Letteratura scientifica selezionata sul tema "Faecal contamination"
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Articoli di riviste sul tema "Faecal contamination"
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Amoroso, Caroline R., Alexa G. Frink e Charles L. Nunn. "Water choice as a counterstrategy to faecally transmitted disease: an experimental study in captive lemurs". Behaviour 154, n. 13-15 (2017): 1239–58. http://dx.doi.org/10.1163/1568539x-00003466.
Testo completoAbstract (sommario):
Abstract Many parasites and pathogens are transmitted via water, including through faecal contamination of water sources. Yet water is essential for survival, and some species gain nutritional and other benefits from coprophagy. We investigated how primates balance the risks of faecal pathogen transmission with potential benefits of faeces ingestion in their selection of water sources by conducting behavioural experiments with five species of lemurs (Family Lemuridae) in captivity. Subjects were given a choice between clean water and water ‘contaminated’ with disinfected faecal material, which contained cues associated with faecally transmitted parasites, but minimal risk. We found that lemurs exhibited strong preferences for the clean water. This pattern was supported even at low levels of faecal contamination and in species adapted to water-limited habitats, for which choosiness about water quality could present a dehydration risk. Our results strongly support the hypothesis that avoiding faecal contamination is important in water selection.
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Godfree, A. F., D. Kay e M. D. Wyer. "Faecal streptococci as indicators of faecal contamination in water". Journal of Applied Microbiology 83, S1 (ottobre 1997): 110–19. http://dx.doi.org/10.1046/j.1365-2672.83.s1.12.x.
Testo completo
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Leeming, Rhys, Jonathan S. Stark e James J. Smith. "Novel use of faecal sterols to assess human faecal contamination in Antarctica: a likelihood assessment matrix for environmental monitoring". Antarctic Science 27, n. 1 (25 giugno 2014): 31–43. http://dx.doi.org/10.1017/s0954102014000273.
Testo completoAbstract (sommario):
AbstractWastewater containing human sewage is often discharged with little or no treatment into the Antarctic marine environment. Faecal sterols (primarily coprostanol) in sediments have been used for assessment of human sewage contamination in this environment, butin situproduction and indigenous faunal inputs can confound such determinations. Using gas chromatography with mass spectral detection profiles of both C27and C29sterols, potential sources of faecal sterols were examined in nearshore marine sediments, encompassing sites proximal and distal to the wastewater outfall at Davis Station. Faeces from indigenous seals and penguins were also examined. Faeces from several indigenous species contained significant quantities of coprostanol but not 24-ethylcoprostanol, which is present in human faeces.In situcoprostanol and 24-ethylcoprostanol production was identified by co-production of their respectiveepi-isomers at sites remote from the wastewater source and in high total organic matter sediments. A C29sterols-based polyphasic likelihood assessment matrix for human sewage contamination is presented, which distinguishes human from local fauna faecal inputs andin situproduction in the Antarctic environment. Sewage contamination was detected up to 1.5 km from Davis Station.
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Baudišová, D. "Microbial pollution of water from agriculture". Plant, Soil and Environment 55, No. 10 (21 ottobre 2009): 429–35. http://dx.doi.org/10.17221/131/2009-pse.
Testo completoAbstract (sommario):
Microbial contamination of small streams in agricultural areas was monitored for two years. Microbiological indicators of faecal pollution (faecal coliforms, <I>Escherichia coli</I> and intestinal enterococci were detected by standard methods based on the cultivation of bacteria on selective media). The obtained results showed that running contamination of streams from agricultural areas was not extremely high, but it showed marked seasonal fluctuations (the average values and maximal values revealed great differences). Microbial contamination also increased several times in relation to high precipitation. The water quality in three (and/or four) localities exceeded the acceptable counts of faecal coliforms and enterococci given by the Czech legislation (40 CFU/ml for faecal coliforms and 20 CFU/ ml for enterococci). In agriculturally polluted streams, there were detected more enterococci than faecal coliforms, and also some less frequent species related to farm animals (<I>Streptococcus equines</I> and <I>S. bovis</I>) or plant rests (<I>E. mundtii, E. gallinarum, E. casseliflavus</I>) were present. <I>E. faecalis</I> and <I>E. faecium</I> strains (these are the most common species related to human faecal pollution) were less frequent there.
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Leeming, R., N. Bate, R. Hewlett e P. D. Nichols. "Discriminating faecal pollution: a case study of stormwater entering Port Phillip Bay, Australia". Water Science and Technology 38, n. 10 (1 novembre 1998): 15–22. http://dx.doi.org/10.2166/wst.1998.0369.
Testo completoAbstract (sommario):
This investigation was designed to provide preliminary information to the Environment Protection Authority concerning the input of faecal matter to stormwater drains in the Rippleside area of Geelong, Victoria. Results derived from the combined use of sterol biomarkers (e.g. coprostanol and 24-ethylcoprostanol) and four sub-groups of bacterial indicators (e.g. thermotolerant coliforms, E. coli, faecal streptococci and enterococci) indicated that during wet weather, all sites sampled were affected by significant human faecal contamination. Ratios of coprostanol to bacterial indicators were similar to those for samples collected from nearby sewer mains. During dry weather, there were still severely elevated levels of faecal contamination based on bacterial indicators, but correspondingly low concentrations of faecal sterols suggesting minimal human or herbivore faecal contamination. The origin of the majority of the faecal pollution in dry weather therefore remains to be fully explained. It is clear from this and related studies that the combined measurement of faecal sterols and bacterial indicators can greatly assist distinguishing sources of faecal pollution. It is also shown for aquatic environments that the measurement of coprostanol or other single indicators alone, is inadequate to fully discern faecal contamination from human sources.
