Absorbance Analysis of Escherichia coli (E. coli) Bacteria Suspension in Polydimethylsiloxane (PDMS)-Glass Based Microfluidic

2016 ◽  
Vol 1133 ◽  
pp. 65-69 ◽  
Author(s):  
Nurulazirah Md Salih ◽  
Uda Hashim ◽  
Nayan Nafarizal ◽  
Chin Fhong Soon ◽  
Mohd Zainizan Sahdan
Keyword(s):  
Escherichia Coli ◽  
Optical Measurement ◽  
Low Cost ◽  
Microfluidic Platform ◽  
Absorbance Measurement ◽  
E Coli ◽  
Non Invasive ◽  
Graph Pattern ◽  
Alternative Approach ◽  
Microfluidic Chambers

The emerging of bacteria/cell culturing in biological/biomedical research and industry is in demand for low cost, fast, non-invasive, and reliable alternative/approach for evaluation and measurement. Microfluidic approach is one of the promising alternatives for replacing the expensive commercial cuvvete for bacteria/cell culture and suspension for optical measurement. This study demonstrates the integration of absorbance measurement with microfluidic platform forEscherichia coli(E. coli) bacteria suspension analysis. TheE. coliwas cultured and prepared for suspension medium which then transferred inside the PDMS-glass based microfluidic. Then, the absorbance measurement is carried out using UV-Visible spectrophotometer. We demonstrate this method by measuring absorption of light transmitted through microfluidic chambers within the visible light range (350nm - 750nm). From the result, it had indicates that the graph pattern and growth behavior ofE. colisuspension in microfluidic platform are reliable and comparable to commercial cuvvete reading. This finding

scholarly journals Estimating the Prevalence of Potential Enteropathogenic Escherichia coli and Intimin Gene Diversity in a Human Community by Monitoring Sanitary Sewage

2013 ◽  
Vol 80 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Kun Yang ◽  
Eulyn Pagaling ◽  
Tao Yan
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Gene Diversity ◽  
Content Type ◽  
E Coli ◽  
Enteric Diseases ◽  
Detection Frequency ◽  
Alternative Approach ◽  
Prevalent Subtype ◽  
Qpcr Quantification

ABSTRACTPresently, the understanding of bacterial enteric diseases in the community and their virulence factors relies almost exclusively on clinical disease reporting and examination of clinical pathogen isolates. This study aimed to investigate the feasibility of an alternative approach that monitors potential enteropathogenicEscherichia coli(EPEC) and enterohemorrhagicE. coli(EHEC) prevalence and intimin gene (eae) diversity in a community by directly quantifying and characterizing target virulence genes in the sanitary sewage. The quantitative PCR (qPCR) quantification of theeae,stx1, andstx2genes in sanitary sewage samples collected over a 13-month period detectedeaein all 13 monthly sewage samples at significantly higher abundance (93 to 7,240 calibrator cell equivalents [CCE]/100 ml) thanstx1andstx2, which were detected sporadically. The prevalence level of potential EPEC in the sanitary sewage was estimated by calculating the ratio ofeaetouidA, which averaged 1.0% (σ = 0.4%) over the 13-month period. Cloning and sequencing of theeaegene directly from the sewage samples covered the majority of theeaediversity in the sewage and detected 17 uniqueeaealleles belonging to 14 subtypes. Among them,eae-β2 was identified to be the most prevalent subtype in the sewage, with the highest detection frequency in the clone libraries (41.2%) and within the different sampling months (85.7%). Additionally, sewage and environmentalE. coliisolates were also obtained and used to determine the detection frequencies of the virulence genes as well aseaegenetic diversity for comparison.

scholarly journals Cyclomodulins and Hemolysis in E. coli as Potential Low-Cost Non-Invasive Biomarkers for Colorectal Cancer Screening

