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1.
Water Res ; 178: 115838, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32361344

RESUMO

Biofilm formation and removal from dead-ends is a particularly difficult and understudied area of water distribution system biology. In this work, we have built a model drinking water distribution system to probe the effect of different hydrodynamic flow regimes on biofilm formation and removal in the main pipe and in the dead-end. The test rig was built to include all major drinking water distribution system components with materials and dimensions used in standard plumbing systems. We have simulated the effect of stagnant, laminar, turbulent, and intense turbulent flushing conditions on the growth and removal of biofilms from the main pipe and the dead-end. The growth of the biofilm in the main pipe was not prevented at a volumetric flow rate of 9.4 L min-1 and flow velocity of 2 m s-1. Mature biofilms were more difficult to remove. Biofilms grown under shear stress conditions could withstand significantly higher shear stresses than those to which they were exposed to during growth. The biofilms grew twice as fast in the dead-end when flow in the main pipe was turbulent compared to stagnant conditions. Biofilms in the dead-end were not affected by the flushing conditions in the main pipe (Q = 52 L min-1, Re = 9.0 · 104). The computational fluid dynamics simulation suggests that biofilms cannot be hydrodynamically removed from the dead-end at depths that are larger than one pipe diameter. Biofilms beyond this limit present a possible source for reinoculation and recolonization of the rest of the water distribution system.


Assuntos
Água Potável , Biofilmes , Hidrodinâmica , Modelos Biológicos , Engenharia Sanitária , Microbiologia da Água , Abastecimento de Água
2.
Med Hypotheses ; 141: 109781, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32361528

RESUMO

The world is facing a pandemic of unseen proportions caused by a corona virus named SARS-CoV-2 with unprecedent worldwide measures being taken to tackle its contagion. Person-to-person transmission is accepted but WHO only considers aerosol transmission when procedures or support treatments that produce aerosol are performed. Transmission mechanisms are not fully understood and there is evidence for an airborne route to be considered, as the virus remains viable in aerosols for at least 3 h and that mask usage was the best intervention to prevent infection. Heating, Ventilation and Air Conditioning Systems (HVAC) are used as a primary infection disease control measure. However, if not correctly used, they may contribute to the transmission/spreading of airborne diseases as proposed in the past for SARS. The authors believe that airborne transmission is possible and that HVAC systems when not adequately used may contribute to the transmission of the virus, as suggested by descriptions from Japan, Germany, and the Diamond Princess Cruise Ship. Previous SARS outbreaks reported at Amoy Gardens, Emergency Rooms and Hotels, also suggested an airborne transmission. Further studies are warranted to confirm our hypotheses but the assumption of such way of transmission would cause a major shift in measures recommended to prevent infection such as the disseminated use of masks and structural changes to hospital and other facilities with HVAC systems.


Assuntos
Microbiologia do Ar , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/transmissão , Ambiente Controlado , Pandemias , Pneumonia Viral/transmissão , Ventilação , Aerossóis , Ar Condicionado/efeitos adversos , Ar Condicionado/instrumentação , Ar Condicionado/métodos , Poluição do Ar em Ambientes Fechados , Infecções por Coronavirus/prevenção & controle , Infecção Hospitalar/transmissão , Contaminação de Equipamentos , Desenho de Equipamento , Falha de Equipamento , Fômites/virologia , Calefação/efeitos adversos , Calefação/instrumentação , Calefação/métodos , Humanos , Doença dos Legionários/epidemiologia , Doença dos Legionários/transmissão , Modelos Biológicos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Engenharia Sanitária/instrumentação , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/transmissão , Esgotos/virologia , Ventilação/instrumentação , Ventilação/métodos
4.
PLoS One ; 15(3): e0229681, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160218