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Wicki, Melanie, Adrian Auckenthaler, Richard Felleisen, Marcel Tanner e Andreas Baumgartner. "Novel Bacteroides host strains for detection of human- and animal-specific bacteriophages in water". Journal of Water and Health 9, n. 1 (3 febbraio 2011): 159–68. http://dx.doi.org/10.2166/wh.2010.165.
Testo completoAbstract (sommario):
Bacteriophages active against specific Bacteroides host strains were shown to be suitable for detection of human faecal pollution. However, the practical application of this finding is limited because some specific host strains were restricted to certain geographic regions. In this study, novel Bacteroides host strains were isolated that discriminate human and animal faecal pollution in Switzerland. Two strains specific for bacteriophages present in human faecal contamination and three strains specific for bacteriophages indicating animal faecal contamination were evaluated. Bacteriophages infecting human strains were exclusively found in human wastewater, whereas animal strains detected bacteriophages only in animal waste. The newly isolated host strains could be used to determine the source of surface and spring water faecal contamination in field situations. Applying the newly isolated host Bacteroides thetaiotaomicron ARABA 84 for detection of bacteriophages allowed the detection of human faecal contamination in spring water.
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Höglund, C., T. A. Stenström, H. Jönsson e A. Sundin. "Evaluation of faecal contamination and microbial die-off in urine separating sewage systems". Water Science and Technology 38, n. 6 (1 settembre 1998): 17–25. http://dx.doi.org/10.2166/wst.1998.0232.
Testo completoAbstract (sommario):
An important feature for recirculated products from a sewage system is that the risk for transmission of disease is low. In a urine source separating system faeces may contaminate the collected urine through the toilet. The concentrations of faecal indicator organisms were measured in 14 urine collection tanks. The survival of these and some pathogenic microorganisms in source separated human urine was studied. Total coliforms, E. coli and clostridia were found in low concentrations while faecal streptococci occurred in concentrations up to 105/ml urine solution. The results from phenotyping of faecal streptococci and the high counts indicate growth within the system. The majority of the pathogenic microorganisms investigated had a rapid die-off. A higher temperature, a low degree of dilution and a pH far from neutral had a negative effect on survival. E. coli had a rapid die-off and is not suitable for indicating faecal contamination of the collected urine. Quantification of faecal sterols is a possible alternative to microbial analysis for this purpose. The amounts of coprostanol showed that the faecal contamination varied from not detected to up to 13.3 mg/ml urine solution with a concentration in the urine sludge of up to 417.5 mg/kg.
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van Lieverloo, J. Hein M., E. J. Mirjam Blokker e Gertjan Medema. "Quantitative microbial risk assessment of distributed drinking water using faecal indicator incidence and concentrations". Journal of Water and Health 5, S1 (1 settembre 2007): 131–49. http://dx.doi.org/10.2166/wh.2007.134.
Testo completoAbstract (sommario):
Quantitative Microbial Risk Assessments (QMRA) have focused on drinking water system components upstream of distribution to customers, for nominal and event conditions. Yet some 15—33% of waterborne outbreaks are reported to be caused by contamination events in distribution systems. In the majority of these cases and probably in all non-outbreak contamination events, no pathogen concentration data was available. Faecal contamination events are usually detected or confirmed by the presence of E.coli or other faecal indicators, although the absence of this indicator is no guarantee of the absence of faecal pathogens. In this paper, the incidence and concentrations of various coliforms and sources of faecal contamination were used to estimate the possible concentrations of faecal pathogens and consequently the infection risks to consumers in event-affected areas. The results indicate that the infection risks may be very high, especially from Campylobacter and enteroviruses, but also that the uncertainties are very high. The high variability of pathogen to thermotolerant coliform ratios estimated in environmental samples severely limits the applicability of the approach described. Importantly, the highest ratios of enteroviruses to thermotolerant coliform were suggested from soil and shallow groundwaters, the most likely sources of faecal contamination that are detected in distribution systems. Epidemiological evaluations of non-outbreak faecal contamination of drinking water distribution systems and thorough tracking and characterisation of the contamination sources are necessary to assess the actual risks of these events.
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Geary, P. M., C. A. Evans, M. T. Maswabi, C. CC Lee, A. Zammit, G. Webster e M. Hunter. "Monitoring and tracking contaminant sources in catchments and estuaries". Water Practice and Technology 10, n. 3 (1 settembre 2015): 601–8. http://dx.doi.org/10.2166/wpt.2015.070.
Testo completoAbstract (sommario):
In managing water quality in catchments and estuaries, faecal contamination is typically assessed using microbial indicators, such as faecal coliform bacteria. Bacteriological indicators however cannot be used to distinguish whether the faecal contamination has been derived from human or animal sources. The ability to track contamination and distinguish between sources is particularly important where water is used for potable supply, recreational purposes and where commercial aquaculture for human consumption is undertaken. Various chemicals associated with human metabolism and activities which are present in faecal material (such as faecal sterol, pharmaceutical and fluorescent whitening compounds present in wastewaters) can be utilized to identify a human signal and therefore whether the faecal contamination in water is likely to have been derived from human sources. This paper demonstrates an approach and methodology for future work using a combination of these methods to distinguish human contaminant sources in stormwater runoff in an estuary where aquaculture is practised.
