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1.
PLoS One ; 15(9): e0238385, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936810

RESUMO

A lack of replicable test systems that realistically simulate hot water premise plumbing conditions at the laboratory-scale is an obstacle to identifying key factors that support growth of opportunistic pathogens (OPs) and opportunities to stem disease transmission. Here we developed the convectively-mixed pipe reactor (CMPR) as a simple reproducible system, consisting of off-the-shelf plumbing materials, that self-mixes through natural convective currents and enables testing of multiple, replicated, and realistic premise plumbing conditions in parallel. A 10-week validation study was conducted, comparing three pipe materials (PVC, PVC-copper, and PVC-iron; n = 18 each) to stagnant control pipes without convective mixing (n = 3 each). Replicate CMPRs were found to yield consistent water chemistry as a function of pipe material, with differences becoming less discernable by week 9. Temperature, an overarching factor known to control OP growth, was consistently maintained across all 54 CMPRs, with a coefficient of variation <2%. Dissolved oxygen (DO) remained lower in PVC-iron (1.96 ± 0.29 mg/L) than in PVC (5.71 ± 0.22 mg/L) or PVC-copper (5.90 ± 0.38 mg/L) CMPRs as expected due to corrosion. Further, DO in PVC-iron CMPRs was 33% of that observed in corresponding stagnant pipes (6.03 ± 0.33 mg/L), demonstrating the important role of internal convective mixing in stimulating corrosion and microbiological respiration. 16S rRNA gene amplicon sequencing indicated that both bulk water (Padonis = 0.001, R2 = 0.222, Pbetadis = 0.785) and biofilm (Padonis = 0.001, R2 = 0.119, Pbetadis = 0.827) microbial communities differed between CMPR versus stagnant pipes, consistent with creation of a distinct ecological niche. Overall, CMPRs can provide a more realistic simulation of certain aspects of premise plumbing than reactors commonly applied in prior research, at a fraction of the cost, space, and water demand of large pilot-scale rigs.


Assuntos
Água Potável/efeitos adversos , Água Potável/microbiologia , Engenharia Sanitária/instrumentação , Microbiologia da Água , Biofilmes/crescimento & desenvolvimento , Fenômenos Químicos , Cobre/química , Desenho de Equipamento , Humanos , Ferro/química , Microbiota/genética , Modelos Biológicos , Infecções Oportunistas/etiologia , Infecções Oportunistas/microbiologia , Cloreto de Polivinila/química , RNA Ribossômico 16S/genética , Temperatura , Abastecimento de Água
2.
Int J Food Microbiol ; 334: 108850, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32919261

RESUMO

The complex and highly diverse microbial environment of drinking water, consisting mainly of bacteria at different metabolic states, is still underexplored. The aim of this work was to characterize the bacterial communities in tap water and bottled mineral water, the two predominant sources of drinking water in modern societies. A total of 11 tap water samples from a range of locations and distribution networks and 10 brands of bottled natural mineral water were analysed using two approaches: a) heterotrophic plate counts by matrix-assisted laser desorption/ionization time of flight mass-spectrometry (MALDI-TOF MS) for the culturable heterotrophic communities, and b) Illumina amplicon sequencing for total bacteria including non-culturable bacteria. Culturable heterotrophic bacteria were isolated in WPCA (ISO) agar at 22 ± 2 °C for 72 h and 2046 isolates were identified using MALDI-TOF MS. The Bruker Daltonics Library and a previously customized library (Drinking Water Library) were used as reference databases. For the total bacteria fraction, DNA was extracted from 6 L of water and submitted to Illumina 16S rRNA sequencing of the v4 region. Significant differences were observed between mineral and tap water, with a general dominance of Alphaproteobacteria (mainly the genus Blastomonas) in tap water and Gammaproteobacteria in mineral water with Acidovorax being the dominant genus in 3 out of 7 mineral water brands. The bacterial communities in the different brands of mineral water were highly diverse and characteristic of each one. Moreover, the season in which the water was bottled also affected the species distribution, with some of them identified in only one season. Among the culturable bacteria, the most abundant phylum was Proteobacteria (around 85% of the isolates), followed by Actinobacteria, Firmicutes and Bacteroidetes. Proteobacteria was also the most abundant phylum detected with Illumina sequencing (>99% of the reads). The two methods gave distinct results at the different taxonomic levels and could therefore have a complimentary application in the study of microbiota in mineral water environments. MALDI-TOF MS is a promising method for the rapid identification of heterotrophic bacteria in routine water analysis in the bottling industry. SIGNIFICANCE AND IMPACT OF THE STUDY: The complementarity of MALDI-TOF MS and NGS in the assessment of bacterial community diversity has been demonstrated in water intended for human consumption. The two methods are suitable for routine use in the water industry for water quality management.