RESUMO

PURPOSE: To determine whether Acanthamoeba keratitis (AK) patients have higher rates of Acanthamoeba and free-living amoeba (FLA) colonising domestic sinks than control contact lens (CL) wearers, and whether these isolates are genetically similar to the corneal isolates from their CL associated AK. METHODS: 129 AK patients from Moorefield Eye Hospital, London and 64 control CL wearers from the Institute of Optometry were included in this study. The participants self-collected home kitchen and bathroom samples from tap-spouts, overflows and drains using an instructional kit. The samples were cultured by inoculating onto a non-nutrient agar plate seeded with Escherichia coli, incubated at 32°C and examined for amoebae by microscopy for up to 2 weeks. Partial sequences of mitochondrial cytochrome oxidase genes (coxA) of Acanthamoeba isolates from four AK patients were compared to Acanthamoeba isolated from the patient's home. The association between sampling sites was analysed with the chi-square test. RESULTS: A total of 513 samples from AK patients and 189 from CL controls were collected. The yield of FLA was significantly greater in patients' bathrooms (72.1%) than CL controls' bathrooms (53.4%) (p<0.05). Spouts (kitchen 6.7%, bathroom 11%) had the lowest rate of Acanthamoeba isolation compared to drains (kitchen 18.2%, bathroom 27.9%) and overflow (kitchen 39.1%, bathroom 25.9%) either in kitchens or bathrooms (p<0.05). There was no statistically significant difference between the average prevalence of Acanthamoeba in all three sample sites in kitchens (16.9%) compared to all three sample sites in bathrooms (21.5%) and no association for Acanthamoeba prevalence between AK patients and CL controls. All four corneal isolates had the same coxA sequence as at least one domestic water isolate from the patients' sink of the kitchen and the bathroom. CONCLUSION: The prevalence of Acanthamoeba and FLA was high in UK homes. FLA colonisation was higher in AK patients compared to controls but the prevalence of Acanthamoeba between AK patients and CL controls domestic sinks was similar. This study confirms that domestic water isolates are probably the source of AK infection. Advice about avoiding water contact when using CL's should be mandatory.


Assuntos
Ceratite por Acanthamoeba/epidemiologia , Ceratite por Acanthamoeba/parasitologia , Acanthamoeba/isolamento & purificação , Acanthamoeba/genética , Acanthamoeba/patogenicidade , Amebozoários/isolamento & purificação , Estudos de Casos e Controles , Lentes de Contato/efeitos adversos , Lentes de Contato/parasitologia , Suscetibilidade a Doenças , Meio Ambiente , Habitação , Humanos , Londres/epidemiologia , Fatores de Risco , Engenharia Sanitária , Água/parasitologia
5.
Nat Commun ; 11(1): 466, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980604

RESUMO

Carbapenem-resistant Enterobacteriaceae (CRE) represent an urgent threat to human health. Here we report the application of several complementary whole-genome sequencing (WGS) technologies to characterise a hospital outbreak of blaIMP-4 carbapenemase-producing E. hormaechei. Using Illumina sequencing, we determined that all outbreak strains were sequence type 90 (ST90) and near-identical. Comparison to publicly available data linked all outbreak isolates to a 2013 isolate from the same ward, suggesting an environmental source in the hospital. Using Pacific Biosciences sequencing, we resolved the complete context of the blaIMP-4 gene on a large IncHI2 plasmid carried by all IMP-4-producing strains across different hospitals. Shotgun metagenomic sequencing of environmental samples also found evidence of ST90 E. hormaechei and the IncHI2 plasmid within the hospital plumbing. Finally, Oxford Nanopore sequencing rapidly resolved the true relationship of subsequent isolates to the initial outbreak. Overall, our strategic application of three WGS technologies provided an in-depth analysis of the outbreak.


Assuntos
Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Surtos de Doenças , Enterobacter/enzimologia , Enterobacter/genética , Infecções por Enterobacteriaceae/epidemiologia , beta-Lactamases/biossíntese , beta-Lactamases/genética , Queimaduras/microbiologia , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Enterobacter/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Genoma Bacteriano , Humanos , Queensland/epidemiologia , Fatores R/genética , Engenharia Sanitária , Centros de Atenção Terciária , Sequenciamento Completo do Genoma/métodos , Resistência beta-Lactâmica/genética
6.
Lett Appl Microbiol ; 70(4): 232-240, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31904109