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Alexander, L. M., e A. Heaven. "Contamination of urine and faecal specimens." BMJ 306, n. 6883 (10 aprile 1993): 998. http://dx.doi.org/10.1136/bmj.306.6883.998.
Testo completoTesi sul tema "Faecal contamination"
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Turner, Susan Jane. "Microbiological Indicators of Faecal Contamination in Aquatic Environments". Thesis, University of Auckland, 1996. http://hdl.handle.net/2292/2375.
Testo completoAbstract (sommario):
1. The aim of this research was to determine appropriate microbial indicator systems for use in monitoring the occurrence and source of faecal contamination in aquatic environments. Particular emphasis has been placed on the identification of indicators which might enable faecal contamination of human origin to be distinguished from that of non-human derivation. Two lines of investigation have been pursued; the use of alternative microbial indicator systems for water quality monitoring, and the development of diagnostic molecular methods for identifying the origin of faecal organisms. 2. Field and treatment plant studies were undertaken to investigate the utility of three indicator systems for monitoring water quality impacts in the coastal area surrounding the discharge from Auckland's North Shore City wastewater treatment plant. F-specific bacteriophage (F-phage) and ratios of F-phage to enterococci and faecal coliforms were examined over a twelve month period in which indicator levels at various stages of the wastewater treatment process were measured. These indicators and levels of Clostridium perfringens spores in sediment were measured in four outfall impact studies. 3. F-phage levels in effluent from the treatment plant (median=2.5 x 102 cfu/l00 ml) were too low to enable their use as source-specific tracers of effluent dispersion. However, higher F-phage levels in raw sewage (median=6.2 x l05 cfu/l00 ml) suggested that phage may be an appropriate indicator of raw sewage contamination in the receiving environment. F-phage was detected in coastal waters remote from the sewage outfall, providing presumptive evidence of sewage contamination entering the sea from sources other than the outfall discharge itself. 4. F-phage/enterococci and F-phage/faecal coliform ratios that were determined for sewage and treated effluent derived from the North Shore plant proved to be highly variable and were therefore unreliable for determining the source faecal contamination. 5. The concentration of Clostridium perfringens spores in sediments did not provide a useful means for tracing the distribution of faecal contaminants in the coastal system because the spore levels were found to be similar throughout the study area. This widespread occurrence of C. perfringens spores prevented identification of defined impact zones for any of the potential sources of faecal contaminants examined. 6. Randomly Amplified Polymorphic DNA (RAPD) analysis was used to investigate whether genetic markers could be identified for Escherichia coli isolates derived from different sources. RAPD profiling was found to be a highly discriminative method able to subtype E. coli strains present in both sewage and in the wastewater stream of a mechanical wood-pulping operation. In the pulp mill effluent, RAPD analysis indicated the presence of a restricted range of E. coli strains compared to the range found in the water intake and sewage effluent discharges. The results obtained provide presumptive evidence for the multiplication of E. coli strains within the wastewater stream. 7. Comparison of RAPD profiles derived from a range of human and environmental E. coli isolates led to the identification of a 1.6-kb marker. present in a subset of human isolates, but found only infrequently in isolates from animal origin. Primers based on sequence information obtained from this region of the genome yielded a direct PCR assay for the 'human' marker. The reliability and utility of the assay was improved when fluorescently-labelled primers and an automated DNA detection system was employed for the analysis of the amplified PCR products. 8. The diagnostic polymorphism was localised to the region immediately downstream of the gene encoding the glycine decarboxylase P-protein (gcvP). Comparison of DNA sequences from this region in 'marker-positive' and 'marker-negative' E. coli isolates revealed an abrupt loss of homology immediately downstream of the transcription termination point of the gcvP gene. The region of non-homology extends for at least 130 base pairs beyond the gcvP transcription terminator. Sequences spanning this region in marker-negative isolates exhibited a high level homology with that determined for E. coli K-12. The origin of the sequence for the same region in marker-positive isolates was unable to be identified. 9. The utility of the marker for environmental monitoring was investigated in a field study of a rural stream receiving bacterial contamination of both human and animal origin. The marker was consistently detected both in isolates derived from sewage effluents and in those found immediately downstream from sewage inputs-despite the presence of a high background of E. coli of animal origin. However the utility of the marker as a sewage-specific tracer was limited by the relatively low numbers of marker-positive d. coli in sewage effluents (approximately 8%). 10. In summary, the work described in this thesis has confirmed the need for multiple indicator systems in water quality monitoring and has identified appropriate areas for further research. The most promising area for future research is in the development of molecular tools which might provide both a better understanding of genetic variation in indicator organisms and enable methods to be developed for the detection of host-specific strains. Location of other polymorphisms likely to be present in the E. coli genome should enable further host-specific markers to be identified which could complement the 'human' marker identified in this study.Whole document restricted, but available by request, use the feedback form to request access.
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Miller, Layla. "Determining specific sources of faecal contamination within shellfisheries". Thesis, University of Exeter, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495762.
Testo completo
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Geary, Phillip M., University of Western Sydney, of Science Technology and Environment College e of Science Food and Horticulture School. "On-site system effluent source tracking using geochemical and microbial tracers in a coastal catchment". THESIS_CSTE_SFH_Geary_P.xml, 2004. http://handle.uws.edu.au:8081/1959.7/566.
