Label-free 1D microfluidic dipstick counting of microbial colonies and bacteriophage plaques

Dönmez, Sultan İlayda; Needs, Sarah; Osborn, Helen M. I.; Reis, Nuno M.; Edwards, Alexander D.

doi:10.1039/d2lc00280a

Cited by 10 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nonetheless, a complete automation process should not be considered as such if it does not include the last part of the process, which is plate reading and PFU count. Fortunately, automation of these tasks is already under development, which will certainly contribute to improving phage potency assessment [30][31][32].…”

Section: Discussionmentioning

confidence: 99%

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method

Dufour,

Delattre,

Debarbieux

2024

Biomedicines

View full text Add to dashboard Cite

The development of bacteriophages (phages) as active pharmaceutical ingredients for the treatment of patients is on its way and regulatory agencies are calling for reliable methods to assess phage potency. As the number of phage banks is increasing, so is the number of phages that need to be tested to identify therapeutic candidates. Currently, assessment of phage potency on a semi-solid medium to observe plaque-forming units is unavoidable and proves to be labor intensive when considering dozens of phage candidates. Here, we present a method based on automated pipetting and phage drop-off performed by a liquid-handling robot, allowing high-throughput testing and phage potency determination (based on phage titer and efficiency of plaquing). Ten phages were tested, individually and assembled into one cocktail, against 126 Escherichia coli strains. This automated method was compared to the reference one (manual assay) and validated in terms of reproducibility and concordance (ratio of results according to the Bland and Altman method: 0.99; Lin’s concordance correlation coefficient: 0.86). We found that coefficients of variation were lower with automated pipetting (mean CV: 13.3% vs. 24.5%). Beyond speeding up the process of phage screening, this method could be used to standardize phage potency evaluation.

show abstract

Section: Discussionmentioning

confidence: 99%

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method

Dufour,

Delattre,

Debarbieux

2024

Biomedicines

View full text Add to dashboard Cite

show abstract

“…Dönmez and colleagues found that a rapid count of phage plaques in a dip-and-test format could be achieved by incorporating digital imaging with fluoropolymer microcapillaries. 271 Additionally, Ogawa and colleagues successfully differentiated between live E. coli and heat-treated E. coli within 20 min utilizing a near-field sensor array. 272…”

Section: Biosensor-based Assaysmentioning

confidence: 99%

Progress in methods for the detection of viable Escherichia coli

Zhuang,

Gong,

Zhao

et al. 2024

Analyst

View full text Add to dashboard Cite

show abstract

“…Dönmez et al also utilized bacteriophages for live bacteria detection but instead of using a reporter phage, they exploited the phage's natural ability to produce lytic plaques. [75] Plaque forming units (PFU) are commonly produced in solid agar plates and require a laborious procedure and overnight incubation. In this study a microfluidic dipstick was developed for fast and simple PFU measurements, achieving a limit of detection of 250 CFU mL −1 in 4-8 h of incubation depending on the target organism.…”

Section: Metabolic Activity and Cell Culturementioning

confidence: 99%

Microfluidics for Rapid Detection of Live Pathogens

Rossi

Coulon

et al. 2023

Adv Funct Materials

View full text Add to dashboard Cite

Rapid, sensitive, and selective detection of live pathogens remains a key priority for quality control and risk assessment. While conventional methods often require complicated workflows, costly reagents, lab equipment, and are time-consuming, rendering them inadequate for field testing and lowresource settings. Increased attention has been drawn to developing alternative low-cost and rapid methods to detect on-site live pathogens in different environmental matrices. Among them, microfluidic devices that integrate various laboratory functions in a miniaturized manner have proven to be a promising tool for the rapid and sensitive detection of pathogens. Herein, the development of microfluidic devices specifically designed for the detection of live pathogens is discussed along a concise summary of novel microfluidics systems recently developed, contrasted to conventional methods regarding assay time, the limit of detection, and target organisms. These include a variety of micro total analysis systems (µTAS) and micro fluidic paper-based analytical devices (µPADs) in combination with molecular methods and traditional live cell detection techniques, such as cell culture, DNA intercalating dyes, resazurin, and immobilized bioreceptors (e.g., aptamers and capture antibodies). Furthermore, insights on the future perspectives of microfluidics for live pathogen detection with a highlight on the rapid and low-cost method development for field testing are provided.

show abstract

Label-free 1D microfluidic dipstick counting of microbial colonies and bacteriophage plaques

Abstract: Miniaturised 1D liquid colony and plaque counting method. Counting viable bacterial cells and functional bacteriophage is fundamental to microbiology underpinning research, surveillance, biopharmaceuticals and diagnostics.

Cited by 10 publications

References 34 publications

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method

Progress in methods for the detection of viable Escherichia coli

Microfluidics for Rapid Detection of Live Pathogens

Contact Info

Product

Resources

About