scholarly journals Quantification of human norovirus GII, human adenovirus, and fecal indicator organisms in wastewater used for irrigation in Accra, Ghana

2013 ◽  
Vol 11 (3) ◽  
pp. 473-488 ◽  
Author(s):  
Andrea I. Silverman ◽  
Mark O. Akrong ◽  
Philip Amoah ◽  
Pay Drechsel ◽  
Kara L. Nelson
Keyword(s):  
Water Reuse ◽  
Wastewater Irrigation ◽  
World Health ◽  
Quantitative Microbial Risk Assessment ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
E Coli ◽  
Human Viruses ◽  
Human Specific

Quantitative microbial risk assessment (QMRA) is frequently used to estimate health risks associated with wastewater irrigation and requires pathogen concentration estimates as inputs. However, human pathogens, such as viruses, are rarely quantified in water samples, and simple relationships between fecal indicator bacteria and pathogen concentrations are used instead. To provide data that can be used to refine QMRA models of wastewater-fed agriculture in Accra, stream, drain, and waste stabilization pond waters used for irrigation were sampled and analyzed for concentrations of fecal indicator microorganisms (human-specific Bacteroidales, Escherichia coli, enterococci, thermotolerant coliform, and somatic and F+ coliphages) and two human viruses (adenovirus and norovirus genogroup II). E. coli concentrations in all samples exceeded limits suggested by the World Health Organization, and human-specific Bacteroidales was found in all but one sample, suggesting human fecal contamination. Human viruses were detected in 16 out of 20 samples, were quantified in 12, and contained 2–3 orders of magnitude more norovirus than predicted by norovirus to E. coli concentration ratios assumed in recent publications employing indicator-based QMRA. As wastewater irrigation can be beneficial for farmers and municipalities, these results should not discourage water reuse in agriculture, but provide motivation and targets for wastewater treatment before use on farms.

scholarly journals Salmonella enterica Serovar Typhimurium and Escherichia coli Survival in Estuarine Bank Sediments

2018 ◽  
Vol 15 (11) ◽  
pp. 2597 ◽  
Author(s):  
Mahbubul Siddiqee ◽  
Rebekah Henry ◽  
Rebecca Coulthard ◽  
Christelle Schang ◽  
Richard Williamson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Growth Patterns ◽  
Estuarine Sediments ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
E Coli ◽  
Serovar Typhimurium

Estuarine bank sediments have the potential to support the survival and growth of fecal indicator organisms, including Escherichia coli. However, survival of fecal pathogens in estuarine sediments is not well researched and therefore remains a significant knowledge gap regarding public health risks in estuaries. In this study, simultaneous survival of Escherichia coli and a fecal pathogen, Salmonella enterica serovar Typhimurium, was studied for 21 days in estuarine bank sediment microcosms. Observed growth patterns for both organisms were comparable under four simulated scenarios; for continuous-desiccation, extended-desiccation, periodic-inundation, and continuous-inundation systems, logarithmic decay coefficients were 1.54/day, 1.51/day, 0.14/day, and 0.20/day, respectively, for E. coli, and 1.72/day, 1.64/day, 0.21/day, and 0.24/day for S. Typhimurium. Re-wetting of continuous-desiccated systems resulted in potential re-growth, suggesting survival under moisture-limited conditions. Key findings from this study include: (i) Bank sediments can potentially support human pathogens (S. Typhimurium), (ii) inundation levels influence the survival of fecal bacteria in estuarine bank sediments, and (iii) comparable survival rates of S. Typhimurium and E. coli implies the latter could be a reliable fecal indicator in urban estuaries. The results from this study will help select suitable monitoring and management strategies for safer recreational activities in urban estuaries.

scholarly journals Thermotolerant Coliforms Are Not a Good Surrogate for Campylobacter spp. in Environmental Water