Testo completoAbstract (sommario):
The principal aims of this thesis were to examine whether there were hydraulic links between individual on-site wastewater systems in sandy soils at Salt Ash and the Tilgerry Creek estuary near Port Stephens, New South Wales, and whether the chemical and microbiological contaminants from on-site systems could reach surface and groundwaters, and possibly lead to impacts on estuarine oyster growing waters. The research outcomes are contained within the thesis and in four refereed papers presented at conferences, and which have been subsequently published, or are in press. Copies of each of these papers are contained within the thesis Appendices. The presence of faecal contamination from domestic systems in the estuary, and surface drains in particular, has been confirmed by work contained in this thesis. The potential level of risk to human health from the consumption of contaminated oysters is, however, regarded as very low, although an assessment of health risk using established microbial assessment models has not been undertakenDoctor of Philosophy (PhD)
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Leeming, Rhys, e n/a. "Coprostanol and related sterols as tracers for feacal contamination in Australian aquatic environments". University of Canberra. School of Resource, Environmental & Heritage Sciences, 1996. http://erl.canberra.edu.au./public/adt-AUC20060816.172519.
Testo completoAbstract (sommario):
Pollution from human and animal faecal waste is a major cause of deteriorating water
quality and increased nutrient loads in coastal and inland waterways. Management of
this problem depends on knowing which sources of faecal matter are the cause and
what is the degree and extent of the pollution. Bacterial indicator organisms have long
been the principal method used to test water samples for faecal contamination.
However, none of the currently used bacterial indicators on their own are source
specific enough to distinguish different sources of faecal matter. The use of faecal
sterol biomarkers in conjunction with existing bacterial indicators offers a new way to
distinguish sources of faecal contamination.
This study investigates the sources of faecal sterols, the relationship of coprostanol to
existing bacterial indicators of faecal pollution, the degradation of faecal sterols and the
problem of determining the sources of faecal contamination and the distribution of
faecal contamination using faecal sterol biomarkers. 5p-Stanols (i.e. faecal sterols)
were found to be significant constituents of human, herbivore (i.e. cows, sheep etc.)
and pig and cat faeces. Human faeces contained 73 ± 4% coprostanol in relation to
the sum of coprostanol and 24-ethylcoprostanol and primary treated effluent contained
86 ± 0.4% coprostanol. Herbivore faeces contained 38 ± 4% coprostanol and 62 ±
4% 24-ethylcoprostanol whereas pig faeces contained 50 � 5% of each compound.
Both birds and dogs faeces contained either trace amounts of 5B-stanols or they could
not be detected. Notable differences were observed in the abundance of Closthdium
perfringens spores between the faeces of birds and domestic pets such as cats and
dogs. The above differences were subsequently exploited to distinguish faecal
contamination in Lake Tuggerah. An examination of the relationships between
coprostanol and bacterial indicator concentrations from several environments revealed
that 60 and 400 ng L of coprostanol corresponded to currently defined primary and
secondary contact limits for bacteria measured as either thermotolerant coliforms or
enterococci in the environment.
Four degradation experiments showed faecal sterols and related sterols such as
cholesterol decay at similar rates. An induction period was observed in all
experiments which meant that simple exponential equations to describe the rate of
decay of coprostanol were inadequate; a complimentary log - log transformation of the
data was used and the equation:
Y = l-Exp(-Exp(time x -0.01 + temp x -0.158 + 3.33)) x 100
was derived where Y equals the predicted percentage of coprostanol remaining over
time at a given temperature. In terms of persistence in the environment, Clostridium
perfringens spores > coprostanol > enterococci > thermotolerant coliforms.
Two field studies were undertaken to highlight the use of faecal sterols. In the Lake
Tuggerah study, the results indicated that faecal contamination of receiving waters in
the Tuggerah Lakes during rain events was significant, but was not derived from
human faecal matter; rather it appears to be principally derived from native birds and,
to a lesser extent, domestic pets. In the Derwent Estuary study, based on the
distribution of the faecal biomarker coprostanol, the mid estuary and parts of the upper
estuary (from Newtown Bay to Taroona), were found to be severely contaminated by
sewage. In summary, the use of faecal sterols to trace faecal contamination were found
to be an invaluable addition to the tools water managers use to investigate faecal
pollution.
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Florini, Styliani. "Identification of species-specific source(s) of faecal contamination in Salcott Creek, Blackwater Estuary". Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416715.
Testo completo
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Lang, Cassandra C., e University of Lethbridge Faculty of Arts and Science. "Identification and metabolic characterization of host-specific enterococci for use in source-tracking faecal contamination". Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2005, 2005. http://hdl.handle.net/10133/265.
Testo completoAbstract (sommario):
Metabolic were used to evaluate Enterococcus as an indicator of faecal pollution. Enterococci were isolated using m-Enterococcus agar and speciated using conventional biochemical tests. Forty percent of the isolates were identified and metabolically characterized by the automated Biolog system. The biochemical test scheme recognized 16 enterococcal species, while Biolog recognized nine. Both methods identified E. faecalis at the greatest frequency. Overall species frequencies varied between the two methods. Biolog was unable to identify 31% of the isolates; 7% of the isolates were unidentified by the biochemical test scheme. Of the identified isolates, metabolic profiling with Biolog achieved speciation with 60 substrates. Unique profiles were obtained for 89% of the isolates. Isolates also demonstrated inter-trial differntial metabolism of substrates. This and the large number of unidentified isolates suggest great diversity among enterococci. Diversity and inter-trial metabolic inconsistencies will complicate use of enterococcal metabolic profiles as a source-tracking tool.xxiii, 264 leaves ; 29 cm.
