RESUMEN
Reclaimed water poses environmental and human health risks due to residual organic micropollutants and pathogens. Ozonation of reclaimed water to control pathogens and trace organics is an important step in advanced water treatment systems for potable reuse of reclaimed water. Ensuring efficient pathogen reduction while controlling disinfection byproducts remains a significant challenge to implementing ozonation in reclaimed water reuse applications. This study aimed to investigate ozonation conditions using a plug flow reactor (PFR) to achieve effective pathogen removal/inactivation while minimizing bromate and N-Nitrosodimethylamine (NDMA) formation. The pilot scale study was conducted using three doses of ozone (0.7, 1.0 and 1.4 ozone/total organic carbon (O3/TOC) ratio) to determine the disinfection performance using actual reclaimed water. The disinfection efficiency was assessed by measuring total coliforms, Escherichia coli (E. coli), Pepper Mild Mottle Virus (PMMoV), Tomato Brown Rugose Fruit Virus (ToBRFV) and Norovirus (HNoV). The ozone CT values ranged from 1.60 to 13.62 mg min L-1, resulting in significant reductions in pathogens and indicators. Specifically, ozone treatment led to concentration reductions of 2.46-2.89, 2.03-2.18, 0.46-1.63, 2.23-2.64 and > 4 log for total coliforms, E. coli, PMMoV, ToBRFV, and HNoV, respectively. After ozonation, concentrations of bromate and NDMA increased, reaching levels between 2.8 and 12.0 µg L-1, and 28-40.0 ng L-1, respectively, for average feed water bromide levels of 86.7 ± 1.8 µg L-1 and TOC levels of 7.2 ± 0.1 mg L-1. The increases in DBP formation were pronounced with higher ozone dosages, possibly requiring removal/control in subsequent treatment steps in some potable reuse applications.
Asunto(s)
Desinfección , Ozono , Purificación del Agua , Desinfección/métodos , Purificación del Agua/métodos , Proyectos Piloto , Escherichia coli/efectos de los fármacos , Desinfectantes/análisis , Agua Potable/microbiología , Agua Potable/química , Norovirus/efectos de los fármacos , Microbiología del Agua , Bromatos/análisisRESUMEN
Surveillance indicators of the quality of water for human consumption in the Amazon were analysed from 2016 to 2020 using 185,528 samples from 11 microregions. Of the samples analysed, 93.20% were from urban areas, 66.65% were from the public water supply system (WSS), 31.02% were from the Collective Alternative Solution-CAS, and 2.33% from the Individual Alternative Solution-IAS. There was an increase in the number of records by the WSS, with a downwards trend and fluctuations in records for the CAS and the IAS. The quality indicators of chemical and physical parameters for urban areas were higher than those for rural areas and traditional communities. Most of the samples presented pH values below the recommended level. In the quantification of microbiological parameters, a higher presence of total coliforms and E. coli was identified in samples from rural areas and in traditional communities. In conclusion, there were inadequacies in the chemical, physical and microbiological parameters as well as problems related to the supply, storage and surveillance of water distributed for human consumption. These findings indicate the need to build an agenda for public management to address water insecurity and its likely effects on food insecurity in the region.
Analisaram-se indicadores de vigilância da qualidade da água para consumo humano no Amazonas, de 2016 a 2020, utilizando 185.528 amostras provenientes de 11 microrregiões. Das amostras analisadas, 93,20% são da área urbana, 66,65% provinham do sistema público (SAA), 31,02% da Solução Alternativa Coletiva (SAC) e 2,33% da Solução de Alternativa Individual (SAI). Observou-se aumento do número de registros pelo SAA, com tendência de queda e oscilações de registros para a SAC e a SAI. Os indicadores de qualidade dos parâmetros químicos e físicos da área urbana foram superiores aos das áreas rurais e de comunidades tradicionais. A maior parte das amostras apresentou valores de pH abaixo do recomendado. Na quantificação dos parâmetros microbiológicos, identificou-se maior presença de coliformes totais e E.coli na área rural e em comunidades tradicionais. Em conclusão, verificaram-se inadequações nos parâmetros químicos, físicos e microbiológicos, assim como problemas relativos ao abastecimento, armazenamento e à vigilância da água distribuída para consumo humano. Tais achados indicam a necessidade de construir uma agenda, pela gestão pública, para o enfrentamento da insegurança hídrica e seus prováveis efeitos sobre a insegurança alimentar existente na região.
