Antimicrobial Susceptibility Testing Features

Accurate antimicrobial susceptibility testing (AST) is of critical importance in managing antimicrobial resistance. Sensititre AST plates and Oxoid AST discs consistently rank high in quality studies conducted by scientific regulatory agencies.

For example, in 2014 and 2017, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) conducted disc diffusion studies of AST discs from nine manufacturers against EUCAST target values and ranges for 16 antimicrobial drugs.¹ The heat map shows the results from 2017, in which only Thermo Fisher Scientific’s Oxoid disc results were color-coded green for all 16 drugs, signifying close alignment with the target ranges.

Similarly, in a 2018 study, Jayol et al tested commercial AST products from three vendors using the broth microdilution (BMD) plate method, including Thermo Scientific Sensititre plates, for their ability to measure the susceptibility of 185 isolates of Gram-negative bacilli to the polymyxin antibiotic colistin.² The products were tested against the laborious manual BMD reference method recommended by a joint CLSI-EUCAST working group. The researchers found that “the Sensititre system was the most reliable marketed BMD panel with a categorical agreement of 97.8%.” They concluded, "The Sensititre system showed excellent concordance with the BMD reference method and was reliable for testing colistin susceptibility for all the species of Gram-negative bacilli tested."

The value of a true MIC. Current AST methods are based on assessing the ability of an antimicrobial to inhibit bacterial growth. The minimum inhibitory concentration (MIC) is the level of antimicrobic required to achieve inhibition against the tested pathogen. However, some AST systems calculate the MIC value by extrapolating growth curves and applying dedicated algorithms.

The Sensititre System generates true MIC results based on actual growth of the organism. A true MIC reveals the difference between whether a bacterial isolate is susceptible, how susceptible the organism is against a particular drug, and the exact breakpoint at which the isolate is considered resistant. When comparing our results against the latest clinical breakpoints from EUCAST and CLSI, you can trust the value of a true MIC to deliver the accuracy required to guide antibiotic usage decisions and to track emerging resistance.

After nearly 100 years of widespread antibiotic use, the threat posed by evolving bacterial resistance to common antibiotics has emerged as one of the most significant global health issues of the 21st century⁴. Antimicrobial resistance is present in every country, increases healthcare costs, and is accelerating due to the misuse and overuse of antibiotics in both people and animals.

Sensititre AST testing plates are exceptionally well positioned to provide insights into emerging resistance since they broadly cover all AST domains—human clinical, animal food production, companion animals, and surveillance. The same Sensititre technology and equipment generate ongoing new AST data across these domains, adding to understanding and facilitating rapid action by both clinicians and regulatory bodies to minimize resistance.

The Sensititre Software System, called SWIN, combines manual and automated read options on a single, robust software platform, to easily consolidate your test program and streamline data entry. The software is compatible with all Sensititre instruments and plates.

SWIN Software features a customizable expert system that provides three tiers of expert messages, including Information, Modification (based on FDA, CLSI, and EUCAST recommendations), and Warning Levels. It also includes a quality control module to easily manage MIC results and broth information for auditing purposes, and automated alerts and reports to enhance workflow and expedite release of results. Simple touchscreen navigation puts results at your fingertips while drop-down fields eliminate manual entry errors for all manual, semi-automated, and fully automated reads.

Additionally, you can track and monitor local antibiotic resistance trends with the comprehensive reporting options in the SWIN Epidemiology Module. This module makes it easy to generate complete, real-time reports and bar graphs to support your antimicrobial stewardship program and surveillance of antimicrobial resistance patterns.

If our extensive catalog of AST plates doesn’t quite fit your needs, feel free to design your own! Choose from more than 300 antimicrobials to design a Thermo Scientific Sensititre Custom Plate tailored to your formulary, dilution ranges, and patient population.

Through collaboration with many pharmaceutical companies, the Sensititre System gives you access to the latest antimicrobials and the ability to conveniently update formats. You get relevant results based on real-time resistance trends and local epidemiology, allowing you to improve clinical success and effectively manage antimicrobial resistance within your institution.

One key advantage of custom AST testing is the flexibility of choosing among more than 300 antimicrobials for clinical and veterinary applications, available in either frozen or dried format. Custom plates also allow you to consolidate multiple tests into one format to reduce unnecessary protocols. You can choose from a variety of automation options to streamline your workflow within your workload and budget requirements.

Designing a Sensitire custom plate consists of four simple steps as shown in the interactive graphic. Our team of microbiology experts will guide you through the process, from design to approval to order to delivery.

Sensisitre SWIN Software serves as the glue that binds together these instruments and options. All the data generated within the Sensititre System, whether manual or automated, can be consolidated seamlessly in SWIN Software.