scholarly journals A Syringe-Based Biosensor to Rapidly Detect Low Levels of Escherichia Coli (ECOR13) in Drinking Water Using Engineered Bacteriophages

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1953 ◽  
Author(s):  
Troy C. Hinkley ◽  
Spencer Garing ◽  
Paras Jain ◽  
John Williford ◽  
Anne-Laure M. Le Ny ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Genetically Engineered ◽  
World Health ◽  
Selective Enrichment ◽  
E Coli ◽  
Detection Assay ◽  
Colony Forming Units ◽  
Health Organization

A sanitized drinking water supply is an unconditional requirement for public health and the overall prosperity of humanity. Potential microbial and chemical contaminants of drinking water have been identified by a joint effort between the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF), who together establish guidelines that define, in part, that the presence of Escherichia coli (E. coli) in drinking water is an indication of inadequate sanitation and a significant health risk. As E. coli is a nearly ubiquitous resident of mammalian gastrointestinal tracts, no detectable counts in 100 mL of drinking water is the standard used worldwide as an indicator of sanitation. The currently accepted EPA method relies on filtration, followed by growth on selective media, and requires 24–48 h from sample to results. In response, we developed a rapid bacteriophage-based detection assay with detection limit capabilities comparable to traditional methods in less than a quarter of the time. We coupled membrane filtration with selective enrichment using genetically engineered bacteriophages to identify less than 20 colony forming units (CFU) E. coli in 100 mL drinking water within 5 h. The combination of membrane filtration with phage infection produced a novel assay that demonstrated a rapid, selective, and sensitive detection of an indicator organism in large volumes of drinking water as recommended by the leading world regulatory authorities.

scholarly journals Enumeration of Total and Faecal Coliform Bacteria in Drinking Water of Khairpur City

1970 ◽  
Vol 24 (2) ◽  
pp. 163-165 ◽  
Author(s):  
Abdul Hussain Shar ◽  
Yasmeen F Kazi ◽  
Miandad Zardari ◽  
Irshad Hussain Soomro
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Total Coliform ◽  
Faecal Coliform ◽  
World Health ◽  
Source Distribution ◽  
Coliform Bacteria ◽  
Residual Chlorine ◽  
Health Organization

Total coliform (TC) and faecal coliform (FC) bacteria were analyzed in drinking water of Khairpur city. Ninty samples were collected from main reservoir (source), distribution line and consumer taps. pH and residual chlorine of water samples were also determined. For bacteriological analysis inductively membrane filtration (MF) method was used for total coliform (TC) as well as faecal (FC) coliform bacteria. All samples were found contaminated with total coliform (TC) and faecal coliform (FC) and the counts were higher than the maximum microbial contaminant level (MMCL) established by World Health Organization (WHO). It was observed that pH was within the limits of WHO standard (6.5-8.5). The residual chlorine was not detected in any sample of drinking water. Bacteriologically the water quality of the drinking water is unsatisfactory.Keywords: Coliform, Escherichia coli, Water quality, Contamination, SanitationDOI: http://dx.doi.org/10.3329/bjm.v24i2.1266

scholarly journals Performance of three pilot-scale hybrid constructed wetlands for total coliforms and Escherichia coli removal from primary effluent – a 2-year study in a subtropical climate

2014 ◽  
Vol 13 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Florentina Zurita ◽  
Alejandra Carreón-Álvarez
Keyword(s):  
Escherichia Coli ◽  
Constructed Wetlands ◽  
Pilot Scale ◽  
World Health ◽  
First Year ◽  
Subtropical Climate ◽  
Total Coliforms ◽  
E Coli ◽  
Stage System ◽  
Health Organization

Three pilot-scale two-stage hybrid constructed wetlands were evaluated in order to compare their efficiency for total coliforms (TCol) and Escherichia coli removal and to analyze their performances in two 1-year periods of experimentation. System I consisted of a horizontal flow (HF) constructed wetland (CW) followed by a stabilization pond. System II was also configured with a HF CW as a first stage which was then followed by a vertical flow (VF) CW as a second stage. System III was configured with a VF CW followed by a HF CW. In the first year of evaluation, the HF–VF system was the most effective for TCol removal (p < 0.05) and achieved a reduction of 2.2 log units. With regard to E. coli removal, the HF–VF and VF–HF systems were the most effective (p < 0.05) with average reductions of 3.2 and 3.8 log units, respectively. In the second year, the most effective were those with a VF component for both TCol and E. coli which underwent average reductions of 2.34–2.44 and 3.44–3.74 log units, respectively. The reduction achieved in E. coli densities, in both years, satisfy the World Health Organization guidelines that require a 3–4 log unit pathogen reduction in wastewater treatment systems.

