Environmental Water Sources Research Articles

“Orange alert”: A fluorescent detector for bisphenol A in water environments

Due to the prevalent use of polycarbonate plastics and epoxy resins in packaging materials and paints for ships, there has been a widespread global contamination of environmental water sources with bisphenol A (BPA). BPA, an endocrine disruptor, has been found to cause tremendous health problems. Therefore, there is an urgent need for detecting BPA in a convenient and sensitive manner to ensure water safety. Herein, we develop a fluorescent turn-on BPA probe, named Bisphenol Orange (BPO), which could conveniently detect BPA in a wide variety of real water samples including sea water, drain water and drinking water. BPO shows superior selectivity toward BPA and up to 70-fold increase in fluorescence emission at 580nm when mixed with BPA in water. Mechanistic studies suggest a plausible water-dependent formation of hydrophobic BPA clusters which favorably trap and restrict the rotation of BPO and recover its inherent fluorescence.

Isolation and identification of Legionella pneumophila from environmental water sources in Khartoum State

[email protected]2 core-shell nanoparticles that AgBiS2 coated on the surface of upconversion nanoparticles (UCNPs) was successfully prepared through an ion exchange reaction. The photothermal conversion efficiency of AgBiS2 can be improved from 14.7% to 45% due to the cross relaxation between Nd ions and AgBiS2. The doping concentration of Nd ions played a critical role in the production of reactive oxygen species (ROS) and enhanced the photothermal conversion efficiency. The NaYF4:Yb/Er/[email protected]4:Nd nanoparticles endows strong upconversion emissions when the doped concentration of Nd ions is 1% in the inner core, which excites the AgBiS2 shell to produce ROS for photodynamic therapy (PDT) of cancer cells. As a result, the as-prepared NaYF4:Yb/Er/[email protected]4:[email protected]2 core-shell nanoparticles showed combined photothermal/photodynamic therapy (PTT/PDT) against malignant tumors. This work provides an alternative near-infrared light-active multimodal nanostructures for applications such as fighting against cancers.

Serratia marcescens osteomyelitis in the hand of a non-debilitated, immunocompetent woman

Serratia marcescens is an aerobic, gram-negative bacillus of the Enterobacteriaceae family that exists as a saprophyte in soil and environmental water sources. This bacterium colonizes the gastrointestinal, urinary, and respiratory tracts of humans and was long considered benign until the 1950s, when it was found to cause nosocomial infections in debilitated patients [1]. In the hospital setting, S. marcescens may contaminate saline bottles, intravenous solutions, hand lotions, and even disinfectants [1]. In debilitated and immunocompromised individuals, S. marcescens causes a wide variety of infections, including chronic osteomyelitis, septic arthritis, endocarditis, and meningitis [1–4]. In immunocompetent individuals, S. marcescens infections are uncommon and those involving the skin, soft tissue, and bone of the upper extremity are extremely rare. While acute osteomyelitis in the upper extremity has been observed in intravenous drug-abusing (IVDA) individuals, this condition has not been reported in healthy, non-IVDA individuals. Since S. marcescens is frequently multidrug-resistant, any infection with this bacterium is best treated with thirdor fourth-generation cephalosporins.

The Prevalence, Isolation and Morphotyping of Potentially Pathogenic Free-Living Amoebae from Tap Water and Environmental Water Sources in Sivas

To our knowledge, there is no study dealing with the prevalence of free-living amoebas (FLA) in water sources in Turkey, previous studies were mostly case presentations. The aim of the present study was to investigate the prevalence of FLA from tap water and natural water sources in different parts of the city. In the study, 250 samples were collected from the city centre, districts and villages. Two litres of water was collected from each source and filtered through a vacuum filtration system. The filter papers were washed in "Page's Amoeba Saline (PAS)" solution and incubated overnight. Filter papers were removed from the tubes and centrifuged; the final pellet was inoculated on non-nutrient agar (NNA) plates. The growth rate of FLA was checked after three days of inoculation and the flagellation test was performed to determine the presence of Naegleria spp. Heat tolerance of isolated strains was checked at 37, 42 and 52°C for the presence of pathogenic Acanthamoeba species. The cyst and trophozoite morphology of amoebas were examined under a light microscope and the genera was identified according to morphotyping keys. FLA were found in 75 (30.0%) of examined water samples. Eleven (4.4%) were identified as Acanthamoeba spp., 25 (10.0%) as Naegleria spp. and 39 (15.6%) as Hartmannella spp. after microscopic examination. Our study revealed that FLA are common inhabitants of household water as they are in the environment, so their own potential risks as well as transferring bacteria as other pathogens is important for human health.

