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1.
Environ Monit Assess ; 193(6): 373, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34061239

RESUMEN

Water quality surveillance systems are hardly applied in rural contexts. To provide a comprehensive analysis of drinking-water quality in two rural settlements in the Colombian Caribbean drinking-water samples were collected and analyzed from storage containers in 42 homes. The results of physical, chemical, and microbiological analyses of the water samples were compared with values established by the World Health Organization (WHO) Guidelines for Drinking-water Quality, and Colombian regulations. The Kruskal-Wallis test was applied to compare each parameter for supply source, season (rainy or dry), settlement, and types of storage. Drinking-water Quality Risk Index (IRCA) was calculated for each of the samples. The water supply sources were varied: well (33.3%), rainwater (23.8%), artificial pond (23.8%), and river (19.0%). One-hundred percent of the samples contained Escherichia coli and total coliforms. The IRCA varied between 57.3 and 83.9, with a median of 72.9. Eighty-eight percent of the samples exhibited high risk levels (35.1 < IRCA < 80.0) and 12% were unsanitary (80.1 < IRCA < 100.0). Artificial pond water was the source of supply with the worst IRCA (83.79). Drinking water in the El Cascajo and La Delfina settlements does not meet international and national drinking-water standards. A change is required whereby monitoring and quality control policies take into account the reality of rural settings.


Asunto(s)
Agua Potable , Calidad del Agua , Región del Caribe , Colombia , Monitoreo del Ambiente , Humanos , Microbiología del Agua , Abastecimiento de Agua
2.
Wei Sheng Yan Jiu ; 50(3): 472-475, 2021 May.
Artículo en Chino | MEDLINE | ID: mdl-34074371

RESUMEN

OBJECTIVE: To understand the health status and influencing factors of people in bathing beach after bathing. METHODS: A questionnaire survey was conducted among the beach tourists in Hebei, Shandong and Shanghai Provinces from May to September, 2019-2020, including personal basic information, seawater/beach exposure in the last 7 days, beach activities, personal protective measures, physical health, related symptoms or diseases after bathing, etc. The seawater samples and sand of the three bathing beaches were sampled and detected. RESULTS: A total of 1222 valid questionnaires were collected. Skin infection(26. 19%), nasal congestion(12. 36%) and eye infection(8. 18%) were the most common symptoms of the tourist after seawater bath. Multivariate logistic regression analysis showed that previous physical discomfort(OR=0. 08-140. 73, 95%CI 0. 04-443. 64) was the common factor of all symptoms(P& lt; 0. 05), the risk factors of stomach cramps, eye infection, nasal congestion and sore throat were no wear of turbinate(OR=4. 65, 95% CI 1. 53-14. 08) and goggles(OR=541. 52, 95% CI 121. 58-2411. 85), swallowing seawater(OR=2. 29-79. 78, 95%CI 19. 83-296. 78) respectively(P& lt; 0. 05). CONCLUSION: Personal protective measures and physical conditions affect people& apos; s symptoms and diseases after bathing. There is microbial pollution in beach water and sand.


Asunto(s)
Playas , Microbiología del Agua , China/epidemiología , Ciudades , Monitoreo del Ambiente , Humanos , Agua de Mar , Agua
3.
Biosensors (Basel) ; 11(5)2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34062907

RESUMEN

The development of sensitive methods for the determination of potential bacterial contamination is of upmost importance for environmental monitoring and food safety. In this study, we present a new method combining a fast pre-enrichment step using a microporous cryogel and a detection and identification step using antimicrobial peptides (AMPs) and labelled antibodies, respectively. The experimental method consists of: (i) the capture of large amounts of bacteria from liquid samples by using a highly porous and functionalized cryogel; (ii) the detection and categorisation of Gram-positive and Gram-negative bacteria by determining their affinities toward a small set of AMPs; and (iii) the identification of the bacterial strain by using labelled detection antibodies. As proof of concept, the assessment of the three steps of the analysis was performed by using Escherichia coli and Bacillus sp. as models for Gram-negative and Gram-positive bacteria, respectively. The use of AMPs with broad specificity combined with labelled antibodies enabled the detection and potential categorization of a large spectrum of unknown or unexpected bacteria.


