scholarly journals Assessment of Giardia and Cryptosporidium spp. as a Microbial Source Tracking Tool for Surface Water: Application in a Mixed-Use Watershed

2014 ◽  
Vol 80 (8) ◽  
pp. 2328-2336 ◽  
Author(s):  
Natalie Prystajecky ◽  
Peter M. Huck ◽  
Hans Schreier ◽  
Judith L. Isaac-Renton

ABSTRACTKnowledge of host specificity, combined with genomic sequencing ofGiardiaandCryptosporidiumspp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period.Cryptosporidiumwas detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters.Giardiawas detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% ofCryptosporidiumsamples and 98% ofGiardiasamples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy.Cryptosporidiumgenotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared toGiardia, since 98% ofGiardiaisolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows thatCryptosporidiumsubtyping for MST purposes is superior to the use ofGiardiasubtyping, based on better detection limits forCryptosporidium-positive samples than forGiardia-positive samples and on greater host specificity amongCryptosporidiumspecies. These additional tools could be used for risk assessment in public health and watershed management decisions.

2013 ◽  
Vol 79 (8) ◽  
pp. 2682-2691 ◽  
Author(s):  
W. Ahmed ◽  
T. Sritharan ◽  
A. Palmer ◽  
J. P. S. Sidhu ◽  
S. Toze

ABSTRACTThis study was aimed at evaluating the host specificity and host sensitivity of two bovine feces-associated bacterial (BacCow-UCD and cowM3) and one viral [bovine adenovirus (B-AVs)] microbial source tracking (MST) markers by screening 130 fecal and wastewater samples from 10 target and nontarget host groups in southeast Queensland, Australia. In addition, 36 water samples were collected from a reservoir and tested for the occurrence of all three bovine feces-associated markers along with fecal indicator bacteria (FIB),Campylobacterspp.,Escherichia coliO157, andSalmonellaspp. The overall host specificity values of the BacCow-UCD, cowM3, and B-AVs markers to differentiate between bovine and other nontarget host groups were 0.66, 0.88, and 1.00, respectively (maximum value of 1.00). The overall host sensitivity values of these markers, however, in composite bovine wastewater and individual bovine fecal DNA samples were 0.93, 0.90, and 0.60, respectively (maximum value of 1.00). Among the 36 water samples tested, 56%, 22%, and 6% samples were PCR positive for the BacCow-UCD, cowM3, and B-AVs markers, respectively. Among the 36 samples tested, 50% and 14% samples were PCR positive for theCampylobacter16S rRNA andE. coliO157rfbEgenes, respectively. Based on the results, we recommend that multiple bovine feces-associated markers be used if possible for bovine fecal pollution tracking. Nonetheless, the presence of the multiple bovine feces-associated markers along with the presence of potential zoonotic pathogens indicates bovine fecal pollution in the reservoir water samples. Further research is required to understand the decay rates of these markers in relation to FIB and zoonotic pathogens.


2021 ◽  
Vol 12 ◽  
Author(s):  
Annastiina Rytkönen ◽  
Ananda Tiwari ◽  
Anna-Maria Hokajärvi ◽  
Sari Uusheimo ◽  
Asko Vepsäläinen ◽  
...  