Identifiability and estimation of multiple transmission pathways in cholera and waterborne disease

Cholera and many waterborne diseases exhibit multiple characteristic timescales or pathways of infection, which can be modeled as direct and indirect transmission. A major public health issue for waterborne diseases involves understanding the modes of transmission in order to improve control and prevention strategies. An important epidemiological question is: given data for an outbreak, can we determine the role and relative importance of direct vs. environmental/waterborne routes of transmission? We examine whether parameters for a differential equation model of waterborne disease transmission dynamics can be identified, both in the ideal setting of noise-free data (structural identifiability) and in the more realistic setting in the presence of noise (practical identifiability). We used a differential algebra approach together with several numerical approaches, with a particular emphasis on identifiability of the transmission rates. To examine these issues in a practical public health context, we apply the model to a recent cholera outbreak in Angola (2006). Our results show that the model parameters—including both water and person-to-person transmission routes—are globally structurally identifiable, although they become unidentifiable when the environmental transmission timescale is fast. Even for water dynamics within the identifiable range, when noisy data are considered, only a combination of the water transmission parameters can practically be estimated. This makes the waterborne transmission parameters difficult to estimate, leading to inaccurate estimates of important epidemiological parameters such as the basic reproduction number (R0). However, measurements of pathogen persistence time in environmental water sources or measurements of pathogen concentration in the water can improve model identifiability and allow for more accurate estimation of waterborne transmission pathway parameters as well as R0. Parameter estimates for the Angola outbreak suggest that both transmission pathways are needed to explain the observed cholera dynamics. These results highlight the importance of incorporating environmental data when examining waterborne disease.

CHARACTERIZATION OF CAMPYLOBACTER FROM RESIDENT CANADA GEESE IN AN URBAN ENVIRONMENT

Waterfowl are natural reservoirs for zoonotic pathogens, and abundant resident (nonmigratory) Canada Geese (Branta canadensis) in urban and suburban environments pose the potential for transmission of Campylobacter through human contact with fecal deposits and contaminated water. In June 2008 and July 2009, we collected 318 fecal samples from resident Canada Geese at 21 locations in and around Greensboro, North Carolina, to test for Campylobacter. All campylobacter species detected were C. jejuni isolates, and prevalences in 2008 and 2009 were 5.0% and 16.0%, respectively. Prevalence of C. jejuni-positive sampling sites was 21% (3/14) and 40% (6/15) in 2008 and 2009, respectively. All C. jejuni isolates were susceptible to a panel of six antimicrobial agents (tetracycline, streptomycin, erythromycin, kanamycin, nalidixic acid, and ciprofloxacin). We used pulsed-field gel electrophoresis and fla-typing to identify several strain types among these isolates. Multilocus sequence typing of representative isolates revealed six sequence types, of which two (ST-3708 and ST-4368) were new, two (ST-702 and ST-4080) had been detected previously among C. jejuni from geese, and two (ST-991 and ST-4071) were first reported in C. jejuni from an environmental water source and a human illness, respectively. These results indicate a diverse population of antibiotic-susceptible C. jejuni in resident Canada Geese in and around Greensboro, North Carolina, and suggest a need for additional assessment of the public health risk associated with resident Canada Geese in urban and suburban areas.

