Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Entomol ; 52(6): 998-1007, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37802890

RESUMO

An adventive population of the exotic parasitoid wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), discovered in Michigan in 2018, is a promising biological control agent of the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Following its discovery, field releases of Tr. japonicus were conducted over 2 yr in southern Michigan, to test how release size or release frequency impacts establishment. Sentinel eggs of H. halys and of the native Podisus maculiventris (Say) (Hemiptera: Pentatomidae) were used alongside yellow sticky cards to monitor parasitoids. In 2019 and 2020, 7,200 Tr. japonicus were released at 16 sites. Monitoring between 2019 and 2021 yielded only 49 individuals. The captures suggest reproductive activity and overwintering success in the field but do not allow for evaluation of best release methods. Parasitism by native parasitoids was below 7%, which is similar to other states and unlikely to provide sufficient control of H. halys. The placement of sentinel eggs or sticky traps either in the lower or middle canopy of trees did not influence parasitoid capture rates. Frozen and fresh H. halys sentinel eggs were attacked at the same rate, but more native parasitoids emerged from frozen eggs. We did not find signs of nontarget effects on P. maculiventris thus parasitism rates overall were very low. These results could indicate dispersal of Tr. japonicus from the release sites or slow population growth. The latter may be due to the relatively low densities of H. halys in Michigan or may stem from the small founding size of our laboratory colony.


Assuntos
Heterópteros , Vespas , Animais , Michigan , Árvores , Reprodução
2.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35165193

RESUMO

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.


Assuntos
Rios/química , Poluição Química da Água/análise , Poluição Química da Água/prevenção & controle , Ecossistema , Exposição Ambiental , Monitoramento Ambiental , Humanos , Preparações Farmacêuticas , Águas Residuárias/análise , Águas Residuárias/química , Água/análise , Água/química , Poluentes Químicos da Água/análise
3.
Environ Sci Pollut Res Int ; 29(14): 20530-20541, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34739670

RESUMO

The co-occurrence of heavy metals, antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) from hospital effluents spreading into the river receiving systems and evaluating associated risks are topics of scientific interest and still under-studied in developing countries under tropical conditions. To understand the selectors of the ARGs, we examined the occurrence of heavy metals (Cr, Co, Ni, Cu, Cd, Pb and Zn), associated ARB (ß-lactam-resistant Escherichia coli, ß-lactam-resistant Enterobacteriaceae, and carbapenem-resistant Enterobacteriaceae) and ARGs (blaOXA, blaCTX-M, blaIMP, blaTEM) in water and sediments from two sub-urban rivers receiving urban and hospital effluent waters in the Democratic Republic of the Congo (DRC). High abundances of ARB and ARGs were observed in all sediment samples. All the metal contents correlated negatively with grain size (- 0.94 ≤ r ≤ - 0.54, p < 0.05) except for Ni and positively with organic matter content and total copies of 16 s rRNA (0.42 ≤ r ≤ 0.79, p < 0.05), except for Ni and Zn. The metals had a significant positive correlation with the faecal indicator Enterococcus except for Ni and Cd (0.43 ≤ r ≤ 0.67, p < 0.05). Carbapenem-resistant Enterobacteriaceae correlated negatively with Zn (r = - 0.44, p < 0.05) and positively with all the rest of toxic metals (0.58 ≤ r ≤ 1.0, p < 0.05). These results suggested that some metals had a great influence on the persistence of ARB and ARGs in sediments. Overall, this study strongly recommends the managing urban wastewater to preserve water resources used for human and agricultural purposes. Additionally, we recommend the utilizing biological indicators (faecal indicator bacteria, ARB, ARGs) when investigating urban wastewater pollutions.


Assuntos
Metais Pesados , Rios , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Antibacterianos/análise , Antibacterianos/farmacologia , Bactérias/genética , Monitoramento Ambiental/métodos , Sedimentos Geológicos/microbiologia , Humanos , Metais Pesados/análise , Rios/microbiologia , Clima Tropical , Águas Residuárias/análise
4.
Artigo em Inglês | MEDLINE | ID: mdl-34790861