Asunto(s)
Bacterias/aislamiento & purificación , Microbiología del Agua , Bacillus , Monitoreo del Ambiente , Escherichia coli , Inocuidad de los Alimentos
4.
Sci Total Environ ; 784: 147107, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34088069

RESUMEN

A Quantitative Microbial Risk Assessment (QMRA) framework was applied to assess 312 drinking water supply systems across regional New South Wales (NSW). The framework was needed to support the implementation of a recommendation in the Australian Drinking Water Guidelines (ADWG) for appropriate treatment barriers to be operating in systems 'at risk' for Cryptosporidium. The objective was to prioritise systems so that those with the highest risk could be identified and addressed first. The framework was developed in a pilot study of 30 systems, selected to represent the range of water supplies across regional NSW. From these, source water categories were defined to represent local conditions with reference to the literature and Cryptosporidium risk factors. Values for Cryptosporidium oocyst concentration were assigned to the categories to allow quantification of the health risk from those water sources. The framework was then used to assess the risks in all 312 regional drinking water supply systems. Combining the disciplined approach of QMRA with simple catchment and treatment information and categorical risk outputs provided a useful and transparent method for prioritising systems for further investigation and potential risk management intervention. The risk rankings for drinking water supplies from this QMRA process have been used to set priorities for a large State Government funding program.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Agua Potable , Purificación del Agua , Australia , Criptosporidiosis/epidemiología , Humanos , Nueva Gales del Sur , Proyectos Piloto , Medición de Riesgo , Microbiología del Agua , Abastecimiento de Agua
5.
Sci Total Environ ; 783: 147086, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088114

RESUMEN

Determining the source of fecal contamination in a water body is important for the application of appropriate remediation measures. However, it has been suggested in the extant literature that this can best be achieved using a 'toolbox' of molecular- and culture-based methods. In response, this study deployed three indicators (Escherichia coli (EC), intestinal enterococci (IE) and somatic coliphages (SC)), one culture-dependent human marker (Bacteroides (GB-124) bacteriophage) and five culture-independent markers (human adenovirus (HAdV), human (HMMit), cattle (CWMit), pig (PGMit) and poultry (PLMit) mitochondrial DNA markers (mtDNA)) within the River Tagus catchment (n = 105). Water samples were collected monthly over a 13-month sampling campaign at four sites (impacted by significant specific human and non-human inputs and influenced by differing degrees of marine and freshwater mixing) to determine the dominant fecal inputs and assess geographical, temporal, and meteorological (precipitation, UV, temperature) fluctuations. Our results revealed that all sampling sites were not only highly impacted by fecal contamination but that this contamination originated from human and from a range of agricultural animal sources. HMMit was present in a higher percentage (83%) and concentration (4.20 log GC/100 mL) than HAdV (32%, 2.23 log GC/100 mL) and GB-124 bacteriophage with the latter being detected once. Animal mtDNA markers were detected, with CWMit found in 73% of samples with mean concentration of 3.74 log GC/100 mL. Correlation was found between concentrations of fecal indicators (EC, IE and SC), CWMit and season. Levels of CWMit were found to be related to physico-chemical parameters, such as temperature and UV radiation, possibly as a result of the increasing presence of livestock outside in warmer months. This study provides the first evaluation of such a source-associated 'toolbox' for monitoring surface water in Portugal, and the conclusions may inform future implementation of surveillance and remediation strategies for improving water quality.