Asunto(s)
Microbiología del Agua , Calidad del Agua , Abastecimiento de Agua , Brasil , Humanos , Abastecimiento de Agua/normas , Calidad del Agua/normas , Agua Potable/microbiología , Agua Potable/normas , Población Rural , Abastecimiento de Alimentos/estadística & datos numéricos , Población Urbana , Escherichia coli/aislamiento & purificación , Concentración de Iones de HidrógenoRESUMEN
OBJECTIVE: The effects of sanitation and hygiene interventions on the gut microbiome and enteric pathogen burden are not well understood. We measured the association between free chlorine residue (FCR) levels in drinking water, microbiome composition, and stool enteric pathogens in infants and young children in Haiti. METHODS: FCR levels were measured in household drinking water and enteric pathogen burden was evaluated using multiplex RT-PCR of stool among 131 children from one month to five years of age living in Mirebalais, Haiti. Microbiome profiling was performed using metagenomic sequencing. RESULTS: Most individuals lived in households with undetectable FCR measured in the drinking water (112/131, 86%). Detection of enteric pathogen DNA in stool was common and did not correlate with household water FCR. The infant microbiome in households with detectable FCR demonstrated reduced richness (fewer total number of species, P = 0.04 Kruskall-Wallis test) and less diversity by Inverse Simpson measures (P = 0.05) than households with undetectable FCR. Infants in households with a detectable FCR were more likely to have abundant Bifidobacterium. Using in vitro susceptibility testing, we found that some Bifidobacterium species were resistant to chlorine. CONCLUSIONS: FCR in household drinking water did not correlate with enteric pathogen burden in our study.
Asunto(s)
Cloro , Agua Potable , Heces , Microbioma Gastrointestinal , Humanos , Haití/epidemiología , Cloro/farmacología , Agua Potable/microbiología , Lactante , Preescolar , Microbioma Gastrointestinal/efectos de los fármacos , Heces/microbiología , Masculino , Femenino , Purificación del AguaRESUMEN
Helicobacter pylori is a microorganism that infects 60% of the population and is considered the main cause of atrophic gastritis, gastric and duodenal ulcers, and gastric cancer. Different emerging pathogens have been found in drinking water and their presence is considered to be an important public health problem. For this reason, it is necessary to carry out the validation of reliable technologies for this type of pathogens and evaluate their performance. This paper reports, for the first time, H. pylori reduction in a drinking water pilot plant of two slow sand filters (SSF). Inlet water was taken from a gravel filtration system of a rural water supply in Colombia and then inoculated with viable cells of H. pylori. By determining the Genomic Units (GU) through quantitative Polymerase Chain Reaction (qPCR), the concentration of GU/sample was measured. In the inlet water amplification for SSF1 and SSF2 were 5.13 × 102 ± 4.48 × 102 and 6.59 × 102 ± 7.32 × 102, respectively, while for the treated water they were 7.0 ± 5.6 and 2.05 × 101 ± 2.9 × 101 GU/sample for SSF1 and SSF2, respectively. The SSF pilot plant reached up to 3 log reduction units of H. pylori; therefore, since there is not an H. pylori contamination indicator and its periodic monitoring is financially complicated, the SSF could guarantee the drinking water quality necessity that exists in rural areas and small municipalities in developing countries, where infection rates and prevalence of this pathogen are high.