RESUMO

In many suburban municipalities of developing countries, the household drinking water comes mainly from groundwater including, wells, streams and springs. These sources are vulnerable because poor hygienic conditions and sanitation prevail causing persistence and recurrent waterborne diseases. In this research, a survey study on water resource use and an epidemiological survey of waterborne diseases were conducted among users of water points and medical institutions in suburban communes of Selembao and Kimbanseke (Kinshasa, the Democratic Republic of the Congo). In addition, physicochemical (temperature, pH, O2, electrical conductivity, and soluble ions: Na+, K+, PO4 3-, SO4 2-, NO3 -, NO2 -) and bacteriological (FIB: faecal indicator bacteria) analyses of water from 21 wells and springs were performed according to the seasonal variations. FIB included Escherichia coli (E. coli), Enterococcus and Total Coliforms. The survey results indicate that more than 75% of the patients admitted to local medical institutions between 2016 and 2019 are affected by waterborne diseases, including typhoid fever, amoebic dysentery, diarrhoea, gastroenteritis disorders and cholera. Except for NO3 - in some sites, the water physicochemical parameter values are within WHO permissible limits for drinking/domestic water quality. On the contrary, the results revealed high FIB levels in water from unmanaged wells and springs during rainy and dry seasons. The microbiological pollution was significantly higher in the rainy season compared to the dry season. Interestingly, no FIB contamination was observed in water samples from managed/developed wells. The results from this study will guide local government decisions on improving water quality to prevent recurrent waterborne diseases.

5.
Sci Total Environ ; 754: 142175, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920409

RESUMO

The contamination of water resource and food chain by persistent organic pollutants (POPs) constitutes a major environmental and human health concern worldwide. The aim of this study was to investigate the levels of POPs in irrigation water, soil and in Amaranthus viridis (A. viridis) from different gardening sites in Kinshasa to evaluate the potential environmental and human health risks. A survey study for the use of pesticides and fertilizers was carried out with 740 market gardeners. The levels of POPs (including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) were analyzed in irrigation water and 144 vegetable samples collected from different gardening sites. The assessment of potential human health risk was estimated by calculating daily intake and toxic equivalency to quantify the carcinogenicity. The results show highest PAH levels in A. viridis from all studied sites. The concentrations of the sum of seven PCBs (Σ7PCBS) congeners in analyzed plants ranged between 15.89 and 401.36 ng g-1. The distributions of OCPs in both water and A. viridis were congener specific, chlorpyrifos-ethyl and p,p'-DDE were predominantly detected. Among PBDEs, only BDE47 was quantified with noticeable concentration in A. viridis, while no PBDEs were detected in irrigation water. Higher estimated daily intake values indicate that consuming leafy vegetables might associate with increased human health risks. However, calculated incremental lifetime cancer risk values indicates no potential carcinogenic risk for the local population. The results of this study provide important information on A. viridis contamination by POPs and strongly recommend implementing the appropriate measures to control the use of chemicals used in studied gardening areas. Thus in Kinshasa, urban agriculture control programs for POPs and fertilizers is very important in order to protect the public health through direct and dietary exposure pathways.


Assuntos
Amaranthus , Hidrocarbonetos Clorados , Praguicidas , Bifenilos Policlorados , República Democrática do Congo , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Humanos , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Medição de Risco
6.
Pathogens ; 9(11)2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33114079

RESUMO

Over the past decades, the rising antibiotic resistance bacteria (ARB) are continuing to emerge as a global threat due to potential public health risk. Rapidly evolving antibiotic resistance and its persistence in the environment, have underpinned the need for more studies to identify the possible sources and limit the spread. In this context, not commonly studied and a neglected genetic material called extracellular DNA (eDNA) is gaining increased attention as it can be one of the significant drivers for transmission of extracellular ARGS (eARGs) via horizontal gene transfer (HGT) to competent environmental bacteria and diverse sources of antibiotic-resistance genes (ARGs) in the environment. Consequently, this review highlights the studies that address the environmental occurrence of eDNA and encoding eARGs and its impact on the environmental resistome. In this review, we also brief the recent dedicated technological advancements that are accelerating extraction of eDNA and the efficiency of treatment technologies in reducing eDNA that focuses on environmental antibiotic resistance and potential ecological health risk.

