scholarly journals Digital E. coli Counter: A Microfluidics and Computer Vision-Based DNAzyme Method for the Isolation and Specific Detection of E. coli from Water Samples

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Sakandar Rauf ◽  
Nouran Tashkandi ◽  
José Ilton de Oliveira Filho ◽  
Claudia Iluhí Oviedo-Osornio ◽  
Muhammad S. Danish ◽  
...  
Keyword(s):  
Computer Vision ◽  
Water Samples ◽  
Droplet Microfluidics ◽  
Fluorescence Signal ◽  
E Coli ◽  
Biological Water ◽  
Detection And Counting ◽  
Simple Detection ◽  
Large Water ◽  
Positive Results

Biological water contamination detection-based assays are essential to test water quality; however, these assays are prone to false-positive results and inaccuracies, are time-consuming, and use complicated procedures to test large water samples. Herein, we show a simple detection and counting method for E. coli in the water samples involving a combination of DNAzyme sensor, microfluidics, and computer vision strategies. We first isolated E. coli into individual droplets containing a DNAzyme mixture using droplet microfluidics. Upon bacterial cell lysis by heating, the DNAzyme mixture reacted with a particular substrate present in the crude intracellular material (CIM) of E. coli. This event triggers the dissociation of the fluorophore-quencher pair present in the DNAzyme mixture leading to a fluorescence signal, indicating the presence of E. coli in the droplets. We developed an algorithm using computer vision to analyze the fluorescent droplets containing E. coli in the presence of non-fluorescent droplets. The algorithm can detect and count fluorescent droplets representing the number of E. coli present in the sample. Finally, we show that the developed method is highly specific to detect and count E. coli in the presence of other bacteria present in the water sample.

scholarly journals Membrane filtration media for the enumeration of coliform organisms and Escherichia coli in water: comparison of Tergitol 7 and lauryl sulphate with Teepol 610

1980 ◽  
Vol 85 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
False Positive ◽  
Membrane Filtration ◽  
Sodium Lauryl Sulphate ◽  
Standard Medium ◽  
E Coli ◽  
Laboratory Trial ◽  
Positive Results ◽  
Filtration Technique

SUMMARYIn a multi-laboratory trial with the mombrane filtration technique, three surfactants – Teepol 610 (T610), Tergitol 7 (T7) and sodium lauryl sulphate (LS) – were compared in media for the enumeration of coliform organisms and Escherichia coli in water. A total of 170 samples of water (87 raw and 92 marginally chlorinated) were examined for colony counts of coliform organisms, and 185 water samples (94 raw and 91 marginally chlorinated) for E. coli. Slight differences in the confirmed colony counts between the three media were noted, but few of these were observed consistently in every laboratory. In most laboratories, T7 gave slightly higher counts of E. coli than LS with chlorinated waters; a higher incidence of false-positive results for E. coli at 44 °C was also noted with T7. As there were no outstanding differences in the trial, sodium lauryl sulphate, which is chemically defined, cheap and readily available, is therefore recommended for use at a concentration of 0·1% instead of Teepol 610 in the standard medium for the enumeration of coliform organisms and E. coli in water by the membrane filtration technique.

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.

Applying Bacteriological Parameters for Evaluating Underground Water Quality

1988 ◽  
Vol 20 (11-12) ◽  
pp. 425-428 ◽  
Author(s):  
H. T. El-Zanfaly ◽  
A. M. Shabaan
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Anaerobic Bacteria ◽  
Underground Water ◽  
Faecal Coliforms ◽  
Bacterial Pollution ◽  
Important Approach ◽  
Positive Results ◽  
Faecal Streptococci

A total of 111 water samples were drawn from 15 wells. These samples were subjected to bacteriological examinations to determine the suitability of the monitored wells as source for drinking water. Significant levels of bacterial pollution indicators were detected in the underground water samples during the period of study. Total bacterial counts ranged between 10-104CFU/ml. Faecal streptococci was the most common and detected in 9 6% of water samples. Lower percentages of samples (92, 55 and 45%) were contaminated with total coliforms, faecal coliforms and total clostridia, respectively. Faecal coliforms: faecal streptococci was less than 0.7 in 86% of the examined samples. Anaerobic bacteria were detected in the examined well water samples. Only 101 water samples were tested for anaerobic spore-formers and all showed positive results. Most examined wells do not meet the water quality standards for drinking water. Accordingly, the necessity of controllin bacterial pollution in ground-water through disinfection was clearly confirmed. Testing the underground water for more than one indicator represents an important approach for water quality assurance.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

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.