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1165
Author(s):  
Kristýna Mezerová ◽  
Lubomír Starý ◽  
Pavel Zbořil ◽  
Ivo Klementa ◽  
Martin Stašek ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Low Cost ◽  
E Coli ◽  
Crc Screening ◽  
Non Invasive ◽  
Detection Approach ◽  
Gene Assay ◽  
Immunochemical Test ◽  
The Mean ◽  
And Performance

The frequent occurrence of E. coli positive for cyclomodulins such as colibactin (CLB), the cytotoxic necrotizing factor (CNF), and the cytolethal distending factor (CDT) in colorectal cancer (CRC) patients published so far provides the opportunity to use them as CRC screening markers. We examined the practicability and performance of a low-cost detection approach that relied on culture followed by simplified DNA extraction and PCR in E. coli isolates recovered from 130 CRC patients and 111 controls. Our results showed a statistically significant association between CRC and the presence of colibactin genes clbB and clbN, the cnf gene, and newly, the hemolytic phenotype of E. coli isolates. We also observed a significant increase in the mean number of morphologically distinct E. coli isolates per patient in the CRC cohort compared to controls, indicating that the cyclomodulin-producing E. coli strains may represent potentially preventable harmful newcomers in CRC patients. A colibactin gene assay showed the highest detection rate (45.4%), and males would benefit from the screening more than females. However, because of the high number of false positives, practical use of this marker must be explored. In our opinion, it may serve as an auxiliary marker to increase the specificity and/or sensitivity of the well-established fecal immunochemical test (FIT) in CRC screening.

scholarly journals Sanitizing action of triple-strength vinegar against Escherichia coli on lettuce

2018 ◽  
Vol 36 (3) ◽  
pp. 414-418 ◽  
Author(s):  
Giovanna C Souza ◽  
Wilma A Spinosa ◽  
Tereza CRM Oliveira
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Low Cost ◽  
Titratable Acidity ◽  
Total Acidity ◽  
Total Coliforms ◽  
E Coli ◽  
Total Titratable Acidity ◽  
Carcinogenic Effects ◽  
Interesting Alternative

ABSTRACT Vegetable sanitization protocols recommend the use of chlorine, which has adverse effects on the environment and carcinogenic effects on humans. Acetic acid is an interesting alternative to chlorine because it possesses no risk to human health and is widely available in the form of vinegar. This study aimed to evaluate the sanitizing action of vinegar, 130 g L-1 total titratable acidity expressed as acetic acid, on lettuce. Vinegar was chosen because it is a low-cost product widely available in the Brazilian market. The minimum inhibitory concentration and minimum bactericidal concentration of vinegar against Escherichia coli were 2.5 and 15 g L-1 total acidity, respectively. Lettuce leaves artificially contaminated with E. coli or naturally contaminated with total coliforms were washed with water and immersed in vinegar solution (15 g L-1 total acidity) for 15 min. This period was sufficient to reduce E. coli counts in artificially contaminated samples and total coliforms in naturally contaminated samples. There were no visual changes in lettuce leaves, which indicates that vinegar at 15 g L-1 total acidity can be used to sanitize vegetables without affecting their appearance.

scholarly journals Hydrothermal Fabrication of Spindle-Shaped ZnO/Palygorskite Nanocomposites Using Nonionic Surfactant for Enhancement of Antibacterial Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1453 ◽  
Author(s):  
Aiping Hui ◽  
Shuqing Dong ◽  
Yuru Kang ◽  
Yanmin Zhou ◽  
Aiqin Wang
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Low Cost ◽  
Ionic Surfactants ◽  
E Coli ◽  
Antibacterial Performance ◽  
Good Antibacterial Activity ◽  
Controllable Growth ◽  
And Staphylococcus Aureus