Asunto(s)
Adenovirus Humanos , Bacteriófagos , Animales , Bovinos , ADN Mitocondrial , Monitoreo del Ambiente , Heces , Portugal , Ríos , Porcinos , Microbiología del Agua , Contaminación del Agua/análisis
6.
MMWR Morb Mortal Wkly Rep ; 70(20): 733-738, 2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34014907

RESUMEN

Outbreaks associated with treated recreational water can be caused by pathogens or chemicals in aquatic venues such as pools, hot tubs, water playgrounds, or other artificially constructed structures that are intended for recreational or therapeutic purposes. For the pseriod 2015-2019, public health officials from 36 states and the District of Columbia (DC) voluntarily reported 208 outbreaks associated with treated recreational water. Almost all (199; 96%) of the outbreaks were associated with public (nonbackyard) pools, hot tubs, or water playgrounds. These outbreaks resulted in at least 3,646 cases of illness, 286 hospitalizations, and 13 deaths. Among the 155 (75%) outbreaks with a confirmed infectious etiology, 76 (49%) were caused by Cryptosporidium (which causes cryptosporidiosis, a gastrointestinal illness) and 65 (42%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms). Cryptosporidium accounted for 2,492 (84%) of 2,953 cases resulting from the 155 outbreaks with a confirmed etiology. All 13 deaths occurred in persons affected by a Legionnaires' disease outbreak. Among the 208 outbreaks, 71 (34%) were associated with a hotel (i.e., hotel, motel, lodge, or inn) or a resort, and 107 (51%) started during June-August. Implementing recommendations in CDC's Model Aquatic Health Code (MAHC) (1) can help prevent outbreaks associated with treated recreational water in public aquatic venues.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Recreación , Purificación del Agua/estadística & datos numéricos , Baños/efectos adversos , Enfermedades Transmisibles/etiología , Cryptosporidium/aislamiento & purificación , Colonias de Salud/estadística & datos numéricos , Humanos , Legionella/aislamiento & purificación , Piscinas/estadística & datos numéricos , Estados Unidos/epidemiología , Microbiología del Agua
7.
Nat Commun ; 12(1): 2491, 2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33941780

RESUMEN

Mycobacterium kansasii can cause serious pulmonary disease. It belongs to a group of closely-related species of non-tuberculous mycobacteria known as the M. kansasii complex (MKC). Here, we report a population genomics analysis of 358 MKC isolates from worldwide water and clinical sources. We find that recombination, likely mediated by distributive conjugative transfer, has contributed to speciation and on-going diversification of the MKC. Our analyses support municipal water as a main source of MKC infections. Furthermore, nearly 80% of the MKC infections are due to closely-related M. kansasii strains, forming a main cluster that apparently originated in the 1900s and subsequently expanded globally. Bioinformatic analyses indicate that several genes involved in metabolism (e.g., maintenance of the methylcitrate cycle), ESX-I secretion, metal ion homeostasis and cell surface remodelling may have contributed to M. kansasii's success and its ongoing adaptation to the human host.


Asunto(s)
Agua Potable/microbiología , Genoma Bacteriano/genética , Enfermedades Pulmonares/epidemiología , Infecciones por Mycobacterium no Tuberculosas/epidemiología , Mycobacterium kansasii/genética , Metabolismo Energético/genética , Variación Genética/genética , Genética de Población/métodos , Genómica , Humanos , Enfermedades Pulmonares/microbiología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium kansasii/aislamiento & purificación , Virulencia/genética , Microbiología del Agua
8.
Water Res ; 198: 117147, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33962239

RESUMEN

A new conceptual model to describe and understand the role of assimilable organic carbon (AOC) within drinking water distribution systems is proposed. The impact of AOC on both drinking water biofilm and water quality was studied using bespoke pipe loop experimental facilities installed at three carefully selected operational water treatment works. Integrated physical, chemical and biological monitoring was undertaken that highlights the central role of biofilms in AOC cycling, forming the basis of the new conceptual model. Biofilms formed under high AOC conditions were found to pose the highest discoloration response, generating a turbidity (4.3 NTU) and iron (241.5 µg/l) response sufficient to have caused regulatory failures from only 20 m of pipe in only 12 months of operation. This new knowledge of the role of biofilms in AOC cycling, and ultimately impacts on water quality, can be used to inform management and help ensure the supply of high-quality, biostable drinking water.


