scholarly journals Phenotypic library-based microbial source tracking methods: Efficacy in the California collaborative study

2003 ◽  
Vol 1 (4) ◽  
pp. 153-166 ◽  
Author(s):  
Valerie J. Harwood ◽  
Bruce Wiggins ◽  
Charles Hagedorn ◽  
R. D. Ellender ◽  
Jan Gooch ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Water Samples ◽  
False Positive ◽  
Collaborative Study ◽  
Microbial Source Tracking ◽  
Fecal Coliforms ◽  
Source Tracking ◽  
E Coli ◽  
Fecal Streptococci ◽  
Positive Rate

As part of a larger microbial source tracking (MST) study, several laboratories used library-based, phenotypic subtyping techniques to analyse fecal samples from known sources (human, sewage, cattle, dogs and gulls) and blinded water samples that were contaminated with the fecal sources. The methods used included antibiotic resistance analysis (ARA) of fecal streptococci, enterococci, fecal coliforms and E. coli; multiple antibiotic resistance (MAR) and Kirby-Bauer antibiotic susceptibility testing of E. coli; and carbon source utilization for fecal streptococci and E. coli. Libraries comprising phenotypic patterns of indicator bacteria isolated from known fecal sources were used to predict the sources of isolates from water samples that had been seeded with fecal material from the same sources as those used to create the libraries. The accuracy of fecal source identification in the water samples was assessed both with and without a cut-off termed the minimum detectable percentage (MDP). The libraries (∼300 isolates) were not large enough to avoid the artefact of source-independent grouping, but some important conclusions could still be drawn. Use of a MDP decreased the percentage of false-positive source identifications, and had little effect on the high percentage of true-positives in the most accurate libraries. In general, the methods were more prone to false-positive than to false-negative errors. The most accurate method, with a true-positive rate of 100% and a false-positive rate of 39% when analysed with a MDP, was ARA of fecal streptococci. The internal accuracy of the libraries did not correlate with the accuracy of source prediction in water samples, showing that one should not rely solely on parameters such as the average rate of correct classification of a library to indicate its predictive capabilities.

Comparison of genotypic-based microbial source tracking methods requiring a host origin database

2003 ◽  
Vol 1 (4) ◽  
pp. 167-180 ◽  
Author(s):  
Samuel P. Myoda ◽  
C. Andrew Carson ◽  
Jeffry J. Fuhrmann ◽  
Byoung-Kwon Hahm ◽  
Peter G. Hartel ◽  
...  
Keyword(s):  
Water Samples ◽  
False Positive ◽  
Pattern Analysis ◽  
Repetitive Element ◽  
Microbial Source Tracking ◽  
Pulsed Field Gel Electrophoresis ◽  
Source Tracking ◽  
Fecal Material ◽  
Database Construction ◽  
Host Origin

Microbial source tracking (MST) results, obtained using identical sample sets and pulsed field gel electrophoresis (PFGE), repetitive element PCR (rep-PCR) and ribotyping techniques were compared. These methods were performed by six investigators in analysis of duplicate, blind sets of water samples spiked with feces from five possible sources (sewage, human, dog, cow and seagull). Investigators were provided with samples of the fecal material used to inoculate the water samples for host origin database construction. All methods correctly identified the dominant source in the majority of the samples. Modifications of some of these methods correctly identified the dominant sources in over 90% of the samples; however, false positive rates were as high as 57%. The high false positive rates appeared to be indirectly proportional to the levels of stringency applied in pattern analysis. All the methods produced useful data but the results highlighted the need to modify and optimize these methods in order to minimize sources of error.

Experience with the antibiotic resistance analysis and DNA fingerprinting in tracking faecal pollution at two lake beaches

2007 ◽  
Vol 56 (11) ◽  
pp. 51-58 ◽  
Author(s):  
T.A. Edge ◽  
S. Hill ◽  
G. Stinson ◽  
P. Seto ◽  
J. Marsalek
Keyword(s):  
Antibiotic Resistance ◽  
Dna Fingerprinting ◽  
Microbial Source Tracking ◽  
Source Tracking ◽  
Faecal Contamination ◽  
E Coli ◽  
Resistance Analysis ◽  
Antibiotic Resistance Analysis ◽  
Environmental Challenge ◽  
Made In

