New Technology Offers Hope for Faster, More Targeted Antibiotic Treatment
Antimicrobial resistance (AMR) is rapidly becoming one of the most significant threats to global health, undermining decades of medical progress. As bacteria evolve and become increasingly resistant to existing treatments, the need for rapid and accurate identification of effective antibiotics is paramount. Now, a breakthrough technology developed by iFAST Diagnostics Ltd, a spinout from the University of Southampton, promises to deliver just that – potentially transforming clinical practice and slowing the spread of AMR.
The Scale of the Antimicrobial Resistance Crisis
Antimicrobial resistance is a complex challenge impacting human and animal health, agriculture, and the environment. It occurs when microorganisms, including bacteria and fungi, develop the ability to survive exposure to drugs designed to eliminate them. This leads to more difficult-to-treat infections, prolonged illness, and increased risk of serious disease and death.
The global impact of AMR is staggering. A 2019 analysis published in The Lancet estimated that bacterial AMR was responsible for 1.27 million deaths globally, and was associated with a total of 4.95 million deaths – exceeding the mortality rates of HIV/AIDS or malaria. The threat is particularly acute in low- and middle-income countries, though high-income nations are also experiencing rising resistance rates. Recent reports from the ECDC highlight antimicrobial resistance as a major public health threat within the EU/EEA, with increasing bloodstream infections caused by resistant bacteria, resulting in over 35,000 deaths annually.
A key driver of AMR is the misuse and overuse of antimicrobials in humans, animals, and plants. Currently, antibiotics are often prescribed empirically – based on symptoms and clinical experience – because traditional diagnostic methods are too slow to provide timely results. This practice increases the likelihood of using ineffective or unnecessarily broad-spectrum antibiotics, accelerating the development and spread of resistance.
Limitations of Current Antimicrobial Susceptibility Testing
Antimicrobial susceptibility testing (AST) determines which antibiotic will be most effective against a specific bacterial infection. However, traditional AST methods, which rely on classical culture-dependent microbiology, typically require one to two days – or even longer – to generate a complete susceptibility profile from a positive blood culture.
For patients with serious infections, particularly sepsis, this delay can be critical. Clinicians often initiate broad-spectrum antibiotic therapy before AST results are available, a practice that, while potentially life-saving, carries significant consequences:
- Suboptimal therapy: The initial antibiotic may not be the most effective, leading to treatment failure or delayed recovery.
- Increased resistance: Overuse of broad-spectrum antibiotics encourages the survival and spread of resistant strains.
- Higher healthcare burden: Prolonged illness, longer hospital stays, and more intensive care contribute to increased healthcare costs.
- Greater risk of severe outcomes: Delays in effective therapy are associated with worse outcomes and higher mortality, especially in bloodstream infections and sepsis.
iFAST: A Rapid, Accurate Diagnostic Solution
iFAST Diagnostics has developed a novel rapid AST system that delivers results in three hours or less from a positive blood culture – a significant improvement over conventional methods. At the core of this technology is a miniaturized microfluidic impedance cytometer. This device analyzes the phenotypic response of thousands of individual bacteria to antibiotics by measuring their electrical properties.
Instead of waiting for bacteria to grow in the presence of antibiotics, the iFAST system detects rapid biophysical changes that occur when susceptible bacteria respond to antimicrobial exposure. The process involves several key steps:
- Sample preparation: Bacteria are extracted from a positive blood culture and processed.
- Antibiotic exposure: The bacterial suspension is exposed to a range of antibiotics at defined concentrations and incubated for approximately two hours.
- High-throughput measurement: The iFAST reader passes thousands of individual bacteria through a microfluidic channel, analyzing them at speed.
- Phenotypic fingerprinting: Susceptible bacteria undergo measurable changes in their electrical characteristics following antibiotic exposure, while resistant bacteria show little or no change.
- Result generation: The system generates qualitative (Sensitive, Intermediate, or Resistant) and quantitative (Minimum Inhibitory Concentration) results after confirmation of a positive blood culture.
This phenotypic approach works across a wide range of bacterial species, regardless of Gram stain status, because it relies on fundamental biophysical responses rather than specific molecular markers.
How Impedance Flow Cytometry Works
Impedance flow cytometry is a high-throughput technology that analyzes individual cells by measuring their electrical impedance as they pass through a microfluidic channel. Changes in impedance at different frequencies reveal key cellular properties, including cell size, membrane capacitance, and internal structure. When antibiotics successfully harm or destroy bacteria, they alter proteins, resulting in a unique electrical “fingerprint” indicating susceptibility.
iFAST Diagnostics has miniaturized this technology, creating a compact, cost-effective instrument suitable for routine use in clinical microbiology laboratories, unlike traditional optical flow cytometers which are large and expensive.
Clinical Impact and Benefits
The speed and depth of information provided by the iFAST system offer several clinical and operational benefits. By delivering results in approximately three hours, clinicians can transition from empirical to targeted therapy within a single shift, which is particularly critical for life-threatening infections like sepsis.
iFAST Diagnostics has demonstrated at least 95% concordance with traditional disk diffusion methods, providing confidence in the reliability of the rapid results. Earlier, more precise antibiotic selection can reduce mortality and morbidity, shorten hospital stays, lower the risk of complications, and improve overall patient outcomes.
the iFAST system’s ability to quickly identify the optimal narrow-spectrum antibiotic reduces reliance on broad-spectrum agents, helping to curb the development and spread of resistance. The system is designed for operational efficiency, with high throughput, a compact footprint, cost-effective operation, and reduced plastic waste.
Validation, Certification, and Future Outlook
iFAST Diagnostics has successfully validated its technology through clinical trials and has received UKCA certification for gram-negative positive blood cultures, with a gram-positive panel planned for the future. The company has also achieved ISO 13485 certification for the design, manufacture, and distribution of its devices. Currently available in Great Britain, iFAST is planning an EU rollout in 2026/27.
The iFAST Diagnostics innovation has been recognized with accolades such as the Institute of Physics Lee Lucas Award 2025 and is part of the 2024 AMR Innovation Programme led by the Healthcare Innovation Consortium.
In the face of the growing global threat of antimicrobial resistance, innovations like the iFAST rapid AST system are essential. By maximizing the effectiveness of existing antibiotics, iFAST Diagnostics offers a promising step forward in the fight against AMR, improving patient outcomes and contributing to a more sustainable future for antibiotic therapy.