Asunto(s)
Agua Potable , Filtración , Helicobacter pylori , Microbiología del Agua , Purificación del Agua , Abastecimiento de Agua , Filtración/métodos , Agua Potable/microbiología , Purificación del Agua/métodos , Arena , ColombiaRESUMEN
Groundwater is the primary source of water for people living in rural areas, especially during seasons when surface water is contaminated or unavailable. In Colombia, people use groundwater as drinking water without additional treatment. In addition, there is no infrastructure for wastewater collection and sewage treatment in the region of the Middle Magdalena Valley. The current study aims to evaluate the quality of groundwater in this region to determine any potential health hazards associated with its consumption. To reach the objective, three (3) physicochemical and microbiological sampling campaigns were carried out during different hydrological periods. A total of 428 groundwater samples were analyzed for over 28 parameters. The results were compared with the water quality standards proposed by the US EPA and Colombian regulations for human consumption. The analysis revealed the presence of total and fecal coliforms in 89% and 58% of the analyzed samples, respectively, identifying them as the main contaminants in groundwater. Furthermore, the pH levels did not meet the standards set by the US EPA in 33.8% of the cases and by Colombian regulations in 31.02%. Additionally, 32.8%, 17.6%, 14.3%, and 10.9% of the samples failed to meet the established thresholds for apparent color, magnesium, iron, and nitrates, respectively, under both standards. Moreover, only the analyses of selenium, mercury, and zinc complied with the quality standards under both regulatory frameworks. Based on the Colombian Drinking-Water Quality Risk Index (CDWQRI-IRCA), the risk associated with water quality meant for human consumption was assessed. The results showed that over 84% of the samples analyzed posed a high risk to human health, 4.6% posed a medium risk, 5.5% posed a low risk, and only 5.7% posed no risk at all. Additionally, official mortality statistics for children under four years old were reviewed, which revealed two deaths in 2019 due to Acute Diarrheal Disease (ADD) caused by consumption of contaminated water. Therefore, it is crucial to implement water treatment systems, establish aqueducts in rural areas, and conduct rigorous and systematic monitoring of drinking water to ensure it is safe for human consumption. It is also important to track morbidity and mortality rates associated with water consumption.
Asunto(s)
Agua Potable , Agua Subterránea , Calidad del Agua , Colombia , Agua Subterránea/análisis , Humanos , Agua Potable/análisis , Agua Potable/microbiología , Medición de Riesgo , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Microbiología del AguaRESUMEN
This study assessed the bacterial community composition of a drinking water system (DWS) serving a mid-sized city (120,000 inhabitants) in Brazil. Water samples, including raw and treated water, were collected at seven points throughout the DWS. DNA was extracted and analysed using high-throughput sequencing (Ion Torrent). Free chlorine and turbidity were measured in situ. Results showed that the highest relative abundance of 16S rRNA genes was from phyla Proteobacteria, followed by Bacteroidetes and Actinobacteria. The next most abundant phylum was Cyanobacteria, represented by Arthronema, Calothrix, and Synechococcus. An interesting observation was that the DNA-based analysis suggested a bacterial community change in the distribution network, with treated reservoir water being very different from the network samples. This suggests active microbiology within the distribution network and a tendency for bacterial diversity to decrease after chlorine disinfection but increase after pipeline distribution. In raw water, a predominance of Proteobacteria was observed with reduced Cyanobacteria, showing a negative correlation. In treated water, Proteobacteria were negatively correlated with Bacteroidetes. Finally, 16S rRNA genes from Firmicutes (especially Staphylococcus) had a high abundance in the chlorinated water, which may indicate the phylum's resistance to chlorine residuals. Opportunistic pathogens, e.g., Mycobacteria, Legionella, and Staphylococcus, were also observed.
Asunto(s)
Cianobacterias , Agua Potable , Agua Potable/microbiología , Cloro/farmacología , ARN Ribosómico 16S/genética , Brasil , Proteobacteria/genética , Cianobacterias/genética , Bacteroidetes/genética , Abastecimiento de AguaRESUMEN
Antibiotic resistance genes (ARGs) are widespread in the environment due to the overuse of antibiotics and other pollutants, posing a threat to human and animal health. In this study, we evaluated antimicrobial residues, bacterial diversity and ARGs in two important watersheds, Guandu and São João, that supply drinking water to Rio de Janeiro city, Brazil. In addition, tap water samples were collected from three different cities in Rio de Janeiro State, including the metropolitan area of Rio de Janeiro city. Clarithromycin, sulfamethoxazole and azithromycin were found in untreated water and drinking water in all samples. A greater abundance of Proteobacteria was observed in Guandu and São João watersheds, with most of the sequences belonging to the Gammaproteobacteria class. A plasmidome-focused metagenomics approach revealed 4881 (Guandu), 3705 (São João) and 3385 (drinking water) ARGs mainly associated with efflux systems. The genes encoding metallo-ß-lactamase enzymes (blaAIM, blaGIM, blaIMP, and blaVIM) were detected in the two watersheds and in drinking water samples. Moreover, we demonstrated the presence of the colistin resistance genes mcr-3 and mcr-4 (both watersheds) and mcr-9 (drinking water and Guandu) for the first time in Brazil. Our data emphasize the importance of introducing measures to reduce the disposal of antibiotics and other pollutants capable of promoting the occurrence and spread of the microbial resistome on aquatic environments and predicting possible negative impacts on human health.