Occurrences of Giardia cysts in beach water

1998 ◽  
Vol 38 (12) ◽  
pp. 73-76 ◽  
Author(s):  
B. S. W. Ho ◽  
T.-Y Tam
Keyword(s):  
Health Risk ◽  
Water Sample ◽  
Water Samples ◽  
High Concentration ◽  
Potential Health ◽  
Infectious Dose ◽  
Potential Health Risk ◽  
E Coli ◽  
Beach Water ◽  
Giardia Cysts

A total of 64 beach water samples with various bacteriological quality (Grades 1 to 4) were analysed for their bacteriological and parasitological contents (E coli and Giardia cysts respectively). Results indicated that Giardia cysts were detected in less than 10% of the Grade 1 beach water samples with E coli concentrations of <24/100mL. For Grades 2, 3 & 4 beach water samples, Giardia cysts were found, respectively, in 85, 50 and 64% of the samples. Except for one beach water sample which had an unusually high concentration of Giardia cysts (23 cysts/L), they were generally present at moderate concentrations (<10 cysts/L) in all other beach water samples. Despite moderate levels of Giardia cysts present in beach water of different grades, the potential health risk faced by swimmers bathing in local beach water needs to be carefully assessed as Giardia is known to have a low infectious dose.

scholarly journals A computer vision-based object detection and counting for COVID-19 protocol compliance: a case study of Jakarta

2020 ◽  
Author(s):  
Muhammad Lanang Afkaar Ar ◽  
Sulthan Muzakki Adytia S ◽  
Yudhistira Nugraha ◽  
Farizah Rizka R ◽  
Andy Ernesto ◽  
...  
Keyword(s):  
Computer Vision ◽  
Object Detection ◽  
Detection And Counting ◽  
Protocol Compliance

scholarly journals Microbiological evaluation of lettuce produced by conventional and organic systems in farms of Londrina, PR

2017 ◽  
Vol 38 (1) ◽  
pp. 175 ◽  
Author(s):  
Natalia Harumi Niguma ◽  
Jacinta Sanchez Pelayo ◽  
Tereza Cristina Rocha Moreira de Oliveira
Keyword(s):  
Irrigation Water ◽  
Water Samples ◽  
Total Coliform ◽  
Organic Production ◽  
Conventional System ◽  
Salmonella Spp ◽  
Organic System ◽  
E Coli ◽  
Organic Systems ◽  
Production Practices

The aims of this study were to evaluate the contamination of lettuce (Lactuca sativa), produced in Londrina, Paraná (PR), with total coliform, coliform at 45 °C, E. coli, and Salmonella spp.; and to determine the E. coli contamination of irrigation water used at the farms studied. Four farms were evaluated, of which three produced lettuce using a conventional system and one using an organic system. An evaluation of the production practices of the farms was also carried out. A total of 111 samples were analyzed, 71 lettuce samples from the conventional system and 40 samples from the organic system. A total of eight irrigation water samples were collected for analysis. Coliform at 45 °C counts above the limit tolerated by Brazilian legislation were observed in 2.8% (2/71) of conventionally grown lettuce samples, and Salmonella spp. was isolated in 1.4% (1/71) of those samples. In the organic lettuce samples, 12.5% (5/40) had coliform at 45 °C counts above the limit tolerated and Salmonella spp. was not detected. Irrigation water samples from three farms were unsatisfactory, with counts higher than 102MPN of E. coli per 100mL. The results of this study demonstrate that most conventionally grown lettuce samples show good sanitary conditions in production, and that lettuce contamination is not related to contamination found in irrigation water samples. The results also showed that the organic production practices required by Brazilian certification agencies should be applied to ensure that contamination of produced lettuce remains controlled.