Impact of Urban Wastewater on Soil Properties and Lepidium sativum in an Arid Region

The reuse of wastewater for purposes such as agricultural irrigation can reduce the amount of water that needs to be extracted from environmental water sources. The aims of the study were the effects of municipal wastewater on soil properties and Lepidium sativum. Soil samples of 0 to 20 cm depth were taken from agricultural field in Isfahan (center of Iran). Lepidium sativum was transplanted in pots containing 7 kg of these soils. The experiment consisted of two treatments (with three replications) including soil irrigation with water (T1) and soil irrigation with wastewater (T2). After 30 days, samples were taken for testing. Soil properties such as electrical conductivity, organic matter, total nitrogen, sodium ions, chloride ions and heavy metals were measured. Morphological parameters of Lepidium sativum and accumulation of heavy metals in this plant were measured. The evidences provided by this experiment indicated that the application of wastewater caused an increase of EC, OM, TN, Cl, Na, Cr, Ni, Fe, Mn and Zn in soil. The irrigation with wastewater caused accumulation of heavy metals in Lepidium sativum. Accumulation of heavy metals in roots was important than in leaves. Results also showed that Lepidium sativum irrigated with wastewater caused an increase of root length and shoot length.

Campylobacter spp. Recovered from the Upper Oconee River Watershed, Georgia in a 4-Year Study

Waterways should be considered in the migration routes of Campylobacter, and the genus has been isolated from several water sources. Inferences on migration routes can be made from tracking genetic types in populations found in specific habitats and testing how they are linked to other types. Water samples were taken over a 4-year period from waterways in the Upper Oconee River Watershed, Georgia, to recover isolates of thermophilic Campylobacter. The isolates were typed by multilocus sequence typing (MLST) and analyzed to determine the overall diversity of Campylobacter in that environment. Forty-seven independent isolates were recovered from 560 samples (8.4%). Two (~4%) isolates were Campylobacter coli, three (~6%) isolates were putatively identified as Campylobacter lari, and the remaining 42 (~90%) were Campylobacter jejuni. The C. jejuni and C. coli isolates were typed by the Oxford MLST scheme. Thirty sequence types (STs) were identified including 13 STs that were not found before in the MLST database, including 24 novel alleles. Of the 17 previously described STs, 10 have been isolated from humans, 6 from environmental water, and 6 from wild birds (five types from multiple sources). Seven sites had multiple positive samples, and on two occasions, the same ST was isolated at the same site. The most common type was STST61 with four isolates, and the most common clonal complex was CC179 with nine isolates. CC179 has been commonly associated with environmental water. Although some Campylobacter STs that were found in the Oconee River engage in widespread migration, most are tightly associated with or unique to environmental water sources.

Catheter-associated bloodstream infection caused by Leifsonia aquatica in a haemodialysis patient: a case report

Leifsonia aquatica is an aquatic coryneform rod that is capable of forming biofilms in environmental water sources. It has rarely been associated with human infections and its pathogenicity and clinical significance are uncertain. We describe a case of catheter-related bloodstream infection in a haemodialysis patient. The isolate grew on conventional media as a yellow-pigmented colony, but identification required molecular methods. Although the strain displayed reduced sensitivity to vancomycin, the clinical outcome was favourable after catheter removal and intravenous treatment with this antibiotic. Our report gives further evidence of the capability of this aquatic bacterium to cause human infection.

Development of a magnetic bead fluorescence microscopy immunoassay to detect and quantify Leptospira in environmental water samples