Posting or closing of swimming beaches because of faecal contamination is a widespread problem reported in many locations. In a risk-based approach to this problem, the risk to swimmers' health is assessed by field monitoring of indicator bacteria and the associated risks are managed by source controls and other remedial measures. In risk assessment, great advances have been made in recent years with the introduction of microbial source tracking (MST) techniques. Two such techniques, antibiotic resistance analysis and DNA fingerprinting, were applied in a study of causes of faecal contamination at two lake beaches in Toronto, Ontario. Both methods identified bird faeces as the dominant sources of E. coli. Coping with this type of pollution presents a major environmental challenge.

scholarly journals Environmental Antimicrobial Resistance (En-Amr) in Surface Water of Thiruvananthapuram City, Kerala

2020 ◽  
pp. 22-32
Author(s):  
C. R. Sreelakshmi ◽  
Sheela A. Moses ◽  
Salom Gnana Thanga Vincent
Keyword(s):  
Antibiotic Resistance ◽  
Surface Water ◽  
Antimicrobial Resistance ◽  
Water Samples ◽  
Water Bodies ◽  
Fecal Coliforms ◽  
Diffusion Method ◽  
E Coli ◽  
Coliform Count ◽  
Bacterial Cultures

Aim: The study was done to understand the microbial contamination and antibiotic resistance pattern in surface water environment. Study Area and Sampling: Water samples collected from selected water bodies in the main urban area of Thiruvananthapuram were analysed for the presence of coliforms and the pattern of antimicrobial resistance in bacterial cultures isolated from the water samples. Methodology: The total coliform count and faecal coliform count was determined using the multiple tube fermentation technique and the total heterotrophic bacterial count was performed using nutrient agar media. The bacterial cultures were identified using biochemical characterization and Antibiotic susceptibility patterns for the various bacterial isolates were determined using commercial antibiotic disks (Hi Media, Mumbai) in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines by Kirby-Bauer disc diffusion method. The antibiotics used were Ampicillin, Chloramphenicol, Ciprofloxacin, Gentamicin, Tetracycline and Meropenem. Multiple Antibiotic resistances (MAR) index was determined for those isolates which showed resistance to more than three antibiotics. Results: The total heterotrophic bacteria, total coliforms and fecal coliforms were significantly high in all the sites, indicating that the water bodies are sewage contaminated. The biochemical identification of bacterial strains isolated from water sample showed the presence of E. coli, Bacillus sp, Staphylococcus sp, Klebsiella sp, Clostridium sp, Neisseria sp, Enterobacter sp, Enterococcus sp and Streptococcus sp in varying frequencies in different sites. Among these 58 isolates, 26 strains were found to be resistant against 3 or more antibiotics and hence, designated as multi drug resistant. The isolates were highly resistant to Ampicillin (98%), Chloramphenicol (53%) and Gentamycin (44%); and highly susceptible to Meropenem (86%), Ciprofloxacin (69%) and Tetracyclin (58%). E. coli showed maximum resistance to all the antibiotics. One- way ANOVA of the obtained data revealed that there is no significance difference in spatial distribution of antibiotic resistance.

scholarly journals Microbial source tracking of private well water samples across at-risk regions in southern Ontario and analysis of traditional fecal indicator bacteria assays including culture and qPCR

2016 ◽  
Vol 14 (6) ◽  
pp. 1047-1058 ◽  
Author(s):  
Julia Krolik ◽  
Allison Maier ◽  
Shawna Thompson ◽  
Anna Majury
Keyword(s):  
At Risk ◽  
Water Samples ◽  
Rural Areas ◽  
Fecal Contamination ◽  
Microbial Source Tracking ◽  
Source Tracking ◽  
Well Water ◽  
Prevention Strategies ◽  
E Coli ◽  
Bacteriological Testing

Many people living in rural areas rely on privately owned wells as their primary source of drinking water. These water sources are at risk for fecal contamination of human, wildlife, and livestock origin. While traditional bacteriological testing involves culture-based methods, microbial source tracking (MST) assays present an opportunity to additionally determine the source of fecal contamination. This study investigated the main host sources of contamination in private well water samples with high levels of Escherichia coli (E. coli), using MST with human and multi-species specific markers. Fecal contamination of human origin was detected in approximately 50% of samples, indicating that current contamination prevention strategies require reconsideration. The relationship between cattle density and fecal contamination of bovine origin was investigated using a Bovine Bacteroidales specific MST assay. Regional variations of microbial sources were examined, and may inform local primary prevention strategies. Additionally, in order to assess MST and E. coli quantitative real time polymerase chain reaction (qPCR) assays as indicators of fecal contamination, these were compared to E. coli culture methods. Variation in results was observed across all assay methods investigated, suggesting the most appropriate routine bacteriological testing methodology cannot be determined without comparison to a method that directly detects the presence of fecal contamination.