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Benselfelt, Tobias. "Flow Cytometry Sensor System Targeting Escherichia Coli as an Indicator of Faecal Contamination of Water Sources". Thesis, Linköpings universitet, Teknisk biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108004.
Testo completoAbstract (sommario):
Poor water quality is a global health concern affecting one billion people around the world. It is important to monitor water sources in order to maintain the quality of our drinking water and to avoid disease outbreaks. Targeting Escherichia coli as a faecal indicator is a widely used procedure, but the current methods are time consuming and not adequate to prevent spreading of faecal influence. This Master thesis demonstrates the development of a near infrared fluorescence flow cytometer sensor system targeting Escherichia coli, using fluorescently labeled chicken IgY antibodies. The near infrared light was chosen to avoid fluorescence from blue-green algae that are present in the water source. The hardware was developed with a 785 nm laser line to detect Alexa Fluor 790 labeled antibodies, using a photomultiplier tube or two different CMOS cameras. The antibodies were labeled using a commercial labeling kit, and evaluated using antibody binding assays and the developed hardware. The IgY antibodies were successfully labeled with Alexa Fluor 790 and the function was maintained after the labeling process. The result demonstrates the principles of the sensor system and how it solved to the problem with fluorescence from blue-green algae. An aperture was used to overcome the suboptimal laser and filter setup, and to increase the sensitivity of the system. However, only a small fraction of the cells could be detected, due to challenges with the focal depth and loss of sensitivity in the photomultiplier tube at near infrared wavelengths. Further development is required to create a working product.
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Luyt, Catherine Diane. "Faecal source tracking and water quality in the Eastern Cape, South Africa". Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1018242.
Testo completoAbstract (sommario):
Water quality is concerning as many still lack access to safe drinking water. Alternate sources such as rivers (FC up to 1600 CFUs/100 mL) and rainwater are often polluted. Rainwater tanks require maintenance to improve water quality, but could be used for non-potable purposes or irrigation. Grahamstown infrastructural failures initiate deviations from DWAF 1996 domestic water guidelines for microorganisms within the distribution system. Frequent testing can decrease risks of waterborne diseases. Limitations to this are inaccessibility of rural areas, distances from testing centres and costs. The low cost H2S strip test able to be used onsite by communities, may aid in risk assessment. H2S strip test results are not affected by sulphate (14 to 4240 mg/L) or nitrite (up to 47 mg/L). Transportation of the H2S strip tests between 10 and 32°C does not modify results significantly. Similarly to other studies: Klebsiella spp.; Enterobacter spp. and Serratia spp. were isolated from H2S strip tests. The mH2S strip test corresponds best with HPC in treated water, while in untreated river water it has approximately 90% correspondence with FCs, while survival of FC causes discrepancies with the H2S test after 22 days. A faecal coliform inactivation rate of 0.1 CFUs/ day, may be longer than many pathogens. Faecal source tracking, not currently practised in South Africa, could aid health risk assessments for disaster management, which would improve the NMMP programme. Bacterial survival times could propose the time period for which water is unsafe. Bifidobacteria and Rhodococcus are proposed to help identify the faecal pollution source. But enumeration of Rhodococcus is too lengthy (21 days). The tracking ratio of bifidobacteria (between 0.1 to 6.25) is not source definitive. The bifidobacteria survival rate, could indicator the time since faecal pollution. The bifidobacteria average survival rate is 2.3 CFUs per day for both groups. The culturability and selectivity of agar is still poor, with total bifidobacteria less selectively culturable. Enterococci overgrowth of TB was decreased by Beerens media. SUB is still useful to identify potential human faecal inputs. A single tracking method is thus not suitable alone, but requires a combination of techniques.
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Huda, T. M. "Role of sanitation in preventing faecal contamination of the domestic environment and protecting health : an observational study". Thesis, London School of Hygiene and Tropical Medicine (University of London), 2016. http://researchonline.lshtm.ac.uk/4189867/.