2009 ◽  
Vol 75 (21) ◽  
pp. 6736-6744 ◽  
Author(s):  
Karen St-Pierre ◽  
Simon Lévesque ◽  
Eric Frost ◽  
Nathalie Carrier ◽  
Robert D. Arbeit ◽  
...  
Keyword(s):  
Environmental Water ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
E Coli ◽  
Microbial Monitoring ◽  
Environmental Surface ◽  
Thermotolerant Coliforms ◽  
Eastern Townships ◽  
Campylobacter Spp

ABSTRACT This study aimed to assess the importance of quantitatively detecting Campylobacter spp. in environmental surface water. The prevalence and the quantity of Campylobacter spp., thermotolerant coliforms, and Escherichia coli in 2,471 samples collected weekly, over a 2-year period, from 13 rivers and 12 streams in the Eastern Townships, Québec, Canada, were determined. Overall, 1,071 (43%), 1,481 (60%), and 1,463 (59%) samples were positive for Campylobacter spp., thermotolerant coliforms, and E. coli, respectively. There were weak correlations between the weekly distributions of Campylobacter spp. and thermotolerant coliforms (Spearman's ρ coefficient = 0.27; P = 0.008) and between the quantitative levels of the two classes of organisms (Kendall tau-b correlation coefficient = 0.233; P < 0.0001). Well water samples from the Eastern Townships were also tested. Five (10%) of 53 samples from private surface wells were positive for Campylobacter jejuni, of which only 2 were positive for thermotolerant coliforms. These findings suggest that microbial monitoring of raw water by using only fecal indicator organisms is not sufficient for assessing the occurrence or the load of thermophilic Campylobacter spp. Insights into the role of environmental water as sources for sporadic Campylobacter infection will require genus-specific monitoring techniques.

scholarly journals Microbial water quality at contrasting recreational areas in a mixed-use watershed in eastern Canada

2021 ◽  
Author(s):  
Ainslie J. Butler ◽  
Katarina Pintar ◽  
Janis L. Thomas ◽  
Manon Fleury ◽  
Stefanie Kadykalo ◽  
...  
Keyword(s):  
Human Health ◽  
Health Risks ◽  
Human Health Risk ◽  
Indicator Organisms ◽  
Eastern Canada ◽  
Recreational Waters ◽  
Fecal Indicator ◽  
E Coli ◽  
Main River ◽  
Pathogen Testing

Abstract Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible.

Determination of Norovirus Contamination in Oysters from Two Commercial Harvesting Areas over an Extended Period, Using Semiquantitative Real-Time Reverse Transcription PCR

2008 ◽  
Vol 71 (7) ◽  
pp. 1427-1433 ◽  
Author(s):  
JAMES A. LOWTHER ◽  
KATHLEEN HENSHILWOOD ◽  
DAVID N. LEES
Keyword(s):  
Human Health Risk ◽  
Extended Period ◽  
Epidemiological Data ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
E Coli ◽  
Reverse Transcription Pcr ◽  
The United Kingdom ◽  
Male Specific ◽  
Production Areas

The human health risk associated with the consumption of molluscan shellfish grown in sewage-contaminated waters is well established. Noroviruses, which cause gastroenteritis, are the principal agents of shellfish-related illness. Fecal-indicator quality standards based on Escherichia coli are well established in Europe and elsewhere. However, norovirus outbreaks after consumption of shellfish meeting these standards still occur, and the need to improve consumer health protection is well recognized. Alternative approaches proposed include direct monitoring of viral pathogens and the use of alternative indicator organisms capable of providing a better indication of virus risk. This study applies a recently developed TaqMan PCR assay to assess norovirus contamination in shellfish. Comparison was made with E. coli as the existing sanitary standard and a male-specific RNA bacteriophage as a possible alternative. Two commercial pacific oyster (Crassostrea gigas) harvesting areas were monitored over a 31-month period. The results show peaks of norovirus contamination in both areas during winter months, with average levels approximately 17 times higher in oysters sampled October to March than during the remainder of the year, consistent with epidemiological data for the United Kingdom showing oyster-associated illness is confined to winter months. While there was no apparent association with E. coli, an association between levels of norovirus contamination and the male-specific RNA bacteriophage was noted, with average norovirus levels over 40 times higher in samples with male-specific RNA bacteriophage counts of &gt;1,000 PFU/100 g than in samples with &lt;100 PFU/100 g. Overall, these results suggest that norovirus monitoring in shellfish production areas could be an effective strategy for reduction of virus risk.

