scholarly journals Quantification of Human and Animal Viruses to Differentiate the Origin of the Fecal Contamination Present in Environmental Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Sílvia Bofill-Mas ◽  
Marta Rusiñol ◽  
Xavier Fernandez-Cassi ◽  
Anna Carratalà ◽  
Ayalkibet Hundesa ◽  
...  

Many different viruses are excreted by humans and animals and are frequently detected in fecal contaminated waters causing public health concerns. Classical bacterial indicator such asE. coliand enterococci could fail to predict the risk for waterborne pathogens such as viruses. Moreover, the presence and levels of bacterial indicators do not always correlate with the presence and concentration of viruses, especially when these indicators are present in low concentrations. Our research group has proposed new viral indicators and methodologies for determining the presence of fecal pollution in environmental samples as well as for tracing the origin of this fecal contamination (microbial source tracking). In this paper, we examine to what extent have these indicators been applied by the scientific community. Recently, quantitative assays for quantification of poultry and ovine viruses have also been described. Overall, quantification by qPCR of human adenoviruses and human polyomavirus JC, porcine adenoviruses, bovine polyomaviruses, chicken/turkey parvoviruses, and ovine polyomaviruses is suggested as a toolbox for the identification of human, porcine, bovine, poultry, and ovine fecal pollution in environmental samples.

2010 ◽  
Vol 10 (2) ◽  
pp. 209-215
Author(s):  
M. S. Mthembu ◽  
P. T. Biyela ◽  
T. G. Djarova ◽  
A. K. Basson

Fecal contamination of source waters and its associated intestinal pathogens continues to pose risks to public health although the extent and effect of microbial contamination of source waters gets very little attention in designing treatment plants in most developing countries. Coliform counts give an indication of the overall bacterial contamination of water and thus its safety for human consumption. However, their presence fails to provide information about the source of fecal contamination which is vital to managing fecal contamination problems in surface waters. This study explored the use of multiple antibiotic resistance (MAR) indexing as means of differentiating E. coli isolates from different sources. A total of 322 E. coli isolates were obtained from municipal wastewater and from fecal samples from domestic and wild animals. Conventional culture methods and standard chemical and biochemical tests were used for isolation and identification of E. coli. Isolates were assayed against 10 antibiotics using the micro-dilution technique. The results obtained generated antibiotic resistance profiles which were used to statistically group the isolates into different subsets. Correct source classification was obtained for 60% of human-derived and 95% non-human-derived E. coli respectively. These results indicate the validity of the usefulness of MAR indexing as a method of bacterial source tracking.


2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Danielle D. Cloutier ◽  
Sandra L. McLellan

ABSTRACT Alternative indicators have been developed that can be used to identify host sources of fecal pollution, yet little is known about how their distribution and fate compare to traditional indicators. Escherichia coli and enterococci were widely distributed at the six beaches studied and were detected in almost 95% of water samples (n = 422) and 100% of sand samples (n = 400). Berm sand contained the largest amount of E. coli (P < 0.01), whereas levels of enterococci were highest in the backshore (P < 0.01). E. coli and enterococci were the lowest in water, using a weight-to-volume comparison. The gull-associated Catellicoccus marimammalium (Gull2) marker was found in over 80% of water samples, regardless of E. coli levels, and in 25% of sand samples. Human-associated Bacteroides (HB) and Lachnospiraceae (Lachno2) were detected in only 2.4% of water samples collected under baseflow and post-rain conditions but produced a robust signal after a combined sewage overflow, despite low E. coli concentrations. Burdens of E. coli and enterococci in water and sand were disproportionately high in relation to alternative indicators when comparing environmental samples to source material. In microcosm studies, Gull2, HB, and Lachno2 quantitative PCR (qPCR) signals were reduced twice as quickly as those from E. coli and enterococci and approximately 20% faster than signals from culturable E. coli. High concentrations of alternative indicators in source material illustrated their high sensitivity for the identification of fecal sources; however, differential survival and the potential for long-term persistence of traditional fecal indicators complicate the use of alternative indicator data to account for the levels of E. coli and enterococci in environmental samples. IMPORTANCE E. coli and enterococci are general indicators of fecal pollution and may persist in beach sand, making their use problematic for many applications. This study demonstrates that gull fecal pollution is widespread at Great Lakes beaches, whereas human and ruminant contamination is evident only after major rain events. An exploration of sand as a reservoir for indicators found that E. coli was ubiquitous, while gull host markers were detected in only 25% of samples. In situ sand beach microcosms provided decay rate constants for E. coli and enterococci relative to alternative indicators, which establish comparative benchmarks that would be helpful to distinguish recent from past pollution. Overall, alternative indicators are useful for identifying sources and assessing potentially high health risk contamination events; however, beach managers should be cautious in attempting to directly link their detection to the levels of E. coli or enterococci.