7.
Sci Total Environ ; 727: 138129, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32498199

RESUMO

The occurrence and dissemination of toxic metals, antibiotic resistant bacteria and their resistance genes (ARGs) in the aquatic ecosystems of sub-Saharan African countries are still understudied, despite their potential to threat human health and aquatic organisms. In this context, the co-contamination and seasonal distribution of toxic metals and ARG in river sediments receiving untreated urban sewages and hospital effluents from Kinshasa, the capital city of the Democratic Republic of the Congo were investigated. ARGs including ß-lactam resistance (blaCTX-M and blaSHV), carbapenem resistance (blaVIM, blaIMP, blaKPC, blaOXA-48 and blaNDM) and total bacterial load were quantified by using quantitative polymerase chain reaction (qPCR) in total DNA extracted from sediment. The amount of toxic metals in sediments was quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results highlight high abundance of 16S rRNA and ARGs copy numbers in sediment samples. Strong pollution of rivers by toxic metals was found, with max values (mg kg-1) of 81.85(Cr), 5.09(Co), 33.84(Ni), 203.46 (Cu), 1055.92(Zn), 324.24(Pb) and 2.96(Hg). Results also highlight the high abundance of bacterial markers (8.06 × 109-2.42 × 1012 16S rRNA/g-1 DS) as well as antibiotic resistance genes (up to 4.58 × 108 ARG. g-1 DS) in the studied rivers. Significant correlations were observed between (i) metals (except Cd and Hg) and organic matter (R > 0.60, p < 0.05); and (ii) ARGs (except blaNDM) and 16S rRNA (R > 0.57, p < 0.05) suggesting a tight link between (i) metal contamination and anthropogenic pressure and (ii) microbial contamination of river and dissemination of antibiotic resistance. Results demonstrated that multi-diffuse pollution originating from human activity contribute to the spread of toxic metals and ARGs into the aquatic ecosystems.


Assuntos
Rios , Carbapenêmicos , Cidades , República Democrática do Congo , Ecossistema , Monitoramento Ambiental , Sedimentos Geológicos , Metais , RNA Ribossômico 16S , Poluentes Químicos da Água , beta-Lactamases
8.
Ecotoxicol Environ Saf ; 200: 110767, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32470679

RESUMO

The occurrence and dissemination of antibiotic resistant genes (ARGs) that are associated with clinical pathogens and the evaluation of associated risks are still under-investigated in developing countries under tropical conditions. In this context, cultivable and molecular approaches were performed to assess the dissemination of bacteria and the antibiotic resistance genes in aquatic environment in Kinshasa, Democratic Republic of the Congo. Cultivable approach quantified ß-lactam, carbapenem resistant, and total Escherichia coli and Enterobacteriaceae in river sediments and surface waters that receive raw hospital effluents. The molecular approach utilized Quantitative Polymerase Chain Reaction (qPCR) to quantify the total bacteria and the richness of relevant bacteria (Escherichia coli, Enterococcus, and Pseudomonas), and antibiotic resistance genes (ARGs: blaOXA-48, blaCTX-M, blaIMP, blaTEM) in sediment samples. Statistical analysis were employed to highlight the significance of hospital contribution and seasonal variation of bacteria and ARGs into aquatic ecosystems in suburban municipalities of Kinshasa, Democratic Republic of the Congo. The contribution of hospitals to antibiotic resistance proliferation is higher in the dry season than during the wet season (p < 0.05). Hospital similarly contributed Escherichia coli, Enterococcus, and Pseudomonas and ARGs significantly to the sediments in both seasons (p < 0.05). The organic matter content correlated positively with E. coli (r = 0.50, p < 0.05). The total bacterial load correlated with Enterococcus, and Pseudomonas (0.49 < r < 0.69, p < 0.05). Each ARG correlated with the total bacterial load or at least one relevant bacteria (0.41 < r < 0.81, p < 0.05). Our findings confirm that hospital wastewaters contributed significantly to antibiotic resistance profile and the significance of this contribution increased in the dry season. Moreover, our analysis highlights this risk from untreated hospital wastewaters in developing countries, which presents a great threat to public health.