Microbial Survey of Pennsylvania Surface Water Used for Irrigating Produce Crops

2016 ◽  
Vol 79 (6) ◽  
pp. 902-912 ◽  
Author(s):  
AUDREY D. DRAPER ◽  
STEPHANIE DOORES ◽  
HASSAN GOURAMA ◽  
LUKE F. LaBORDE
Keyword(s):  
Surface Water ◽  
Physicochemical Characteristics ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
Environmental Characteristics ◽  
E Coli ◽  
Contaminated Irrigation Water ◽  
Aerobic Plate Count

ABSTRACT Recent produce-associated foodborne illness outbreaks have been attributed to contaminated irrigation water. This study examined microbial levels in Pennsylvania surface waters used for irrigation, relationships between microbial indicator organisms and water physicochemical characteristics, and the potential use of indicators for predicting the presence of human pathogens. A total of 153 samples taken from surface water sources used for irrigation in southeastern Pennsylvania were collected from 39 farms over a 2-year period. Samples were analyzed for six microbial indicator organisms (aerobic plate count, Enterobacteriaceae, coliform, fecal coliforms, Escherichia coli, and enterococci), two human pathogens (Salmonella and E. coli O157), and seven physical and environmental characteristics (pH, conductivity, turbidity, air and water temperature, and sampling day and 3-day-accumulated precipitation levels). Indicator populations were highly variable and not predicted by water and environmental characteristics. Only five samples were confirmed positive for Salmonella, and no E. coli O157 was detected in any samples. Predictive relationships between microbial indicators and the occurrence of pathogens could therefore not be determined.

scholarly journals A risk-based evaluation of onsite, non-potable reuse systems developed in compliance with conventional water quality measures

2020 ◽  
Vol 18 (3) ◽  
pp. 331-344
Author(s):  
Mary E. Schoen ◽  
Michael A. Jahne ◽  
Jay Garland
Keyword(s):  
Water Quality ◽  
Water Reuse ◽  
Wastewater Reuse ◽  
Quality Measures ◽  
Quantitative Microbial Risk Assessment ◽  
Fecal Indicator ◽  
Adequate Treatment ◽  
Potable Reuse ◽  
Risk Levels ◽  
Treatment Performance

Abstract Water quality standards (WQSs) based on water quality measures (e.g., fecal indicator bacteria (FIB)) have been used by regulatory agencies to assess onsite, non-potable water reuse systems. A risk-based approach, based on quantitative microbial risk assessment, was developed to define treatment requirements that achieve benchmark levels of risk. This work compared these approaches using the predicted annual infection risks for non-potable reuse systems that comply with WQSs along with the benchmark risk levels achieved by the risk-based systems. The systems include a recirculating synthetic sand filter or an aerobic membrane bioreactor (MBR) combined with disinfection. The greywater MBR system had predicted risks in the range of the selected benchmark levels. However, wastewater reuse with systems that comply with WQSs had uncertain and potentially high predicted risks (i.e., &gt;10−2 infections per person per year) in residential applications, due to exposures to viruses and protozoa. The predicted risks illustrate that WQSs based on FIB treatment performance do not ensure adequate treatment removal of viruses and protozoa. We present risk-based log10 pathogen reduction targets for intermediate-sized non-potable systems, which are 0.5 log10 less than those previously proposed for district-sized systems. Still, pathogen treatment performance data are required to better manage non-potable reuse risk.