For microbial source tracking (MST), the 16S ribosomal RNA genes (rDNA) of host-specific bacteria and mitochondrial DNA (mtDNA) of animal species, known to cause fecal contamination of water, have been commonly used as molecular targets. However, low levels of contamination might remain undetected by using these DNA-based qPCR assays. The high copy numbers of ribosomal RNA (rRNA) could offer a solution for such applications of MST. This study compared the performance of eight MST assays: GenBac3 (general Bacteroidales), HF183 (human), BacCan (dog), Rum-2-Bac (ruminant), Pig-2-Bac (swine), Gull4 (gull), GFD, and Av4143 (birds) between rRNA-based and rDNA-based approaches. Three mtDNA-based approaches were tested: DogND5, SheepCytB, and HorseCytB. A total of 151 animal fecal samples and eight municipal sewage samples from four regions of Finland were collected for the marker evaluation. The usability of these markers was tested by using a total of 95 surface water samples with an unknown pollution load. Overall, the performance (specificity, sensitivity, and accuracy) of mtDNA-based assays was excellent (95–100%), but these markers were very seldom detected from the tested surface water samples. The rRNA template increased the sensitivity of assays in comparison to the rDNA template. All rRNA-based assays (except Av4143) had more than 80% sensitivity. In contrast, only half (HF183, Rum-2-Bac, Pig-2-Bac, and Gull4) of rDNA-based assays reached this value. For markers targeted to bird feces, the use of the rRNA-based assay increased or at least did not change the performance. Regarding specificity, all the assays had >95% specificity with a DNA template, except the BacCan assay (71%). While using the RNA template for the assays, HF183 and BacCan exhibited only a low level of specificity (54 and 55%, respectively). Further, the HF183 assay amplified from multiple non-targeted animal fecal samples with the RNA template and the marker showed cross-amplification with the DNA template as well. This study recommends using the rRNA-based approach for MST assays targeting bird fecal contamination. In the case of mammal-specific MST assays, the use of the rRNA template increases the sensitivity but may reduce the specificity and accuracy of the assay. The finding of increased sensitivity calls for a further need to develop better rRNA-based approaches to reach the required assay performance.


2001 ◽  
Vol 67 (3) ◽  
pp. 1123-1127 ◽  
Author(s):  
Otto D. Simmons ◽  
Mark D. Sobsey ◽  
Christopher D. Heaney ◽  
Frank W. Schaefer ◽  
Donna S. Francy

ABSTRACT The protozoan parasite Cryptosporidium parvumis known to occur widely in both source and drinking water and has caused waterborne outbreaks of gastroenteritis. To improve monitoring, the U.S. Environmental Protection Agency developed method 1622 for isolation and detection of Cryptosporidium oocysts in water. Method 1622 is performance based and involves filtration, concentration, immunomagnetic separation, fluorescent-antibody staining and 4′,6-diamidino-2-phenylindole (DAPI) counterstaining, and microscopic evaluation. The capsule filter system currently recommended for method 1622 was compared to a hollow-fiber ultrafilter system for primary concentration of C. parvum oocysts in seeded reagent water and untreated surface waters. Samples were otherwise processed according to method 1622. Rates of C. parvumoocyst recovery from seeded 10-liter volumes of reagent water in precision and recovery experiments with filter pairs were 42% (standard deviation [SD], 24%) and 46% (SD, 18%) for hollow-fiber ultrafilters and capsule filters, respectively. Mean oocyst recovery rates in experiments testing both filters on seeded surface water samples were 42% (SD, 27%) and 15% (SD, 12%) for hollow-fiber ultrafilters and capsule filters, respectively. Although C. parvum oocysts were recovered from surface waters by using the approved filter of method 1622, the recovery rates were significantly lower and more variable than those from reagent grade water. In contrast, the disposable hollow-fiber ultrafilter system was compatible with subsequent method 1622 processing steps, and it recovered C. parvum oocysts from seeded surface waters with significantly greater efficiency and reliability than the filter suggested for use in the version of method 1622 tested.


Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 807-813 ◽  
Author(s):  
David R. Shaw ◽  
Stephen M. Schraer ◽  
Joby Prince ◽  
Michele Boyette

A two-year surface water reconnaissance of the Bogue Phalia and its tributaries was conducted in 1997 and 1998. Cyanazine and metolachlor in surface water samples were quantified using enzyme-linked immunosorbent assays (ELISA). Cyanazine and metolachlor were detected in 101 and 132 of 160 samples, respectively. Cyanazine concentrations ranged from 0.1 to 2.2 g L−1and exceeded the U.S. Environmental Protection Agency (EPA) lifetime health advisory level (HAL) of 1 g L−1in eight samples. However, concentrations never exceeded the HAL for shorter exposure times. Metolachlor concentrations never reached the lifetime HAL of 100 g L−1. Metolachlor concentrations ranged from 0.1 to 20.6 g L−1. Metolachlor was detected more frequently and found to be more persistent throughout the growing season than was cyanazine. Higher cyanazine and metolachlor concentrations were detected at sampling dates that coincided with herbicide applications. One of the Bogue Phalia's tributaries, Clear Creek, was found to be a point-source of cyanazine for the watershed.