Asunto(s)
Agua Potable , Purificación del Agua , Biopelículas , Carbono/análisis , Microbiología del Agua , Abastecimiento de Agua
9.
Environ Monit Assess ; 193(6): 339, 2021 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-33988761

RESUMEN

About one-half of the homes on First Nations (FN) reserves in Manitoba, Canada, receive piped water from a water treatment plant (WTP). Many other homes (31%) are equipped with cisterns that are filled by a water truck, and our objective was to determine how the use of cisterns affects drinking water safety relative to drinking water piped directly to homes from the WTP. The study included belowground concrete cisterns, belowground fiberglass cisterns, and aboveground polyethylene cisterns stored in insulated shelters, and all the data collection methods showed that the tap water in homes with cisterns were relatively more contaminated with coliform bacteria than the tap water in piped homes. The frequency and severity of Escherichia coli and total coliform contamination were numerically greater in drinking water samples from belowground concrete and fiberglass cisterns than in piped water samples in each community, and the contamination of belowground cisterns by coliform bacteria was greatest in late spring. As well, data obtained under the Access to Information Act showed no statistical differences in the percent of satisfactory samples (no detects) between 2014 and 2018, suggesting no clear indication of improved water quality in any of the Tribal Councils in which these three and other communities are a member off. Our results point to the need for additional treatment of drinking water in homes supplied by belowground concrete or fiberglass cisterns and replacement of belowground cisterns with aboveground cisterns or piped water to reduce the risk of water-borne illnesses.


Asunto(s)
Agua Potable , Canadá , Agua Potable/análisis , Monitoreo del Ambiente , Manitoba , Microbiología del Agua , Abastecimiento de Agua
10.
Mar Pollut Bull ; 168: 112478, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33993043

RESUMEN

Libreville, the largest city in Gabon, adversely impacts the Komo Estuary and the Akanda National Park aquatic ecosystems through discharge of domestic and industrial waste. Fecal Indicator Bacteria (FIB: Escherichia coli and fecal streptococci) were enumerated using culture-based methods in water from 40 sites between 2017 and 2019 including coastal outlets, mangrove channels, open bays and littoral rivers. Contamination levels were high in discharge waters from small urban rivers in Libreville agglomeration, frequently exceeding international safety guidelines, whereas FIB concentrations decreased downstream from the city in main mangrove channels. Littoral forest rivers were significantly impacted by fecal contamination despite the absence of settlements in the watersheds. Protected areas are not effective in avoiding FIB contamination, indicating inefficient waste management. Dedicated management policies should be implemented to reduce both the sanitary concern and global pollution, poorly assessed in a context of demographic increase in tropical littoral zones.


Asunto(s)
Ecosistema , Microbiología del Agua , África Occidental , Bacterias , Ciudades , Monitoreo del Ambiente , Heces , Gabón
11.
Int J Food Microbiol ; 349: 109233, 2021 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-34022616