Assessment of E. coli and Salmonella spp. infection risks associated with different fecal sludge disposal practices in Thailand

2009 ◽  
Vol 8 (2) ◽  
pp. 355-364 ◽  
Author(s):  
A. Yajima ◽  
T. Koottatep
Keyword(s):  
High Water ◽  
Developed Countries ◽  
World Health ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Risk Levels ◽  
E Coli ◽  
Fecal Sludge

The proper management of fecal sludge (FS), to block the transmission pathways of pathogens, is rarely enforced in many parts of the world. Health risks associated with different disposal practices of FS in peri-urban settings of a large metropolis in Thailand were assessed; Tha Klong sub-district with indiscriminate FS dumping, and Klong Luang sub-district which has an FS treatment system. The study showed that indiscriminate FS dumping from along the canal banks and discharge of market waste were likely the major sources of E. coli and Salmonella spp. in contamination of the canal water. The increased microbial pathogen concentrations near the FS treatment facility also indicated contamination risks from poorly designed treatment facilities. Quantitative microbial risk assessment (QMRA) indicated very high water-related infection risk levels compared to the actual locally recorded disease occurrences. These results indicated that the QMRA model needs to be modified to take account of immunological differences between populations in developed countries, where the model was developed, and developing countries. In addition, further sensitivity factors are needed to reflect different societal behavior patterns, and therefore contact with potentially contaminated water, in different sub-populations of many less developed communities.

scholarly journals Multitiered Approach Using Quantitative PCR To Track Sources of Fecal Pollution Affecting Santa Monica Bay, California

2006 ◽  
Vol 72 (2) ◽  
pp. 1604-1612 ◽  
Author(s):  
Rachel T. Noble ◽  
John F. Griffith ◽  
A. Denene Blackwood ◽  
Jed A. Fuhrman ◽  
Jason B. Gregory ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Fecal Indicator Bacteria ◽  
Fecal Contamination ◽  
Fecal Pollution ◽  
Indicator Bacteria ◽  
Fecal Indicator ◽  
E Coli ◽  
Santa Monica Bay ◽  
Santa Monica ◽  
Human Specific

ABSTRACT The ubiquity of fecal indicator bacteria such as Escherichia coli and Enterococcus spp. in urban environments makes tracking of fecal contamination extremely challenging. A multitiered approach was used to assess sources of fecal pollution in Ballona Creek, an urban watershed that drains to the Santa Monica Bay (SMB) near Los Angeles, Calif. A mass-based design at six main-stem sites and four major tributaries over a 6-h period was used (i) to assess the flux of Enterococcus spp. and E. coli by using culture-based methods (tier 1); (ii) to assess levels of Enterococcus spp. by using quantitative PCR and to detect and/or quantify additional markers of human fecal contamination, including a human-specific Bacteroides sp. marker and enterovirus, using quantitative reverse transcriptase PCR (tier 2); and (iii) to assess the specific types of enterovirus genomes found via sequence analysis (tier 3). Sources of fecal indicator bacteria were ubiquitous, and concentrations were high, throughout Ballona Creek, with no single tributary dominating fecal inputs. The flux of Enterococcus spp. and E. coli averaged 109 to 1010 cells h−1 and was as high at the head of the watershed as at the mouth prior to discharge into the SMB. In addition, a signal for the human-specific Bacteroides marker was consistently detected: 86% of the samples taken over the extent during the study period tested positive. Enteroviruses were quantifiable in 14 of 36 samples (39%), with the highest concentrations at the site furthest upstream (Cochran). These results indicated the power of using multiple approaches to assess and quantify fecal contamination in freshwater conduits to high-use, high-priority recreational swimming areas.

scholarly journals Seasonal persistence and population characteristics of Escherichia coli and enterococci in deep backshore sand of two freshwater beaches

