Male-specific coliphages for source tracking fecal contamination in surface waters and prevalence of Shiga-toxigenic Escherichia coli in a major produce production region of the Central Coast of California

2015 ◽  
Vol 17 (7) ◽  
pp. 1249-1256 ◽  
Author(s):  
Subbarao V. Ravva ◽  
Chester Z. Sarreal ◽  
Michael B. Cooley
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Fecal Contamination ◽  
Enteric Pathogens ◽  
Source Tracking ◽  
Central Coast ◽  
Prevalence Data ◽  
Production Region ◽  
Male Specific

F+ RNA coliphages are invaluable for predicting the sources of fecal contamination in the environment and their prevalence data may aid in preventing the spread of enteric pathogens from likely sources.

scholarly journals Evaluation of microbial source tracking methods using mixed fecal sources in aqueous test samples

2003 ◽  
Vol 1 (4) ◽  
pp. 141-151 ◽  
Author(s):  
John F. Griffith ◽  
Stephen B. Weisberg ◽  
Charles D. McGee
Keyword(s):  
Surface Waters ◽  
Water Samples ◽  
Fecal Contamination ◽  
Source Material ◽  
Source Tracking ◽  
Fecal Material ◽  
Comparative Testing ◽  
Specific Pcr ◽  
Phenotypic Methods ◽  
Better Than

Microbiological source tracking (MST) methods are increasingly being used to identify fecal contamination sources in surface waters, but these methods have been subjected to limited comparative testing. In this study, 22 researchers employing 12 different methods were provided sets of identically prepared blind water samples. Each sample contained one to three of five possible fecal sources (human, dog, cattle, seagull or sewage). Researchers were also provided with portions of the fecal material used to inoculate the blind water samples for use as library material. No MST method that was tested predicted the source material in the blind samples perfectly. Host-specific PCR performed best at differentiating between human and non-human sources, but primers are not yet available for differentiating between all of the non-human sources. Virus and F+ coliphage methods reliably identified sewage, but were unable to identify fecal contamination from individual humans. Library-based isolate methods correctly identified the dominant source in most samples, but also had frequent false positives in which fecal sources not in the samples were incorrectly identified as being present. Among the library-based methods, genotypic methods generally performed better than phenotypic methods.

Occurrence of antibiotic resistance inEscherichia colifrom surface waters and fecal pollution sources near Hamilton, Ontario

2005 ◽  
Vol 51 (6) ◽  
pp. 501-505 ◽  
Author(s):  
Thomas A Edge ◽  
Stephen Hill
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Surface Waters ◽  
Municipal Wastewater ◽  
Average Rate ◽  
Fecal Pollution ◽  
Pollution Sources ◽  
Source Tracking ◽  
E Coli ◽  
Bird Feces

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.

scholarly journals Development of Goose- and Duck-Specific DNA Markers To Determine Sources of Escherichia coli in Waterways

2006 ◽  
Vol 72 (6) ◽  
pp. 4012-4019 ◽  
Author(s):  
Matthew J. Hamilton ◽  
Tao Yan ◽  
Michael J. Sadowsky
Keyword(s):  
Escherichia Coli ◽  
Dna Markers ◽  
Fecal Contamination ◽  
Cost Effective ◽  
Source Tracking ◽  
E Coli ◽  
Hybridization Probes ◽  
Animal Hosts ◽  
Maximum Daily Loads ◽  
Microarray Screening

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.

scholarly journals Escherichia coli Contamination of Lettuce Grown in Soils Amended with Animal Slurry

2013 ◽  
Vol 76 (7) ◽  
pp. 1137-1144 ◽  
Author(s):  
A. N. JENSEN ◽  
C. STORM ◽  
A. FORSLUND ◽  
D. L. BAGGESEN ◽  
A. DALSGAARD
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Growth Period ◽  
Soil Samples ◽  
Enteric Pathogens ◽  
Human Pathogens ◽  
Safety Hazards ◽  
E Coli ◽  
Animal Slurry ◽  
Frequent Finding

A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish agricultural fields prior to the planting of lettuce seedlings. At harvest, leaves (25 g) of 10 lettuce heads were pooled into one sample unit (n = 147). Soil samples (100 g) were collected from one field before slurry application and four times during the growth period (n = 75). E. coli was enumerated in slurry, soil, and lettuce on 3M Petrifilm Select E. coli Count Plates containing 16 mg/liter streptomycin, 16 mg/liter ampicillin, or no antimicrobial agent. Selected E. coli isolates (n = 83) originating from the slurry, soil, and lettuce were genotyped by pulsed-field gel electrophoresis (PFGE) to determine the similarity of isolates. The slurry applied to the fields contained 3.0 to 4.5 log CFU/g E. coli. E. coli was found in 36 to 54% of the lettuce samples, streptomycin-resistant E. coli was found in 10.0 to 18.0% of the lettuce samples, and ampicillin-resistant E. coli in 0 to 2.0% of the lettuce samples (the detection limit was 1 log CFU/g). The concentration of E. coli exceeded 2 log CFU/g in 19.0% of the lettuce samples. No E. coli was detected in the soil before the slurry was applied, but after, E. coli was present until the last sampling day (harvest), when 10 of 15 soil samples contained E. coli. A relatively higher frequency of E. coli in lettuce compared with the soil samples at harvest suggests environmental sources of fecal contamination, e.g., wildlife. The higher frequency was supported by the finding of 21 different PFGE types among the E. coli isolates, with only a few common PFGE types between slurry, soil, and lettuce. The frequent finding of fecal-contaminated lettuce indicates that human pathogens such as Salmonella and Campylobacter can be present and represent food safety hazards.