Asunto(s)
Agua Potable , Contaminantes Ambientales , Microbiota , Animales , Humanos , Agua Potable/microbiología , Brasil , Antibacterianos/farmacología , Genes BacterianosRESUMEN
Chemical and microbiological drinking water contaminants pose risks to child health but are not often evaluated concurrently. At two consecutive visits to 96 households in Piura, Peru, we collected drinking water samples, administered health and exposure questionnaires, and collected infant stool samples. Standard methods were used to quantify heavy metals/metalloids, pesticides, and Escherichia coli concentrations in water samples. Stool samples were assayed for bacterial, viral, and parasitic enteropathogens. The primary drinking water source was indoor piped water for 70 of 96 households (73%); 36 households (38%) stored drinking water from the primary source in containers in the home. We found high prevalence of chemical and microbiological contaminants in household drinking water samples: arsenic was detected in 50% of 96 samples, ≥ 1 pesticide was detected in 65% of 92 samples, and E. coli was detected in 37% of 319 samples. Drinking water samples that had been stored in containers had higher odds of E. coli detection (adjusted odds ratio [aOR]: 4.50; 95% CI: 2.04-9.95) and pesticide detection (OR: 6.55; 95% CI: 2.05-21.0) compared with samples collected directly from a tap. Most infants (68%) had ≥ 1 enteropathogen detected in their stool. Higher odds of enteropathogen infection at the second visit were observed among infants from households where pesticides were detected in drinking water at the first visit (aOR: 2.93; 95% CI: 1.13-7.61). Results show concurrent risks of exposure to microbiological and chemical contaminants in drinking water in a low-income setting, despite high access to piped drinking water.
Asunto(s)
Arsénico , Agua Potable , Metales Pesados , Plaguicidas , Cohorte de Nacimiento , Niño , Agua Potable/microbiología , Escherichia coli , Humanos , Lactante , Perú/epidemiología , Prevalencia , Abastecimiento de AguaRESUMEN
BACKGROUND: Unsafe drinking water, poor sanitation and hygiene, exposure to household air pollution and low cognitive and socio-emotional stimulation are risk factors affecting children in low- and middle-income countries. We implemented an integrated home-environmental intervention package (IHIP), comprising a kitchen sink, hygiene education and a certified improved biomass cookstove, and an early child development (ECD) programme to improve children´s health and developmental outcomes in the rural high-altitude Andes of Peru. METHODS: We conducted a one-year cluster-randomised controlled trial among 317 children < 36 months divided into 4 arms (IHIP + ECD, IHIP, ECD, and Control) and 40 clusters (10 clusters per arm). ECD status (socio-emotional, fine and gross motor, communication, cognitive skills, and an overall performance) measured with the Peruvian Infant Development Scale and the occurrence of self-reported child diarrhoea from caretakers were primary outcomes. Secondary outcomes included the occurrence of acute respiratory infections and the presence of thermo-tolerant faecal bacteria in drinking water. The trial was powered to compare each intervention against its control arm but it did not allow pairwise comparisons among the four arms. Primary analysis followed the intention-to-treat principle. For the statistical analysis, we employed generalised estimating equation models with robust standard errors and an independent correlation structure. RESULTS: We obtained ECD information from 101 children who received the ECD intervention (individually and combined with IHIP) and 102 controls. Children who received the ECD intervention performed better in all the domains compared to controls. We found differences in the overall performance (64 vs. 39%, odd ratio (OR): 2.8; 95% confidence interval (CI): 1.6-4.9) and the cognitive domain (62 vs 46%, OR: 1.9; 95% CI: 1.1-3.5). Data analysis of child morbidity included 154 children who received the IHIP intervention (individually and combined with ECD) and 156 controls. We recorded 110,666 child-days of information on diarrhoea morbidity and observed 1.3 mean episodes per child-year in the children who received the IHIP intervention and 1.1 episodes in the controls. This corresponded to an incidence risk ratio of 1.2 (95% CI: 0.8-1.7). CONCLUSIONS: Child stimulation improved developmental status in children, but there was no health benefit associated with the home-environmental intervention. Limited year-round access to running water at home and the possible contamination of drinking water after boiling were two potential factors linked to the lack of effect of the home-environmental intervention. Potential interactions between ECD and home-environmental interventions need to be further investigated. TRIAL REGISTRATION: ISRCTN, ISRCTN-26548981. Registered 15 January 2018-Retrospectively registered, https://doi.org/10.1186/ISRCTN26548981 .