2006 ◽  
Vol 4 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Muruleedhara N. Byappanahalli ◽  
Richard L. Whitman ◽  
Dawn A. Shively ◽  
W. T. Evert Ting ◽  
Charles C. Tseng ◽  
...  
Keyword(s):  
Water Table ◽  
Laboratory Experiments ◽  
Lake Michigan ◽  
Population Characteristics ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
E Coli ◽  
Pollution Events

We studied the shoreward and seasonal distribution of E. coli and enterococci in sand (at the water table) at two southern Lake Michigan beaches—Dunbar and West Beach (in Indiana). Deep, backshore sand (∼20 m inland) was regularly sampled for 15 months during 2002–2003. E. coli counts were not significantly different in samples taken at 5-m intervals from 0–40 m inland (P=0.25). Neither E. coli nor enterococci mean counts showed any correlation or differences between the two beaches studied. In laboratory experiments, E. coli readily grew in sand supplemented with lake plankton, suggesting that in situ E. coli growth may occur when temperature and natural organic sources are adequate. Of the 114 sand enterococci isolates tested, positive species identification was obtained for only 52 (46%), with E. faecium representing the most dominant species (92%). Genetic characterization by ribotyping revealed no distinct genotypic pattern (s) for E. coli, suggesting that the sand population was rather a mixture of numerous strains (genotypes). These findings indicate that E. coli and enterococci can occur and persist for extended periods in backshore sand at the groundwater table. Although this study was limited to two beaches of southern Lake Michigan, similar findings can be expected at other temperate freshwater beaches. The long-term persistence of these bacteria, perhaps independent of pollution events, complicates their use as indicator organisms. Further, backshore sand at the water table may act as a reservoir for these bacteria and potentially for human pathogens.

scholarly journals Evaluation of Potential Indicators of Viral Contamination in Shellfish and Their Applicability to Diverse Geographical Areas

2003 ◽  
Vol 69 (3) ◽  
pp. 1556-1563 ◽  
Author(s):  
M. Formiga-Cruz ◽  
A. K. Allard ◽  
A.-C. Conden-Hansson ◽  
K. Henshilwood ◽  
B. E. Hernroth ◽  
...  
Keyword(s):  
Hepatitis A Virus ◽  
Human Adenovirus ◽  
Fecal Indicator ◽  
Viral Contamination ◽  
E Coli ◽  
The North ◽  
The United Kingdom ◽  
Before And After ◽  
Microbiological Parameters ◽  
Human Viruses

ABSTRACT The distribution of the concentration of potential indicators of fecal viral pollution in shellfish was analyzed under diverse conditions over 18 months in diverse geographical areas. These microorganisms have been evaluated in relation to contamination by human viral pathogens detected in parallel in the analyzed shellfish samples. Thus, significant shellfish-growing areas from diverse countries in the north and south of Europe (Greece, Spain, Sweden, and the United Kingdom) were defined and studied by analyzing different physicochemical parameters in the water and the levels of Escherichia coli, F-specific RNA bacteriophages, and phages infecting Bacteroides fragilis strain RYC2056 in the shellfish produced, before and after depuration treatments. A total of 475 shellfish samples were studied, and the results were statistically analyzed. According to statistical analysis, the presence of human viruses seems to be related to the presence of all potential indicators in the heavily contaminated areas, where E. coli would probably be suitable as a fecal indicator. The F-RNA phages, which are present in higher numbers in Northern Europe, seem to be significantly related to the presence of viral contamination in shellfish, with a very weak predictive value for hepatitis A virus, human adenovirus, and enterovirus and a stronger one for Norwalk-like virus. However, it is important to note that shellfish produced in A or clean B areas can sporadically contain human viruses even in the absence of E. coli or F-RNA phages. The data presented here will be useful in defining microbiological parameters for improving the sanitary control of shellfish consumed raw or barely cooked.

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