Proprietary Technology

P‑AST™

Pooled Antibiotic Susceptibility Testing

P-AST™ accounts for the bacterial interactions in polymicrobial infections that change antibiotic resistance and sensitivity — surfacing the personalized therapy options a culture-based result misses.

The Clinical Problem

When more than one organism is present,
standard susceptibility breaks down.

52%

Polymicrobial infections are common

More than half of positive UTI cases are polymicrobial — multiple organisms present in the same specimen, each potentially affecting how the others respond to therapy.1

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Bacterial interactions change susceptibility

When multiple organisms share an environment, pathogens may respond differently to antibiotics than they do in isolation — sometimes more susceptible, sometimes more resistant.2,3 The presence of a resistance gene doesn’t always translate into actual resistance, and facility-wide antibiograms aren’t tailored to the strains in front of you.

Two Approaches, Two Results

Test in isolation, or test in context.

Standard culture isolates each organism and tests it on its own. P-AST™ tests how antibiotics actually perform against the patient’s infection as a whole.

Standard Culture

Each organism, tested alone.

Three organisms each tested separately, producing three separate results Result A Result B Result C Three results. No interaction data.
  • Susceptibility tested per organism
  • Bacterial interactions are not measured
  • Generic, isolate-level result
P-AST™

All organisms, tested together.

All organisms pooled into one mixed environment, producing one infection-aware result POOLED One personalized result Captures the interactions a culture would miss.
  • Antibiotics tested against the pooled infection
  • Bacterial interactions are accounted for
  • Patient-specific susceptibility profile
Why It Matters

P-AST™ is personalized.

Pooled Antibiotic Susceptibility Testing evaluates antibiotics against the full pool of organisms in the patient’s specimen — not against each isolate on its own. The result accounts for the bacterial interactions that can change resistance and sensitivity within a patient-specific polymicrobial infection. The clinician sees what will actually work for this infection, in this patient.

Tests That Incorporate P-AST™

Where you’ll find it in our diagnostics.

Flagship Test

Guidance® UTI with P-AST™

Precision diagnostic testing for complicated, recurrent, or persistent UTIs — combining PCR organism identification and resistance-gene detection with the P-AST™ phenotypic panel. Less than one day from receipt at lab.

Explore Guidance UTI

Prostatitis

Guidance® Prostatitis

Advanced diagnostic testing for suspected acute or chronic prostatitis — same dual approach (PCR + P-AST™) applied to two sample types: voided post-DRE-massage urine, and semen.

Explore Guidance Prostatitis

Ready to put P-AST™ to work in your practice?

Connect with a representative to learn how Guidance® tests with P-AST™ can support better-informed first-pass therapy.

Talk to a Rep Order Test Kits
References
  1. Vollstedt A, Baunoch D, Wojno KJ, Luke N, Cline K, et al. Multisite prospective comparison of multiplex polymerase chain reaction testing with urine culture for diagnosis of urinary tract infections in symptomatic patients. J Sur Urology. 2020. DOI: 10.29011/JSU-102.100002
  2. Vollstedt A, Baunoch D, Wolfe A, Luke N, Wojno KJ, et al. Bacterial interactions as detected by pooled antibiotic susceptibility testing (P-AST) in polymicrobial urine specimens. J Sur Urology. 2020. DOI: 10.29011/JSU-101.100001
  3. Vos MG de, Zagorski M, McNally A, Bollenbach T. Interaction networks, ecological stability, and collective antibiotic tolerance in polymicrobial infections. PNAS. 2017;114:10666–10671. DOI: 10.1073/pnas.1713372114