RESUMO

Unregulated private wells are understudied potential sources of community-acquired Legionnaires' disease. Here we conducted a comprehensive survey of 44 homes supplied by private wells in Wake County, North Carolina, quantifying Legionella spp. DNA, Legionella pneumophila DNA, and total bacterial 16S rRNA genes via real-time polymerase chain reaction in hot and cold drinking water samples, along with culturable L. pneumophila via IDEXX Legiolert in cold drinking water samples. Legionella spp. DNA, L. pneumophila DNA and culturable L. pneumophila were detected in 100, 65·5 and 15·9% of the 44 homes, respectively, and culturable levels were comparable to some municipal surveys applying the same methods. Total coliforms and Escherichia coli were monitored as representative faecal indicators and were found in 20·4 and 0·0% of homes. Within certain sample types, Legionella spp. and L. pneumophila gene copy numbers were positively associated with total bacteria (i.e. total 16S rRNA genes) and water softener use, but were not associated with faecal indicator bacteria, inorganic water parameters or other well characteristics. These findings confirm that occurrence of Legionella and L. pneumophila is highly variable in private wells. SIGNIFICANCE AND IMPACT OF THE STUDY: Legionella is the leading identified cause of waterborne disease outbreaks associated with US municipal water systems. While Legionella is known to occur naturally in groundwater, prior efforts to characterize its occurrence in unregulated private wells are limited to sampling at the wellhead and not in the home plumbing where Legionella can thrive. This work documents much higher levels of Legionella in home plumbing versus water directly from private wells and examines factors associated with higher Legionella occurrence.


Assuntos
Água Potável/microbiologia , Legionella pneumophila/isolamento & purificação , DNA Bacteriano/genética , Humanos , Legionella pneumophila/classificação , Legionella pneumophila/genética , Doença dos Legionários/microbiologia , North Carolina , RNA Ribossômico 16S/genética , Engenharia Sanitária , Microbiologia da Água , Abastecimento de Água
7.
Water Res ; 168: 115163, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614239

RESUMO

Respiratory infections from opportunistic bacterial pathogens (OBPs) have heightened research interests in drinking water distribution systems, premise plumbing, and point-of-use technologies. In particular, biofilm growth in showerheads increases OBP content, and inhalation of shower aerosols is a major exposure route for Legionellae and Mycobacteria infections. Incorporation of UVC LEDs into showerheads has thus been proposed as a point-of-use option for healthcare facilities. Herein we have examined incongruities between the nature of OBP contamination in shower water and the hypothetical application of conventional UV disinfection engineering concepts. Effective UV dosing within showerheads must overcome significant shielding effects imparted by the biological matrices in which common OBPs reside, including biofilm particles and protozoan hosts. Furthermore, prevention of biofilm growth in showerhead interiors requires a different UV irradiation approach and is lacking in established design parameters. Development of showerhead devices is also likely to face a trade-off between bathing functionality and simpler form factors that are more conducive to internal UV irradiation.


Assuntos
Legionella , Bactérias , Biofilmes , Desinfecção , Desenho de Equipamento , Engenharia Sanitária , Microbiologia da Água
8.
Artigo em Inglês | MEDLINE | ID: mdl-31635303

RESUMO

Recently in Australia concerns have been raised regarding the contamination of municipal drinking water supplies with lead. This is of particular concern to children due to the impact of lead exposure on cognitive development and as such these findings have received much media attention. The response from legislators has been swift, and The Victorian School Building Authority has announced that all new schools and school upgrade works will only use lead-free tapware and piping systems. However, while the immediate replacement of lead-containing brass fittings may seem a logical and obvious response, it does not consider the potential implications on microbial contamination. This is particularly concerning given the increasing public health threat posed by opportunistic premise plumbing pathogens (OPPPs). This commentary explores this public health risk of lead exposure from plumbing materials compared to the potential public health risks from OPPPs. Non-tuberculous mycobacterium was chosen as the example OPPP, and the influence on plumbing material and its public health burden in Australia is explored. This commentary highlights the need for future research into the influence of plumbing material on OPPPs prior to any changes in legislation regarding plumbing material.