Assuntos
Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/efeitos dos fármacos , Hospitais , Rios/microbiologia , Águas Residuárias/microbiologia , Antibacterianos/análise , Antibacterianos/farmacologia , Cidades , República Democrática do Congo , Ecossistema , Enterococcus/efeitos dos fármacos , Enterococcus/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Pseudomonas/efeitos dos fármacos , Pseudomonas/genética , Rios/química , Clima Tropical , Águas Residuárias/química
9.
Environ Sci Pollut Res Int ; 27(16): 20000-20013, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32232759

RESUMO

The pollution assessment and the evaluation of potential risks in the Atlantic Coastal Region of the Democratic Republic of the Congo are still very limited. Consequently, the present study investigates for the first time the concentrations of heavy metals and persistent organic pollutants (organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) in river, estuary, and marine sediments from this area. The results highlighted high concentrations of Cr, Zn, As, and Pb exceeding the probable effect level (PEL) on aquatic life. Zn was the most dominant element detected at a range of 180-480 mg kg-1 in marine sediment, 132-382 mg kg-1 in estuary sediment, and 121-687 mg kg-1 in river sediment. Total PCBs (∑7 × 4.3) ranged from 1995 to 20,156 µg kg-1, 2013-12,058 µg kg-1, and 1861-36,417 µg kg-1 in marine, estuary, and river sediments, respectively. Total PCBs (∑7 × 4.3) were above PEL for all sediments, suggesting potential adverse effects on benthic organisms. The OCP, PBDE, and PAH levels were low to moderate for all sediments. Taking into consideration, the concentrations of Zn, Pb, PCBs, and DDTs, probable environmental risks, are present.


Assuntos
Poluentes Ambientais , Metais Pesados/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , República Democrática do Congo , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Rios
11.
Pathogens ; 8(4)2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31581701

RESUMO

In the past few decades, infectious diseases have become increasingly challenging to treat, which is explained by the growing number of antibiotic-resistant bacteria. Notably, carbapenem-resistant Enterobacteriaceae (CRE) infections at global level attribute a vast, dangerous clinical threat. In most cases, there are enormous difficulties for CRE infection except a few last resort toxic drugs such as tigecycline and colistin (polymyxin E). Due to this, CRE has now been categorized as one among the three most dangerous multidrug resistance (MDR) pathogens by the US Centres for Disease Control and Prevention (CDC). Considering this, the study of the frequency of CRE infections and the characterization of CRE is an important area of research in clinical settings. However, MDR bacteria are not only present in hospitals but are spreading more and more into the environment, thereby increasing the risk of infection with resistant bacteria outside the hospital. In this context, developing countries are a global concern where environmental regulations are often insufficient. It seems likely that overcrowding, poor sanitation, socioeconomic status, and limited infrastructures contribute to the rapid spread of MDR bacteria, becoming their reservoirs in the environment. Thus, in this review, we present the occurrence of CRE and their resistance determinants in different environmental compartments in India.

12.
Sci Rep ; 9(1): 14847, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619758

RESUMO

Antibiotic resistant bacteria and genes which confer resistance to antibiotics from human/animal sources are currently considered a serious environmental and a public health concern. This problem is still little investigated in aquatic environment of developing countries according to the different climatic conditions. In this research, the total bacterial load, the abundance of relevant bacteria (Escherichia coli (E. coli), Enterococcus (Ent), and Pseudomonas), and antibiotic resistance genes (ARGs: blaOXA-48, blaCTX-M, sul1, sul2, sul3, and tet(B)) were quantified using Quantitative Polymerase Chain Reaction (qPCR) in sediments from two rivers receiving animal farming wastewaters under tropical conditions in Kinshasa, capital city of the Democratic Republic of the Congo. Human and pig host-specific markers were exploited to examine the sources of contamination. The total bacterial load correlated with relevant bacteria and genes blaOXA-48, sul3, and tet(B) (P value < 0.01). E. coli strongly correlated with 16s rDNA, Enterococcus, Pseudomonas spp., blaOXA-48, sul3, and tet(B) (P value < 0.01) and with blaCTX-M, sul1, and sul2 at a lower magnitude (P value < 0.05). The most abundant and most commonly detected ARGs were sul1, and sul2. Our findings confirmed at least two sources of contamination originating from pigs and anthropogenic activities and that animal farm wastewaters didn't exclusively contribute to antibiotic resistance profile. Moreover, our analysis sheds the light on developing countries where less than adequate infrastructure or lack of it adds to the complexity of antibiotic resistance proliferation with potential risks to the human exposure and aquatic living organisms. This research presents useful tools for the evaluation of emerging microbial contaminants in aquatic ecosystems which can be applied in the similar environment.


