scholarly journals Relative Decay of Bacteroidales Microbial Source Tracking Markers and Cultivated Escherichia coli in Freshwater Microcosms

2010 ◽  
Vol 76 (10) ◽  
pp. 3255-3262 ◽  
Author(s):  
Linda K. Dick ◽  
Erin A. Stelzer ◽  
Erin E. Bertke ◽  
Denise L. Fong ◽  
Donald M. Stoeckel

ABSTRACT Fecal indicator bacteria (FIB), commonly used to regulate sanitary water quality, cannot discriminate among sources of contamination. The use of alternative quantitative PCR (qPCR) methods for monitoring fecal contamination or microbial source tracking requires an understanding of relationships with cultivated FIB, as contamination ages under various conditions in the environment. In this study, the decay rates of three Bacteroidales 16S rRNA gene markers (AllBac for general contamination and qHF183 and BacHum for human-associated contamination) were compared with the decay rate of cultivated Escherichia coli in river water microcosms spiked with human wastewater. The following five sets of microcosms were monitored over 11 days: control, artificial sunlight, sediment exposure, reduced temperature, and no autochthonous predation. Decay was characterized by estimation of the time needed to produce a 2-log reduction (t 99). No treatment-associated differences in the decay of the 4 targets were evident except with reduced predation, where E. coli, qHF183, and BacHum markers had lower levels of decay by day 3. However, there were substantial target-associated differences. Decay curves for the AllBac marker indicated a larger persistent population than those of the other targets. Exposure to sunlight, sediment, and reduced predation resulted in more rapid decay of the human-associated markers relative to cultivable E. coli, but there were no differences in t 99 values among the 4 targets under control conditions or at reduced temperatures. Further evaluation of epidemiological relationships will be needed in order to relate the markers directly to health risk. These findings suggest that the tested human-associated markers can complement E. coli as indicators of the human impact on sanitary water quality under the constrained conditions described in this paper.

2013 ◽  
Vol 80 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Adelumola Oladeinde ◽  
Thomas Bohrmann ◽  
Kelvin Wong ◽  
S. T. Purucker ◽  
Ken Bradshaw ◽  
...  

ABSTRACTUnderstanding the survival of fecal indicator bacteria (FIB) and microbial source-tracking (MST) markers is critical to developing pathogen fate and transport models. Although pathogen survival in water microcosms and manure-amended soils is well documented, little is known about their survival in intact cow pats deposited on pastures. We conducted a study to determine decay rates of fecal indicator bacteria (Escherichia coliand enterococci) and bovine-associated MST markers (CowM3, Rum-2-bac, and GenBac) in 18 freshly deposited cattle feces from three farms in northern Georgia. Samples were randomly assigned to shaded or unshaded treatment in order to determine the effects of sunlight, moisture, and temperature on decay rates. A general linear model (GLM) framework was used to determine decay rates. Shading significantly decreased the decay rate of theE. colipopulation (P< 0.0001), with a rate of −0.176 day−1for the shaded treatment and −0.297 day−1for the unshaded treatment. Shading had no significant effect on decay rates of enterococci, CowM3, Rum-2-bac, and GenBac (P> 0.05). In addition,E. colipopulations showed a significant growth rate (0.881 day−1) in the unshaded samples during the first 5 days after deposition. UV-B was the most important parameter explaining the decay rate ofE. colipopulations. A comparison of the decay behaviors among all markers indicated that enterococcus concentrations exhibit a better correlation with the MST markers thanE. coliconcentrations. Our results indicate that bovine-associated MST markers can survive in cow pats for at least 1 month after excretion, and although their decay dynamic differs from the decay dynamic ofE. colipopulations, they seem to be reliable markers to use in combination with enterococci to monitor fecal pollution from pasture lands.


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.


2007 ◽  
Vol 73 (15) ◽  
pp. 4857-4866 ◽  
Author(s):  
Michèle Gourmelon ◽  
Marie Paule Caprais ◽  
Raphaël Ségura ◽  
Cécile Le Mennec ◽  
Solen Lozach ◽  
...  

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.


