Development and validation of a FISH-based method for the detection and quantification of E. coli and coliform bacteria in water samples

2011 ◽  
Vol 64 (7) ◽  
pp. 1435-1442 ◽  
Author(s):  
Michael Hügler ◽  
Karin Böckle ◽  
Ingrid Eberhagen ◽  
Karin Thelen ◽  
Claudia Beimfohr ◽  
...  

Monitoring of microbiological contaminants in water supplies requires fast and sensitive methods for the specific detection of indicator organisms or pathogens. We developed a protocol for the simultaneous detection of E. coli and coliform bacteria based on the Fluorescence in situ Hybridization (FISH) technology. This protocol consists of two approaches. The first allows the direct detection of single E. coli and coliform bacterial cells on the filter membranes. The second approach includes incubation of the filter membranes on a nutrient agar plate and subsequent detection of the grown micro-colonies. Both approaches were validated using drinking water samples spiked with pure cultures and naturally contaminated water samples. The effects of heat, chlorine and UV disinfection were also investigated. The micro-colony approach yielded very good results for all samples and conditions tested, and thus can be thoroughly recommended for usage as an alternative method to detect E. coli and coliform bacteria in water samples. However, during this study, some limitations became visible for the single cell approach. The method cannot be applied for water samples which have been disinfected by UV irradiation. In addition, our results indicated that green fluorescent dyes are not suitable to be used with chlorine disinfected samples.

2004 ◽  
Vol 4 (2) ◽  
pp. 39-45 ◽  
Author(s):  
M.-L. Hänninen ◽  
R. Kärenlampi

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.


1991 ◽  
Vol 24 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Ivor T. Knight ◽  
Jocelyne DiRuggiero ◽  
Rita R. Colwell

Direct detection and enumeration of pathogenic bacteria, rather than indicator organisms, in aquatic environments is desirable but hindered by the difficulties of culturing and identifying specific pathogens from these environments. We have developed a method for concentrating bacteria from water samples and extracting their DNA and RNA for use as targets for pathogen-specific gene probes. The method has been used to detect and enumerate Salmonella spp. in estuarine water samples. The probe binds Salmonella DNA quantitatively, making it possible to estimate relative amounts of target in each sample. Salmonella spp. were detected in samples which yielded no Salmonella spp. using culturing. Since the probe method does not require culturing the target organism, both culturable and non-culturable forms are detected. We have also used polymerase chain reaction to amplify a region of the enterotoxin gene in enterotoxigenic Escherichiacoli and Vibriocholerae (ltx and ctx, respectively). The amplified products are then identified with ctx and ltx probes, making specific, highly sensitive detection possible.


1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.


2016 ◽  
Vol 79 (10) ◽  
pp. 1789-1793 ◽  
Author(s):  
HIDEMI IZUMI ◽  
YUJI NAKATA ◽  
AYANO INOUE

ABSTRACT Chemical sanitizers may induce no injury (bacteria survive), sublethal injury (bacteria are injured), or lethal injury (bacteria die). The proportion of coliform bacteria that were injured sublethally by chlorine and fungicide mixed with agricultural water (pond water), which was used to dilute the pesticide solution, was evaluated using the thin agar layer (TAL) method. In pure cultures of Enterobacter cloacae, Escherichia coli, and E. coli O157:H7 (representing a human pathogen), the percentage of chlorine-injured cells was 69 to 77% for dilute electrolyzed water containing an available chlorine level of 2 ppm. When agricultural water was mixed with electrolyzed water, the percentage of injured coliforms in agricultural water was 75%. The isolation and identification of bacteria on TAL and selective media suggested that the chlorine stress caused injury to Enterobacter kobei. Of the four fungicide products tested, diluted to their recommended concentrations, Topsin-M, Sumilex, and Oxirane caused injury to coliform bacteria in pure cultures and in agricultural water following their mixture with each pesticide, whereas Streptomycin did not induce any injury to the bacteria. The percentage of injury was 45 to 97% for Topsin-M, 80 to 87% for Sumilex, and 50 to 97% for Oxirane. A comparison of the coliforms isolated from the pesticide solutions and then grown on either TAL or selective media indicated the possibility of fungicide-injured Rahnella aquatilis, Yersinia mollaretii, and E. coli. These results suggest the importance of selecting a suitable sanitizer and the necessity of adjusting the sanitizer concentration to a level that will kill the coliforms rather than cause sanitizer-induced cell injury that can result in the recovery of the coliforms.