2012 ◽  
Vol 78 (16) ◽  
pp. 5788-5795 ◽  
Author(s):  
Marta Gómez-Doñate ◽  
Elisenda Ballesté ◽  
Maite Muniesa ◽  
Anicet R. Blanch

ABSTRACTBifidobacteriumspp. belong to the commensal intestinal microbiota of warm-blooded animals. Some strains ofBifidobacteriumshow host specificity and have thus been proposed as host-specific targets to determine the origin of fecal pollution. Most strains have been used in microbial-source-tracking (MST) studies based on culture-dependent methods. Although some of these approaches have proved very useful, the low prevalence of culturableBifidobacteriumstrains in the environment means that molecular culture-independent procedures could provide practical applications for MST. Reported here is a set of common primers and fourBifidobacteriumsp. host-associated (human, cattle, pig, and poultry) probes for quantitative-PCR (qPCR) assessment of fecal source tracking. This set was tested using 25 water samples of diverse origin: urban sewage samples, wastewater from four abattoirs (porcine, bovine, and poultry), and water from a river with a low pollution load. The selected sequences showed a high degree of host specificity. There were no cross-reactions between the qPCR assays specific for each origin and samples from different fecal origins. On the basis of the findings, it was concluded that the host-specific qPCRs are sufficiently robust to be applied in environmental MST studies.


2020 ◽  
Vol 86 (23) ◽  
Author(s):  
Mauricio Durigan ◽  
Helen R. Murphy ◽  
Alexandre J. da Silva

ABSTRACT Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne diarrheal illness outbreaks worldwide. Most of these outbreaks are associated with the consumption of fresh produce. Sensitive and specific methods to detect C. cayetanensis in agricultural water are needed to identify the parasite in agricultural water used to irrigate crops that have been implicated in outbreaks. In this study, a method to detect C. cayetanensis in water by combining dead-end ultrafiltration (DEUF) with sensitive and specific molecular detection was developed and evaluated. Triplicates of 10-liter agricultural water samples were seeded with 200, 100, 25, 12, and 6 C. cayetanensis oocysts. Surface water samples were also collected in the Mid-Atlantic region. All water samples were processed by DEUF and backflushed from the ultrafilters. DNA was extracted from concentrated samples and analyzed by quantitative PCR (qPCR) targeting the C. cayetanensis 18S rRNA gene. All water samples seeded with 12, 25, 100, and 200 oocysts were positive, and all unseeded samples were negative. Samples seeded with 6 oocysts had a detection rate of 66.6% (8/12). The method was also able to detect C. cayetanensis isolates in surface water samples from different locations of the Chesapeake and Ohio Canal (C&O Canal) in Maryland. This approach could consistently detect C. cayetanensis DNA in 10-liter agricultural water samples contaminated with low levels of oocysts, equivalent to the levels that may be found in naturally incurred environmental water sources. Our data demonstrate the robustness of the method as a useful tool to detect C. cayetanensis from environmental sources. IMPORTANCE Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne outbreaks of diarrheal illness worldwide. These foodborne outbreaks associated with the consumption of fresh produce and agricultural water could play a role in the contamination process. In this study, a method to detect C. cayetanensis in agricultural water by combining a robust filtration system with sensitive and specific molecular detection was developed and validated by the FDA. The results showed that this approach could consistently detect low levels of C. cayetanensis contamination in 10 liters of agricultural water, corresponding to the levels that may be found in naturally occurring environmental water sources. The method was also able to detect C. cayetanensis in surface water samples from a specific location in the Mid-Atlantic region. Our data demonstrate the robustness of the method to detect C. cayetanensis in agricultural water samples, which could be very useful to identify environmental sources of contamination.