Climate change, world population growth, and poverty have led to an increase in the incidence of leptospirosis. Leptospirosis is caused by pathogenic spirochaete bacteria that belong to the genus Leptospira. The bacteria are maintained in the renal tubules of the reservoir hosts (typically a rodent), then shed into the environment via the urine. Water is key for environmental survival and transmission, as leptospires can survive for several weeks in a moist environment. Therefore, environmental epidemiological studies are needed to study the contamination of environmental water sources. However, few such studies have been performed using cultivation of the isolates and PCR assays. But, leptospira cultivation can be easily contaminated by other organisms and takes usually several weeks. Moreover, PCR is a complex and costly analysis for the underdeveloped countries that have the highest incidence of leptospirosis. In this study, we describe two modifications of a fluorescence microscopy assay based on immuno-magnetic separation (IMS) to detect leptospires in environmental water samples that mainly differ in fluorescent dye staining. The first type uses acridine orange fluorescent dye staining combined with multiplexed IMS for sample screening. The detection limit ranged from 102 to 103 organisms per mL and largely depended on the capture efficiency (CE) of the immuno-magnetic particles. The second type uses serogroup-specific immuno-particles and direct fluorescence antibody staining (DFA) to detect leptospires; the detection limit of this second assay was approximately 101 cells per mL. Both assay types were applied to natural and experimentally infected water samples, which were also analysed with DFM and real-time PCR. Our data show that the fluorescent microscopy immunoassay successfully identified experimental leptospire contamination and was as sensitive as PCR. This modified immune-fluorescence assay may therefore enable epidemiological studies of leptospirosis.

The use of a high resolution melt real-time polymerase chain reaction (PCR) assay for the environmental monitoring of Vibrio cholerae

A real-time polymerase chain reaction (PCR) assay utilizing high resolution melt (HRM) curve analysis was developed and tested for the monitoring of Vibrio cholerae in water samples. The assay utilized previously published primers that are specific to regions of the V. cholerae ompWand ctxAB genes, allowing it to differentiate between toxigenic and non-toxigenic strains. TheompW and ctxAB primers amplify target regions of 588 and 564 bp in length (respectively) and the amplicons could be accurately identified using HRM curve analysis. High resolution melt curve analysis provided additional accuracy for the determination of amplicon melting temperatures, and allowed amplification of the two targets in a multiplex reaction. Two laboratories employed the assay to analyse 178 water samples obtained from diverse environmental water sources, for the presence of V. cholerae. The assay was found to be a rapid, highly accurate, sensitive and cost effective method for the detection and distinction between toxigenic and non-toxigenic V. cholerae strains in water. Key words: Vibrio cholerae, high resolution melt, real-time polymerase chain reaction (PCR).

Simultaneous screening of estrogens, progestogens, and phenols and their metabolites in potable water and river water by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

In this study, a method employing ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was developed to simultaneously screen for 36 endocrine-disrupting chemicals (EDCs; e.g., estrogens, progestogens, phenols, and their metabolites) both in potable and river water. From the selected compounds, 21 target compounds, for which reference standards were available, were used as model compounds for method development and optimization. The other target compounds, for which reference standards were unavailable, were investigated in post-target analysis on the basis of their theoretical molecular masses. The solid-phase extraction and chromatographic separation steps were optimized. For this method, limits of detection for the target compounds were less than 0.72ngL−1, and the overall recoveries varied between 46% and 134% with relative standard deviations ranging from 7% to 35%. The mass errors between theoretical and experimental mass for all resulting precursor and characteristic fragment ions ranged from −1.9 to 2.8mDa. The method developed was successfully used to analyze the composition of potable and river water in Shanghai City; in addition, some compounds of interest (estriol, estrone, and bisphenol A) were identified accurately. Further, a post-target analysis was performed and an estrogen metabolite was hypothesized in the water samples due to the excellent sensitivity of the method in full-spectrum acquisition mode and the valuable accurate mass information in MS and tandem MS mode. Therefore, UPLC-Q-TOF-MS has proven to be a powerful technique for wide-scope screening and identification of relevant EDCs in environmental water sources.

Isolation of Acanthamoeba species in surface waters of Gilan province-north of Iran

We analyzed water samples to determine the prevalence of free-living Acanthamoeba in water sources from Gilan, greater area, Iran. A total of 27 surface water samples were collected from environmental sources, including natural (rivers, lakes, springs, and lagoon) and freshwater source. The samples were filtrated and transferred to non-nutrient agar plates seeded with Escherichia coli and incubated for 2 to 7days at 30°C or 42°C. The plates were examined by microscopy to morphologically identify Acanthamoeba species. Following DNA extraction, PCR was used to confirm the microscopically identification. A total of 19 out of 27 samples (70.3%) were positive for Acanthamoeba species based on the morphological criteria, and 14 (73.7%) were confirmed by PCR method. The high frequency of Acanthamoeba spp. in different environmental water sources of Gilan is an alert for the public health related to water sources in Iran.

