Antibiotic Susceptibility Testing (AST)

Be sure to have senaite.ast installed

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AST, Antibiotic Susceptibility Testing

A la Wikipedia, Antibiotic Sensitivity as the susceptibility of bacteria to antibiotics

Antibiotic susceptibility testing, AST, is carried out to determine which antibiotic will be most successful in treating a bacterial infection. Minimum Inhibitory Concentration (MIC) is at its heart

Small wafers containing antibiotics are placed onto a plate upon which bacteria are growing. If the bacteria are sensitive to the antibiotic, a clear ring, or zone of inhibition, is seen around the wafer indicating poor growth.

Clinically, minimum inhibitory concentrations are used to determine the amount of antibiotic that a patient will receive and also the type of antibiotic used

Also see https://senaiteast.readthedocs.io/en/latest/index.html

Qualitative Outcomes

The plates are incubated for say 24 hours and the results are determined by the diameter of the growth inhibition around each antibiotic disk and reported in accordance with e.g. EUCAST's definitions

Recommended thresholds, breakpoints, for the diameter of the ring sizes per susceptibility category, are available for most known bacterium and antibiotics combinations. These are the concentrations at which bacteria are susceptible to successful treatment

The numeric diameter readings are interpreted using the breakpoint tables and  reported as:

• S - Susceptible, standard dosing regimen, when there is a high likelihood of therapeutic success using a standard dosing regimen of the agent.
• I: Susceptible, increased exposure, exposure to the agent is increased by adjusting the dosing regimen
• R: Resistant, not effective at inhibiting the growth of the organism

An example, P aeruginosa has breakpoints for the antibiotic Cefepime of S ≥  50 mm and R < 13 mm

In Bika

This configuration is broken down as:

Microorganisms

Configure the Microorganisms in their categories, then select them from there for identification tests, and use in AST panels

Antibiotics

Set up the Antibiotics you are going to use 

Breakpoint Tables

Set-up the breakpoint tables for the organism-antibiotics combinations for looking up the growth diameters for interpretation 

AST Panels

Requested on Samples

Results Capture