2012 ◽  
Vol 78 (12) ◽  
pp. 4338-4345 ◽  
Author(s):  
Hodon Ryu ◽  
Jingrang Lu ◽  
Jason Vogel ◽  
Michael Elk ◽  
Felipe Chávez-Ramírez ◽  
...  

ABSTRACTWhile the microbial water quality in the Platte River is seasonally impacted by excreta from migrating cranes, there are no methods available to study crane fecal contamination. Here we characterized microbial populations in crane feces using phylogenetic analysis of 16S rRNA gene fecal clone libraries. Using these sequences, a novel crane quantitative PCR (Crane1) assay was developed, and its applicability as a microbial source tracking (MST) assay was evaluated by determining its host specificity and detection ability in environmental waters. Bacteria from crane excreta were dominated by bacilli and proteobacteria, with a notable paucity of sequences homologous toBacteroidetesandClostridia. The Crane1 marker targeted a dominant clade of unclassifiedLactobacillalessequences closely related toCatellicoccus marimammalium. The host distribution of the Crane1 marker was relatively high, being positive for 69% (66/96) of the crane excreta samples tested. The assay also showed high host specificity, with 95% of the nontarget fecal samples (i.e.,n= 553; 20 different free-range hosts) being negative. Of the presumed crane-impacted water samples (n= 16), 88% were positive for the Crane1 assay, whereas none of the water samples not impacted by cranes were positive (n= 165). Bayesian statistical models of the Crane1 MST marker demonstrated high confidence in detecting true-positive signals and a low probability of false-negative signals from environmental water samples. Altogether, these data suggest that the newly developed marker could be used in environmental monitoring studies to study crane fecal pollution dynamics.


2006 ◽  
Vol 6 (2) ◽  
pp. 47-53 ◽  
Author(s):  
D. Simazaki ◽  
M. Asami ◽  
T. Nishimura ◽  
S. Kunikane ◽  
T. Aizawa ◽  
...  

Nationwide surveys of 1,4-dioxane and methyl-t-butyl ether (MTBE) levels in raw water used for the drinking water supply were conducted at 91 water treatment plants in Japan in 2001 and 2002, prior to the revision of the drinking water quality standards. 1,4-dioxane was widely and continuously detected in raw water samples and its occurrence was more frequent and its concentrations higher in groundwater than in surface water. However, its maximum concentration in raw water was much lower than its new standard value (50 μg/L), which was determined as a level of 10−5 excessive cancer risk to humans. Trace levels of MTBE were also detected in several surface water samples.


Author(s):  
Kamran Bashir ◽  
Zhimin Luo ◽  
Guoning Chen ◽  
Hua Shu ◽  
Xia Cui ◽  
...  

Griseofulvin (GSF) is clinically employed to treat fungal infections in humans and animals. GSF was detected in surface waters as a pharmaceutical pollutant. GSF detection as an anthropogenic pollutant is considered as a possible source of drug resistance and risk factor in ecosystem. To address this concern, a new extraction and enrichment method was developed. GSF-surface molecularly imprinted polymers (GSF-SMIPs) were prepared and applied as solid phase extraction (SPE) sorbent. A dispersive solid phase extraction (DSPE) method was designed and combined with HPLC for the analysis of GSF in surface water samples. The performance of GSF-SMIPs was assessed for its potential to remove GSF from water samples. The factors affecting the removal efficiency such as sample pH and ionic strength were investigated and optimized. The DSPE conditions such as the amount of GSF-SMIPs, the extraction time, the type and volume of desorption solvents were also optimized. The established method is linear over the range of 0.1–100 µg/mL. The limits of detection and quantification were 0.01 and 0.03 µg/mL respectively. Good recoveries (91.6–98.8%) were achieved after DSPE. The intra-day and inter-day relative standard deviations were 0.8 and 4.3% respectively. The SMIPs demonstrated good removal efficiency (91.6%) as compared to powder activated carbon (67.7%). Moreover, the SMIPs can be reused 10 times for water samples. This is an additional advantage over single-use activated carbon and other commercial sorbents. This study provides a specific and sensitive method for the selective extraction and detection of GSF in surface water samples.


Sign in / Sign up

Export Citation Format

Share Document