Assuntos
Água Potável/microbiologia , Metais Pesados/análise , Saúde Pública , Austrália , Criança , Humanos , Engenharia Sanitária , Abastecimento de Água
9.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(9): 865-870, 2019 Sep 06.
Artigo em Chinês | MEDLINE | ID: mdl-31474065

RESUMO

According to different epochs and development needs, a series of practices on environmental health and sanitary engineering were carried out, which played significant roles in promoting national economic and social developments and protecting the public health. This paper reviewed the main achievements in the past 70 years infields of patriotic health campaign, water sanitation and toilet improvement in rural areas, surveillance and investigation, health standard system, sanitary engineering equipment, stove improvement etc., and then proposed several prospects in the future.


Assuntos
Saúde Ambiental , População Rural , Engenharia Sanitária , Saneamento , China , Saúde Ambiental/normas , Saúde Ambiental/tendências , Humanos , Saúde Pública/normas , Engenharia Sanitária/tendências , Saneamento/normas , Saneamento/tendências , Toaletes/normas
10.
Sci Total Environ ; 694: 133646, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390577

RESUMO

Tap water mistrust has adverse impacts on health and welfare. This study identifies, defines and motivates attention to cases of mistrust of tap water which originate between the treatment plant and the tap where people ultimately consume it. Between treatment and the tap, water quality contamination can be introduced within two segments of the built environment with two distinct responsible parties- community water system's distributional networks and property owner's premise plumbing. This contamination is considered secondary from a health perspective but elevates consumer concern. We use examples from Los Angeles County, an area with high resident tap water mistrust especially among disadvantaged communities, despite there being relatively few health-related water quality violations. We triangulate evidence from primary and secondary sources to illustrate how such water quality concerns occur. We identify potential solutions to address concerns using a series of case studies of communities with high levels of tap water mistrust, a stakeholder workshop and associated working group on premise plumbing concerns, and customer concern data from the city of Los Angeles' water system. Findings suggest that there are numerous instances where the distributional network, and secondarily premise plumbing, introduce water quality contamination which contributes to tap mistrust in urban communities by making water unclean, but not necessarily unsafe per existing regulation. In cases where water systems' distributional networks have introduced water quality contamination, responses to assuage concerns have largely rested upon pressure from the press and advocates. Premise plumbing issues have been harder to address. Our study suggests that an evidence-based path forward to comprehensively addressing these issues involves new requirements for systems to report quality contamination in distributional networks and incentives for property owners to upgrade premise plumbing. Moreover, this study reasserts that infrastructure neglect contributes to rational, but costly decision-making by disadvantaged urban communities to consume tap alternatives.


Assuntos
Água Potável , Engenharia Sanitária , Purificação da Água , Los Angeles , Qualidade da Água , Abastecimento de Água
11.
Chemosphere ; 236: 124329, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31310967

RESUMO

Plastic pipes have been and are being installed downstream of metal drinking water plumbing components. Prior research has suggested that such pipe configurations may induce plastic pipe degradation and even system failure. To explore the impact of upstream metal plumbing components on downstream plastic pipes, field- and bench-scale experiments were conducted. Six month old galvanized iron pipes (GIPs) and downstream crosslinked polyethylene (PEX) pipes were exhumed from a residential home. Calcium, iron, manganese, phosphorous, and zinc were the most abundant elements on both GIPs and PEX pipes. Black and yellow deposits were found on some of the exhumed PEX pipe inner walls, which were mainly copper, iron, and manganese oxides (CuO, Cu(OH)2, Fe2O3, FeOOH and MnO2). Follow-up bench-scale experiments revealed that metal levels in the drinking water did not always predict metal loadings on plastic pipe surfaces. The pH 4 water resulted in a greater amount of metals released into the bulk water, but the pH 7.5 water resulted in a greater amount of metals deposited on the PEX pipe surfaces. Hot water (55 °C) induced a greater amount of organics released and higher metal loadings on PEX pipe surfaces at pH 7.5. ATR-FTIR analysis showed that at 55 °C, PEX pipes connected to copper and brass components had the greatest oxidation functional group peak intensity (COOC, CO, and COC). This study highlights potential downstream plastic pipe degradation and metal deposition, which may cause plumbing problems and failures for building owners, inhabitants, and water utilities.