Asunto(s)
Salud Infantil , Agua Potable , Altitud , Niño , Desarrollo Infantil/fisiología , Diarrea/epidemiología , Diarrea/prevención & control , Agua Potable/microbiología , Humanos , Lactante , Perú/epidemiología , Población RuralRESUMEN
Fecal contamination in natural water sources is a common problem in low-income countries. Several health risks are associated with unprotected water sources, such as gastrointestinal infections caused by parasites, viruses, and bacteria. Moreover, antibiotic-resistant bacteria in water sources have become an increasing problem worldwide. This study aimed to evaluate the bacterial pathogens present in water within a rural context in Ecuador, along with the efficiency of black ceramic water filters (BCWFs) as a sustainable household water treatment. We monitored five natural water sources that were used for human consumption in the highlands of Ecuador and analyzed the total coliforms and E. coli before and after BCWF installation. The results indicated a variable bacterial contamination (29-300 colony-forming units/100mL) in all unfiltered samples, and they were considered as high risk for human consumption, but after filtration, no bacteria were present. Moreover, extended-spectrum beta-lactamase-producing E. coli with blaTEM, blaCTX-M9, and blaCTX-M1 genes, and two E. coli classified in the clonal complex ST10 (ST98) were detected in two of the locations sampled; these strains can severely impact public health. The clonal complex ST10, found in the E. coli isolates, possesses the potential to spread bacteria-resistant genes to humans and animals. The results of the use of BCWFs, however, argue for the filters' potential impact within those contexts, as the BCWFs completely removed even antibiotic-resistant contaminants from the water.
Asunto(s)
Agua Potable , Infecciones por Escherichia coli , Escherichia coli , Filtración , Animales , Cerámica , Agua Potable/microbiología , Farmacorresistencia Bacteriana , Ecuador , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Filtración/métodos , Humanos , beta-Lactamasas/genéticaRESUMEN
The cyanotoxin cylindrospermopsin (CYN) has become a significant environmental and human health concern due to its high toxicological potential and widespread distribution. High concentrations of cyanotoxins may be produced during cyanobacterial blooms. Special attention is required when these blooms occur in sources of water intended for human consumption since extracellular cyanotoxins are not effectively removed by conventional water treatments, leading to the need for advanced water treatment technologies such as the Fenton process to produce safe water. Thus, the present study aimed to investigate the application of the Fenton process for the degradation of CYN at bench-scale. The oxidation of CYN was evaluated by Fenton reaction at H2O2/Fe(II) molar ratio in a range of 0.4 to 4.0, with the highest degradation of about 81% at molar ratio of 0.4. Doubling the concentrations of reactants for the optimized H2O2/Fe(II) molar ratio, the CYN degradation efficiency reached 91%. Under the conditions studied, CYN degradation by the Fenton process followed a pseudo-first-order kinetic model with an apparent constant rate ranging from 0.813 × 10-3 to 1.879 × 10-3 s-1.
Asunto(s)
Toxinas de Cianobacterias/química , Toxinas de Cianobacterias/metabolismo , Agua Potable/química , Agua Potable/microbiología , Peróxido de Hidrógeno/metabolismo , Hierro/metabolismo , Oxidación-Reducción/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Cinética , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodosRESUMEN
This research presents the results of a pilot system used for water treatment to be supplied to single-family or small housing nucleus at rural sector. The pilot system is constituted by an up-flow aerated filter with ceramic carrier, followed by a second down-flow filter of silica sand. The pilot plant was installed in a rural sector of the province of Loja, Ecuador, with the main purpose of monitoring the reduction in bacteria in the water for human consumption. Two natural clays from the area were tested. They were transformed into sphere-type ceramics, and then, they were placed in the pilot filters. These both natural clays are inorganic materials with high content of aluminosilicate clay minerals with favourable characteristics to achieve greater efficiency for the reduction in bacteria. The acclimatization time of 60 days allowed to achieve optimum treatment efficiency performance until 90 days of operation. The physicochemical parameters, namely temperature, pH, dissolved oxygen and total dissolved solids, were monitored throughout the experiments. Regarding microbiological parameters, up to 99% of total coliforms removal was reached for the clay called CF-CC and 79% for the other, called CF-CV. In addition, 100% of total coliforms and Escherichia Coli removal was reached for both clay systems. Social and economic viability of the proposed treatment is also analysed in the manuscript.