In order to improve the antibacterial performance of natural palygorskite, spindle-like ZnO/palygorskite (ZnO/PAL) nanocomposites with controllable growth of ZnO on the surface of PAL were prepared in the presence of non-ionic surfactants using an easy-to-operate hydrothermal method. The obtained ZnO/PAL nanocomposites have a novel and special spindle-shaped structure and good antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and are also low cost. The minimum inhibitory concentrations of ZnO/PAL nanocomposites toward E. coli and S. aureus reached 1.5 and 5 mg/mL, respectively.

scholarly journals Microwave-Assisted Synthesis of Amikacin Modified N,S co-Doped Carbon Dots for Escherichia coli Detection

Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 61
Author(s):  
Fajar Amelia Rachmawati Putri ◽  
Mudasir Mudasir ◽  
Kinichi Morita ◽  
Suherman Suherman
Keyword(s):  
Escherichia Coli ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
E Coli ◽  
Microwave Assisted ◽  
Average Size ◽  
Doped Carbon Dots ◽  
Co Doped

Fluorescent amikacin modified nitrogen, sulfur co-doped carbon dots (amikacin modified N,S-CDs) were synthesized by a facile and low-cost one-step microwave-assisted specifically for selective detection of Gram-negative bacteria Escherichia coli (E. coli). Amikacin is a semi-synthetic amino glycoside antibiotic and it was employed in this study to increase the fluorescence response of N,S-CDs by providing binding ligand towards E. coli. The effect of thiourea content as the source of nitrogen and sulfur dopants was investigated prior to the preparation of amikacin modified N,S-CDs. The formation of amikacin modified N,S-CDs were characterized by using Fourier transform infrared (FTIR), X-ray diffraction (XRD), Transmission electron microscope (TEM), UV-Vis spectrophotometer, and spectrofluorometer. Amikacin modified N,S-CDs was identified to be successfully synthesized from the wavenumber shift of the C=O stretching mode. Amikacin modified N,S-CDs were amorphous with an average size of 7 nm. Fluorescence spectra showed that the highest intensity was obtained at thiourea content of 50% and amikacin mass of 25 mg. By comparing fluorescence responses of all the investigated amikacin modified N,S-CDs, the limit of detection (LOD) was attained by 25 mg amikacin modified N,S-CDs at 1.526 cfu mL−1.

scholarly journals Electroceutical disinfection strategies impair the motility of pathogenic Pseudomonas aeruginosa and Escherichia coli

2016 ◽  
Author(s):  
Kristina Doxsee ◽  
Ryan Berthelot ◽  
Suresh Neethirajan
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Acetic Acid ◽  
Mammalian Cells ◽  
Pathogenic Bacteria ◽  
Electrical Potential ◽  
Microfluidic Platform ◽  
E Coli ◽  
Therapeutic Benefits ◽  
The Impact

Electrotaxis or galvanotaxis refers to the migration pattern of cells induced in response to electrical potential. Although it has been extensively studied in mammalian cells, electrotaxis has not been explored in detail in bacterial cells; information regarding the impact of current on pathogenic bacteria is severely lacking. Therefore, we designed a series of single and multi-cue experiments to assess the impact of varying currents on bacterial motility dynamics in pathogenic multi-drug resistant (MDR) strains of Pseudomonas aeruginosa and Escherichia coli using a microfluidic platform. Motility plays key roles in bacterial migration and the colonization of surfaces during the formation of biofilms, which are inherently recalcitrant to removal and resistant to traditional disinfection strategies (e.g. antibiotics). Use of the microfluidic platform allows for exposure to current, which can be supplied at a range that is biocidal to bacteria, yet physiologically safe in humans (single cue). This system also allows for multi-cue experiments where acetic acid, a relatively safe compound with anti-fouling/antimicrobial properties, can be combined with current to enhance disinfection. These strategies may offer substantial therapeutic benefits, specifically for the treatment of biofilm infections, such as those found in the wound environment. Furthermore, microfluidic systems have been successfully used to model the unique microfluidic dynamics present in the wound environment, suggesting that these investigations could be extended to more complex biological systems. Our results showed that the application of current in combination with acetic acid has profound inhibitory effects on MDR strains of P. aeruginosa and E. coli, even with brief applications. Specifically, E. coli motility dynamics and cell survival were significantly impaired starting at a concentration of 125 μA DC and 0.31% acetic acid, while P. aeruginosa was impaired at 70 μA and 0.31% acetic acid. As these strains are relevant wound pathogens, it is likely that this strategy would be effective against similar strains in vivo and could represent a new approach to hasten wound healing.