Seasonal field metabolic rate and water influx of captive-bred reintroduced yellow-footed rock-wallabies (Petrogale xanthopus celeris)

Captive breeding and release is a tool used by conservation biologists to re-establish populations of endangered or locally extinct species. Reintroduced animals that have been bred in captivity must learn to meet the challenges posed by free living, and to adjust to local environmental conditions, food and water sources. How well reintroduced animals might meet these challenges is uncertain as few longitudinal studies have investigated the physiology of reintroduced animals or the implications of this for successful establishment of new populations. Here we have evaluated long-term, seasonal energy and water use by reintroduced yellow-footed rock-wallabies (Petrogale xanthopus celeris), an endangered medium-sized marsupial that inhabits rocky outcrops across Australia’s arid and semiarid rangelands. Captive-bred rock-wallabies were reintroduced to an area within the known boundaries of their former range, in south-western Queensland, Australia. Post-release water turnover rates (WTR) and field metabolic rates (FMR) were measured during their first wet summer and dry winter, by means of the doubly labelled water method. Total body water (73.1%), FMR (1650.0 kJ day–1), female fecundity (100%), and male and female body masses and survival were consistent between seasons, but rates of water turnover were significantly lower for all animals during the dry winter (174.3 mL day–1) than during the wet summer (615.0 mL day–1). There were no significant differences in WTR or FMR between males and lactating females (in either season).

Legionnaires' disease: pathology, detection and management

Legionnaires' disease is a potentially fatal form of pneumonia, which is caused by the bacterium Legionella pneumophila and related bacteria that can be found naturally in environmental water sources. In the UK, all dental premises are required to have a written scheme and a Legionella risk assessment. Barry Quinn and Richard Johnson explain

Genomic diversity of Legionella pneumophila serogroup 1 from environmental water sources and clinical specimens using pulsed-field gel electrophoresis (PFGE) from 1985 to 2007, Korea

The molecular typing of 202 Legionella pneumophila sg 1 isolates obtained from environmental water sources and clinical specimens from 1985 to 2007 was conducted using pulsed-field gel electrophoresis (PFGE). In this study, a total of 212 isolates were grouped into 35 different PFGE types and Type 1 was the predominant type, accounting for 28.7% in PFGE types. Type 1 and Type 8 were observed continuously from 1985 to 2007. In the analysis of the distribution of PFGE types in six geographic regions (Seoul-Incheon, Gangwon, Chungcheong, Gyeongsang, Jeolla, and Jeju), Type 1 was predominant throughout four regions except for Jeolla and Jeju, and Type 6 was observed in four regions except two regions (Gangwon and Jeju). Six clinical isolates belonged to PFGE Type 1, Type 6, Type 9, and Type 15. Type 1 among these types, was isolated from 3 patients with confirmed nosocomial infection at the hospital and Type 6, Type 9, and Type 15 were isolated 3 patients with suspected community-acquired infection. Type R, PFGE pattern of L. pneumophila sg 1 (ATCC 33152, Philadelphia-1), was not observed in the isolates evaluated in this study. Therefore, our results suggest that PFGE Type 1 was very prevalent in the environmental and clinical isolates in Korea. Type 1 was distributed continuously for many years throughout Korea.

Distribution of Legionella species from environmental water sources of public facilities and genetic diversity of L. pneumophila serogroup 1 in South Korea.