Assuntos
Resistência Microbiana a Medicamentos , Enterococcus/isolamento & purificação , Escherichia coli/isolamento & purificação , Pseudomonas/isolamento & purificação , Rios/microbiologia , Águas Residuárias/microbiologia , Animais , Cidades , República Democrática do Congo , Países em Desenvolvimento , Enterococcus/genética , Escherichia coli/genética , Fazendas , Genes Bacterianos , Humanos , Pseudomonas/genética , Suínos , Microbiologia da Água , Qualidade da Água
13.
Bioinformation ; 15(6): 412-418, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31312078

RESUMO

Identification of gene clusters in Streptomyces holds promise for the discovery of regulatory pathways linked to bioactive metabolites. We isolated a broad-spectrum antibacterial potential Streptomyces sp BDUSMP 02 from mangrove sediment. We further found a distinct of phylogeny pattern for NRPS A-domain in the Streptomyces sp BDUSMP 02. The result suggests that Streptomyces sp BDUSMP 02 has the potential to produce a new type of antibacterial compounds belonging to NRPS type.

14.
Int J Microbiol ; 2019: 5283948, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354829

RESUMO

Antimicrobial resistance (AR) is recognized as one of the greatest threats to public health and in global concern. Consequently, the increased morbidity and mortality, which are associated with multidrug resistance bacteria, urgently require the discovery of novel and more efficient drugs. Conversely, cancer is a growing complex human disease that demands new drugs with no or fewer side effects. Most of the drugs currently used in the health care systems were of Streptomyces origin or their synthetic forms. Natural product researches from Streptomyces have been genuinely spectacular over the recent years from extreme environments. It is because of technical advances in isolation, fermentation, spectroscopy, and genomic studies which led to the efficient recovering of Streptomyces and their new chemical compounds with distinct activities. Expanding the use of the last line of antibiotics and demand for new drugs will continue to play an essential role for the potent Streptomyces from previously unexplored environmental sources. In this context, deep-sea, desert, cryo, and volcanic environments have proven to be a unique habitat of more extreme, and of their adaptation to extreme living, environments attribute to novel antibiotics. Extreme Streptomyces have been an excellent source of a new class of compounds which include alkaloids, angucycline, macrolide, and peptides. This review covers novel drug leads with antibacterial and cytotoxic activities isolated from deep-sea, desert, cryo, and volcanic environment Streptomyces from 2009 to 2019. The structure and chemical classes of the compounds, their relevant bioactivities, and the sources of organisms are presented.

15.
Artigo em Inglês | MEDLINE | ID: mdl-30964378

RESUMO

An epidemiological survey conducted among users of water points and medical institutions in the N'djili Kilambu neighborhood of Kinshasa in Democratic Republic of the Congo, indicates that waterborne diseases have already affected more than 60% of the patients admitted to local clinics between 2013 and 2017. In order to raise public and political awareness about this hazardous health issue resulting from the lack of safely managed sanitation systems, this study investigates the microbial quality of drinking water from local water resources. Water samples were collected from nine wells and streams used as drinking sources, and analyzed for Fecal Indicator Bacteria (FIB), including Escherichia coli, Enterococcus, and Total Coliforms. Physicochemical parameters (pH, electrical conductivity, O2, and soluble ions (Na+, K+, PO43-, SO42-, NO3-, NO2-) were also analyzed. Except for NO3- and NO2-, the average concentrations of the physicochemical parameters and dissolved ions generally meet the guidelines for drinking/domestic water quality. By contrast, the results reveal high levels of FIB in the water samples collected during both dry and wet seasons. The contamination is significantly higher during the wet season compared to dry season, due to increased runoff, open defecation practices, and more frequent overflow of onsite sanitation systems and septic tanks.


Assuntos
Bactérias/isolamento & purificação , Água Potável/microbiologia , Água Subterrânea/microbiologia , Doenças Transmitidas pela Água/epidemiologia , Bactérias/classificação , Cidades , República Democrática do Congo/epidemiologia , Água Potável/química , Água Potável/normas , Fezes/microbiologia , Água Subterrânea/química , Humanos , Prevalência , Estações do Ano
16.
Heliyon ; 5(12): e03049, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32083201