2006 ◽  
Vol 72 (12) ◽  
pp. 7886-7893 ◽  
Author(s):  
Ayalkibet Hundesa ◽  
Carlos Maluquer de Motes ◽  
Silvia Bofill-Mas ◽  
Nestor Albinana-Gimenez ◽  
Rosina Girones

ABSTRACT The Adenoviridae and Polyomaviridae families comprise a wide diversity of viruses which may be excreted for long periods in feces or urine. In this study, a preliminary analysis of the prevalence in the environment and the potential usefulness as source-tracking tools of human and animal adenoviruses and polyomaviruses has been developed. Molecular assays based on PCR specifically targeting human adenoviruses (HAdV), porcine adenoviruses (PAdV), bovine adenoviruses (BAdV), and bovine polyomaviruses (BPyV) were applied to environmental samples including urban sewage, slaughterhouse, and river water samples. PAdV and BPyV were detected in a very high percentage of samples potentially affected by either porcine or bovine fecal contamination, respectively. However, BAdV were detected in only one sample, showing a lower prevalence than BPyV in the wastewater samples analyzed. The 22 slaughterhouse samples with fecal contamination of animal origin showed negative results for the presence of HAdV. The river water samples analyzed were positive for the presence of both human and animal adenoviruses and polyomaviruses, indicating the existence of diverse sources of contamination. The identities of the viruses detected were confirmed by analyses of the amplified sequences. All BPyV isolates showed a 97% similarity in nucleotide sequences. This is the first time that PAdV5, BAdV6, and BPyV have been reported to occur in environmental samples. Human and porcine adenoviruses and human and bovine polyomaviruses are proposed as tools for evaluating the presence of viral contamination and for tracking the origin of fecal/urine contamination in environmental samples.


2005 ◽  
Vol 71 (10) ◽  
pp. 5992-5998 ◽  
Author(s):  
Zexun Lu ◽  
David Lapen ◽  
Andrew Scott ◽  
Angela Dang ◽  
Edward Topp

ABSTRACT Repetitive extragenic palindromic PCR fingerprinting of Escherichia coli is one microbial source tracking approach for identifying the host source origin of fecal pollution in aquatic systems. The construction of robust known-source libraries is expensive and requires an informed sampling strategy. In many types of farming systems, waste is stored for several months before being released into the environment. In this study we analyzed, by means of repetitive extragenic palindromic PCR using the enterobacterial repetitive intergenic consensus primers and comparative analysis using the Bionumerics software, collections of E. coli obtained from a dairy farm and from a swine farm, both of which stored their waste as a slurry in holding tanks. In all fecal samples, obtained from either barns or holding tanks, the diversity of the E. coli populations was underrepresented by collections of 500 isolates. In both the dairy and the swine farms, the diversity of the E. coli community was greater in the manure holding tank than in the barn, when they were sampled on the same date. In both farms, a comparison of stored manure samples collected several months apart suggested that the community composition changed substantially in terms of the detected number, absolute identity, and relative abundance of genotypes. Comparison of E. coli populations obtained from 10 different locations in either holding tank suggested that spatial variability in the E. coli community should be accounted for when sampling. Overall, the diversity in E. coli populations in manure slurry storage facilities is significant and likely is problematic with respect to library construction for microbial source tracking applications.