RESUMEN

Escherichia coli O157:H7, a Shiga-producing E. coli is a major pathogenic E. coli strain which since the early 1980s has become a crucial food and water-borne pathogen. Several management strategies can be applied to control the spread of infection; however early diagnosis represents the optimum preventive strategy to minimize the infection. Therefore, it is crucial to detect this pathogen in a fast and efficient manner in order to reduce the morbidity and mortality. Currently used gold standard tests rely on culture and pre-enrichment of E. coli O157:H7 from the contaminated source; they are time consuming and laborious. Molecular methods such as polymerase chain reaction are sensitive; however, they require expensive instrumentation. Therefore, there is a requirement for Accurate, Sensitive, Specific, User friendly, Rapid, Equipment free and Deliverable (ASSURED) detection methods for use in the laboratory and in the field. Emerging technologies such as isothermal amplification methods, biosensors, surface enhanced Raman Spectroscopy, paper-based diagnostics and smartphone-based digital methods are recognized as new approaches in the field of E. coli O157:H7 diagnostics and are discussed in this review. Mobile PCR and CRISPR-Cas diagnostic platforms have been identified as new tools in E. coli O157:H7 POC diagnostics with the potential for implementation by industry. This review describes advances and progress in the field of E. coli O157:H7 diagnosis in the context of food and water industry. The focus is on emerging high throughput point-of-care (POC) E. coli O157:H7 diagnostics and the requirement for the transformation to service routine diagnostics in the food and water industry.


Asunto(s)
Técnicas Bacteriológicas , Escherichia coli O157/aislamiento & purificación , Microbiología de Alimentos , Sistemas de Atención de Punto , Microbiología del Agua , Técnicas Biosensibles , Sistemas CRISPR-Cas , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Humanos , Reacción en Cadena de la Polimerasa
12.
Sci Total Environ ; 786: 147433, 2021 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-33971597

RESUMEN

Microbial communities are considered to be functionally redundant, but few studies have tested this hypothesis empirically. In this study, we performed an in situ reciprocal transplant experiment on the surface and bottom waters of two lakes (Tsuei-Feng (T) and Yuan-Yang (Y)) with disparate trophic states and tracked changes in their microbial community composition and functions for 6 weeks using high-throughput sequencing and functional approaches. T lake's surface (Ts) and bottom (Tb) water active bacterial community (16S rRNA gene-transcript) was dominated by Actinobacteria, Bacteroidia, and Cyanobacteria, whereas Y lake's surface (Ys) and bottom (Yb) water had Gammaproteobacteria, Alphaproteobacteria, and Bacteroidia as the dominant classes. The community composition was resistant to changes in environmental conditions following the reciprocal transplant, but their functions tended to become similar to the incubating lakes' functional profiles. A significant linear positive relationship was observed between the microbial community and functional attributes (surface: R2 = 0.5065, p < 0.0001; bottom: R2 = 0.4592, p < 0.0001), though with varying scales of similarity (1-Bray Curtis distance), suggesting partial functional redundancy. Also, the entropy-based L-divergence measure identified high divergence in community composition (surface: 1.21 ± 0.54; bottom: 1.17 ± 0.51), and relatively low divergence in functional attributes (surface: 0.04 ± 0.01; bottom: 0.04 ± 0.01) in the two lakes' surface and bottom waters, providing further support for the presence of partial functional redundancy. This study enriches our understanding of community functional relationships and establishes the presence of partial functional redundancy in freshwater ecosystems.


Asunto(s)
Microbiota , Microbiología del Agua , Lagos , Filogenia , ARN Ribosómico 16S/genética
13.
Artículo en Inglés | MEDLINE | ID: mdl-33999788