RESUMO

Oysters and shrimp are abundant and commonly consumed seafood by the indigenous population of the Kongo central region of the Democratic Republic of the Congo (DRC). Literature reviews suggest that no data were available for the metal concentrations in these species. Consequently, the purpose of this study is to determine the metal concentrations in tissues of oysters (Egeria congica) and shrimp (Macrobrachium spp., Parapenaeus spp., Penaeus spp.) collected in November 2017 from the Atlantic Ocean Coast of DRC in the territory of Muanda. Metal levels in the seafood species studied here were put into context using international regulation for human consumption set by the Food and Agriculture Organization (FAO), Canadian Food Inspection Agency (CFIA), European Union (EU), and World Health Organization (WHO). Our results demonstrated that the concentration of heavy metals varied considerably between sampling sites and analyzed species (P < 0.05), with the values (in mg kg1) ranged between 0.05-0.41, 0.03-2.25,

17.
Int J Hyg Environ Health ; 221(3): 400-408, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29396027

RESUMO

In many urban and peri-urban areas of developing countries, shallow wells and untreated water from urban rivers are used for domestic purposes, including drinking water supply, population bathing and irrigation for urban agriculture. The evaluation and monitoring of water quality are therefore necessary for preventing potential human risk associated with the exposure to contaminated water. In this study, physicochemical and bacteriological parameters were assessed in an urban river (named Kokolo Canal/Jerusalem River) draining the municipality of Lingwala (City of Kinshasa, Democratic Republic of the Congo) and in two shallow wells used as drinking water supplies, during the wet and dry seasons in order to estimate the seasonal variation of contamination. The faecal indicator bacteria (FIB) isolated strains (Escherichia coli (E. coli) and Enterococcus (ENT)) from water and surface sediment, were characterized for human-specific bacteroides by molecular approach. The results revealed very high faecal contamination of water from the shallow wells, and of water and sediments from the river, during both wet and dry seasons. During the wet season, E. coli reached the values of 18.6 × 105 and 4.9 × 105 CFU 100 mL-1 in Kokolo Canal and shallow wells, respectively; and Enterococcus reached the values of 7.4 × 104 and 2.7 × 104 CFU 100 mL-1. Strong mutually positive correlation was observed between E. coli and ENT, with the range of R-value being 0.93 < r < 0.97 (p-value < 0.001, n = 15). The PCR assays for human-specific Bacteroides indicated that more than 98% of 500 isolated FIB strains were of human origin, pointing out the effect of poor household sanitation practices on surface water but also on groundwater contamination. The water samples from the shallow wells and Kokolo Canal were highly polluted with faecal matter in both seasons. However, the pollution level was significantly higher during the wet season compared to the dry season. Physicochemical analysis revealed also very high water electrical conductivity, with values much higher than the recommended limits of the World Health Organization guideline for drinking water. These results highlight the potential human health risk associated with the exposure to water contamination from shallow wells and Kokolo Canal, due to the very high level of human FIB. Rapid, unplanned and uncontrolled population growth in the city of Kinshasa is increasing considerably the water demand, whereas there is a dramatic lack of appropriate sanitation and wastewater facilities, as well as of faecal sludge (and solid waste) management and treatment. The lack of hygiene and the practice of open defecation is leading to the degradation of water quality, consequently the persistence of waterborne diseases in the neighbourhoods of sub-rural municipalities, and there is a growing threat to the sustainability to water resources and water quality. The results of this study should encourage municipality policy and strategy on increasing the access to safely managed sanitation services; in order to better protect surface water and groundwater sources, and limit the proliferation of epidemics touching regularly the city.


Assuntos
Bactérias/crescimento & desenvolvimento , Água Potável/microbiologia , Fezes , Recreação , Saneamento , Estações do Ano , Poluição da Água , Bacteroides/crescimento & desenvolvimento , Cidades , Defecação , República Democrática do Congo , Enterococcus/crescimento & desenvolvimento , Escherichia coli/crescimento & desenvolvimento , Características da Família , Fezes/microbiologia , Água Subterrânea/microbiologia , Humanos , Higiene , Reação em Cadeia da Polimerase , Rios , População Rural , Microbiologia da Água , Qualidade da Água , Abastecimento de Água , Poços de Água
18.
ISME J ; 12(3): 802-812, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29321692