scholarly journals Development of an Internal Control for Evaluation and Standardization of a Quantitative PCR Assay for Detection of Helicobacter pylori in Drinking Water

2007 ◽  
Vol 73 (22) ◽  
pp. 7380-7387 ◽  
Author(s):  
Keya Sen ◽  
Nancy A. Schable ◽  
Dennis J. Lye
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Quantitative Pcr ◽  
Water Samples ◽  
Sodium Thiosulfate ◽  
Qpcr Assay ◽  
E Coli ◽  
H Pylori ◽  
Labeled Probe ◽  
Treated Drinking Water

ABSTRACT Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

scholarly journals Case report on the human infection with Tularemia in Mykolaiv Region, 2018

2020 ◽  
Vol 6 (1) ◽  
pp. 15-17
Author(s):  
O. B. Zlenko ◽  
O. S. Ignatenkov ◽  
K. V. Vinokurova ◽  
A. P. Gerilovych
Keyword(s):  
Case Report ◽  
Western Blot ◽  
Blood Serum ◽  
Francisella Tularensis ◽  
Water Samples ◽  
Human Infection ◽  
Agglutination Test ◽  
Surrounding Area ◽  
Type Settlement ◽  
Positive Results

The work aims to provide a study and report the case with a 47-year-old white man from urban-type settlement Oleksandrivka (Voznesensk District, Mykolaiv Region) diagnosed with pharyngitis, amygdalitis, polylymphoadenopathy, and buboadenitis caused by Francisella tularensis. The tularemia diagnosis in the patient was confirmed with agglutination test and western blot of patient’s blood serum in dilutions 1:100 and 1:200 respectively. The additional surveillance study (rodents, ticks, and water samples) in the surrounding area of the patient’s house showed positive results for F. tularensis in ticks in dilution 1:160++++

scholarly journals Detection of antimicrobial resistance genes of carbapenem-resistant Enterobacteriaceae in Escherichia coli isolated from the water supply of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand

2020 ◽  
Vol 6 (1) ◽  
pp. 1-5
Author(s):  
Natapol Pumipuntu ◽  
Sangkom Pumipuntu
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Water Samples ◽  
Dairy Farms ◽  
Drug Resistant ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae ◽  
Smallholder Dairy Farms

Background and Aim: The problem of antimicrobial resistance of bacteria in both humans and animals is an important public health concern globally, which is likely to increase, including in Thailand, where carbapenem-resistant Enterobacteriaceae (CRE), such as Escherichia coli, are of particular concern. They are pathogens found in the gastrointestinal tract of humans and other animals as well as in the environment. They may cause opportunistic infection and are often resistant to antibiotics in various fields especially in animal husbandry, such as pets or livestock farms. This study aimed to investigate the occurrence of carbapenem-resistant E. coli from water samples of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand. Materials and Methods: Sixty-four water samples were collected from 32 dairy farms in Kaeng Khoi district, Muak Lek district, and Wang Muang district of Saraburi Province, and Kantharawichai district and Mueang district of Maha Sarakham Province, Thailand. All samples were cultured and isolated for E. coli by biochemical tests. All E. coli isolates were tested for drug susceptibility using imipenem, meropenem, and drug resistance genes of carbapenemases such as blaNDM, blaIMP, and blaOXA48 of drug-resistant E. coli isolates detected by polymerase chain reaction (PCR) technique. Results: A total of 182 E. coli isolates were found (140 and 42 isolates from Saraburi and Maha Sarakham, respectively). Drug sensitivity tests found that two isolates of E. coli from water in Kaeng Khoi were resistant to imipenem; therefore, the incidence of E. coli resistance to carbapenem was 1.43% of Saraburi Province. On the other hand, there was no incidence of drug-resistant E. coli in Maha Sarakham. In addition, the detection of the drug-resistant gene of E. coli in both isolates by PCR showed the expression of blaNDM. Conclusion: This study reports E. coli resistance to antimicrobial drugs on livestock farms. It can be considered to be the first report of E. coli CRE detection in a dairy farm at Saraburi, which should be the subject of further extended study.

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