Assuntos
Técnicas Bacteriológicas , Água Potável/microbiologia , Microbiota , Águas Minerais/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Técnicas Bacteriológicas/métodos , Meios de Cultura/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , RNA Ribossômico 16S/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
3.
Am J Trop Med Hyg ; 103(4): 1405-1415, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32840201

RESUMO

Enteric infections early in life have been associated with poor linear growth among children in low-resource settings. Point-of-use water treatment technologies provide effective and low-cost solutions to reduce exposure to enteropathogens from drinking water, but it is unknown whether the use of these technologies translates to improvements in child growth. We conducted a community-based randomized controlled trial of two water treatment technologies to estimate their effects on child growth in Limpopo, South Africa. We randomized 404 households with a child younger than 3 years to receive a silver-impregnated ceramic water filter, a silver-impregnated ceramic tablet, a safe-storage water container alone, or no intervention, and these households were followed up quarterly for 2 years. We estimated the effects of the interventions on linear and ponderal growth, enteric infections assessed by quantitative molecular diagnostics, and diarrhea prevalence. The silver-impregnated ceramic water filters and tablets consistently achieved approximately 1.2 and 3 log reductions, respectively, in total coliform bacteria in drinking water samples. However, the filters and tablets were not associated with differences in height (height-for-age z-score differences compared with no intervention: 0.06, 95% CI: -0.29, 0.40, and 0.00, 95% CI: -0.35, 0.35, respectively). There were also no effects of the interventions on weight, diarrhea prevalence, or enteric infections. Despite their effectiveness in treating drinking water, the use of the silver-impregnated ceramic water filters and tablets did not reduce enteric infections or improve child growth. More transformative water, sanitation, and hygiene interventions that better prevent enteric infections are likely needed to improve long-term child growth outcomes.


Assuntos
Diarreia/prevenção & controle , Água Potável/microbiologia , Filtração/métodos , Purificação da Água/métodos , Desenvolvimento Infantil , Saúde da Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia Infantil , Características da Família , Humanos , Higiene , Lactente , Recém-Nascido , Controle de Infecções , Enteropatias/prevenção & controle , África do Sul/epidemiologia , Doenças Transmitidas pela Água/epidemiologia , Doenças Transmitidas pela Água/prevenção & controle
4.
J Water Health ; 18(4): 602-612, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32833686

RESUMO

Sand dams can be an effective community-scale solution to increasing water supplies in some arid and semi-arid regions, but there are few studies that have investigated water quality at sand dams. This study investigated the levels of coliform bacteria and salt content as parameters of potential concern. Most water taken from sand dam sources had fecal coliforms present. Median fecal coliforms were in the range of 150-800 cfu/100 ml for unprotected sources (scoop holes, surface water or hand dug wells), levels which are considered high or very high health risk. Pump wells had less contamination, with fecal coliforms detected in one-third of samples in the dry season. Despite this contamination, user surveys indicated that 74% of communities generally view water as clean for drinking, and 72% reported that no or few people in their community treat their water. Salt content in the dry season was in the poor or unacceptable range (above 900 ppm as total dissolved solids) in 33% of water samples. Results suggest that fecal coliforms and salt content represent two types of challenges to water quality at sand dams: fecal coliforms are a health hazard, whereas high salt content potentially reduces the amount of usable water that is available.


Assuntos
Água Potável/microbiologia , Salinidade , Microbiologia da Água , Abastecimento de Água/estatística & dados numéricos , Bactérias , Água Potável/química , Fezes , Quênia , Areia
5.
PLoS One ; 15(8): e0237335, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790793