Comparison of three different media for the detection of E. coli and coliforms in water

2006 ◽  
Vol 54 (3) ◽  
pp. 141-145 ◽  
Author(s):  
C. Bernasconi ◽  
G. Volponi ◽  
L. Bonadonna
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Simultaneous Detection ◽  
Alternative Methods ◽  
Phenotypic Characteristic ◽  
Iso Standard ◽  
E Coli ◽  
Microbiological Parameters ◽  
Filtration Technique

The European Drinking Water Directive defines reference methods for the enumeration of microbiological parameters in drinking water. The method to be used for Escherichia coli and coliforms is the membrane filtration technique on Lactose TTC agar with Tergitol 7. Many technical drawbacks of the procedure, as well as its limitations regarding the recent taxonomy of coliforms, make it necessary to evaluate alternative methods. Two alternative assays, a chromogenic media (m-ColiBlu24®) and a defined substrate technology-DST test (Colilert 18/Quanty Tray™) were compared with the ISO standard with attention to the phenotypic characteristic of the isolates. Results showed that the ISO method failed to detect an important percentage of coliforms and E. coli while m-ColiBlu24® and Colilert 18 provided results in a shorter time allowing the simultaneous detection of E. coli and coliforms with no further confirmation steps.

scholarly journals Assessment of Microbial Load in Water and Sediments of Rivers Otamiri and Nworie in Owerri, South Eastern Nigeria

2021 ◽  
pp. 27-39
Author(s):  
Okere J. Kelechi ◽  
Azorji J. Nnawuike ◽  
Iheagwam S. Kelechi ◽  
Emeka J. Emmanuel ◽  
Nzenwa P. Odinaka
Keyword(s):  
Drinking Water ◽  
Rainy Season ◽  
Bacterial Count ◽  
Total Coliform ◽  
World Health ◽  
Total Bacterial Count ◽  
E Coli ◽  
Average Value ◽  
Waste Dumps ◽  
Health Organization

Water pollution is a global problem. The study was carried out to assess the microbial constituents in water and sediment of Rivers Otamiri and Nworie during dry and rainy seasons (March and September, 2020) with comparison to WHO benchmark for drinking water .Samples were randomly collected at six (6) sampling points and analyzed using routine microbiological protocols.  The results revealed detectable amount of microbial activates in surface water of both rivers during the dry and rainy season. During the rainy season, a THB bioload average of 2.02x104 and 5.1x104CFU/mL for Nworie and Otamiri river respectively were measured. For the TCC, the average was 9.8x103 and 2.5x104 CFU/mL, while in the dry period there was corresponding reduction in the bioload value for both rivers. THB average value for Nworie river was 1.34x104 CFU/mL, with corresponding 3.5x104 values for Otamiri river, while in same inclination, TCC measured 6.1x103 and 1.8x104 CFU/mL. There were noteworthy variations in the values for the two rivers as well as in the two seasons. TBC value for Otamiri measured about 1.5 folds than the value for Nworie. In same trend, TCC value for Nworie measured about 39%. All values measured were above WHO permissible limit for drinking water. The biochemical and cultural features of the isolated microorganism in water showed the presence of E. coli identified in the entire stations (100%), Salmonella and faecal coliform occurred 83.3% each, while Vibrio and Shigella were detected in 4 of the 6 stations. The mean total bacterial count, total coliform count and total E. coli, were not in conformity with World Health Organization (WHO) Standard for drinking water and thus constitute a threat to the River; these were attributed to indiscriminate waste dumps around the rivers. The study underscores the need for adequate waste management system to forestall outbreak of pathogenic diseases in the area.

scholarly journals Physicochemical and Microbiological Assessment of Drinking Water in Kari Estate Bauchi Nigeria

2020 ◽  
pp. 12-17
Author(s):  
Muhammad M Abubakar ◽  
Ibrahim Khalil Abubakar
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Physicochemical Analysis ◽  
World Health ◽  
Total Hardness ◽  
Faecal Coliforms ◽  
E Coli ◽  
Hygiene Practices ◽  
Health Organization ◽  
Industrial Standards

Some sources of drinking water in Kari Estate in Bauchi Metropolis were analyzed for physicochemical contents and coliform contamination. A total of five samples were collected from different sources as follows: 2 sachets water, 2 wells, and tap water. The physicochemical analysis included the determinations of temperature, pH, electrical conductivity, total dissolved solids, turbidity, colour, suspended solids, odour, taste, total hardness, iron, nitrate, nitirite, manganese, ammonia, fluoride and cyanide. The two wells had total coliforms of 6 and 10 and faecal coliforms of 4 and 5 respectively. Tap water had total and faecal coliforms of 7 and 3 respectively. E. coli were identified in the samples from wells while Bacillus sp. were found in the tap water. Although the physicochemical contents of the samples were normal range, coliform counts of the wells and tap water were above those set by the Nigerian Industrial Standards (NIS) and the World Health Organization (WHO) standards. Presence coliforms above the standards indicates contamination and that the water may be unsafe for drinking. The presence of E. coli suggests that improvement in monitoring and water hygiene practices should be employed to improve the drinking water quality.