RESUMO

Microbial mercury (Hg) methylation in sediments can result in bioaccumulation of the neurotoxin methylmercury (MMHg) in aquatic food webs. Recently, the discovery of the gene hgcA, required for Hg methylation, revealed that the diversity of Hg methylators is much broader than previously thought. However, little is known about the identity of Hg-methylating microbial organisms and the environmental factors controlling their activity and distribution in lakes. Here, we combined high-throughput sequencing of 16S rRNA and hgcA genes with the chemical characterization of sediments impacted by a waste water treatment plant that releases significant amounts of organic matter and iron. Our results highlight that the ferruginous geochemical conditions prevailing at 1-2 cm depth are conducive to MMHg formation and that the Hg-methylating guild is composed of iron and sulfur-transforming bacteria, syntrophs, and methanogens. Deltaproteobacteria, notably Geobacteraceae, dominated the hgcA carrying communities, while sulfate reducers constituted only a minor component, despite being considered the main Hg methylators in many anoxic aquatic environments. Because iron is widely applied in waste water treatment, the importance of Geobacteraceae for Hg methylation and the complexity of Hg-methylating communities reported here are likely to occur worldwide in sediments impacted by waste water treatment plant discharges and in iron-rich sediments in general.


Assuntos
Deltaproteobacteria/genética , Sedimentos Geológicos/microbiologia , Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Sedimentos Geológicos/química , Ferro/análise , Lagos/microbiologia , Metilação , RNA Ribossômico 16S/análise , Enxofre/análise , Águas Residuárias/química
19.
Chemosphere ; 191: 1008-1020, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29145129

RESUMO

Abandoned mines and mining activities constitute important sources of toxic metals and Rare Earth Elements (REEs) affecting surrounding environmental compartments and biota. This study investigates the contamination degree and distribution of toxic metals and REEs in contrasting sediment, soil and plant samples surrounding rivers in the African copperbelt area characterized by the presence of numerous abandoned mines, artisanal and industrial mining activities. ICP-MS results highlighted the highest concentration of Cu, Co and Pb in sediments reaching values of 146,801, 18,434 and 899 mg kg-1, respectively. In soil, the values of 175,859, 21,134 and 1164 mg kg-1 were found for Cu, Co and Pb, respectively. These values are much higher than the sediment guidelines for the protection of aquatic life and international soil clean-up standards. Enrichment factor and geoaccumulation index results indicated important contribution of mining activities to the study sites pollution in addition to natural background. Highest metal accumulation in leaves of Phalaris arundinacea L., was observed, reaching values of 34,061, 5050 and 230 mg kg-1 for Cu, Co, and Pb, respectively. The ∑REE concentration reached values of 2306, 733, 2796 mg kg-1 in sediment, soil and plant samples, respectively. The above results were combined with geographical information including satellite imagery, hydrography and mining concessions. Maps were produced to present the results in a comprehensive and compelling visual format. The results will be disseminated through an innovative mapping online platform to simplify access to data and to facilitate dialogue between stakeholders.


Assuntos
Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Rios/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , República Democrática do Congo , Metais Pesados/análise , Metais Pesados/normas , Mineração , Poluentes do Solo/normas , Poluentes Químicos da Água/normas
20.
Ecol Evol ; 7(17): 6680-6690, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28904750

RESUMO

Temperature-based degree-day models describe insect seasonality and to predict key phenological events. We expand on the use of a temperature-based process defining timing of reproduction through the incorporation of female reproductive physiology for the invasive pentatomid species Halyomorpha halys, the brown marmorated stink bug. A five-stage ranking system based on ovary development was able to distinguish between the reproductive statuses of field-collected females. Application of this ranking method described aspects of H. halys' seasonality, overwintering biology, and phenology across geographic locations. Female H. halys were collected in the US from NJ, WV, NC, OR, and two sites in PA in 2006-2008 (Allentown, PA only) and 2012-2014. Results identify that H. halys enters reproductive diapause in temperate locations in the fall and that a delay occurs in developmental maturity after diapause termination in the spring. Modification of the Snyder method to identify biofix determined 12.7-hr photoperiod as the best fit to define initiation of reproduction in the spring. Applying the biofix, we demonstrated significant differences between locations for the rate at which the overwintering generation transition into reproductive status and the factors contributing to this difference require further study. For example, after including abiotic variables influencing development such as temperature and photoperiod (critical diapause cue), reproduction occurred earlier in OR and for an extended period in NJ. This data describe a method to investigate insect seasonality by incorporating physiological development across multiple regions that can clarify phenology for insects with overlapping generations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...