scholarly journals Cross-Flow Filtration of Escherichia coli at a Nanofluidic Gap for Fast Immobilization and Antibiotic Susceptibility Testing

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 691 ◽  
Author(s):  
Jan F. Busche ◽  
Svenja Möller ◽  
Matthias Stehr ◽  
Andreas Dietzel
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Cross Flow ◽  
Test Time ◽  
Microfluidic Chips ◽  
Cross Flow Filtration ◽  
Antibiotic Susceptibility Test ◽  
Flow Filtration ◽  
On Chip

Infections with antimicrobial-resistant (AMR) bacteria are globally on the rise. In the future, multi-resistant infections will become one of the major problems in global health care. In order to enable reserve antibiotics to retain their effect as long as possible, broad-spectrum antibiotics must be used sparingly. This can be achieved by a rapid microfluidic phenotypic antibiotic susceptibility test, which provides the information needed for a targeted antibiotic therapy in less time than conventional tests. Such microfluidic tests must cope with a low bacteria concentration. On-chip filtering of the samples to accumulate bacteria can shorten the test time. By means of fluorescence microscopy, we examined a novel nanogap filtration principle to hold back Escherichia coli and to perform cultivation experiments with and without antibiotics present. Microfluidic chips based on the nanogap flow principle showed to be useful for the concentration and cultivation of E. coli. With a concentration of 106 cells/mL, a specific growth rate of 0.013 min−1 and a doubling time of 53 min were achieved. In the presence of an antibiotic, no growth was observed. The results prove that this principle can, in future, be used in fast and marker-free antimicrobial susceptibility testing (AST).

scholarly journals A New Colorimetric Method for Rapid Detection of Antibiotic Resistance in Escherichia coli Isolates

2022 ◽  
Vol 14 (11) ◽  
Author(s):  
Mehmet Akif Gun ◽  
Yeliz Tanriverdi Cayci ◽  
Belma Durupinar ◽  
Ahmet Yilmaz Coban
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Colorimetric Method ◽  
Reference Method ◽  
Clinical Isolates ◽  
E Coli ◽  
Antibiotic Susceptibility Test ◽  
Short Period ◽  
Broth Microdilution Method

Background: The quick diagnosis and early initiation of antibiotic therapy in bacteria-induced infections is of paramount importance. Accordingly, the rapid identification of the causative agent, the short-term results of antibiotic sensitivity, the selection and use of right antibiotics for treatment further highlights the significance of this issue. Objectives: This study aimed to develop a new susceptibility testing method to provide rapid results in Escherichia coli clinical isolates and report the antibiotic susceptibility test results to clinicians in a short period. Methods: In the study, one hundred and ten E. coli clinical isolates were tested. In this regard, antibiotics recommended by the "Clinical and Laboratory Standards Institute (CLSI)" for testing the sensitivity of E. coli isolates, including amoxicillin-clavulanate, cefixime, ceftriaxone, ertapenem, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, and nitrofurantoin were tested. For quality control, E. coli ATCC25922, E. coli ATCC35218, Staphylococcus aureus ATCC29213, and E. coli 13846NTCC strains were used. The broth microdilution method recommended by CLSI was used as the reference method. Minimum inhibitory concentration values were determined, and antimicrobial susceptibilities were then determined according to the “European Committee on Antimicrobial Susceptibility Testing (EUCAST)” criteria. In the next phase, the results of the resazurin microplate method (RMM) were compared. Results: The comparison of the RMM developed in the present study with the reference method revealed that the calculated essential agreement ratios for eight antibiotics varied from 82.72 to 100%, and the categorical agreement values ranged from 95.45 to100%. Conclusions: According to the findings, the RMM results were highly in agreement with the results of the reference method. RMM allows the detection of antibiotic susceptibility quickly (e.g., within 5 hours) as such it is preferred, especially for laboratories with limited facilities. However, further multi-center studies are recommended to use this method in routine laboratories.

Epidemiology, risk factors and antimicrobial resistance of Escherichia coli bacteremia

2021 ◽  
Vol 11 (Number 2) ◽  
pp. 58-67
Author(s):  
Mahjuba Umme Salam ◽  
Selina Yasmin ◽  
Md. Rashedul Haque ◽  
Sharmin Ahmed ◽  
Shahidul Alam ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Antibiotic Susceptibility ◽  
Antimicrobial Agents ◽  
Blood Stream Infection ◽  
Incidence Rates ◽  
Diffusion Method ◽  
Antibiotic Susceptibility Test ◽  
Multiple Drugs

Background: Escherichia coli is a common causative of blood stream infection having potentials to produce significant morbidity and mortality. This organism also has the ability to develop resistance against antimicrobial agents. Knowing its epidemiology, risk factors and antimicrobial resistance patterns can help preventing and managing bacteremia caused by this organism. Materials and methods: This was across sectional observational study carried out from February 2017 to February 2018 on 64 blood culture positive Escherichia coli infected patients admitted in Medicine inpatient of a medical college hospital. Age, sex, mode of acquisition of infection, history of prior empiric antibiotic treatment, duration of hospital stay, development of complication were observed and noted. Antibiotic susceptibility test for all isolates was performed by Kirby-Bauer disc diffusion method. Predesigned semi-structured data collection from was used and collected data were analyzed manually and expressed in descriptive statistical terms. Results: Of the 64 enrolled patients, 47(73.43%) were female. Average age of affection was 53.48±20.65 years and increased incidence rates (51.56%) was observed at age >60 years. Infection was communityacquired in 35.84% cases and urinary tract infection was the most frequent (46.3) risk factor. More than eighty seven percent of samples showed resistance to at least one antimicrobial agent and resistance to multiple drugs was associated with complications. Conclusion: Escherichia coli bacteremia has high incidence rates for antimicrobial resistance and mortality. Continuous surveillance and antibiotic susceptibility pattern monitoring is essential to develop regional antibiotic therapy protocols.

Cross-Flow Ultrafiltration Used in Algal High Rate Oxidation Pond Treatment of Saline Organic Effluents with the Recovery of Products of Value

1992 ◽  
Vol 25 (10) ◽  
pp. 319-327 ◽  
Author(s):  
P. D. Rose ◽  
B. A. Maart ◽  
T. D. Phillips ◽  
S. L. Tucker ◽  
A. K. Cowan ◽  
...  
Keyword(s):  
Waste Treatment ◽  
Production Systems ◽  
Algal Cell ◽  
Cross Flow ◽  
Viable Cell ◽  
High Rate ◽  
Limiting Factor ◽  
Algal Biotechnology ◽  
Cross Flow Filtration ◽  
Flow Filtration

An algal high rate oxidation ponding process for treating organic s present in saline effluents has been described. The extreme halophile Dunaliella salina can be made to predominate in the system by manipulating salinity, producing products of value together with a waste treatment function. Application in treating tannery saline organic wastes was examined. Techniques appropriate for the harvesting of micro-algae from this and other algal production systems presents a limiting factor in the development of algal biotechnology. Cross-flow filtration was evaluated as a technique for micro-algal cell separation. Both microfiltration and ultrafiltration were found to produce effective algal removal from the medium, Cross-flow ultrafiltration with a polyethersulfone coated tubular filter produced effective separation with the production of cell concentrates in a viable condition. Flux rates of 30 - 40 LMH fall within acceptable levels for application in industrial processes. Cell shattering observed with microfiltration precludes its use for recovering whole or viable cell concentrates.

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