The effect of increasing grain size in biosand water filters in combination with ultraviolet disinfection

2013 ◽  
Vol 4 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Timothy E. Frank ◽  
Matthew L. Scheie ◽  
Victoria Cachro ◽  
Andrew S. Muñoz
Keyword(s):  
Grain Size ◽  
Drinking Water ◽  
Produced Water ◽  
Uv Light ◽  
World Health ◽  
E Coli ◽  
Data Points ◽  
Clear Plastic ◽  
Health Organization ◽  
Water Filters

With sand less than 0.70 mm often difficult to source in the field, it is of interest to study larger grained sand for use in biosand water filters (BSF). This study examined how sand grain size affects biological sand water filtration and how the combination of biological sand filtration and ultraviolet (UV) disinfection affects drinking water quality. Two BSFs were built: a control with maximum grain size, dmax = 0.70 mm and an experimental with grain sizes ranging from 0.70 mm to dmax = 2.0 mm. Untreated water was passed through each BSF daily. Results show Escherichia coli and turbidity removal characteristics of the control and experimental BSFs were not significantly different from one another. Both BSFs produced water that met World Health Organization (WHO) drinking water guidelines for turbidity, and although E. coli reduction was over 98% for each BSF, a high initial bacteria concentration resulted in effluent levels above WHO guidelines. Subsequently, effluent from each BSF was placed in clear plastic bottles under UV light, after which water from each BSF met E. coli guidelines. The data yielded promising results for using larger sand in BSFs, but longer duration studies with more data points are needed.

scholarly journals Prevalence and characterization of Escherichia coli in the Kelantan River and its adjacent coastal waters

2020 ◽  
Vol 20 (3) ◽  
pp. 930-942
Author(s):  
Chui Wei Bong ◽  
Siong Kiat Chai ◽  
Lay Ching Chai ◽  
Ai Jun Wang ◽  
Choon Weng Lee
Keyword(s):  
Escherichia Coli ◽  
Coastal Waters ◽  
Membrane Filtration ◽  
Sea Water ◽  
Phylogenetic Group ◽  
Animal Origin ◽  
Phylogenetic Groups ◽  
E Coli ◽  
Colony Forming Units ◽  
Phylogenetic Grouping

Abstract The presence of Escherichia coli in river and sea water may cause different levels of infections and constitutes a risk to public health. In this study, water samples were collected from 15 sites along the Kelantan River, estuaries and its adjacent coastal waters to investigate the prevalence and diversity of E. coli. A membrane filtration technique was used to enumerate E. coli and phylogenetic grouping was performed using triplex polymerase chain reaction. E. coli abundance ranged from 3.1 × 10 to 1.6 × 105 colony forming units 100 mL−1, and total suspended solids correlated significantly with E. coli abundance (r2 = 0.165, p < 0.001) and rainfall (r2 = 0.342, p < 0.001). Phylogenetic group B1 and A (59.4%) were the most prevalent, whereas groups B2 and D were least abundant. The higher abundance of phylogenetic group D at upstream sites of the Kelantan River suggested fecal contamination mainly of animal origin. Canonical-correlation analysis showed phylogenetic group B2, and phylogenetic groups A and D were greater in waters with higher inorganic nutrients (e.g. NH4, NO2 and NO3), whereas phylogenetic group B1 appeared to have better salinity tolerance between phylogenetic groups.

scholarly journals The implementation of the five keys to safer food in campus cafeterias and the effects on Escherichia coli contamination

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Dewi Susanna ◽  
Aria Kusuma ◽  
Tiara Mairani ◽  
Lassie Fitria
Keyword(s):  
Escherichia Coli ◽  
Cross Sectional Study ◽  
World Health ◽  
Food Handlers ◽  
Cross Sectional ◽  
E Coli ◽  
Two Factors ◽  
Health Organization ◽  
And Behavior ◽  
Attitudes And Behavior

The World Health Organization developed five keys to safer food’s guidelines. This study aimed to determine the relationships between food handlers’ knowledge, attitudes, and behavior to the guideline and Escherichia coli (E. coli) contamination of food served at campus cafeterias. This cross-sectional study was carried out by interviewing 98 food handlers selling food and by testing samples for E. coli. The dependent variable was E. coli contamination, while the independent variables were the knowledge, attitudes, and behavior of food handlers based on the guideline. Each independent variable had five sub-variables that corresponded to the guideline. The data were analyzed using chisquare and logistic regression tests. The results showed that food handlers’ knowledge of cooking food thoroughly was significantly related to E. coli contamination (P=0.54 [P<0.05]; OR=2.990;95%CI:1.093– 8.180). Furthermore, the food handlers’ attitudes toward cooking food thoroughly were related to E. coli contamination (P=0.58 [P<0.05]; OR=0.385;95%CI:0.157– 0.944). There were two factors related to E. coli contamination: the food handlers’ knowledge of and attitudes toward the third key of the five keys to food safety.