Assuntos
Água Potável/química , Metais/química , Engenharia Sanitária/métodos , Corrosão , Abastecimento de Água/métodos
12.
Environ Monit Assess ; 191(6): 340, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053969

RESUMO

Stormwater management in an urban environment is beset by uncertainties about future development. Dynamic strategies must be devised to cope with such uncertain environment. This work proposes a simulation-optimization model that minimizes the costs of low-impact development (LID) measures for mitigating impacts of future urban development on runoff. This paper's methodology is tested in an urban watershed in Tehran, Iran, relying on the stormwater management model (SWMM) coupled with the genetic algorithm (GA) to function as a simulation-optimization method for urban-runoff control by means of LID stormwater control measures. A sensitivity analysis of the calculated optimal solution revealed the impacts the most sensitive LIDs would have on runoff considering a set of plausible future development scenarios in the urban catchment. A comparison of the results from two different scenarios of future development with the existing stormwater system's performance shows the cost increase in redesigning the existing system to make it LID sensitive would equal 20% of the existing system's cost. The additional cost of redesigning the existing system without LID features would be 45% of the existing system's cost. These results demonstrate the importance of assessing the sensitivity of designed units in a stormwater management system and studying the trade-offs between possible decisions and future uncertainties concerning development in the watershed.


Assuntos
Algoritmos , Engenharia Sanitária , Irã (Geográfico) , Chuva , Incerteza
13.
Int J Hyg Environ Health ; 222(4): 687-694, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31085113

RESUMO

Opportunistic premise plumbing pathogens present in drinking water are linked to a significant number of infections for health compromised patients. However, their monitoring is not required in current water potability standards and they have been poorly studied in a full-scale network. In this study, we quantified, by qPCR, three opportunistic pathogens, Mycobacterium spp., Legionella pneumophila, Pseudomonas aeruginosa throughout the Paris drinking water network over a one-year sampling campaign. While Mycobacteria spp. seemed ubiquitous whatever the distribution system and the time of the year, the occurrence of L. pneumophila and P. aeruginosa showed seasonal variations. Unlike L. pneumophila and P. aeruginosa, the concentration (copies number/L) of Mycobacterium spp. varied between sampling sites. The variation in microbial numbers did not demonstrate any correlations with temperature, pH, chlorine, conductivity, orthophosphate or nitrate levels. In conclusion, Mycobacterium spp. are common inhabitants of the Paris network while L. pneumophila and P. aeruginosa presence fluctuate over space and time. Such qPCR approach would help to better understand the behaviour of opportunistic premise plumbing pathogens.


Assuntos
Água Potável/microbiologia , Legionella pneumophila/isolamento & purificação , Mycobacterium/isolamento & purificação , Pseudomonas aeruginosa/isolamento & purificação , Engenharia Sanitária , Monitoramento Ambiental , Legionella pneumophila/genética , Mycobacterium/genética , Paris , Pseudomonas aeruginosa/genética
14.
Artigo em Inglês | MEDLINE | ID: mdl-31074704

RESUMO

A field study was conducted to test the effectiveness of faucet-mounted point of use (POU) water filters for removing high concentrations of lead in drinking water from premise plumbing sources and lead service lines (LSL). These filters were concurrently certified for total lead removal under NSF/ANSI Standard 53 (NSF/ANSI-53) and for fine particulate (Class I) reduction under NSF/ANSI Standard 42 (NSF/ANSI-42). In 2016, filtered and unfiltered drinking water samples were collected at over 345 locations in Flint, Michigan. Over 97% of filtered water samples contained lead below 0.5 µg/L. The maximum lead concentration in filtered water was 2.9 µg/L, well below the bottled water standard. The effectiveness of the POU activated carbon block filters in reducing lead concentrations, even above the 150 µg/L NSF/ANSI-53 challenge standard, is likely related to trapping particles due to the small effective pore size of the filters, in addition to ion-exchange or sorption removal of soluble lead. Properly installed and maintained POU filters, certified under both NSF/ANSI-53 (for total lead) and NSF/ANSI-42 (for fine particulate), can protect all populations, including pregnant women and children, by reducing lead in drinking water to levels that would not result in a significant increase in overall lead exposure.