2005 ◽  
Vol 51 (6) ◽  
pp. 501-505 ◽  
Author(s):  
Thomas A Edge ◽  
Stephen Hill

Antibiotic resistance was examined in 462 Escherichia coli isolates from surface waters and fecal pollution sources around Hamilton, Ontario. Escherichia coli were resistant to the highest concentrations of each of the 14 antibiotics studied, although the prevalence of high resistance was mostly low. Two of 12 E. coli isolates from sewage in a CSO tank had multiple resistance to ampicillin, ciprofloxacin, gentamicin, and tetracycline above their clinical breakpoints. Antibiotic resistance was less prevalent in E. coli from bird feces than from municipal wastewater sources. A discriminant function calculated from antibiotic resistance data provided an average rate of correct classification of 68% for discriminating E. coli from bird and wastewater fecal pollution sources. The preliminary microbial source tracking results suggest that, at times, bird feces might be a more prominent contributor of E. coli to Bayfront Park beach waters than municipal wastewater sources.Key words: antibiotic resistance, Escherichia coli, surface water, fecal pollution.


2020 ◽  
Vol 82 (12) ◽  
pp. 2929-2936
Author(s):  
Pimchanok Nopprapun ◽  
Suwanna Kitpati Boontanon ◽  
Hidenori Harada ◽  
Nawatch Surinkul ◽  
Shigeo Fujii

Abstract High levels of microbial fecal pollution are a major concern in many countries. A human-associated genetic marker for Escherichia coli (H8) has recently been developed for fecal source tracking. The assessment of the H8 marker performance is crucial before it can be applied as a suitable method for fecal source tracking in each country. The performance (specificity and sensitivity) of the H8 marker was evaluated by using non-target host groups (cattle, buffalo, chicken, duck, and pig feces) and target host groups (influent and effluent from a wastewater treatment plant and septages). SYBR based real-time PCR (polymerase chain reaction) was done on 400 E. coli isolates from non-target and target host groups after E. coli isolation. It was found that the specificity from animal feces samples collected in Thailand was 96%. Moreover, influent, effluent, and septage samples showed the values of the sensitivity at 18, 12, and 36%, respectively. All of the non-target host groups were found to be significantly different with positive proportions from the target host group (septage samples) (p ≤ 0.01). Based on the results, this marker is recommended for use as a human-associated E. coli marker for identifying sources of fecal pollution in Thailand.


2003 ◽  
Vol 66 (1) ◽  
pp. 88-93 ◽  
Author(s):  
SEEMA ENDLEY ◽  
LINGENG LU ◽  
EVERARDO VEGA ◽  
MICHAEL E. HUME ◽  
SURESH D. PILLAI

The objective of this study was to evaluate the efficacy of male-specific (F+) coliphages as a fecal-contaminationindicator for fresh carrots. The prevalence of specific pathogens and indicator organisms on the surface of carrots obtained from a farm, truck, and processing shed was studied. Twenty-five carrot samples collected from each of these locations were washed, and aliquots of the wash were analyzed for the presence of F+ coliphages, Escherichia coli, Salmonella, and Shigella. Additionally, the Salmonella isolates were genotyped using pulsed-field gel electrophoresis (PFGE). Our studies detected the presence of F+ coliphages, E. coli, and Salmonella on carrots. All samples, however, tested negative for Shigella. Although none of the carrot samples from the field were positive for E. coli, one sample was positive for Salmonella, and another was positive for F+ coliphages. From the truck, two carrot samples (8%) were positive for Salmonella, four (16%) were positive for F+ coliphages, and four (16%) were positive for E. coli. None of the carrot samples from the processing shed were positive for Salmonella. However, 2 carrot samples (8%) were positive for E. coli, and 14 carrot samples (56%) were positive for F+ coliphages. The PFGE results suggest that there were three distinct Salmonella genotypes among the carrot samples from the truck and that the Salmonella isolates identified on carrot samples from the field and truck locations were different. Microbiological screening of fresh produce such as carrots (which can be exposed to fecal contaminants in soils and water) should ensure the detection of both viral and bacterial contaminants. Overall, in this study, F+ coliphages were detected in 25% of the carrot samples, compared to E. coli (8%), Salmonella (4%), and Shigella (0%). The results suggest F+ coliphages can serve as a conservative indicator of fecally associated viruses on carrots. This suggests that in addition to E. coli screening, F+ coliphages should be included when produce such as carrots that are vulnerable to fecal contaminants are screened. Since the detection of specific enteric viral pathogens is expensive, screening for viral indicators of fecal contamination using F+ coliphages can be an economical approach to providing an additional level of assurance about the microbiological quality of fresh carrots.