scholarly journals Escherichia coli O-Genotyping PCR: a Comprehensive and Practical Platform for Molecular O Serogrouping

2015 ◽  
Vol 53 (8) ◽  
pp. 2427-2432 ◽  
Author(s):  
Atsushi Iguchi ◽  
Sunao Iyoda ◽  
Kazuko Seto ◽  
Tomoko Morita-Ishihara ◽  
Flemming Scheutz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Low Cost ◽  
Epidemiological Studies ◽  
Biosynthesis Gene Cluster ◽  
Content Type ◽  
E Coli ◽  
O Antigen ◽  
Promising Tool ◽  
Outbreak Investigations ◽  
Wild Strains

The O serogrouping of pathogenicEscherichia coliis a standard method for subtyping strains for epidemiological studies and enhancing phylogenetic studies. In particular, the identification of strains of the same O serogroup is essential in outbreak investigations and surveillance. In a previous study, we analyzed the O-antigen biosynthesis gene cluster in all knownE. coliO serogroups (A. Iguchi et al., DNA Res, 22:101–107, 2015,http://dx.doi.org/10.1093/dnares/dsu043). Based on those results, we have arranged 162 PCR primer pairs for the identification or classification of O serogroups. Of these, 147 pairs were used to identify 147 individual O serogroups with unique O-antigen biosynthesis genes, and the other 15 pairs were used to identify 15 groups of strains (Gp1 to Gp15). Each of these groups consisted of strains with identical or very similar O-antigen biosynthesis genes, and the groups represented a total of 35 individual O serogroups. We then used the 162 primer pairs to create 20 multiplex PCR sets. Each set contained six to nine primer pairs that amplify products of markedly different sizes. This genetic methodology (E. coliO-genotyping PCR) allowed for comprehensive, rapid, and low-cost typing. Validation of the PCR system using O-serogroup references and wild strains showed that the correct O serogroups were specifically and accurately identified for 100% (182/182) and 90.8% (522/575) of references and wild strains, respectively. The PCR-based system reported here might be a promising tool for the subtyping ofE. colistrains for epidemiological studies as well as for the surveillance of pathogenicE. coliduring outbreaks.

scholarly journals Magnesium Hydroxide Nanoparticles Kill Exponentially Growing and Persister Escherichia coli Cells by Causing Physical Damage

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1584
Author(s):  
Yohei Nakamura ◽  
Kaede Okita ◽  
Daisuke Kudo ◽  
Dao Nguyen Duy Phuong ◽  
Yoshihito Iwamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Magnesium Hydroxide ◽  
Cell Damage ◽  
Low Cost ◽  
Bactericidal Effect ◽  
Physical Damage ◽  
E Coli ◽  
In The Wild ◽  
Low Toxicity ◽  
Magnesium Hydroxide Nanoparticles

Magnesium hydroxide nanoparticles are widely used in medicinal and hygiene products because of their low toxicity, environment-friendliness, and low cost. Here, we studied the effects of three different sizes of magnesium hydroxide nanoparticles on antibacterial activity: NM80, NM300, and NM700. NM80 (D50 = 75.2 nm) showed a higher bactericidal effect against Escherichia coli than larger nanoparticles (D50 = 328 nm (NM300) or 726 nm (NM700)). Moreover, NM80 showed a high bactericidal effect against not only exponential cells but also persister cells, which are difficult to eliminate owing to their high tolerance to antibiotics. NM80 eliminated strains in which magnesium-transport genes were knocked out and exhibited a bactericidal effect similar to that observed in the wild-type strain. The bactericidal action involved physical cell damage, as confirmed using scanning electron microscopy, which showed that E. coli cells treated with NM80 were directly injured.