2017 ◽  
Vol 76 (5) ◽  
pp. 1158-1166 ◽  
Author(s):  
Lisa Paruch ◽  
Adam M. Paruch ◽  
Anne-Grete Buseth Blankenberg ◽  
Ketil Haarstad ◽  
Trond Mæhlum

This study describes the first Norwegian microbial source tracking (MST) approach for water quality control and pollution removal from catchment run-off in a nature-based treatment system (NBTS) with a constructed wetland. The applied MST tools combined microbial analyses and molecular tests to detect and define the source(s) and dominant origin(s) of faecal water contamination. Faecal indicator bacteria Escherichia coli and host-specific Bacteroidales 16 s rRNA gene markers have been employed. The study revealed that the newly developed contribution profiling of faecal origin derived from the Bacteroidales DNA could quantitatively distinguish between human and non-human pollution origins. Further, the outcomes of the MST test have been compared with the results of both physicochemical analyses and tests of pharmaceutical and personal care products (PPCPs). A strong positive correlation was discovered between the human marker and PPCPs. Gabapentin was the most frequently detected compound and it showed the uppermost positive correlation with the human marker. The study demonstrated that the NBTS performs satisfactorily with the removal of E. coli but not PPCPs. Interestingly, the presence of PPCPs in the water samples was not correlated with high concentrations of E. coli. Neither has the latter an apparent correlation with the human marker.


2021 ◽  
Vol 13 (1) ◽  
pp. 122-127
Author(s):  
Ayomide F. Sowemimo ◽  
Abiola O. Obisesan ◽  
Funmilola A. Ayeni

Kunu is a non-alcoholic fermented cereal beverage consumed primarily as a refreshing drink. This study investigated the effects of storage conditions on viability of Lactic Acid Bacteria (LAB) in kunu and the antibacterial effects of Kunu against diarrhoea caused by Escherichia coli strains. Kunu was prepared according to local traditional method. Viability counts of LAB in kunu stored at two different conditions, cold (4 ℃ average) and room temperature (26 ℃ average), were evaluated. Isolated LAB from kunu were identified by partial sequencing of 16S rRNA gene. Five pathotypes of diarrhoea caused by E. coli strains were co-cultured with kunu to evaluate its antimicrobial activities. Viable LAB count in kunu ranged from 5.0 x 109 to 1.0 x 1011 cfu/mL. Pediococcus pentosaceus, Lactobacillus plantarum and Leuconostoc pseudomesenteroides were identified from kunu. There is a drastic decrease (2-5 log reduction) in E. coli strains co-cultured with kunu. The observed high viable counts of beneficial LAB in kunu with its antimicrobial activities against diarrhoeaogenic E. coli strains indicates that kunu is not just a refreshing drink, but it also has antimicrobial potential against diarrhoea caused by E. coli.


2019 ◽  
Vol 85 (23) ◽  
Author(s):  
Niveen S. Ismail ◽  
Brittney M. Blokker ◽  
Tyler R. Feeney ◽  
Ruby H. Kohn ◽  
Jingyi Liu ◽  
...  

ABSTRACT The fecal indicator bacterial species Escherichia coli is an important measure of water quality and a leading cause of impaired surface waters. We investigated the impact of the filter-feeding metazooplankton Daphnia magna on the inactivation of E. coli. The E. coli clearance rates of these daphnids were calculated from a series of batch experiments conducted under variable environmental conditions. Batch system experiments of 24 to 48 h in duration were completed to test the impacts of bacterial concentration, organism density, temperature, and water type. The maximum clearance rate for adult D. magna organisms was 2 ml h−1 organism−1. Less than 5% of E. coli removed from water by daphnids was recoverable from excretions. Sorption of E. coli on daphnid carapaces was not observed. As a comparison, the clearance rates of the freshwater rotifer Branchionus calyciflorus were also calculated for select conditions. The maximum clearance rate for B. calyciflorus was 6 × 10−4 ml h−1 organism−1. This research furthers our understanding of the impacts of metazooplankton predation on E. coli inactivation and the effects of environmental variables on filter feeding. Based on our results, metazooplankton can play an important role in the reduction of E. coli in natural treatment systems under environmentally relevant conditions. IMPORTANCE Escherichia coli is a fecal indicator bacterial species monitored by the U.S. Environmental Protection Agency to assess microbial water quality. Due to the potential human health implications linked to high levels of E. coli, it is important to understand the inactivation or reduction mechanisms in surface waters. Our research examines the capacities of two types of widespread filter-feeding freshwater metazooplankton, Daphnia magna and Brachionus calyciflorus, to reduce E. coli concentrations. We examine the impacts of different environmentally relevant conditions on the clearance rates. Our results contribute to a better understanding of the importance of metazooplankton in controlling E. coli concentrations and what conditions will reduce or increase grazing. These results provide baseline data to support future efforts to develop a quantitative model relating zooplankton uptake rates to relevant environmental variables.