Campylobacter in waterborne epidemics in Finland

2004 ◽  
Vol 4 (2) ◽  
pp. 39-45 ◽  
Author(s):  
M.-L. Hänninen ◽  
R. Kärenlampi
Keyword(s):  
Campylobacter Jejuni ◽  
Causative Agent ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Risk Level ◽  
Source Water ◽  
Indicator Organisms ◽  
Faecal Contamination ◽  
E Coli ◽  
July August September

The sources for drinking water in Finland are surface water, groundwater or artificially recharged groundwater. There are approximately 1400 groundwater plants in Finland that are microbiologically at a high risk level because in most cases they do not use any disinfection treatment. Campylobacter jejuni has caused waterborne epidemics in several countries. Since the middle of the 1980s, C. jejuni has been identified as the causative agent in several waterborne outbreaks in Finland. Between 1998 and 2001, C. jejuni or C. upsaliensis caused seven reported waterborne epidemics. In these epidemics approximately 4000 people acquired the illness. Most of the outbreaks occurred in July, August , September or October. In four of them source water and net water samples were analysed for total coliforms or fecal coliforms, E. coli and campylobacters. We showed that large volumes of water samples in studies of indicator organisms (up to 5000 ml) and campylobacters (4000–20,000 ml) increased the possibility to identify faecal contamination and to detect the causative agent from suspected sources.

The use of antibiotic resistance profiling as a means of tracing sources of fecal contamination in source waters

2010 ◽  
Vol 10 (2) ◽  
pp. 209-215
Author(s):  
M. S. Mthembu ◽  
P. T. Biyela ◽  
T. G. Djarova ◽  
A. K. Basson
Keyword(s):  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Fecal Contamination ◽  
Source Tracking ◽  
Human Consumption ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Source Waters

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.

scholarly journals Identifying Host Sources of Fecal Pollution: Diversity of Escherichia coli in Confined Dairy and Swine Production Systems

2005 ◽  
Vol 71 (10) ◽  
pp. 5992-5998 ◽  
Author(s):  
Zexun Lu ◽  
David Lapen ◽  
Andrew Scott ◽  
Angela Dang ◽  
Edward Topp
Keyword(s):  
Escherichia Coli ◽  
Dairy Farm ◽  
Sampling Strategy ◽  
Farming Systems ◽  
Microbial Source Tracking ◽  
Fecal Pollution ◽  
Source Tracking ◽  
E Coli ◽  
Repetitive Extragenic Palindromic Pcr ◽  
Repetitive Extragenic Palindromic

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.

scholarly journals Evaluation of Two Library-Independent Microbial Source Tracking Methods To Identify Sources of Fecal Contamination in French Estuaries

2007 ◽  
Vol 73 (15) ◽  
pp. 4857-4866 ◽  
Author(s):  
Michèle Gourmelon ◽  
Marie Paule Caprais ◽  
Raphaël Ségura ◽  
Cécile Le Mennec ◽  
Solen Lozach ◽  
...  
Keyword(s):  
Water Samples ◽  
Fecal Contamination ◽  
Microbial Source Tracking ◽  
Source Tracking ◽  
Rrna Gene ◽  
Specific Marker ◽  
Gene Markers ◽  
High Level ◽  
Bird Feces

