, rocky biofilm nitrification was stimulated by 65% when 200 microM NH4+ was added.


Assuntos
Bactérias Aeróbias/metabolismo , Bactérias Anaeróbias/metabolismo , Biofilmes/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Nitratos/farmacologia , Nitrogênio/metabolismo , Cloreto de Sódio/farmacologia , Nitratos/análise , Nitrogênio/análise , Óxido Nitroso/análise , Óxido Nitroso/metabolismo , Portugal , Compostos de Amônio Quaternário/análise , Compostos de Amônio Quaternário/farmacologia , Rios , Estações do Ano , Água do Mar , Cloreto de Sódio/análise
19.
Mar Environ Res ; 60(5): 531-50, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15919109

RESUMO

The macrobenthic community structure and characteristics of sediments were studied in samples collected seasonally at five stations in the lower mesotidal Douro estuary, Portugal. Sediment characterisation included grain size distribution, total-recoverable metals (Al, Fe, Mn, Zn, Cu, Cr, Pb, Ni and Cd), acid-volatile sulphides (AVS) and simultaneously extracted metals (SEM) and total organic matter contents. Spatial variation surpassed temporal variation both in terms of environmental parameters and community structure. Clear anthropogenic contamination in terms of Zn, Cr, Cu and Pb, and a positive SEM-AVS, indicating the potential bioavailability of these metals, were detected on the north bank of the estuary. Multivariate analysis revealed that in addition to natural sediment characteristics, the anthropogenic metal contamination was influencing the macrobenthic community structure. In fact, greater concentrations of Zn, Cr, Cu and Pb were associated with lower number of species and/or diversity. Finally, the dry weight-normalised metal concentrations appeared as a more useful tool than the SEM-AVS model in predicting disturbance of the macrobenthic community in the studied area.


Assuntos
Invertebrados , Metais Pesados/análise , Poluentes da Água/análise , Animais , Monitoramento Ambiental , Modelos Teóricos , Análise Multivariada , Dinâmica Populacional , Portugal , Estações do Ano
20.
Int Health ; 7(1): 42-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25164169

RESUMO

BACKGROUND: Street vendors of chilled packaged water have an increasing role in meeting the drinking water demand of people on the move in developing nations. Hygienic conditions can be questionable, and water quality screening scarce or non-existent. METHODS: In order to ascertain the quality of the packaged water sold by street vendors in Bissau, the capital of the Western African country Guinea-Bissau, water bags were screened in 2011 and during the 2012 cholera outbreak for key physical, chemical and microbiological parameters. RESULTS: Water used to fill the hand-filled hand-tied bags originated from communal tap water and melted ice. All samples (n=36) were microbiologically contaminated, although levels showed a pronounced variability (e.g. 7-493 372 cfu 250 ml(-1) for Escherichia coli). In 2012, the fecal contamination levels increased (p<0.05), and Vibrio cholerae was detected in all water bags obtained from the neighborhood where the outbreak started. CONCLUSION: Findings showed that all packaged water samples were unfit for human consumption and during the 2012 cholera outbreak represented a potential vehicle for the spread of the disease. The design of measures to decrease the risk associated to the consumption of highly contaminated chilled water is clearly required.


Assuntos
Cólera/epidemiologia , Transmissão de Doença Infecciosa/estatística & dados numéricos , Água Potável/microbiologia , Infecções por Escherichia coli/epidemiologia , Embalagem de Produtos , Adolescente , África Ocidental/epidemiologia , Criança , Cólera/transmissão , Contagem de Colônia Microbiana , Comércio/métodos , Comércio/estatística & dados numéricos , Surtos de Doenças , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/transmissão , Fezes , Feminino , Guiné-Bissau/epidemiologia , Humanos , Masculino , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/patogenicidade , Microbiologia da Água , Qualidade da Água
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