Assuntos
Água Potável/química , Filtração/instrumentação , Chumbo/análise , Poluentes Químicos da Água/análise , Purificação da Água/instrumentação , Criança , Água Potável/normas , Desenho de Equipamento , Feminino , Filtração/métodos , Humanos , Michigan , Minerais/análise , Gravidez , Engenharia Sanitária , Fuligem/química , Purificação da Água/métodos , Abastecimento de Água
15.
J Water Health ; 17(2): 196-203, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30942770

RESUMO

Drinking water distribution system contamination incidents can prompt public agencies and drinking water utilities to issue do-not-drink and do-not-use advisories. After the contaminant is cleared from distribution mains, consumers are often directed to flush their plumbing. However, little validated guidance and few evaluated communications strategies are available on using flushing to decontaminate building water systems. Additionally, limited data support the effectiveness of current practices and recommendations. In this study, expert elicitation was used to assess existing flushing guidance and develop validated flushing guidance and communications for single-family residences. The resulting guidance recommends progressively opening all cold-water taps from the closest to point of entry to the furthest and allowing the water to run for at least 20 minutes. Hot-water taps should be opened progressively and run for at least 75 minutes. The guidance language and format conformed to grade-level and readability scores within recommended health communication ranges. The readability of eight other flushing guidance documents was also evaluated for contamination incidents from 2008-2015. Seven were written at a 10th-12th grade level, above the 6th-7th grade level recommended for health communications.


Assuntos
Comunicação em Saúde , Engenharia Sanitária , Compreensão , Habitação , Humanos , Abastecimento de Água/estatística & dados numéricos
16.
Water Res ; 157: 579-586, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30999256

RESUMO

BACKGROUND: Pseudomonas aeruginosa (PA) is an important opportunistic pathogen that thrives best in the distal elements of plumbing and waste-water systems. Although nosocomial outbreaks of PA have been associated with water sources, the role of the plumbing system of healthcare premises as a reservoir for this pathogen is still unclear. MATERIALS AND METHODS: We collected water samples from 12 technical areas, distant from any medical activity, in a teaching hospital in France once a week for 11 weeks. We used a method that resuscitates persister cells because of the nutrient-poor conditions and the presence of inhibitors (e.g. chlorine and copper ions). Briefly, water was sampled in sterile bottles containing 100 µM of the copper-ion chelating agent diethyldithiocarbamate (DDTC). A portion of the samples was immediately filtered through 0.45-µm membranes, deposited on R2A agar plates, and incubated seven days at 22 °C (following European recommendations). The remaining water was incubated 14 days at 22 °C and then filtered and cultured on R2A, blood-, or cetrimide-containing agar plates. PA isolates were identified by MS MALDI-TOF, genotyped by PFGE and WGS, and tested for survival in a 150 µg/L copper (II) sulphate solution. RESULTS: Although the 12 water sampling points always tested negative with the recommended method, 67% were positive at least once for PA with the adapted method (i.e. with DDTC). The 14 PA persister isolates found throughout the plumbing system were clonal and belong to the high-risk clone ST308. Their genome harbours a 37-kb genomic island (GI-7) containing 13 genes linked to copper resistance. ST308 survived better in the copper solution than comparators that did not harbour GI-7 (P. aeruginosa strains PAO1, PA14, and ST235). The deletion of GI-7 in ST308 abrogated its tolerance to copper. The GI-7 nucleotide sequence shares 98% and 72% identity with sequences from the environmental species Pseudomonas putida and the phytopathogenic species Pseudomonas syringae, respectively. CONCLUSION: We report the contamination of the plumbing system of a healthcare premises by persister cells of the high-risk clone P. aeruginosa ST308. New recommendations for the monitoring of water contamination should consider persister cells. The genomic island GI-7, which confers tolerance to copper, probably originates from Pseudomonas species found in copper-contaminated soils and plants. Agricultural practices may have an unexpected consequence, allowing copper-tolerant pathogens to survive in the hospital environment and contaminate fragile patients.