RESUMO

Anthropogenic activities in catchments used for drinking water production largely contaminates source waters, and this may impact the quality of the final drinking water product. These contaminants may also affect taxonomic and functional profiles of the bacterial communities in the drinking water. Here, we report an integrated insight into the microbiome and water quality of four water treatment plants (NWC, NWE, WCA and NWG) that supply portable water to communities in South Africa. A new scoring system based on combined significant changes of physicochemical parameters and microbial abundance from raw to treated water was used to evaluate the effectiveness of the treatment plants at water purification. Physicochemical parameters which include total soluble solids, turbidity, pH, nitrites and phosphorus among others, were measured in source, treated, and distributed water. There were general statistically significant (P ≤ 0.05) differences between raw and treated water, demonstrating the effectiveness of the purification process. Illumina sequencing of the 16S rRNA gene was used for taxonomic profiling of the microbial communities and this data was used to infer functional attributes of the communities. Structure and composition of the bacterial communities differed significantly (P < 0.05) among the treatment plants, only NWE and NWG showed no significant differences (P > 0.05), this correlated with the predicted functional profile of the microbial communities obtained from Phylogenetic Investigation of Communities by Reconstruction of Observed States (PICRUSt), as well as the likely pollutants of source water. Bacteroidetes, Chlorobi and Fibrobacteres significantly differed (P < 0.05) between raw and distributed water. PICRUSt inferred a number of pathways involved in the degradation of xenobiotics such as Dichlorodiphenyltrichloroethane, atrazine and polycyclic aromatic hydrocarbons. More worryingly, was the presence of pathways involved in beta-lactam resistance, potential pathogenic Escherichia coli infection, Vibrio cholerae infection, and Shigellosis. Also present in drinking and treated water were OTUs associated with a number of opportunistic pathogens.


Assuntos
Bactérias/isolamento & purificação , Água Potável/microbiologia , Purificação da Água , Qualidade da Água , Abastecimento de Água , Bactérias/genética , Humanos , RNA Ribossômico 16S/genética , África do Sul , Microbiologia da Água
6.
BMC Public Health ; 20(1): 1128, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32680495

RESUMO

BACKGROUND: Water is the most abundant resource on earth, however water scarcity affects more than 40% of people worldwide. Access to safe drinking water is a basic human right and is a United Nations Sustainable Development Goal (SDG) 6. Globally, waterborne diseases such as cholera are responsible for over two million deaths annually. Cholera is a major cause of ill-health in Africa and Uganda. This study aimed to determine the physicochemical characteristics of the surface and spring water in cholera endemic communities of Uganda in order to promote access to safe drinking water. METHODS: A longitudinal study was carried out between February 2015 and January 2016 in cholera prone communities of Uganda. Surface and spring water used for domestic purposes including drinking from 27 sites (lakes, rivers, irrigation canal, springs and ponds) were tested monthly to determine the vital physicochemical parameters, namely pH, temperature, dissolved oxygen, conductivity and turbidity. RESULTS: Overall, 318 water samples were tested. Twenty-six percent (36/135) of the tested samples had mean test results that were outside the World Health Organization (WHO) recommended drinking water range. All sites (100%, 27/27) had mean water turbidity values greater than the WHO drinking water recommended standards and the temperature of above 17 °C. In addition, 27% (3/11) of the lake sites and 2/5 of the ponds had pH and dissolved oxygen respectively outside the WHO recommended range of 6.5-8.5 for pH and less than 5 mg/L for dissolved oxygen. These physicochemical conditions were ideal for survival of Vibrio. cholerae. CONCLUSIONS: This study showed that surface water and springs in the study area were unsafe for drinking and had favourable physicochemical parameters for propagation of waterborne diseases including cholera. Therefore, for Uganda to attain the SDG 6 targets and to eliminate cholera by 2030, more efforts are needed to promote access to safe drinking water. Also, since this study only established the vital water physicochemical parameters, further studies are recommended to determine the other water physicochemical parameters such as the nitrates and copper. Studies are also needed to establish the causal-effect relationship between V. cholerae and the physicochemical parameters.


Assuntos
Água Potável/análise , Qualidade da Água , Abastecimento de Água/estatística & dados numéricos , Cólera/epidemiologia , Água Potável/microbiologia , Água Potável/normas , Humanos , Lagos/química , Lagos/microbiologia , Estudos Longitudinais , Nascentes Naturais/química , Nascentes Naturais/microbiologia , Tanques/química , Tanques/microbiologia , Rios/química , Rios/microbiologia , Temperatura , Uganda/epidemiologia , Vibrio cholerae , Microbiologia da Água , Abastecimento de Água/normas
7.
PLoS One ; 15(7): e0235440, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614915