2006 ◽  
Vol 72 (6) ◽  
pp. 4012-4019 ◽  
Author(s):  
Matthew J. Hamilton ◽  
Tao Yan ◽  
Michael J. Sadowsky

ABSTRACT The contamination of waterways with fecal material is a persistent threat to public health. Identification of the sources of fecal contamination is a vital component for abatement strategies and for determination of total maximum daily loads. While phenotypic and genotypic techniques have been used to determine potential sources of fecal bacteria in surface waters, most methods require construction of large known-source libraries, and they often fail to adequately differentiate among environmental isolates originating from different animal sources. In this study, we used pooled genomic tester and driver DNAs in suppression subtractive hybridizations to enrich for host source-specific DNA markers for Escherichia coli originating from locally isolated geese. Seven markers were identified. When used as probes in colony hybridization studies, the combined marker DNAs identified 76% of the goose isolates tested and cross-hybridized, on average, with 5% of the human E. coli strains and with less than 10% of the strains obtained from other animal hosts. In addition, the combined probes identified 73% of the duck isolates examined, suggesting that they may be useful for determining the contribution of waterfowl to fecal contamination. However, the hybridization probes reacted mainly with E. coli isolates obtained from geese in the upper midwestern United States, indicating that there is regional specificity of the markers identified. Coupled with high-throughput, automated macro- and microarray screening, these markers may provide a quantitative, cost-effective, and accurate library-independent method for determining the sources of genetically diverse E. coli strains for use in source-tracking studies. However, future efforts to generate DNA markers specific for E. coli must include isolates obtained from geographically diverse animal hosts.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongxia Liang ◽  
Zhisheng Yu ◽  
Bobo Wang ◽  
Fabrice Ndayisenga ◽  
Ruyin Liu ◽  
...  

It is important to track fecal sources from humans and animals that negatively influence the water quality of rural rivers and human health. In this study, microbial source tracking (MST) methods using molecular markers and the community-based FEAST (fast expectation–maximization microbial source tracking) program were synergistically applied to distinguish the fecal contributions of multiple sources in a rural river located in Beijing, China. The performance of eight markers were evaluated using 133 fecal samples based on real-time quantitative (qPCR) technique. Among them, six markers, including universal (BacUni), human-associated (HF183-1 and BacH), swine-associated (Pig-2-Bac), ruminant-associated (Rum-2-Bac), and avian-associated (AV4143) markers, performed well in the study. A total of 96 water samples from the river and outfalls showed a coordinated composition of fecal pollution, which revealed that outfall water might be a potential input of the Fsq River. In the FEAST program, bacterial 16S rRNA genes of 58 fecal and 12 water samples were sequenced to build the “source” library and “sink,” respectively. The relative contribution (&lt;4.01% of sequence reads) of each source (i.e., human, swine, bovine, or sheep) was calculated based on simultaneous screening of the operational taxonomic units (OTUs) of sources and sinks, which indicated that community-based MST methods could be promising tools for identifying fecal sources from a more comprehensive perspective. Results of the qPCR assays indicated that fecal contamination from human was dominant during dry weather and that fecal sources from swine and ruminant were more prevalent in samples during the wet season than in those during the dry season, which were consistent with the findings predicted by the FEAST program using a very small sample size. Information from the study could be valuable for the development of improved regulation policies to reduce the levels of fecal contamination in rural rivers.


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