scholarly journals Bacteria Detection and Differentiation Using Impedance Flow Cytometry

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3496 ◽  
Author(s):  
Casper Clausen ◽  
Maria Dimaki ◽  
Christian Bertelsen ◽  
Gustav Skands ◽  
Romen Rodriguez-Trujillo ◽  
...  

Monitoring of bacteria concentrations is of great importance in drinking water management. Continuous real-time monitoring enables better microbiological control of the water and helps prevent contaminated water from reaching the households. We have developed a microfluidic sensor with the potential to accurately assess bacteria levels in drinking water in real-time. Multi frequency electrical impedance spectroscopy is used to monitor a liquid sample, while it is continuously passed through the sensor. We investigate three aspects of this sensor: First we show that the sensor is able to differentiate Escherichia coli (Gram-negative) bacteria from solid particles (polystyrene beads) based on an electrical response in the high frequency phase and individually enumerate the two samples. Next, we demonstrate the sensor’s ability to measure the bacteria concentration by comparing the results to those obtained by the traditional CFU counting method. Last, we show the sensor’s potential to distinguish between different bacteria types by detecting different signatures for S. aureus and E. coli mixed in the same sample. Our investigations show that the sensor has the potential to be extremely effective at detecting sudden bacterial contaminations found in drinking water, and eventually also identify them.

2021 ◽  
Vol 8 (1) ◽  
pp. 41-50
Author(s):  
Malavika J P ◽  
Shobana C

Solar disinfection (SODIS) is a technique, which involves utilization of solar energy to make safe drinking water from biologically contaminated water. In the conventional SODIS method, the PET bottles are filled with polluted water and exposed to the sunlight for a certain period depending upon the local weather conditions. However much more effective disinfection system is needed to overcome the problems of inefficient utilization of available solar energy and the health risk posed by treating the water using chemicals during the purification process.  Hence, the present work aims in designing a portable solar disinfection unit that can efficiently use solar energy by manually adjusting the unit according to sunlight availability. Along with it, incorporation of the additional eco-friendly unit with water purifying plants Vetiveria zizanioides (Vetiver) and Hemidesmus indicus (Nannari) is done to achieve high efficiency in producing potable water from biologically contaminated water. The contaminated water samples treated in the solar disinfection unit and eco-friendly water purifying unit are analyzed for the presence of total coliforms and E-coli by using the Most probable Number method and P/A analysis, respectively. A reduction in 99.74% of total coliform count and absence of E-coli was observed in the treated water samples.  The physicochemical analysis was carried out to ensure the suitability of treated water for consumption and the results revealed a notable reduction in the parameters, and all the parameters came under the permissible range of IS drinking water characteristics. The designed system can be used to disinfect the contaminated water sample most efficiently, thereby making the water suitable for consumption.


1970 ◽  
Vol 10 ◽  
pp. 189-193 ◽  
Author(s):  
Rajani Shrestha ◽  
Dev Raj Joshi ◽  
Jyotsna Gopali ◽  
Sujan Piya

Traditionally certain metal pots are used to store drinking water in order to ensure safety. A study was conducted with the aim of evaluating the effect of oligodynamic metals such as copper, silver and brass against enteric gram negative drinking water isolates such as Salmonella paratyphi, Shigella spp., E. coli (MDR), E. coli, Vibrio cholerae and Klebsiella during September 2007 to January 2008. The test was carried out by preparing broth of the respective microorganisms followed with contaminating autoclaved distilled water with 1% (by volume) of the prepared broth culture and incubating the contaminated water in the respective metal pots up to 48 h (holding time). Reduction in the microbial load was assessed by pour plating the water content in the metal pots on Nutrient agar medium in every 0, 4th, 8th, 12th, 24th and 48th h of incubation (holding time). Among three test pots, copper pot showed the maximum bactericidal action compared to silver and brass pots towards most of the enteric gram negative bacterial isolates of water. Complete inhibition of tested organism was recorded within 4 to 48 hours of holding time. This study suggested the promotion of use of water pots made of oligodynamic metals such as silver and copper, and alloy such as brass to control the gram negative enteric pathogens in drinking water.Key words: Oligodynamic action; Heavy metals; Enteric bacteriaDOI: 10.3126/njst.v10i0.2959Nepal Journal of Science and Technology Vol. 10, 2009 Page: 189-193   


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 903 ◽  
Author(s):  
Nikki van Bel ◽  
Luc M. Hornstra ◽  
Anita van der Veen ◽  
Gertjan Medema

To ensure delivery of microbiologically safe drinking water, the physical integrity of the distribution system is an important control measure. During repair works or an incident the drinking water pipe is open and microbiologically contaminated water or soil may enter. Before taking the pipe back into service it must be cleaned. The efficacy of flushing and shock chlorination was tested using a model pipe-loop system with a natural or cultured biofilm to which a microbial contamination (Escherichia coli, Clostridium perfringens spores and phiX174) was added. On average, flushing removed 1.5–2.7 log microorganisms from the water, but not the biofilm. In addition, sand added to the system was not completely removed. Flushing velocity (0.3 or 1.5 m/s) did not affect the efficacy. Shock chlorination (10 mg/L, 1–24 h) was very effective against E. coli and phiX174, but C. perfringens spores were partly resistant. Chlorination was slightly more effective in pipes with a natural compared to a cultured biofilm. Flushing alone is thus not sufficient after high risk repair works or incidents, and shock chlorination should be considered to remove microorganisms to ensure microbiologically safe drinking water. Prevention via hygienic working procedures, localizing and isolating the contamination source and issuing boil water advisories remain important, especially during confirmed contamination events.