RESUMO

BACKGROUND: Cholera remains a significant public health problem in more than one-third of the countries of the world. Cholera outbreak has become more common in Addis Ababa particularly in the rainy seasons; however, there is a paucity of data on risk factors associated with cholera outbreaks rendering interventions difficult. We investigated the outbreak to identify its etiology, source, risk factors and in order to control the outbreak. METHODS: We compared cases with health center-based unmatched controls (1:2). Cases were patients aged ≥5 years with acute watery diarrhea, with or without vomiting while controls were persons aged ≥5 years without history of acute watery diarrhea. We interviewed our study participants using structured questionnaire to collect demographic and cholera risk factors data. We described the outbreak over time, and then tested our hypotheses using unconditional logistic regression. RESULTS: The outbreak began on 7 September, 2017 reaching its peak on 23 September, 2017 and ended on 01 October, 2017. We identified a total of 25 cases (Median age: 38 years; IQR: 20 years) and recruited 50 controls (Median age: 35 years; IQR: 29 years). All case-patients had acute watery diarrhea and dehydration requiring intravenous fluids. All cases were admitted to cholera treatment center but there were no deaths. Stool and water samples yielded isolates of Vibrio cholerae O1 of serological subtype Ogawa. Consumption of contaminated holy water (AOR: 20.5, 95%CI: 3.50, 119.61) and raw vegetables (AOR: 15.3, 95%CI: 3, 81.51) were independent risk factors whereas washing hands with soap after visiting latrine (AOR: 0.04, 95%CI: 0.01, 0.25) was independent protective factor. CONCLUSION: Our findings demonstrated cholera foodborne transmission via consumption of raw vegetables, and its waterborne transmission via consumption of contaminated holy water. Washing hands with soap after visiting latrine was protective. We recommended cooking of vegetables and promoting hand washing.


Assuntos
Cólera/epidemiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Vibrio cholerae O1/isolamento & purificação , Estudos de Casos e Controles , Diarreia/epidemiologia , Diarreia/microbiologia , Água Potável/microbiologia , Etiópia , Fezes/microbiologia , Microbiologia de Alimentos , Desinfecção das Mãos , Fatores de Risco , Inquéritos e Questionários , Toaletes , Verduras/microbiologia , Verduras/envenenamento , Vômito/epidemiologia , Microbiologia da Água
8.
J Environ Public Health ; 2020: 2571293, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612664

RESUMO

Waterborne Escherichia coli are a major reservoir of antimicrobial resistance (AMR). Carbapenem-resistance, especially when mediated by transferable carbapenemase-encoding genes, is spreading worldwide and causing dramatically limiting treatment options. In our country, studies for the detection of carbapenem resistance in drinking water do not exist; therefore, this work was carried out to determine the prevalence of carbapenem-resistant genes "blaKPC, blaIMP, blaNDM, blaSPM, blaVIM, and blaOXA-48" among Escherichia coli isolated from drinking water in Khartoum, Sudan. A total of forty-five E. coli bacteria were isolated from different sources of drinking water. Antimicrobial susceptibility testing was performed using imipenem (10 mg/disc), gentamicin (10 mg/disc), ceftriaxone (30 mg/disc), ciprofloxacin (5 mg/disc), chloramphenicol (30 mg/disc), and tetracycline (30 mg/disc). "Sensitive" or "resistant" patterns of E. coli were judged using antibiotic minimum inhibitory concentration (MIC). Bacterial genomic DNA was extracted by the boiling method, and then multiplex polymerase chain reaction was performed to detect the carbapenemase genes (blaKPC, blaIMP, bla NDM , blaSPM, blaVIM, and blaOXA-48). Multiplex PCR assays confirmed the presence of carbapenemase genes in 28% of all water isolates. OXA-48 gene was the most predominant gene, detected in 15.5% of the isolates. The blaKPC and bla SPM genes were also detected in 4.4% and 8.8% of the isolates, respectively. However, the isolates were negative for bla NDM , blaVIM, and blaIMP genes. The isolates showed a high rate of tetracycline resistance (97.7%), followed by gentamicin (57.7%), ciprofloxacin (46.6%), ceftriaxone (35.5%), and chloramphenicol (31.1%). In conclusion, this study confirmed for the first time the presence of E. coli carried carbapenem-resistant genes in the drinking water of Khartoum state, Sudan. These isolates commonly carried OXA-48 (7/45), followed by SPM (4/45) and KPC (2/45).


Assuntos
Carbapenêmicos/farmacologia , Água Potável/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Resistência beta-Lactâmica/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Sudão , beta-Lactamases/genética
9.
PLoS One ; 15(7): e0236163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32687513

RESUMO

Child open defecation is common in low-income countries and can lead to fecal exposure in the domestic environment. We assessed associations between child feces management practices vs. measures of contamination and child diarrhea among households with children <5 years in rural Bangladesh. We visited 360 households quarterly and recorded caregiver-reported diarrhea prevalence, and defecation and feces disposal practices for children <5 years. We examined caregiver and child hands for visible dirt and enumerated E. coli in child and caregiver hand rinse and stored drinking water samples. Safe child defecation (in latrine/potty) and safe feces disposal (in latrine) was reported by 21% and 23% of households, respectively. Controlling for potential confounders, households reporting unsafe child defecation had higher E. coli prevalence on child hands (prevalence ratio [PR] = 1.12, 1.04-1.20) and in stored water (PR = 1.12,1.03-1.21). Similarly, households reporting unsafe feces disposal had higher E. coli prevalence on child hands (PR = 1.11, 1.02-1.21) and in stored water (PR = 1.10, 1.03-1.18). Effects on E. coli levels were similar. Children in households with unsafe defecation and feces disposal had higher diarrhea prevalence but the associations were not statistically significant. Our findings suggest that unsafe child feces management may present a source of fecal exposure for young children.