scholarly journals Aktivitas Triterpenoid Kulit Batang Waru Jawa (Hibiscus tiliaceus L.) Terhadap Bakteri Escherichia coli

2020 ◽  
Vol 7 (1) ◽  
pp. 41-50
Author(s):  
Lisa Savitri ◽  
Kharisul Ihsan
Keyword(s):  
Escherichia Coli ◽  
World Health Organization ◽  
World Health ◽  
Disc Diffusion ◽  
E Coli ◽  
Ft Ir ◽  
Health Organization

Penyakit infeksi merupakan salah satu masalah kesehatan yang serius, khususnya di negara berkembang. Adanya resistensi antimikroba menyebabkan bahaya penyakit infeksi semakin parah, sehingga menjadi perhatian terbesar bagi kesehatan manusia. World Health Organization (WHO) memperkirakan bahwa pada tahun 2050, septikemia yang disebabkan oleh bakteri resisten antimikroba dapat mengakibatkan 10 juta kematian selama satu tahun. Tujuan penelitian ini adalah untuk melakukan isolasi senyawa triterpenoid yang terkandung dalam tanaman waru jawa (Hibiscus tiliaceus L.) serta melakukan identifikasi terhadap senyawa triterpenoid, dan melakukan pengujian aktivitas antibakteri Escherichia coli. Isolasi triterpenoid dari tanaman waru jawa diawali dengan maserasi menggunakan n-heksana, identifikasi triterpenoid, dan melakukan pengujian untuk aktivitas antibakteri. Hasil penelitian menunjukkan maserasi 3,2 kg serbuk kering kulit batang waru jawa menghasilkan ekstrak kental n-heksana sebesar 13,06 g. Hasil uji fitokimia menggunakan pereaksi Liebermann-Burchard menunjukkan ekstrak kental n-heksana positif mengandung triterpenoid. Pemisahan ekstrak kental n-heksana dengan kromatografi kolom menghasilkan isolat positif mengandung triterpenoid sebanyak 6 fraksi. Hasil identifikasi menggunakan spektrofotometer UV-Vis menunjukkan adanya serapan maksimum untuk fraksi 1, 2, dan 3 pada panjang gelombang 216,50 nm, 217 nm, dan 228,50 nm. Berdasarkan spektrogram FT-IR menunjukkan adanya gugus C-C, C=O,-C-H, -CH3, -CH2, dan C-O. Hasil aktivitas antibakteri dengan metode disc diffusion dan pengenceran dalam tabung menunjukkan bahwa fraksi 1, 3, 5, dan crude n-heksana mampu menghambat pertumbuhan bakteri Eschericia coli. MIC terhadap E. coli fraksi 1 sebesar 0,2 mg/mL.

scholarly journals A comparison of different O-antigen serogroups of Escherichia coli in semen samples of fertile and infertile men

2021 ◽  
Author(s):  
Ali Nabi ◽  
Mohammad Bagher Khalili ◽  
Gilda Eslami ◽  
Mahmood Vakili ◽  
Fatemeh Anbari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
World Health ◽  
Semen Parameters ◽  
E Coli ◽  
O Antigen ◽  
Infertile Men ◽  
Significant Difference ◽  
Genital Tract Infections ◽  
Health Organization ◽  
Tract Infections

Objective: Male genital tract infections have been associated with infertility, and Escherichia coli has drawn increasing attention as an important bacterium in this context. This investigation aimed to characterize and compare the distributions of O-antigen serogroups of E. coli in the semen samples of fertile and infertile men. Methods: In this case-control study, semen samples were collected from 618 fertile and 1,535 infertile men. The E. coli-positive samples were evaluated in terms of concentration, morphology, viability, and motility parameters according to the World Health Organization 2010 guidelines. Finally, different serogroups of E. coli were identified by multiplex polymerase chain reaction targeting the O-antigen variations of the bacterium.Results: The prevalence of E. coli among fertile men was significantly higher than among infertile men (p<0.001). The sperm morphology, viability, and motility in the E. coli-positive fertile group were significantly higher than in the E. coli-positive infertile group (p<0.001). E. coli O6 was the most prevalent serogroup found in both groups. However, there was no significant difference in the frequency of different serogroups of E. coil between the two groups (p=0.55). Conclusion: Despite the higher prevalence of E. coli among fertile men, E. coli had more detrimental effects on semen parameters in infertile men. There was no significant difference in E. coli serogroups between the fertile and infertile groups.

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