CombiANT Interaction Test Technology

Antibiotics modernised medicine. Now antibiotic efficacy is threatened by the spread of antibiotic resistance in bacteria. Our mission at Rx Dynamics is to improve antibiotic treatment and overcome resistance by the clever combination of antibiotics. We have developed the CombiANT TM technology to identify antibiotic pairs that work well against the bacteria from patient samples. The technology fills a gap in clinical diagnostics. CombiANT TM tests for resistance to antibiotics and for synergy between pairs of antibiotics. Thus, antibiotics pairs with validated high efficacy can be identified and antagonistic pairs and resistance avoided.

The innovative CombiANT TM was developed for simplicity.

Each CombiANT TM test produces triangular antibiotic dose landscapes in agar. Bacterial samples are applied on top and incubated. The resulting inhibition zones are imaged and analysed digitally. Antibiotic interactions are quantified from the shape of the triangular growth zones: synergy produces rounded corners and antagonism produces pointed corners. Thus, CombiANT TM test results are immediately intuitive, but you will also get an exact quantification of the interaction using the scientific gold standard FICi (Fractional Inhibitory Concentration index) scale according to Loewe’s model.

Our patented technology has key advantages:

  • High sensitivity, due to our patented dose landscapes
  • Best accuracy, we measure synergy from precise growth isoboles
  • Simplicity, easy lab testing and intuitive results
  • Cost efficiency, you don’t need any special instruments or kits
  • Unaffected by antibiotic induced changes to cell shape

Examples, of what can be done with CombiANT TM:

  • 3 antibiotics, 1 sample:                       1 plate – 3 synergy results
  • 5 antibiotics, 1 sample:                       4 plates – 10 synergy results 
  • 3 antibiotics, 100 samples:                 100 plates – 300 synergy results

Our technology is ready to be tested by you! Apply to join our Beta Test.

While you do, we and scientific collaborators in Switzerland and Sweden are busy with the clinical validation of CombiANT TM tests.

Image credit Sabrina Koehler

For the same species, interaction patterns (synergy, additive, antagonism) can vary depending on the specific clinical isolate and antibiotic interactions are generally not conserved.  Therefore, the interaction needs to be validated for each individual patient isolate. More information in our scientific publications More information in our scientific publications.

Pathogens successfully used with CombiANT TM:

  • Acinetobacter baumanii
  • Enterococcus
  • Escherichia coli (UTI, blood stream isolates)
  • Pseudomonas aeruginosa (also mucoid strains)
  • Salmonella enterica Typhimurium
  • Staphylococcus aureus (MRSA and others)
  • … give it a go!

Antibiotics successfully used with CombiANT TM:

  • Ampicillin
  • Carbenicillin
  • Cefsulodin
  • Cefotaxime
  • Ciprofloxacin
  • Chloramphenicol
  • Colistin
  • Doripenem
  • Erythromycin
  • Fosfomycin
  • Gentamicin
  • Kanamycin
  • Mecillinam
  • Meropenem
  • Nitrofurantoin
  • Spectinomycin
  • Streptomycin
  • Tetracycline
  • Tigecycline
  • Tobramycin
  • Trimethoprim
  • Piperacillin
  • Polymyxin B
  • … more to come!

CombiANT TM plates are manufactured in Europe