Assuntos
Defecação , Diarreia/epidemiologia , Fezes/microbiologia , Higiene das Mãos , População Rural/estatística & dados numéricos , Bangladesh/epidemiologia , Criança , Pré-Escolar , Diarreia/microbiologia , Água Potável/microbiologia , Feminino , Habitação , Humanos , Masculino , Gravidez , Saneamento , Estações do Ano , Poluição da Água
10.
Biomed Environ Sci ; 33(6): 385-395, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32641201

RESUMO

Objective: This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of Aeromonas isolates from clinical patients, tap water systems, and food. Methods: Ninety Aeromonas isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated gyrB-cpn60 sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing. Results: The 90 Aeromonas isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The Aeromonas isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes act, aerA, alt, and ast found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new mcr-3 variant. Conclusions: Sequence type, virulence properties, and antibiotic resistance vary in Aeromonas isolates from clinical patients, tap water systems, and food.


Assuntos
Aeromonas , Água Potável/microbiologia , Farmacorresistência Bacteriana , Microbiologia de Alimentos , Variação Genética , Infecções por Bactérias Gram-Negativas/microbiologia , Aeromonas/efeitos dos fármacos , Aeromonas/genética , Aeromonas/isolamento & purificação , Aeromonas/patogenicidade , Antibacterianos/farmacologia , China , Especificidade da Espécie , Virulência
11.
Chemosphere ; 259: 127483, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32634723

RESUMO

The emergence of antibiotic resistance genes (ARGs) and opportunistic pathogens (OPs) in drinking water system posed potential risks to human health. However, the occurrence of ARGs and OPs in drinking water biofilms is still at its infancy. In this study, we investigated the occurrence of ARGs and OPs in both water and biofilm samples from a drinking water system, and the correlation between ARGs and microbial communities was analyzed. The quantitative PCR results showed that the drinking water treatment process effectively decreased the absolute abundances of ARGs. However, the relative concentration of ARGs did not show a significant difference between raw water and treated water samples. Compared with bulk water and tap water samples, biofilms had higher relative abundances of ARGs. 16 S Illumina Miseq sequencing results showed that microbial communities of biofilms were distinguished with water samples. Meanwhile, qPCR results of OPs also showed that biofilms had higher relative abundances of OPs compared with water samples. Furthermore, the Spearman correlation analysis indicated that Dechloromonas, Desulfovibrio, Methylobacterium and Propionivibrio correlated well with the relative abundance of ARGs. The absolute concentrations of OPs and ARGs also showed a significant correlation. Results of this study suggest that biofilms could serve as the reservoirs for the spread of ARGs and the interaction between biofilms and bulk water requires further research.


Assuntos
Biofilmes , Água Potável/microbiologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Antibacterianos/análise , Água Potável/análise , Humanos , Microbiota , Prevalência , Purificação da Água
12.
J Water Health ; 18(3): 416-429, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32589626

RESUMO

The Sustainable Development Goal drinking water indicators include microbiological safety measures, whereas the Millennium Development Goal indicator 'improved water' may be microbiologically unsafe. In rural Vanuatu, we undertook household surveys, child anthropometry, and tested stored drinking water, to investigate relationships between water and undernutrition. Using Escherichia coli most probable number, we categorized results according to Compartment Bag Test drinking water cutoffs: <1/100 mL (safe), 1-10/100 mL (intermediate risk), >10-100/100 mL (high risk), and >100/100 mL (very high risk). Of 201 households, 191 (95%) had microbiologically unsafe drinking water, regardless of 'improved' status. We investigated cross-sectional associations between households with microbiologically safer drinking water (≤10 E. coli/100 mL) versus 'improved water' and undernutrition among children. Of children under 5, 145 (48.8%, 95% CI: 42.8, 54.8) were stunted and 59 (19.1%, 95% CI: 14.4, 23.8) were underweight. Among households with 'improved water', the adjusted prevalence ratio (95% CI) of stunting was 0.61 (0.46, 0.80) and underweight was 0.46 (0.29, 0.73) compared with 'unimproved water'. However, we found no association between having drinking water with ≤10 E. coli/100 mL at one point in time and undernutrition. Longer-term variations in water quality and unmeasured conditions beyond water may have contributed to these associations.