scholarly journals Microbial source tracking of fecal contamination in Laguna Lake, Philippines using the library-dependent method, rep-PCR

2021 ◽  
Author(s):  
Laurice Beatrice Raphaelle O. dela Peña ◽  
Kevin L. Labrador ◽  
Mae Ashley G. Nacario ◽  
Nicole R. Bolo ◽  
Windell L. Rivera
Keyword(s):  
Surface Waters ◽  
Fecal Contamination ◽  
Microbial Source Tracking ◽  
The Philippines ◽  
Source Tracking ◽  
Source Attribution ◽  
Monitoring Methods ◽  
K Nearest Neighbors ◽  
Fecal Indicator ◽  
Laguna Lake

Abstract Laguna Lake is an economically important resource in the Philippines, with reports of declining water quality due to fecal pollution. Currently, monitoring methods rely on counting fecal indicator bacteria, which does not supply information on potential sources of contamination. In this study, we predicted sources of Escherichia coli in lake stations and tributaries by establishing a fecal source library composed of rep-PCR DNA fingerprints of human, cattle, swine, poultry, and sewage samples (n = 1,408). We also evaluated three statistical methods for predicting fecal contamination sources in surface waters. Random forest (RF) outperformed k-nearest neighbors and discriminant analysis of principal components in terms of average rates of correct classification in two- (84.85%), three- (82.45%), and five-way (74.77%) categorical splits. Overall, RF exhibited the most balanced prediction, which is crucial for disproportionate libraries. Source tracking of environmental isolates (n = 332) revealed the dominance of sewage (47.59%) followed by human sources (29.22%), poultry (12.65%), swine (7.23%), and cattle (3.31%) using RF. This study demonstrates the promising utility of a library-dependent method in augmenting current monitoring systems for source attribution of fecal contamination in Laguna Lake. This is also the first known report of microbial source tracking using rep-PCR conducted in surface waters of the Laguna Lake watershed.

scholarly journals Host Species-Specific Metabolic Fingerprint Database for Enterococci and Escherichia coli and Its Application To Identify Sources of Fecal Contamination in Surface Waters

2005 ◽  
Vol 71 (8) ◽  
pp. 4461-4468 ◽  
Author(s):  
W. Ahmed ◽  
R. Neller ◽  
M. Katouli
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Water Samples ◽  
Fecal Contamination ◽  
E Coli ◽  
Individual Host ◽  
Metabolic Fingerprint ◽  
The Mean ◽  
Species Specific ◽  
Fingerprint Database

ABSTRACT A metabolic fingerprint database of enterococci and Escherichia coli from 10 host groups of animals was developed to trace the sources of fecal contamination in surface waters. In all, 526 biochemical phenotypes (BPTs) of enterococci and 530 E. coli BPTs were obtained from 4,057 enterococci and 3,728 E. coli isolates tested. Of these, 231 Enterococcus BPTs and 257 E. coli BPTs were found in multiple host groups. The remaining 295 Enterococcus BPTs and 273 E. coli BPTs were unique to individual host groups. The database was used to trace the sources of fecal contamination in a local creek. The mean diversities (Di) of enterococci (Di = 0.76 ± 0.05) and E. coli (Di = 0.88 ± 0.04) were high (maximum 1) in water samples, indicating diverse sources of fecal contamination. Overall, 71% of BPTs of enterococci and 67% of E. coli BPTs from water samples were identified as human and animal sources. Altogether, 248 Enterococcus BPTs and 282 E. coli BPTs were found in water samples. Among enterococci, 26 (10%) BPTs were identical to those of humans and 152 BPTs (61%) were identical to those of animals (animal BPTs). Among E. coli isolates, 36 (13%) BPTs were identical to those of humans and 151 (54%) BPTs were identical to those of animals. Of the animal BPTs, 101 (66%) Enterococcus BPTs and 93 (62%) E. coli BPTs were also unique to individual animal groups. On the basis of these unique Enterococcus BPTs, chickens contributed 14% of contamination, followed by humans (10%), dogs (7%), and horses (6%). For E. coli, humans contributed 13% of contamination, followed by ducks (9%), cattle (7%), and chickens (6%). The developed metabolic fingerprint database was able to distinguish between human and animal sources as well as among animal species in the studied catchment.

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