Testo completoAbstract (sommario):
This thesis assesses the potential public health significance of, sanitation quality and coverage by using microbiological indicator and secondary health outcome data. Sanitation was categorised using The Millennium Development Goal (MDG) definition of improved (private pit latrine with a slab or better) and unimproved (toilets connected to open, pit latrine without a slab, hanging toilet, shared toilets). A spot check of sanitation facilities was conducted in 460 target houses and 1,784 neighbouring houses. Faecal contamination of the household environment was assessed by looking for evidence of contamination with faecal coliforms on children’s hands and on ‘sentinel’ toys (standardised toy balls provided by the study). An analysis of secondary data was conducted on sanitation and reported diarrhoea among children < 5 years of age that had been collected as part of an impact evaluation. Households with private improved sanitation had lower faecal coliform contamination than households with unimproved sanitation [difference in means: -0.31 log10 colony forming units (CFU)/toy ball; 95% CI: -0.61, -0.01]. Access to 100% private improved sanitation coverage in the neighbourhood was associated with a small but statistically insignificant difference in contamination of sentinel toys (difference in means: -0.09 log10 CFU/toy; 95% CI: -0.56, 0.38). Other household sanitary practices such as cleanliness of latrine, wastewater disposal and disposal of animal faeces were important and statistically significant (P value ≤0.06) determinants of household faecal contamination. Children from households with access to private improved sanitation had a similar prevalence of diarrhoea to those with unimproved sanitation (Prevalence Ratio [PR] =1.00; 95% CI: 0.89, 1.13). Children from households with appropriate solid waste disposal systems had lower prevalence of diarrhoea compared to those without (PR=0.78; 95% CI: 0.65, 0.95). 4 Improved sanitation infrastructure quality and coverage may have limited roles in preventing transmission of diarrhoea causing enteric pathogens in the study context in which diarrhoea is endemic. Although in this study, private use and cleanliness of latrine were associated reduction in faecal contamination, but these factors were not associated with reduced diarrhoea prevalence. This may be because, firstly data were collected from slightly different contexts and time, secondly indicator organisms are only weakly associated presence of enteric pathogens and thirdly the population in this study context may have developed some degree of immunity to common circulating pathogens. Findings from this observational studies presented in this thesis adds to the evidence base, which do not support the inclusion of shared facilities as improved. There may be other more important source of children’s exposure to enteric pathogens that onsite sanitation access cannot prevent. Other sanitation related factors like maintenance of sanitation facility, use by all household members including children and faecal sludge management should be considered while defining improved sanitation for international monitoring. We also need to increase research efforts to integrate sanitation, water quality, handwashing and nutritional interventions and to understand better ways to monitor the impact of these interventions.
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Sheludchenko, Maxim. "Development and validation of novel methods for microbial source tracking based on Escherichia coli as an indicator of water quality". Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/46703/1/Maxim_Sheludchenko_Thesis.pdf.
Testo completoAbstract (sommario):
Microbial pollution in water periodically affects human health in Australia, particularly in times of drought and flood. There is an increasing need for the control of waterborn microbial pathogens. Methods, allowing the determination of the origin of faecal contamination in water, are generally referred to as Microbial Source Tracking (MST). Various approaches have been evaluated as indicatorsof microbial pathogens in water samples, including detection of different microorganisms and various host-specific markers. However, until today there have been no universal MST methods that could reliably determine the source (human or animal) of faecal contamination. Therefore, the use of multiple approaches is frequently advised. MST is currently recognised as a research tool, rather than something to be included in routine practices.
The main focus of this research was to develop novel and universally applicable methods to meet the demands for MST methods in routine testing of water samples. Escherichia coli was chosen initially as the object organism for our studies as, historically and globally, it is the standard indicator of microbial contamination in water. In this thesis, three approaches are described: single nucleotide polymorphism (SNP) genotyping, clustered regularly interspaced short palindromic repeats (CRISPR) screening using high resolution melt analysis (HRMA) methods and phage detection development based on CRISPR types. The advantage of the combination SNP genotyping and CRISPR genes has been discussed in this study.
For the first time, a highly discriminatory single nucleotide polymorphism interrogation of E. coli population was applied to identify the host-specific cluster. Six human and one animal-specific SNP profile were revealed. SNP genotyping was successfully applied in the field investigations of the Coomera watershed, South-East Queensland, Australia. Four human profiles [11], [29], [32] and [45] and animal specific SNP profile [7] were detected in water. Two human-specific profiles [29] and [11] were found to be prevalent in the samples over a time period of years. The rainfall (24 and 72 hours), tide height and time, general land use (rural, suburban), seasons, distance from the river mouth and salinity show a lack of relashionship with the diversity of SNP profiles present in the Coomera watershed (p values > 0.05). Nevertheless, SNP genotyping method is able to identify and distinquish between human- and non-human specific E. coli isolates in water sources within one day. In some samples, only mixed profiles were detected. To further investigate host-specificity in these mixed profiles CRISPR screening protocol was developed, to be used on the set of E. coli, previously analysed for SNP profiles.
CRISPR loci, which are the pattern of previous DNA coliphages attacks, were considered to be a promising tool for detecting host-specific markers in E. coli. Spacers in CRISPR loci could also reveal the dynamics of virulence in E. coli as well in other pathogens in water. Despite the fact that host-specificity was not observed in the set of E. coli analysed, CRISPR alleles were shown to be useful in detection of the geographical site of sources. HRMA allows determination of ‘different’ and ‘same’ CRISPR alleles and can be introduced in water monitoring as a cost-effective and rapid method.
Overall, we show that the identified human specific SNP profiles [11], [29], [32] and [45] can be useful as marker genotypes globally for identification of human faecal contamination in water. Developed in the current study, the SNP typing approach can be used in water monitoring laboratories as an inexpensive, high-throughput and easy adapted protocol.
The unique approach based on E. coli spacers for the search for unknown phage was developed to examine the host-specifity in phage sequences. Preliminary experiments on the recombinant plasmids showed the possibility of using this method for recovering phage sequences. Future studies will determine the host-specificity of DNA phage genotyping as soon as first reliable sequences can be acquired.
No doubt, only implication of multiple approaches in MST will allow identification of the character of microbial contamination with higher confidence and readability.
Libri sul tema "Faecal contamination"
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Cox, Sara Louise. An investigation to determine indirect contamination by faecal indicator organisms in nursing home staff sanitary accommodation. Cardiff: Cardiff Institute of Higher Education, 1996.