Assuntos
Água Potável/microbiologia , Desnutrição , Criança , Estudos Transversais , Características da Família , Humanos , Vanuatu , Abastecimento de Água
13.
J Water Health ; 18(3): 430-438, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32589627

RESUMO

This study aimed to assess the public health risk of coliforms and Escherichia coli contamination of potable water sources in Egypt. A total of 150 water samples (100 tap and 50 well) were collected from five districts in Gharbia governorate, Egypt. High rates of coliforms contamination were recorded in 52 and 76% of examined tap and well water samples, respectively. E. coli strains were detected in 16% of the water samples (15% tap water and 18% well water; 23.7% rural and 8.1% urban). Rural water sources were 3.5 times more likely to be contaminated than urban sources (P = 0.01). Eight (33.3%) E. coli isolates were Shiga toxin-producing E. coli (STEC). Multiple drug resistance (MDR) was observed for 62.5% of the isolates. Seven (29.2%) E. coli isolates harboured at least one of the extended-spectrum beta-lactamase (ESBL) genes. The majority (87.5%) of the STEC isolates were MDRs and harboured ESBL genes. STEC isolates were significantly more likely to resist six classes of antibiotics than non-STEC isolates. This is the first report of potable water contamination with MDR-STEC in Egypt. This study highlights an alarming public health threat that necessitates preventive interventions for public and environmental safety.


Assuntos
Água Potável/microbiologia , Proteínas de Escherichia coli , Egito , Infecções por Escherichia coli , Humanos , Testes de Sensibilidade Microbiana , Escherichia coli Shiga Toxigênica , Virulência , Fatores de Virulência
14.
PLoS One ; 15(6): e0218698, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542001

RESUMO

Low-income cities that are subject to high population pressure and vulnerable to climate events often have a low capacity to continuously deliver safe drinking water. Here we reported the results of a 32-year survey on the temporal dynamics of drinking water quality indicators in the city of Antananarivo. We analyzed the long-term evolution of the quality of the water supplied and characterized the interactions between climatic conditions and the full-scale water supply system. A total of 25,467 water samples were collected every week at different points in the supplied drinking water system. Samples were analyzed for total coliforms (TC), Escherichia coli (EC), intestinal Enterococci (IE), and Spores of Sulphite-Reducing Clostridia (SSRC). Nine-hundred-eighty-one samples that were identified as positive for one or more indicators were unevenly distributed over time. The breakpoint method identified four periods when the time series displayed changes in the level and profile of contamination (i) and the monthly pattern of contamination (ii), with more direct effects of rainfall on the quality of supplied drinking water. The modeling showed significantly different lags among indicators of bacteria occurrence after cumulative rainfall, which range from 4 to 8 weeks. Among the effects of low-income urbanization, a rapid demographic transition and the degradation of urban watersheds have gradually affected the quality of the water supplied and resulted in the more direct effects of rainfall events. We focused on the need to adopt an alternative perspective of drinking water and urban watersheds management.


Assuntos
Água Potável , Chuva , Qualidade da Água , Água Potável/química , Água Potável/microbiologia , Madagáscar , Fatores de Tempo , Poluição da Água
15.
Am J Trop Med Hyg ; 103(1): 455-464, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32372750

RESUMO

Approximately two billion people lack access to microbiologically safe drinking water globally. Boiling is the most popular household water treatment method and significantly reduces diarrheal disease, but is often practiced inconsistently or ineffectively. The use of low-cost technologies to improve boiling is one approach with potential for increasing access to safe drinking water. We conducted household trials to evaluate the feasibility and acceptability of water pasteurization indicators (WAPIs) in the Peruvian Amazon in 2015. A total of 28 randomly selected households were enrolled from a rural and a peri-urban community. All households trialed two WAPI designs, each for a 2-week period. Ninety-six percent of participants demonstrated the correct use of the WAPIs at the end of each trial, and 88% expressed satisfaction with both WAPI models. Ease of use, short treatment time, knowledge of the association between WAPI use and improved health, and the taste of treated water were among the key factors that influenced acceptability. Ease of use was the key factor that influenced design preference. Participants in both communities preferred a WAPI with a plastic box that floated on the water's surface compared with a WAPI with a wire that was dipped into the pot of drinking water while it was heating (77% versus 15%, P < 0.001); we selected the box design for a subsequent randomized trial of this intervention. The high feasibility and acceptability of the WAPIs in this study suggest that these interventions have potential to increase access to safe water in resource-limited settings.