2013 ◽  
Vol 68 (12) ◽  
pp. 2638-2644 ◽  
Author(s):  
M. Antonelli ◽  
A. Turolla ◽  
V. Mezzanotte ◽  
C. Nurizzo

The paper is a review of previous research on secondary effluent disinfection by peracetic acid (PAA) integrated with new data about the effect of a preliminary flash-mixing step. The process was studied at bench and pilot scale to assess its performance for discharge in surface water and agricultural reuse (target microorganisms: Escherichia coli and faecal coliform bacteria). The purposes of the research were: (1) determining PAA decay and disinfection kinetics as a function of operating parameters, (2) evaluating PAA suitability as a disinfectant, (3) assessing long-term disinfection efficiency, (4) investigating disinfected effluent biological toxicity on some aquatic indicator organisms (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum), (5) comparing PAA with conventional disinfectants (sodium hypochlorite, UV irradiation). PAA disinfection was capable of complying with Italian regulations on reuse (10 CFU/100 mL for E. coli) and was competitive with benchmarks. No regrowth phenomena were observed, as long as needed for agricultural reuse (29 h after disinfection), even at negligible concentrations of residual disinfectant. The toxic effect of PAA on the aquatic environment was due to the residual disinfectant in the water, rather than to chemical modification of the effluent.


2021 ◽  
Author(s):  
Mirjana Grujović ◽  
◽  
Katarina Mladenović ◽  
Zoran Simić ◽  
Simona Đuretanović

This research aimed to investigate the quality of drinking water from the rural area of village Pajsijević (Šumadija, central Serbia). The water is consumed as raw since it is not purified or chlorinated before consumption. The water was collected at three sampling points – in the spring of Kotlenik Mountain stream (W1 sample), in the local reservoir (W2 sample), and from the tap (W3 sample). Also, the sediment samples (soil and sand) were analyzed, too. The health risks related to the presence and concentration of some major and trace elements (Ca, Cr, Cu, Fe, Mg, Mn, Ni, Zn) and N, NO, NN3, NH4, P, P2O5, and PO4 were evaluated. Additionally, the presence and the number of total coliform bacteria and Escherichia coli (as an indicator of fecal contamination) were evaluated. The concentrations of analyzed major and trace elements in all water samples were below those at which toxic effects may occur. The exception was the concentrations of Fe (2.02 – 2012 mg/L), which were higher than is allowed. The origin of Fe in water is from sediment (soil and sand), which also showed high content of Fe (3006.0 mg/g and 2229.9 mg/g, respectively). The results of the Colorimetric test indicated the presence of coliform bacteria as well as the presence of E. coli in all water samples. Further research needs to include characterization of isolated coliform bacteria and serological investigation of E. coli strains in order to evaluate the risks of consumption related to waterborne illness.


Jurnal BIOMA ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Rezki Rachmawati ◽  
Muzajjanah Muzajjanah ◽  
Yoswita Rustam

Refill Water Depot is currently more widely circulated and used as an alternative drinking water supply by the public. However the still unclear about the quality of the drinking water refill generated primarily of biological content. Parameters of biological contamination in drinking water caused by the Escherichia coli and coliform bacterium. This study aims to identify E. coli and coliforms in drinking water refill. Refill drinking water samples obtained from 16 drinking water refill from Jagakarsa subdsitrict. The method used is descriptive. Refill drinking water samples was taken and tested in the MPN (Most Probable Number) method and then to be tested in identification of E. coli. The results of testing the drinking water refill obtained 15 samples positive for coliform bacteria. Samples were positive for E. coli bacteria that sample B.1 and F.2.


2006 ◽  
Vol 54 (3) ◽  
pp. 135-140 ◽  
Author(s):  
K. Horáková ◽  
H. Mlejnková ◽  
P. Mlejnek

The presence of enteric pathogens in water resources represents a serious risk for public health. Therefore, their precise detection, and especially detection of E. coli, which is obviously regarded as the main indicator of faecal contamination of water, is an essential step in ensuring bacterial safety of water. Numerous PCR protocols for detection of E. coli have been published to date. They are usually based on amplification of regions derived from lacZ (β-d-galactosidase) and uidA (β-d-glucuronidase) gene sequences. However, these methods are not universal enough for precise detection of all E. coli strains found in water samples. We developed a novel triplex PCR method for detection of E. coli in which cyd gene coding for cytochrome bd complex was co-amplified along with lacZ and uidA genes. Our triplex PCR approach significantly increases the specificity and reliability of E. coli detection in water samples. This approach allowed us to distinguish Shigella flexneri from E. coli. In addition, we were able to detect even non-coliform Klebsiella and Raoutella spp., some of which can also cause infections to humans.


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