Assuntos
Pseudomonas aeruginosa , Engenharia Sanitária , Cobre , França , Hospitais , Humanos
17.
Artigo em Inglês | MEDLINE | ID: mdl-31013887

RESUMO

Within hospitals and healthcare facilities opportunistic premise plumbing pathogens (OPPPs) are a major and preventable cause of healthcare-acquired infections. This study presents a novel approach for monitoring building water quality using real-time surveillance of parameters measured at thermostatic mixing valves (TMVs) across a hospital water distribution system. Temperature was measured continuously in real-time at the outlet of 220 TMVs located across a hospital over a three-year period and analysis of this temperature data was used to identify flow events. This real-time temperature and flow information was then compared with microbial water quality. Water samples were collected randomly from faucets over the three-year period. These were tested for total heterotrophic bacteria, Legionella spp. and L. pneumophila. A statistically significant association with total heterotrophic bacteria concentrations and the number of flow events seven days prior (rs[865] = -0.188, p < 0.01) and three days prior to sampling (rs[865] = -0.151, p < 0.01) was observed, with decreased heterotrophic bacteria linked to increased flushing events. Only four samples were positive for Legionella and statistical associations could not be determined; however, the environmental conditions for these four samples were associated with higher heterotrophic counts. This study validated a simple and effective remote monitoring approach to identifying changes in water quality and flagging high risk situations in real-time. This provides a complementary surveillance strategy that overcomes the time delay associated with microbial culture results. Future research is needed to explore the use of this monitoring approach as an indicator for different opportunistic pathogens.


Assuntos
Água Potável/microbiologia , Hospitais , Temperatura , Microbiologia da Água , Qualidade da Água , Abastecimento de Água , Engenharia Sanitária
18.
Artigo em Inglês | MEDLINE | ID: mdl-30889830

RESUMO

Lead service lines (LSLs)-lead pipes connecting the water main under the street to a building's plumbing-contribute an estimated 50% to 75% of lead in tap water when they are present. Although Congress banned lead in plumbing materials in 1986, over 6 million LSLs remain in homes across the United States today. This paper summarizes three different home buying or renting scenario-based experimental studies used to evaluate disclosure styles, to assess if these influenced respondents' perceived risk of the LSL in a home, and their willingness to act. In renting scenarios, having landlords disclose the presence of an LSL, but also provide water test results showing lead levels below the EPA's lead action level resulted in lower levels of perceived risk, and of willingness to act. In seller-disclosure home buying scenarios, levels of perceived risk and willingness to act were consistently high, and three different disclosure styles did not differentially influence those outcomes. In home inspector-disclosure home buying scenarios, levels of perceived risk and willingness to act were high, but having explicit recommendations to replace LSLs and/or information about risk did not further influence those outcomes. In some cases, including the specific recommendations backfired. Implications for policy and regulation are discussed.


Assuntos
Revelação/legislação & jurisprudência , Habitação/normas , Chumbo/química , Engenharia Sanitária , Abastecimento de Água , Habitação/economia , Humanos , Políticas , Pesquisa , Engenharia Sanitária/economia , Engenharia Sanitária/normas , Estados Unidos/epidemiologia , Poluentes Químicos da Água/análise
19.
Artigo em Inglês | MEDLINE | ID: mdl-30700061

RESUMO

Public health has always been, and remains, an interdisciplinary field, and engineering was closely aligned with public health for many years. Indeed, the branch of engineering that has been known at various times as sanitary engineering, public health engineering, or environmental engineering was integral to the emergence of public health as a distinct discipline. However, in the United States (U.S.) during the 20th century, the academic preparation and practice of this branch of engineering became largely separated from public health. Various factors contributed to this separation, including an evolution in leadership roles within public health; increasing specialization within public health; and the emerging environmental movement, which led to the creation of the U.S. Environmental Protection Agency (EPA), with its emphasis on the natural environment. In this paper, we consider these factors in turn. We also present a case study example of public health engineering in current practice in the U.S. that has had large-scale positive health impacts through improving water and sanitation services in Native American and Alaska Native communities. We also consider briefly how to educate engineers to work in public health in the modern world, and the benefits and challenges associated with that process. We close by discussing the global implications of public health engineering and the need to re-integrate engineering into public health practice and strengthen the connection between the two fields.


Assuntos
Engenharia/história , Engenharia/estatística & dados numéricos , Saúde Pública/história , Saúde Pública/estatística & dados numéricos , Saneamento/história , Abastecimento de Água/história , Nativos do Alasca , História do Século XX , Humanos , Índios Norte-Americanos , Engenharia Sanitária/história , Engenharia Sanitária/métodos , Estados Unidos
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