Assuntos
Água Potável/microbiologia , Pasteurização/normas , Adolescente , Adulto , Idoso , Disenteria/prevenção & controle , Escherichia coli/isolamento & purificação , Estudos de Viabilidade , Feminino , Humanos , Pessoa de Meia-Idade , Pasteurização/instrumentação , Pasteurização/métodos , Peru , Microbiologia da Água , Abastecimento de Água , Adulto Jovem
16.
Biomed Environ Sci ; 33(4): 248-259, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32438962

RESUMO

Objective: Our objective was to investigate the occurrence of opportunistic pathogens and characterize the bacterial community structures in the water system of a pulmonary hospital. Methods: The water samples were collected from automatic and manual faucets in the consulting room, treatment room, dressing room, respiratory ward, and other non-medical rooms in three buildings of the hospital. Quantitative polymerase chain reaction was used to quantify the load of several waterborne opportunistic pathogens and related microorganisms, including Legionella spp., Mycobacterium spp., and M. avium. Illumina sequencing targeting 16S rRNA genes was performed to profile bacterial communities. Results: The occurrence rates of Legionella spp., Mycobacterium spp., and M. avium were 100%, 100%, and 76%, respectively in all samples. Higher occurrence rates of M. avium were observed in the outpatient service building (building 1, 91.7%) and respiration department and wards (building 2, 80%) than in the office building (building 3), where no M. avium was found. M. avium were more abundant in automatic faucets (average 2.21 × 10 4 gene copies/L) than in manual faucets (average 1.03 × 10 4 gene copies/mL) ( P < 0.01). Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Acidobacteria were the dominant bacterial phyla. Disinfectant residuals, nitrate, and temperature were found to be the key environmental factors driving microbial community structure shifts in water systems. Conclusion: This study revealed a high level of colonization of water faucets by opportunistic pathogens and provided insight into the characteristics of microbial communities in a hospital water system and approaches to reduce risks of microbial contamination.


Assuntos
Água Potável/microbiologia , Legionella/isolamento & purificação , Microbiota , Mycobacterium/isolamento & purificação , Qualidade da Água , China , Genes Bacterianos , Hospitais , Mycobacterium avium/isolamento & purificação , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Abastecimento de Água
17.
Int J Food Microbiol ; 326: 108641, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32371295

RESUMO

Thermotolerant Campylobacter is the leading bacterial cause of foodborne illness in humans worldwide. The objectives of this study were to estimate prevalence and to identify and characterize potential sources of thermotolerant Campylobacter contamination in broilers on farms and at the slaughterhouse; to evaluate the clonal relationship among thermotolerant Campylobacter isolates from different stages of the broiler meat supply chain, and to analyze the presence of virulence genes in different sources of thermotolerant Campylobacter. A total of 1210 samples were collected from three broiler meat supply chains in Santa Fe, Argentina. At the farms, the sampling collection included broilers one week prior to slaughter, wild-living birds, domestic dogs, wild rodents, farm workers' boots, litter, feed, drinking water, flies, and darkling beetles (Alphitobius diaperinus). At the slaughtering line, the samples taken were from the evisceration zone (broiler cecum, working surfaces, evisceration knives and workers' hands), from the chiller zone (surfaces and direct supply water) and from the packing zone (work surfaces, workers' hands and broiler carcasses). The samples taken along each supply chain were in the same batch. The isolates obtained were identified to the species level (C. jejuni and C. coli) by multiplex PCR and were analyzed using pulsed-field gel electrophoresis to compare different profiles according to the source. Finally, the presence of 11 virulence genes was examined (cadF, cdtA, cdtB, cdtC, ciaB, flaA, flhA, iam, wlaN, virB11, racR). From 254 isolates, 128 (50.4%) were Campylobacter jejuni and 126 (49.6%) Campylobacter coli. C. jejuni was the species most prevalent in farm and C. coli the species most prevalent at the slaughterhouse. We detected thermotolerant Campylobacter in samples of wild birds, darkling beetles, farm workers' boots, flies and litter. At the slaughterhouse, the prevalence varied along the process line. By analyzing PFGE results, C. jejuni showed 21 profiles with three predominant genotypes, while C. coli showed 14 profiles with four predominant genotypes. A high genotype diversity was found; however, relationships between isolates from different stages of the broiler meat chain, between broiler and potential sources of thermotolerant Campylobacter contamination and between strains in the farm and in the slaughterhouse were detected. Furthermore, there was evidence of cross-contamination at the slaughterhouse. FlaA, flhA genes were detected in all strains, and the third most prevalent virulence gene was cadF. Only those strains obtained from flies, wild-living birds and broiler carcass samples harbored 10 of 11 pathogenic genes. The prevalence of some pathogenic genes between C. jejuni and C. coli was different. This evidence should contribute the scientific basis to implement risk management measures in public health.