2017 ◽  
Vol 17 (5) ◽  
pp. 1468-1478
Author(s):  
Roohollah Kheiri ◽  
Leili Akhtari

The aim of this study was to analyze the enterobacterial repetitive intergenic consensus (ERIC)-types, phylo-groups and antimicrobial resistance (AMR) patterns of Escherichia coli and to investigate if these approaches are suitable for microbial source tracking (MST). E. coli strains were isolated from cattle faeces and Karaj River. For genetic diversity, AMR profile, and phylo-grouping, we applied ERIC-PCR, disk diffusion, and multiplex-PCR, respectively. Fifty isolates from each sample group were used in the study. ERIC fingerprinting produced ten different bands, demonstrating 64 unique and 36 repetitive profiles. Six isolates from the river showed the same ERIC pattern of the cattle, of which four expressed the same AMR profile. E. coli isolates from water were represented in A, B1, C, and D phylo-groups. Phylo-groups A, B1, and E were more prevalent in the cattle isolates and B2 was absent in both sources. Three of the water isolates with the same ERIC-type and AMR to cattle isolates showed the same phylo-groups. Genetic characteristics, AMR, and phylo-groups of the isolates from the river are diverse and complex. For accurate MST, complementary approaches should be applied together and a comprehensive library should be provided.


2013 ◽  
Vol 67 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
P. Jagals ◽  
T. G. Barnard ◽  
M. M. Mokoena ◽  
N. Ashbolt ◽  
D. J. Roser

Plastic containers in the range of 5–20 L are widely used – especially in rural African settings – to collect, transport and store water for domestic use, including drinking, bathing and hygiene. The pathogen content of the waters in these containers has not been adequately characterized as yet. This paper presents the primary findings of a synoptic survey of drinking water quality samples from these containers and involved collection of bacterial indicator and pathogenicity gene data. In total, 571 samples of a variety of waters were taken in rural communities in South Africa and the Escherichia coli numbers measured. Of the E. coli positive samples, 46% (n = 148) were screened for the presence of E. coli pathogen gene markers. Though synoptic, the survey provided many insights into the issues that drove the study. Container use markedly degraded water quality as judged by indicator counts, even where improved water supply services were in place. Household container use also appeared to promote regrowth or contamination of containers with pathogenic E. coli strains. Polymerase chain reaction (PCR) analysis also showed that the diversity of potential pathogenic E. coli carrying virulence genes was great. All seven genes screened for (Ial, Stx1, Stx2, EaeA, Eagg, ST, LT) were found in the waters, alone or as mixtures (number of different combinations = 31) including those characteristic of the more dangerous invasive and haemorrhagic E. coli strains. Given the central role of containers in the management of water supply to rural communities, it is clear the microbiology of these waters requires much further characterization.


2010 ◽  
Vol 61 (6) ◽  
pp. 1401-1409 ◽  
Author(s):  
M. Gourmelon ◽  
M. P. Caprais ◽  
C. Le Mennec ◽  
S. Mieszkin ◽  
C. Ponthoreau ◽  
...  

Faecal contamination sources were identified in coastal areas around the Guerande-Atlantique peninsula using two microbial source tracking (MST) methods: (i) Bacteroidales host-specific 16S rRNA gene markers measured by real-time PCR and (ii) F-specific bacteriophage (FRNAPH) genotyping. Both methods were used on 63 water samples from 7 water courses. HF183 marker and bacteriophage genogroup II (FRNAPH II) were detected in all water samples and in the majority of water samples, respectively, from La Torre stream (W5), Piriac (W2), R2000 (W3) and Mazy (W7) rain water drains, and also detected, less frequently, in Le Nau drain (W4), suggesting contamination by human faecal sources at these sites. These human markers were weakly detected in Pouliguen channel (W6). Furthermore, BacR and bacteriophage genogroup I (FRNAPH I) were also detected, but at lower concentration and frequency. So, site W6 seems to be contaminated by multiple sources, though mainly human. Finally, BacR was detected twice in Pont d'Armes channel (W1), whereas HF183 was not detected. FRNAPH I and II were detected in only 3 out of 12 water samples. Site W1 seems mainly contaminated by animal sources. As a result of our findings, actions were taken to remediate water and shellfish quality.


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