RESUMEN

A total of 27 Listeria isolates that could not be classified to the species level were obtained from soil samples from different locations in the contiguous United States and an agricultural water sample from New York. Whole-genome sequence-based average nucleotide identity blast (ANIb) showed that the 27 isolates form five distinct clusters; for each cluster, all draft genomes showed ANI values of <95 % similarity to each other and any currently described Listeria species, indicating that each cluster represents a novel species. Of the five novel species, three cluster with the Listeria sensu stricto clade and two cluster with sensu lato. One of the novel sensu stricto species, designated L. cossartiae sp. nov., contains two subclusters with an average ANI similarity of 94.9%, which were designated as subspecies. The proposed three novel sensu stricto species (including two subspecies) are Listeria farberi sp. nov. (type strain FSL L7-0091T=CCUG 74668T=LMG 31917T; maximum ANI 91.9 % to L. innocua), Listeria immobilis sp. nov. (type strain FSL L7-1519T=CCUG 74666T=LMG 31920T; maximum ANI 87.4 % to L. ivanovii subsp. londoniensis) and Listeria cossartiae sp. nov. [subsp. cossartiae (type strain FSL L7-1447T=CCUG 74667T=LMG 31919T; maximum ANI 93.4 % to L. marthii) and subsp. cayugensis (type strain FSL L7-0993T=CCUG 74670T=LMG 31918T; maximum ANI 94.7 % to L. marthii). The two proposed novel sensu lato species are Listeria portnoyi sp. nov. (type strain FSL L7-1582T=CCUG 74671T=LMG 31921T; maximum ANI value of 88.9 % to L. cornellensis and 89.2 % to L. newyorkensis) and Listeria rustica sp. nov. (type strain FSL W9-0585T=CCUG 74665T=LMG 31922T; maximum ANI value of 88.7 % to L. cornellensis and 88.9 % to L. newyorkensis). L. immobilis is the first sensu stricto species isolated to date that is non-motile. All five of the novel species are non-haemolytic and negative for phosphatidylinositol-specific phospholipase C activity; the draft genomes lack the virulence genes found in Listeria pathogenicity island 1 (LIPI-1), and the internalin genes inlA and inlB, indicating that they are non-pathogenic.


Asunto(s)
Riego Agrícola , Listeria/clasificación , Filogenia , Microbiología del Agua , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Genes Bacterianos , Listeria/aislamiento & purificación , New York , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
14.
Water Res ; 198: 117151, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33910143

RESUMEN

Household water treatment (HWT) represents a key engineering intervention for billions of people's daily and emergency water needs. However, established HWT practices experience different challenges to achieve sustainability. Here, five essential principles are identified and discussed for the design of sustainable HWT, including treatment capability, environmental friendliness, user experience, economic viability, and social acceptance. A well-implemented HWT, with a consideration of energy resilience, relies heavily on advanced materials, innovative technologies, and/or creative designs capable of reliably abating both traditional and emerging contaminants, while minimizing undesirable chemical leaching and the formation of harmful disinfection byproducts. Environmental friendliness can be pursued by appreciably reducing environmental and energy footprints and properly managing HWT residuals. Meanwhile, a user-centered design approach and economic consideration need to be integrated into the HWT development to improve end users' willingness to use and pay, respectively. Finally, social acceptance should be intertwined by fostering public acceptance and market adoption for strengthening commercial viability of new-generation HWT products. Given that these principles span across different domains, multidisciplinary collaboration is required throughout different stages of the HWT technology innovation.


Asunto(s)
Purificación del Agua , Agua , Microbiología del Agua
15.
J Hazard Mater ; 411: 125095, 2021 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-33858087

RESUMEN

Biofilm formation has been frequently identified as a pathway of nosocomial infection in polymeric tubes used for patients of all ages. Biofilm formation on tube surfaces can lead to hygienic failure and cause diarrhea, stomach pain, inflammation, and digestive system disease. This study investigated the influence of polymeric tube materials in contact with water on the biomass formation potential and migration potential of microbially available carbon from plasticizers using a BioMig test. The thermoplastic elastomer tube, which is reusable, leached a relatively low amount of assimilable organic carbon to water. In contrast, the assimilable organic carbon migration potential of polyurethane was the most significant, 6-fold greater than that of the thermoplastic elastomer. Moreover, the same materials (e.g., silicone) produced via different manufacturing processes showed significant differences in migration behaviors. The potential biomass formation observed in polyurethane was approximately 7 × 109 cells cm-2 for both Aeromonas hydrophila and Escherichia coli strains. This study highlights the importance of choosing the correct material characteristics of polymeric tubes in contact with water to protect them from bacterial contamination. Therefore, manufacturers can use the BioMig test to evaluate and produce more hygienic and biostable tubes.