Asunto(s)
Arcilla/química , Países en Desarrollo , Agua Potable/microbiología , Enterobacteriaceae/aislamiento & purificación , Filtración/instrumentación , Arena/química , Purificación del Agua/métodos , Ecuador , Escherichia coli/aislamiento & purificación , Dióxido de Silicio/químicaRESUMEN
In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.
Asunto(s)
Femenino , Animales , Pollos/crecimiento & desarrollo , Pollos/sangre , Agua Potable/microbiologíaRESUMEN
In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.(AU)
Asunto(s)
Animales , Femenino , Pollos/sangre , Pollos/crecimiento & desarrollo , Agua Potable/microbiologíaRESUMEN
INTRODUCTION: This study aimed to identify the Helicobacter pylori cagA+ genotype prevalent in a region of north-eastern Brazil and find possible associations between this genotype and socioeconomic variables. METHODS: This cross-sectional study included 751 patients with dyspepsia from a public endoscopy clinic. Genotyping was carried out on 98 samples from gastric tissue with positive urease test for H. pylori using polymerase chain reaction (PCR). Socioeconomic variables were collected via forms. Pearson's χ2 test was used to analyze associations between variables and odds ratios were obtained to compare effects. Statistical significance was defined as p < 0.05 for univariate and multivariate analyses. RESULTS: H. pylori infection was present in 52.7% of the patients and associated with low income and consumption of untreated drinking water. The prevalence of the cagA+ genotype was 25.5%. Low income was inversely related to the presence of cagA+ genotype, even after adjustment. Untreated drinking water consumption was associated with the presence of the cagA+ genotype in both the univariate (p = 0.03; OR = 2.55; 95% CI: 1.008-6.48) and multivariate (p = 0.03; OR = 2.89; 95% CI: 1.08-7.67) analyses. CONCLUSION: The findings of this study suggest that water can be an important vehicle for the transmission of pathogenic H. pylori strains and may be a public health challenge, especially in less developed regions with precarious water and sanitary conditions.
Asunto(s)
Agua Potable/microbiología , Dispepsia/microbiología , Dispepsia/fisiopatología , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/fisiopatología , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Brasil/epidemiología , Estudios Transversales , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores Socioeconómicos , Adulto JovenRESUMEN
Halving the proportion of the people without sustainable access to safe drinking water and basic sanitation is among the Sustainable Development Goals (SDG). Lack of access to safe drinking water has been associated with the prevalence of waterborne diseases. Due to this reported association, the development of household water treatment devices has been an alternative to improve the quality supply of domestic water. In this study, we aimed to evaluate the performance of a ceramic silver-impregnated pot filter (CSF) system coupled with an adsorption process, composed of silver-impregnated granular activated carbon and zeolite (CSF + GAC-Z), to remove waterborne bacteria Escherichia coli and Salmonella spp. from spiked water. The performance of this system was compared with the conventional CSF system. In this respect, we evaluated six CSF and six CSF + GAC-Z using spiked water with 103 and 102 CFU/mL of E. coli and Salmonella spp. The mean percentage of removals ranged between 98% and 99.98%. The highest bacterial removal efficiency was recorded by the CSF + GAC-Z (99%) and CSF (99.98%) for E. coli and Salmonella spp., respectively, but no significant statistical differences were found between filtration systems. Our findings suggest that the CSF + GAC-Z system was effective in the removal of waterborne bacteria from spiked water.
Asunto(s)
Cerámica/química , Agua Potable/microbiología , Filtración/instrumentación , Plata/química , Purificación del Agua/instrumentación , Adsorción , Carbón Orgánico/química , Escherichia coli , Salmonella , Contaminación del Agua , Zeolitas/químicaRESUMEN
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.
Asunto(s)
Agua Potable/microbiología , Pasteurización/normas , Adolescente , Adulto , Anciano , Disentería/prevención & control , Escherichia coli/aislamiento & purificación , Estudios de Factibilidad , Femenino , Humanos , Persona de Mediana Edad , Pasteurización/instrumentación , Pasteurización/métodos , Perú , Microbiología del Agua , Abastecimiento de Agua , Adulto JovenRESUMEN
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.