Assuntos
Campylobacter coli/genética , Campylobacter jejuni/genética , Doenças Transmitidas por Alimentos/microbiologia , Carne/microbiologia , Aves Domésticas/microbiologia , Matadouros/estatística & dados numéricos , Animais , Argentina , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Infecções por Campylobacter/microbiologia , Campylobacter coli/isolamento & purificação , Campylobacter coli/patogenicidade , Campylobacter jejuni/isolamento & purificação , Campylobacter jejuni/patogenicidade , Proteínas de Transporte/genética , Ceco/microbiologia , Galinhas/microbiologia , Besouros/microbiologia , Dípteros/microbiologia , Cães , Água Potável/microbiologia , Eletroforese em Gel de Campo Pulsado , Flagelina/genética , Genótipo , Humanos , Indústria de Embalagem de Carne/estatística & dados numéricos , Proteínas de Membrana/genética , Prevalência , Roedores/microbiologia , Termotolerância , Virulência/genética
18.
Am J Trop Med Hyg ; 103(1): 465-471, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32274986

RESUMO

Diarrheal illness remains a leading cause of morbidity and mortality in children < 5 years in developing countries, and contaminated water contributes to diarrhea risk. To address this problem, a novel hollow fiber ultrafilter (HFU) was developed for household water treatment. To test its impact on water quality and infant health, we conducted a cluster-randomized longitudinal evaluation in 10 intervention and 10 comparison villages in Kenya, attempting to enroll all households with infants (< 12 months old). We conducted a baseline survey, distributed HFUs to intervention households, made biweekly home visits for 1 year to assess water treatment practices and diarrhea in infants, and tested water samples from both groups every 2 months for Escherichia coli. We enrolled 92 infants from intervention households and 74 from comparison households. During the 1-year study period, 45.7% of intervention households and 97.3% of comparison households had at least one stored water sample test positive for E. coli. Compared with comparison households, the odds of E. coli contamination in stored water was lower for intervention households (odds ratio [OR]: 0.42, 95% CI: 0.24, 0.74), but there was no difference in the odds of reported diarrhea in infants, adjusting for covariates (OR: 1.19, 95% CI: 0.74, 1.90). Although nearly all water samples obtained from unprotected sources and filtered by the HFU were free of E. coli contamination, HFUs alone were not effective at reducing diarrhea in infants.


Assuntos
Água Potável/microbiologia , Disenteria/epidemiologia , Escherichia coli/isolamento & purificação , Microbiologia da Água , Purificação da Água/instrumentação , Adolescente , Adulto , Idoso , Feminino , Humanos , Lactente , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Aceitação pelo Paciente de Cuidados de Saúde , População Rural , Purificação da Água/métodos , Adulto Jovem
20.
Am J Public Health ; 110(6): 842-849, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32298181

RESUMO

Objectives. To investigate a shigellosis outbreak in Genesee County, Michigan (including the City of Flint), and Saginaw County, Michigan, in 2016 and address community concerns about the role of the Flint water system.Methods. We met frequently with community members to understand concerns and develop the investigation. We surveyed households affected by the outbreak, analyzed Shigella isolate data, examined the geospatial distribution of cases, and reviewed available water quality data.Results. We surveyed 83 households containing 158 cases; median age was 10 years. Index case-patients from 55 of 83 households (66%) reported contact with a person outside their household who wore diapers or who had diarrhea in the week before becoming ill; results were similar regardless of household drinking water source. Genomic diversity was not consistent with a point source. In Flint, no space-time clustering was identified, and average free chlorine residual values remained above recommended levels throughout the outbreak period.Conclusions. The outbreak was most likely caused by person-to-person contact and not by the Flint water system. Consistent community engagement was essential to the design and implementation of the investigation.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Água Potável/microbiologia , Disenteria Bacilar , Shigella sonnei , Abastecimento de Água , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Cidades , Disenteria Bacilar/epidemiologia , Disenteria Bacilar/microbiologia , Disenteria Bacilar/transmissão , Feminino , Humanos , Lactente , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Shigella sonnei/classificação , Shigella sonnei/genética , Shigella sonnei/isolamento & purificação , Qualidade da Água , Adulto Jovem
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