Asunto(s)
Carbono , Agua Potable , Biopelículas , Humanos , Microbiología del Agua , Abastecimiento de Agua
16.
Analyst ; 146(11): 3549-3556, 2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-33899848

RESUMEN

The detection of pathogens in aquatic environments issues a time-consuming challenge, but it is an essential task to prevent the spread of diseases. We have developed a new point-of-care (POC) method for the fast and efficient detection of Legionella pneumophila in water. The method consists first of the generation of immunocomplexes of bacteria species with its corresponding targeted fluorescence-labelled serogroup-specific antibodies, and second a concentration step of pathogens with a membrane filter. Third, on the filtration membrane, our method can detect the fluorescence intensity corresponding to the pathogen concentration. Thus selective and efficient evidence for the presence of bacteria can be evaluated. We tested our system on fluorescent Escherichia coli bacteria and were able to reach an accurate determination of 1000 cells. The technique was furthermore tested on Legionella pneumophila cells, which were labelled with fluorescence-labelled antibodies as a proof of principle. Furthermore, we were able to verify this method in the presence of other bacteria species. We were able to detect bacteria cells within half an hour, a substantial advancement compared to the prevailling state of the art detection method based on the cultivation of Legionella pneumophila. Hence, this system represents the basis for future developments in analysis of pathogens.


Asunto(s)
Legionella pneumophila , Microbiología del Agua , Anticuerpos , Filtración , Serogrupo
17.
Water Res ; 197: 117047, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33799081

RESUMEN

Efficient control of pathogenic bacteria, specifically Legionella pneumophila, is one of the main concerns when operating industrial cooling towers. Common practices to limit proliferation involves use of disinfectants, leading to formation of disinfection by-product and increase in water corrosiveness. A disinfectant-free Legionella control method would make the industry more environmentally friendly. A pilot-scale cooling tower (1 m3/h) operated with demineralized water was used to investigate the potential of high-pH conditioning as a disinfectant-free alternative for control of L. pneumophila and other pathogens. One control experiment was performed under standard full-scale operation involving sodium hypochlorite dosage. Thereafter 3 alkaline pHs of the cooling water were tested: 9.0, 9.4 and 9.6. The tests lasted between 25 and 35 days. The cooling water from the basins were analysed for total cell count by flow cytometry, L. pneumophila concentration by plate count and occasional qPCR analyses targeting the mip-gene, bacterial and eukaryotic community analyses with 16S and 18S rRNA gene amplicon sequencing, relative abundance of eukaryotic to prokaryotic DNA by qPCR of the 16S and 18S rRNA gene. The L. pneumophila analyses showed considerable growth at pH 9.0 and pH 9.4 but was maintained below detection limit (< 100 CFU/L) at pH 9.6 without disinfection. Interestingly, the results correlated with the overall abundance of protozoa in the water samples but not directly with the relative abundance of specific reported protozoan hosts of Legionella. The pathogenicity based on 16S rRNA gene amplicon sequencing of the cooling water DNA decreased with increasing pH with a strong decline between pH 9.0 and pH 9.4, from 7.1% to 1.6% of relative abundance of pathogenic genera respectively. A strong shift in microbiome was observed between each tested pH and reproducibility of the experiment at pH 9.6 was confirmed with a duplicate test lasting 80 days. High-pH conditioning ≥ 9.6 is therefore considered as an efficient disinfectant-free cooling tower operation for control of pathogenicity, including L. pneumophila.