ABSTRACT In order to identify the origin of the fecal contamination observed in French estuaries, two library-independent microbial source tracking (MST) methods were selected: (i) Bacteroidales host-specific 16S rRNA gene markers and (ii) F-specific RNA bacteriophage genotyping. The specificity of the Bacteroidales markers was evaluated on human and animal (bovine, pig, sheep, and bird) feces. Two human-specific markers (HF183 and HF134), one ruminant-specific marker (CF193′), and one pig-specific marker (PF163) showed a high level of specificity (>90%). However, the data suggest that the proposed ruminant-specific CF128 marker would be better described as an animal marker, as it was observed in all bovine and sheep feces and 96% of pig feces. F RNA bacteriophages were detected in only 21% of individual fecal samples tested, in 60% of pig slurries, but in all sewage samples. Most detected F RNA bacteriophages were from genotypes II and III in sewage samples and from genotypes I and IV in bovine, pig, and bird feces and from pig slurries. Both MST methods were applied to 28 water samples collected from three watersheds at different times. Classification of water samples as subject to human, animal, or mixed fecal contamination was more frequent when using Bacteroidales markers (82.1% of water samples) than by bacteriophage genotyping (50%). The ability to classify a water sample increased with increasing Escherichia coli or enterococcus concentration. For the samples that could be classified by bacteriophage genotyping, 78% agreed with the classification obtained from Bacteroidales markers.

scholarly journals Clonal Populations of ThermotolerantEnterobacteriaceae in Recreational Water and Their Potential Interference with Fecal Escherichia coli Counts

2001 ◽  
Vol 67 (10) ◽  
pp. 4934-4938 ◽  
Author(s):  
Sandra L. McLellan ◽  
Annette D. Daniels ◽  
Alissa K. Salmore
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Environmental Protection Agency ◽  
16S Rrna Gene Sequencing ◽  
Fecal Coliforms ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Diverse Range ◽  
E Coli ◽  
Glucuronidase Activity

ABSTRACT Bacterial strains were isolated from beach water samples using the original Environmental Protection Agency method for Escherichia coli enumeration and analyzed by pulsed-field gel electrophoresis (PFGE). Identical PFGE patterns were found for numerous isolates from 4 of the 9 days sampled, suggesting environmental replication. 16S rRNA gene sequencing, API 20E biochemical testing, and the absence of β-glucuronidase activity revealed that these clonal isolates were Klebsiella, Citrobacter, and Enterobacter spp. In contrast, 82% of the nonclonal isolates from water samples were confirmed to be E. coli, and 16% were identified as other fecal coliforms. These nonclonal isolates produced a diverse range of PFGE patterns similar to those of isolates obtained directly from untreated sewage and gull droppings. β-Glucuronidase activity was critical in distinguishingE. coli from other fecal coliforms, particularly for the clonal isolates. These findings demonstrate that E. coli is a better indicator of fecal pollution than fecal coliforms, which may replicate in the environment and falsely elevate indicator organism levels.

MICROBIOLOGICAL ANALYSIS OF TILAPIA AND WATER IN AQUACULTURE FARMS FROM SINALOA

Biotecnia ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 20-26
Author(s):  
José Antonio Valenzuela-Armenta ◽  
Sylvia Páz Díaz-Camacho ◽  
Julio Adalberto Cabanillas-Ramos ◽  
Magdalena de Jesus Uribe-Beltrán ◽  
Mária del Carmen De la Cruz-Otero ◽  
...  
Keyword(s):  
Water Samples ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Aerobic Bacteria ◽  
Microbiological Analysis ◽  
Enterobacter Agglomerans ◽  
E Coli ◽  
The World ◽  
Fishery Products

Tilapia is the most cultivated fish around the world. The fish’s environment can harbor bacteria, especially coliforms, which are not normal biota of fish. These microorganisms are contamination indicator groups (IGs) reflecting the possible presence of pathogens, which can compromise the safety of fishery products. The IGs prevalence was estimated in tilapia and water from 29 aquaculture farms. Total and fecal coliforms (TC, FC), mesophilic aerobic bacteria (MAB), S. aureus, E. coli, Salmonella sp., and Streptococcus sp., were investigated. In tilapia, TC and FC were detected in 64% and 48% of the samples, ranging from 4.0 x 101 to 9.8 x 105, and from 1.0 x 101 to 6.4 x 103 CFU/g, respectively; MAB were detected in 90% of the samples. In water, TC and FC were detected in 57% and 35% of the samples, oscillating from 1.0 x 101 to 2.28 x104, and from 1.0 x 101 to 1.2 x 103 CFU/mL, respectively. MAB were detected in 89% of the water samples. Mostly E. coli and Enterobacter agglomerans were detected. Generally, IGs concentrations meet the Mexican regulations; however, the tilapia’s microbiological quality must be continuously monitored.

Sign in / Sign up

Export Citation Format

Share Document