A total of 560 Legionella species were isolated from environmental water sources from public facilities from June to September 2008 throughout South Korea. The distribution of Legionella isolates was investigated according to geographical region, facility type, and sample type. The genetic diversity of 104 isolates of Legionella pneumophila serogroup 1 (sg 1) was analyzed by sequence-based typing (SBT). L. pneumophila was distributed broadly throughout Korea, accounting for 85.0% of the isolates, and L. pneumophila sg 1 predominated in all of the public facilities except for the springs. Legionella anisa and Legionella bozemanii predominated among non-L. pneumophila species (48.1% and 21.0%, respectively). The second most dominant strain differed depending on the facility type: L. anisa was the second most dominant strain in the buildings (10.8%), L. pneumophila sg 5 in public baths (21.6%), L. pneumophila sg 6 in factories (12.0%), and L. pneumophila sg 7 in hospitals (13.1%). In the SBT analysis, 104 L. pneumophila sg 1 isolates were differentiated into 26 sequence types (STs) and categorized into 3 clonal groups (CGs) and 10 singleton STs via the eBURST V3 program. ST1, a potential founder of major CG1, was commonly distributed (48.1%). The dominant ST in hot water was ST-K1 (7, 12, 17, 3, 35, 11, 11), which was designated in this study (36.1%). The second most dominant strain differed depending on the type of facility from which the samples were obtained. The unique allelic profile of ST-K1, obtained from hot water, was not found in the European Working Group for Legionella Infections (EWGLI) SBT database.

Modelling hydration and photosystem II activation in relation to in situ rain and humidity patterns: a tool to compare performance of rare and generalist epiphytic lichens

A dynamic water and activity model was developed to assess how efficiently lichens can exploit in situ rain and humid air. The capacity to rehydrate and activate photosynthesis [i.e. photosystem II (PSII)] by these water sources was compared among four hydrophilic and one generalist epiphytic lichen. Hydration status, potential (instant activation) and realized (delayed activation) day-light activity were simulated using a model based on species-specific hydration, PSII activation characteristics and in situ water content for Platismatia norvegica in three microclimatic scenarios. The results showed that delayed PSII activation could have profound effects on lichens' ability to exploit environmental water sources. During rain, realized activity was reduced by 19, 34 and 56% compared to simulations assuming instant activation for three hydrophilic lichens in the driest microclimate. During humid air, the reduction was 81% for the most extreme species and scenario, because of slow hydration and low equilibrium water content. Many and brief hydration events may thus hamper species with slow activation and fast desiccation kinetics. No evidence of compensation by a 'water-holding' morphology was observed among studied species. The developed model may provide a tool for identifying suitable habitats for long-term persistence of lichens with physiological constraints.

A case of endocarditis of difficult diagnosis in dialysis: could “pest” friends be involved?

We report a case of A. xylosoxidans endocarditis of larvate clinical presentation in a central venous catheter-dependent hemodialysis patient of difficult diagnosis and poor evolution despite a high index of suspicion and consequent assessment. A 50-year-old man on hemodialysis presented with inflammatory-malnutrition parameters during the months prior to diagnosis of endocarditis, whilst he was otherwise asymptomatic. No vegetations were detectable on his cardiac valves at repeated echocardiography until third transesophageal echocardiography was performed, and confirmed intraoperatively. On the occasion of positive peripheral blood culture for Alcaligenes (Achromobacter) xylosoxidans, the etiological diagnosis was retrospectively explained given his history of animal exposure - hunting rabbits using his pet ferrets. This bacterium is an emergent and resistant organism, mostly related to nosocomial infections and environmental water sources. Reservoirs include the microflora of the nasal cavity of rabbits and the dentogingival sulcus of ferrets. We presume that A. xylosoxidans endocarditis was transmitted from the patient's pets. It highlights the importance of early recognition of an inflammatory status and investigation of the underlying cause. Additionally, the causative bacterium emphasizes the importance of registering exposure to animals in CVC-dependent patients as well as the need for their awareness of hygienic precautions and the infectious risk associated to catheters.

Ochrobactrum anthropi bacteremia in a preterm infant with meconium peritonitis

Ochrobactrum anthropi is a non-fermenting gram-negative rod that was identified as a pathogenic microorganism during the past decade. O. anthropi is extensively distributed in the environment, and has been found in hospital and environmental water sources. O. anthropi infection is rare in childhood. We report a case of O. anthropi bacteremia in a preterm infant with a peritoneal lavage catheter and meconium peritonitis.