Asunto(s)
Legionella pneumophila , Legionella , Legionella/genética , Legionella pneumophila/genética , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Microbiología del Agua
18.
Sci Total Environ ; 781: 146598, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-33812107

RESUMEN

The goal of most studies published on sand contaminants is to gather and discuss knowledge to avoid faecal contamination of water by run-offs and tide-retractions. Other life forms in the sand, however, are seldom studied but always pointed out as relevant. The Mycosands initiative was created to generate data on fungi in beach sands and waters, of both coastal and freshwater inland bathing sites. A team of medical mycologists and water quality specialists explored the sand culturable mycobiota of 91 bathing sites, and water of 67 of these, spanning from the Atlantic to the Eastern Mediterranean coasts, including the Italian lakes and the Adriatic, Baltic, and Black Seas. Sydney (Australia) was also included in the study. Thirteen countries took part in the initiative. The present study considered several fungal parameters (all fungi, several species of the genus Aspergillus and Candida and the genera themselves, plus other yeasts, allergenic fungi, dematiaceous fungi and dermatophytes). The study considered four variables that the team expected would influence the results of the analytical parameters, such as coast or inland location, urban and non-urban sites, period of the year, geographical proximity and type of sediment. The genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp. and Cryptococcus spp. both in sand and in water. A site-blind median was found to be 89 Colony-Forming Units (CFU) of fungi per gram of sand in coastal and inland freshwaters, with variability between 0 and 6400 CFU/g. For freshwater sites, that number was 201.7 CFU/g (0, 6400 CFU/g (p = 0.01)) and for coastal sites was 76.7 CFU/g (0, 3497.5 CFU/g). For coastal waters and all waters, the median was 0 CFU/ml (0, 1592 CFU/ml) and for freshwaters 6.7 (0, 310.0) CFU/ml (p < 0.001). The results advocate that beaches should be monitored for fungi for safer use and better management.


Asunto(s)
Playas , Arena , Australia , Mar Negro , Hongos , Humanos , Italia , Microbiología del Agua
19.
Mar Pollut Bull ; 166: 112231, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33798816

RESUMEN

Long-term assessments are needed to identify water quality trends and their socio-environmental drivers for coastal management and watershed restoration. This study provides the first long-term assessment of fecal bacterial pollution in the northwestern Gulf of Mexico using enterococci data spanning the Texas coast from 2009 to 2020. The data were representative of 66 beaches, 169 stations, and over 75,000 samples. Findings demonstrate that 22 beaches are 'hotspots' of pollution and experienced enterococci levels that frequently exceeded the USEPA beach action value. Further, enterococci were correlated with time, population size, and sea level. Weak correlations detected in some counties highlight the multifactorial nature of water quality; additional factors are likely influencing enterococci levels. The correlation with sea level is concerning, as counties vulnerable to sea level rise frequently reported enterococci concentrations exceeding the beach action value. In consideration of sea level rise predictions, targeted studies are needed to pinpoint drivers of fecal pollution.


Asunto(s)
Playas , Calidad del Agua , Monitoreo del Ambiente , Heces , Golfo de México , Elevación del Nivel del Mar , Texas , Microbiología del Agua , Contaminación del Agua/análisis
20.
Mar Pollut Bull ; 168: 112384, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33901906

RESUMEN

The May River, South Carolina watershed has undergone rapid increases in population and development from 1999 to 2017. This study aimed to understand the factors that influence salinity and fecal coliform levels in this estuary and how these levels changed from 1999 to 2017. This analysis revealed that salinity levels decreased in the headwaters, while variability increased. Additionally, fecal coliform increased from 1999 to 2017 throughout the hydrological network, with drastic changes occurring in the headwaters. Salinity and fecal coliform were influenced by spatial (distance from the mouth of the river), temporal (year, season, and tidal cycles), environmental (El Niño Southern Oscillation and rainfall), and anthropogenic parameters (population). This analysis suggests that the synergistic nature of climate change, resulting in more intense and frequent El Niño events, and watershed development may lead to further decreases in salinity and increases in fecal coliform levels in the May River estuary.


Asunto(s)
Estuarios , Ríos , Enterobacteriaceae , Monitoreo del Ambiente , Salinidad , South Carolina , Microbiología del Agua
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