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Parker, Louise Michelle. Assessing the relationship between animal cleanliness and carcse faecal contamination as indicated by E.coli levels in beef cattle: A dissertation submitted in partial fulfilment of the Bachelor of Technology (honours) degree in Food production and Land. Ayr: SAC Auchincruive, 1998.
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Deutsche Forschungsgemeinschaft. Senatskommission zur Beurteilung von Stoffen in der Landwirtschaft., a cura di. Potentially harmful organisms and substances in feedstuffs and animal faeces. Weinheim: Wiley-VCH, 2001.
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Berman, Reva Lynne. The prevalence of parasites due to faecal contamination of public parks and playgrounds in Metropolitan Toronto, Ontario, Canada. 1998.
Cerca il testo completoCapitoli di libri sul tema "Faecal contamination"
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Paruch, Lisa, e Adam M. Paruch. "Contributors to Faecal Water Contamination in Urban Environments". In Water Management and the Environment: Case Studies, 215–30. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-79014-5_10.
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Martins, Salonee, Aishwarya Pathare, Purva Salvi, Unnati Bhalerao, Mahalaxmi U. Bhat, Meenakshi Singh, Muneesh Kumar Barman et al. "Microbial indicators and methods for source tracking faecal contamination of groundwater". In Legacy, Pathogenic and Emerging Contaminants in the Environment, 181–201. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003157465-10.
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Anh, Vuong Tuan, Kåre Mølbak, Phung Dac Cam e Anders Dalsgaard. "Factors Associated with Faecal Contamination of Household Drinking Water in a Rural Area, Vietnam". In Alliance for Global Sustainability Bookseries, 123–36. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9914-3_13.
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Bofill-Mas, Sílvia, Marta Rusiñol, Josep Fraile, Teresa Garrido, Antoni Munné e Rosina Girones. "Specific Viruses Present in Polluted Groundwater Are Indicative of the Source of Nitrates and Faecal Contamination in Agricultural Areas". In The Handbook of Environmental Chemistry, 1–24. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/698_2015_426.
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Crawford, Dorothy H. "6. Epidemics and pandemics". In Viruses: A Very Short Introduction, 63–74. Oxford University Press, 2018. http://dx.doi.org/10.1093/actrade/9780198811718.003.0007.
Testo completoAbstract (sommario):
Once an acute emerging virus is successfully established in a population, it generally settles into a mode of cyclical epidemics during which many susceptible people are infected and become immune to further attack. When most are immune, the virus moves on, only returning when a new susceptible population has emerged, generally consisting of those born since the last epidemic. ‘Epidemics and pandemics’ considers historical epidemics of viruses, vaccination programmes, and the spread of viruses from one continent to another—pandemics. Airborne viruses mainly cause respiratory illnesses, like flu, the common cold, or pneumonia, while those transmitted by faecal–oral contamination, like rotaviruses and noroviruses, cause intestinal upsets with nausea, vomiting, and diarrhoea.
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Crawford, Dorothy H. "Past Emerging Viruses". In Viruses, 101–21. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780192845030.003.0005.
Testo completoAbstract (sommario):
This chapter focuses on past emerging viruses. For our ancestors, it was their change in lifestyle from hunter-gatherer to farmer some 10,000 years ago that triggered an onslaught of new, emerging infectious diseases. The switch from the nomadic life to living in fixed communities, along with the change from hunting animals to their domestication, encouraged spillover of new viruses as well as other types of microbes. As such, the early farmers’ emerging viruses jumped from the animals they domesticated, while the cramped conditions of life in villages, and later towns, gave these viruses the opportunity to thrive in their new human host. This was the beginning of many of our acute childhood infections, so-called crowd diseases. The chapter looks at how these ancient afflictions have evolved over the intervening 10,000 years with a view to understanding how diseases like COVID-19 might evolve over time. It considers smallpox and measles, which are both highly infectious, lethal, airborne viruses, as well as polio, which is spread by faecal–oral contamination.
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Nath Mukhopadhyay, Narendra. "Evaluation, Diagnosis and Treatment of Ascariasis: An Updated Review". In Roundworms - A Survey From Past to Present [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.109147.
Testo completoAbstract (sommario):
Ascaris lumbricoides (Round Worm) is the most common human helminth with a world wide distribution. Incidence of ascariasis remain very high in the tropical and sub tropical countries with poor sanitation, personal hygiene, and rural areas where defaecation in open place is still a common practice. Ascariasis is classified as a neglected tropical disease. Infections have no symptoms in more than 85 percent of cases specially if the number of cases are small. Pathogenecity and clinical features are either due to migrating larvae or due to adult worms. Larval migration may lead to allergic reactions, ascaris pneumonia. Adult worms are often responsible for nutritional deficiencies, toxic effects due to hypersensitivity &mechanical effects leading to intestinal obstruction. Ectopic ascariasis can lead to acute biliary obstruction, cholangitis, acute pancreatitis, acute obstructive appendicitis and peritonitis due to perforation of an intestinal ulcer or break down of a post operative suture line. Medical therapy with Albendazole is the first line drug ascariasis can be eliminated by preventing faecal contamination of soil. Advancement in recombinant protein technology may provide first step in discovery of Ascaris vaccine as well as pan helminthic Vaccine. This chapter is a updated review of ascariasis.
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Lainson, R. "Cyclospora and cyclosporiasis". In Oxford Textbook of Medicine, 1105–9. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.070806_update_001.