scholarly journals Horizontally acquired papGII-containing pathogenicity islands underlie the emergence of invasive uropathogenic Escherichia coli lineages

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Biggel ◽  
Basil B. Xavier ◽  
James R. Johnson ◽  
Karen L. Nielsen ◽  
Niels Frimodt-Møller ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Large Scale ◽  
Asymptomatic Bacteriuria ◽  
Pathogenicity Islands ◽  
Phylogenomic Analysis ◽  
E Coli ◽  
Non Invasive ◽  
Genome Wide ◽  
A Genome

AbstractEscherichia coli is the leading cause of urinary tract infection, one of the most common bacterial infections in humans. Despite this, a genomic perspective is lacking regarding the phylogenetic distribution of isolates associated with different clinical syndromes. Here, we present a large-scale phylogenomic analysis of a spatiotemporally and clinically diverse set of 907 E. coli isolates, including 722 uropathogenic E. coli (UPEC) isolates. A genome-wide association approach identifies the (P-fimbriae-encoding) papGII locus as the key feature distinguishing invasive UPEC, defined as isolates associated with severe UTI, i.e., kidney infection (pyelonephritis) or urinary-source bacteremia, from non-invasive UPEC, defined as isolates associated with asymptomatic bacteriuria or bladder infection (cystitis). Within the E. coli population, distinct invasive UPEC lineages emerged through repeated horizontal acquisition of diverse papGII-containing pathogenicity islands. Our findings elucidate the molecular determinants of severe UTI and have implications for the early detection of this pathogen.

scholarly journals Enhanced Heterologous Production of Glycosyltransferase UGT76G1 by Co-Expression of Endogenous prpD and malK in Escherichia coli and Its Transglycosylation Application in Production of Rebaudioside

2020 ◽  
Vol 21 (16) ◽  
pp. 5752
Author(s):  
Wenju Shu ◽  
Hongchen Zheng ◽  
Xiaoping Fu ◽  
Jie Zhen ◽  
Ming Tan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Low Cost ◽  
Expression System ◽  
Steviol Glycosides ◽  
Fusion Partner ◽  
Uridine Diphosphate ◽  
Heterologous Proteins ◽  
E Coli ◽  
Novel Strategy

Steviol glycosides (SGs) with zero calories and high-intensity sweetness are the best substitutes of sugar for the human diet. Uridine diphosphate dependent glycosyltransferase (UGT) UGT76G1, as a key enzyme for the biosynthesis of SGs with a low heterologous expression level, hinders its application. In this study, a suitable fusion partner, Smt3, was found to enhance the soluble expression of UGT76G1 by 60%. Additionally, a novel strategy to improve the expression of Smt3-UGT76G1 was performed, which co-expressed endogenous genes prpD and malK in Escherichia coli. Notably, this is the first report of constructing an efficient E. coli expression system by regulating prpD and malK expression, which remarkably improved the expression of Smt3-UGT76G1 by 200% as a consequence. Using the high-expression strain E. coli BL21 (DE3) M/P-3-S32U produced 1.97 g/L of Smt3-UGT76G1 with a yield rate of 61.6 mg/L/h by fed-batch fermentation in a 10 L fermenter. The final yield of rebadioside A (Reb A) and rebadioside M (Reb M) reached 4.8 g/L and 1.8 g/L, respectively, when catalyzed by Smt3-UGT76G1 in the practical UDP-glucose regeneration transformation system in vitro. This study not only carried out low-cost biotransformation of SGs but also provided a novel strategy for improving expression of heterologous proteins in E. coli.

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