Asunto(s)
Campylobacter coli/genética , Campylobacter jejuni/genética , Enfermedades Transmitidas por los Alimentos/microbiología , Carne/microbiología , Aves de Corral/microbiología , Mataderos/estadística & datos numéricos , Animales , Argentina , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Bacterianas/genética , Infecciones por Campylobacter/microbiología , Campylobacter coli/aislamiento & purificación , Campylobacter coli/patogenicidad , Campylobacter jejuni/aislamiento & purificación , Campylobacter jejuni/patogenicidad , Proteínas Portadoras/genética , Ciego/microbiología , Pollos/microbiología , Escarabajos/microbiología , Dípteros/microbiología , Perros , Agua Potable/microbiología , Electroforesis en Gel de Campo Pulsado , Flagelina/genética , Genotipo , Humanos , Industria para Empaquetado de Carne/estadística & datos numéricos , Proteínas de la Membrana/genética , Prevalencia , Roedores/microbiología , Termotolerancia , Virulencia/genéticaRESUMEN
Drinking water contamination is a frequent problem in developing countries and could be associated with bacterial pathogen carriage in feces. We evaluated the association between the risk of drinking water and bacterial carrier status in children younger than 5 years in a cross-sectional study conducted in 199 households from three Peruvian rural communities. Fecal samples from children were screened for pathogenic Aeromonas, Campylobacter, and Vibrio species, as well as for Enterobacteriaceae, including pathogenic Escherichia coli. The drinking water risk was determined using E. coli as an indicator of contamination. Nineteen (9.5%) children were colonized with pathogens and classified as carriers, all without diarrhea symptoms. Of 199 drinking water samples, 38 (19.1%) were classified as very high risk because of high fecal contamination (> 100 E. coli/100 mL). Shared-use water sources, daily washing of containers, and washing using only water were associated with higher prevalence of bacterial carriage, whereas there was no association between households reporting boiling and chlorination of water and carrier status. The prevalence of carriage in children exposed to very high-risk water was 2.82 (95% CI: 1.21-6.59) times the prevalence of those who consumed less contaminated water, adjusted by the water source and daily washing. Our results suggest that household drinking water plays an important role in the generation of carriers with diarrheal pathogens. Our findings also highlight the importance of interventions to ensure the safety of drinking water. Further studies are needed to validate the observed association and determine its significance with respect to diarrhea in the community.
Asunto(s)
Diarrea/microbiología , Agua Potable/microbiología , Heces/microbiología , Población Rural , Microbiología del Agua , Bacterias/clasificación , Bacterias/aislamiento & purificación , Preescolar , Diarrea/epidemiología , Femenino , Humanos , Lactante , Masculino , Perú/epidemiología , Saneamiento/métodos , Contaminantes del Agua , Abastecimiento de AguaRESUMEN
BACKGROUND: Water scarcity combined with high incidences of diarrhoeal disease amongst many rural communities, suggests that the provision of 'safe' water supplies remains a challenge. Subsequent reliance on multi-source water supplies means that microbial transmission pathways may be numerous and complex. OBJECTIVES: This study aimed to identify and elucidate water supply issues and potential microbial transmission pathways at the household level in rural communities in semi-arid Brazil. METHODS: Community and sanitary surveys were applied to 99 households from 10 communities located in four municipalities of Paraiba State, Brazil. Moreover, physicochemical and microbial parameters were investigated throughout the water supply chain. RESULTS: High levels of faecal indicator organisms (FIO) were detected in water from Water Storage Reservoirs (WSR) and from in-house Drinking Water Storage Containers (DWSC). A decrease in microbial water quality was observed between water stored within WSR's and DWSC's, suggesting potential cross-contamination at the household level. Several common practices were observed among rural residents, such as the use of collection buckets left unprotected outside on the ground, that may have also contributed to the observed decrease. Schematic diagrams illustrating the complex water supply chains and potential microbial transmission pathways were developed to facilitate identification of effective intervention strategies. DISCUSSION: Decreases in water supply quality were found to be predominantly caused by cross-contamination within the domestic environment due to several factors, including, a lack of awareness and knowledge of 'safe' collection, handling and storage of water, as well as inadequate sanitation services and/or unhygienic practices. In order to improve public health in such communities, more effort should be directed towards education and training of all stakeholders involved in the water supply chain. This would, certainly, support the successful implementation of further WASH interventions, consequently increasing the likelihood of achieving reduction of excreta-borne diseases.