Testo completoAbstract (sommario):
Most species of Cyclospora (Protozoa: Apicomplexa: Eimeriidae) are parasites of various reptiles and mammals. C. cayetanensis, which probably infects only humans, is transmitted by way of resistant oocysts voided in the faeces and contaminating food or water. Distribution is worldwide, particularly in regions with a low level of hygiene. Clinical presentation is with explosive outbreaks of acute diarrhoea, with this infection now regarded as an important causative agent of traveller’s diarrhoea. Diagnosis is dependent on detection of oocysts in faeces by direct examination or in stained faecal smears. Aside from supportive care, treatment with trimethoprim–sulfamethoxazole has proved effective in eliminating the parasite in immunocompetent patients, but relapses are common in those with AIDS. Prevention is by ensuring good general hygiene, and in areas of high endemicity water should be boiled before drinking or use in preparation of fruits/vegetables that are to be eaten raw....
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Kelly, Paul, e Ralph Lainson. "Cyclospora and cyclosporiasis". In Oxford Textbook of Medicine, a cura di Christopher P. Conlon, 1432–36. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0164.
Testo completoAbstract (sommario):
Most species of Cyclospora (Protozoa: Apicomplexa: Eimeriidae) are parasites of various reptiles and mammals. C. cayetanensis, which probably infects only humans, is transmitted by way of resistant oocysts voided in the faeces and contaminating food or water. Distribution is worldwide, particularly in regions with a low level of hygiene. Clinical presentation is with explosive outbreaks of acute diarrhoea, with this infection now regarded as an important causative agent of traveller’s diarrhoea. Diagnosis is dependent on detection of oocysts in faeces by direct examination or in stained faecal smears. Aside from supportive care, treatment with trimethoprim–sulfamethoxazole has proved effective in eliminating the parasite in immunocompetent patients, but relapses are common in those with AIDS. Prevention is by ensuring good general hygiene, and in areas of high endemicity water should be boiled before drinking or use in preparation of fruits/vegetables that are to be eaten raw.
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Parry, C. M., e Buddha Basnyat. "Typhoid and paratyphoid fevers". In Oxford Textbook of Medicine, 738–45. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.070608_update_002.
Testo completoAbstract (sommario):
Typhoid and paratyphoid fever (the enteric fevers) are caused by specific serovars of the Gram-negative bacillus, Salmonella enterica. Sources of typhoid transmission are excreting chronic or convalescent carriers and the acutely infected, with transmission occuring through contamination by carriers of food or water by effluents containing infected urine or faeces. There are an estimated 27 million cases of enteric fever in the world each year, almost all in the developing world, with about 200 000 deaths....
Atti di convegni sul tema "Faecal contamination"
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H., Johns. "FUNDAMENTAL AUTARCHICAL SCREENING AND MICROBES EXERTION OF GERMANE SYLVESTRE". In SCIENCE AND MODERN SOCIETY: CURRENT ISSUES, ACHIEVEMENTS AND INNOVATIONS. INTERNATIONAL SCIENTIFIC AND CURRENT RESEARCH CONFERENCES, 2021. http://dx.doi.org/10.37547/iscrc-intconf04-01.
Testo completoAbstract (sommario):
The current investigation was done to assess the autarchical and antimicrobes action of Germane sylvestre against ten microbial strains causing oral contaminations. The subjective autarchical examinations were completed after the Ukn pharmacopeia and the techniques. The MIC estimations of the plant extricates were resolved against the chose test life forms utilizing the techniques as depicted by National Committee for Chemical Laboratory Standard and the in vitro antimicrobes movement was controlled by utilizing the agar plate dissemination strategy. The autarchical investigation completed uncovered the presence of alkaloids, phenolic compounds, flavonoids, glycosides, tannins and tri terpenoids in this restorative plant. The antimicrobes movement of five distinct concentrates of therapeutic plants were assessed utilizing admirably dissemination technique against Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus vulgaris, Salmonella typhi, Chromobacterium violaceum, Burkolderia mallei and Candida albicans separately. The chloroform concentrates of this plant shown best antimicrobes movement against chose organisms. The outcomes give defense to the utilization of the restorative plants to treat different oral contaminations.
Rapporti di organizzazioni sul tema "Faecal contamination"
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A. Komnos, Georgios, Antonios Papadopoulos, Efstratios Athanaselis, Theofilos Karachalios e Sokratis E. Varitimidis. Migrating Periprosthetic Infection from a Total Hip Replacement to a Contralateral Non-Operated Osteoarthritic Knee Joint. Science Repository, gennaio 2023. http://dx.doi.org/10.31487/j.ijscr.2022.03.02.
Testo completoAbstract (sommario):
Introduction: There is a paucity of published data on whether a treated infected arthroplasty is a risk factor for infection in another, non-operated joint. Contamination of a primary, arthritic, non-operated joint from an infected arthroplasty is a relatively rare entity. Case: We report a case of migration of a pathogen (Enterococcus faecalis) from an infected prosthetic joint (hip) to the contralateral native joint (knee). Identification of the pathogen was made with PCR, by obtaining cultures during the implantation of the primary knee prosthesis. Conclusion: Contamination of a primary, arthritic, non-operated joint from an infected arthroplasty has not been widely reported. Management of such cases is extremely challenging and without clear and established guidelines. Our experience shows that tissue samples should be taken intraoperatively and sent for cultures, so as to exclude contamination in those cases.