Jurnal Biota ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 30-36
Author(s):  
Hoetary Tirta Amallia

One of the very needed natural resources on our planet is water. A total of 70% of the Earth's surface is water utilized for human development such as drinking, irrigation and cultivating fish. Contaminated water will have a bad effect on all living creatures and their environment [7]. Sources of water pollution can be derived from manusi stool containing coliform bacteria. The research purposes will be monitoring colifom number and Escherichia coli on some samples of drinking water as a bioindicator of drinking water pollution considering the higher the population consuming drinking water refill. This resource is pure resource experiment that use design of resource descriptive analitic. The data obtained will be displayed in the frequency distribution table to see the figure of coliform and E.coli in refill drinking water. From the results of this study, of 20 samples of drinking water refill there were 14 unqualified samples where the coliform figures exceeded quality standards. And 5 positive samples of E. Coli bacteria


2016 ◽  
Vol 15 (4) ◽  
pp. 899-903 ◽  
Author(s):  
Donald E. Macphee ◽  
Efetobor Scott-Emuakpor ◽  
Graeme I. Paton ◽  
Malcolm J. Todd

2020 ◽  
Author(s):  
Andrew John PENDERY

There are some striking similarities between Legionnaire’s disease and COVID-19. Thesymptoms, age group and sex at risk are identical. The geographical distribution of both diseases is similar in Europe overall, and within the USA, France and Italy. The environmental distributions are also similar. However Legionnaire’s disease is caused by Legionella bacteria while COVID-19 is caused by the Corona virus. Whereas COVID-19 is contagious, Legionnaire’s disease is environmental. Legionella bacteria are commonly found in drinking water systems and near air conditioning cooling towers. Legionnaire’sdisease is caught by inhaling contaminated water droplets. The Legionella bacteria does not spread person to person and only causes disease if it enters the lungs.Could the Corona virus be making it easier for Legionella bacteria to enter the lungs?


2019 ◽  
pp. 60-66
Author(s):  
Viet Quynh Tram Ngo ◽  
Thi Ti Na Nguyen ◽  
Hoang Bach Nguyen ◽  
Thi Tuyet Ngoc Tran ◽  
Thi Nam Lien Nguyen ◽  
...  

Introduction: Bacterial meningitis is an acute central nervous infection with high mortality or permanent neurological sequelae if remained undiagnosed. However, traditional diagnostic methods for bacterial meningitis pose challenge in prompt and precise identification of causative agents. Aims: The present study will therefore aim to set up in-house PCR assays for diagnosis of six pathogens causing the disease including H. influenzae type b, S. pneumoniae, N. meningitidis, S. suis serotype 2, E. coli and S. aureus. Methods: inhouse PCR assays for detecting six above-mentioned bacteria were optimized after specific pairs of primers and probes collected from the reliable literature resources and then were performed for cerebrospinal fluid (CSF) samples from patients with suspected meningitis in Hue Hospitals. Results: The set of four PCR assays was developed including a multiplex real-time PCR for S. suis serotype 2, H. influenzae type b and N. meningitides; three monoplex real-time PCRs for E. coli, S. aureus and S. pneumoniae. Application of the in-house PCRs for 116 CSF samples, the results indicated that 48 (39.7%) cases were positive with S. suis serotype 2; one case was positive with H. influenzae type b; 4 cases were positive with E. coli; pneumococcal meningitis were 19 (16.4%) cases, meningitis with S. aureus and N. meningitidis were not observed in any CSF samples in this study. Conclusion: our in-house real-time PCR assays are rapid, sensitive and specific tools for routine diagnosis to detect six mentioned above meningitis etiological agents. Key words: Bacterial meningitis, etiological agents, multiplex real-time PCR


2012 ◽  
Vol 12 (5) ◽  
pp. 699-706 ◽  
Author(s):  
B. S. Marti ◽  
G. Bauser ◽  
F. Stauffer ◽  
U. Kuhlmann ◽  
H.-P. Kaiser ◽  
...  

Well field management in urban areas faces challenges such as pollution from old waste deposits and former industrial sites, pollution from chemical accidents along transport lines or in industry, or diffuse pollution from leaking sewers. One possibility to protect the drinking water of a well field is the maintenance of a hydraulic barrier between the potentially polluted and the clean water. An example is the Hardhof well field in Zurich, Switzerland. This paper presents the methodology for a simple and fast expert system (ES), applies it to the Hardhof well field, and compares its performance to the historical management method of the Hardhof well field. Although the ES is quite simplistic it considerably improves the water quality in the drinking water wells. The ES knowledge base is crucial for successful management application. Therefore, a periodic update of the knowledge base is suggested for the real-time application of the ES.


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