• if there is suspicion of a complicated infection (Ex. associated with underlying disease),
• if there are rods in cytology,
• if the patient has not responded to therapy,
• if the patient has a history of relapse or re-infection,
• if there is any reason to suspect infection with MDR bacteria.
• if the patient is immunocompromised,
• if the infection is life-threatening.

The device determines the antibiotic susceptibility level of the microbe in the sample by measuring the color spectrum of the reaction well. The result will be qualitative in the form of R (Resistant), I (Intermediate), S (Susceptible)

The specimen that can be used in the device are:

1. Sterile Urine
2. Fecal swab
3. Skin swab
4. Ear swab
5. Pus/Wound swab
6. Tracheal swab
7. Urogenital swab

Note: Blood, pleural effusion, abdominal effusion, tissues, surgical specimens, and non-biological items such as surgical instruments or consumables are not applicable in the device as it may interfere with the result measurement.

The device operates using the broth microdilution method, which involves preparing a liquid broth medium containing varying concentrations of antimicrobial agents. Microorganisms are then inoculated into this medium and evenly distributed on the wells on the disc.  After incubation, the broth is observed for signs of microbial growth. The outcome is determined using a colorimetric method, where the presence of color change indicates whether microbial growth occurred, thus providing information on the organism’s susceptibility to the antimicrobial agents.

The conditions needed for the specimen are:

1. Do not use antiseptic solutions or topical antibiotics before taking the sample.
2. If you are sampling from an animal receiving topical or systemic antibacterial treatment, it is recommended that the sample be collected at least 48 hours after the last administration.
3. To avoid contamination by other microorganisms, aseptic techniques should be followed during sampling and inoculation.

Note:

• Skin infections
  – Obtain sample using a sterile cotton swab.
  – The sample should be taken from the wall of the lesion after removal of the infected dead tissue by surgical debridement.
• Ear infections
  – Remove superficial earwax from the walls of the ear canal.
  – Take a sample from the deep wall of the ear canal with the provided sterile cotton swabs.
• Urinary tract infections
  – Obtain a sterile urine sample by catheterization or bladder puncture (cystocentesis).

For sterile urine: One drop using the provided dropper.

For swab:

The specimens should be processed as soon as possible within 2 hours of collection in room temperature. However, if testing is not possible the sample can be stored up to 24 hours in 2-8 ⁰C refrigerator.

All animals are able to be tested.

The testing of each sample takes around 8 to 24 hours, depending on the microorganism type and amount.

1. Make sure the test disc is correctly positioned, as improper placement can impact the results.
2. Keep the instrument lid closed throughout the testing process.

The result is calculated by comparing the color results from high and low concentration of the antibiotic.

No, each QR code is unique and contains the data tailored a particular lot of test discs. To ensure accuracy in the test results, it is crucial to use the QR code that accompanies each test disc, rather than reusing one from another lot.

A number of factors may be responsible for the divergence between sensitivity results and clinical outcome. The main factors to be considered for a negative response to therapy are:

1. underdosing due to inaccurate weighing of the patient or inadequate tablets for correct dosing (large/small dogs),
2. limited drug tissue penetration or reduced efficacy at the infection site,
3. specific underlying conditions in the patient,
4. inappropriate sample type,
5. contamination,
6. non-compliance by the owner.

Test disc and incubation medium

The test disc and medium should be stored between 2-8°C. The shelf life is 12 months from the date of manufacture. Before use, take it out and let it reach room temperature for 10 minutes.

Please note that the test disc is individually sealed, and once opened, it must be used within 30 minutes.

After removing the disc from the aluminum foil pouch, place it on the machine by aligning the groove as the picture below. Using a pipette, add the sample through the “Sample” hole.

Please wear dust-free gloves during the operation, as dust can cause destructive effects on the optical components of the instrument. Ensure the test disc remains level during and after sample addition. Avoid air bubbles while adding the sample to the test disc. When placing the test disc onto the machine, hold it from the edges.

No, each test disc can only be used once.

No, the test disc should be stored at 2-8°C.

Always add the sample after placing the disc into the analyzer to prevent evaporation and contamination. If spillage occurs, stop the test, discard the disc, disinfect the area thoroughly, and start again with a new disc.

Yes. Bubbles can disrupt fluid distribution and affect optical detection. Avoid bubbles during pipetting.

Pre-warming is unnecessary. However, allow the disc and media bottle to sit at room temperature for 10 minutes before use to prevent condensation.

No. Insufficient volume may lead to uneven bacterial distribution and inaccurate results.

The black swab is preferred for collection and storage. A white cotton swab may be used only if testing is performed immediately after sampling.

No. Pre-culture is essential for standardizing bacterial concentration. Skipping this step risks producing invalid results.

Begin pre-culture within 24 hours of collection.

• Urine: Refrigerate in a sterile centrifuge tube.
• Other samples: Store at room temperature in sterile tubes. Seal with wax film and place in a sealed bag to prevent leakage. Do not refrigerate.

Not recommended. Blood interferes with detection, and pleural effusion often contains mixed flora, including anaerobes, which are outside miniAST’s test scope.

Wait at least 48–72 hours after the last antibiotic dose to minimize the risk of false-negative results due to reduced bacterial viability.

Yes, but only for a short period. Store at 4°C and test within 2 hours. Beyond this, bacterial die-off may affect accuracy.

Customization is available based on regional or market-wide demand.

Up to 16 antibiotics per disc can be supported.

Approximately 92% compared with the disk diffusion method.

Around 8 hours, depending on bacterial number and species.

If insufficient growth is detected after 8 hours, the system will automatically report “no growth.”

“S” is preferred. “I” may be used with dose adjustment, but clinical judgment is needed.

Most users can operate the system proficiently after 1–2 supervised sessions. Training resources are available.

Some bacteria will produce gas when they grow, which will push the top cover open.

For such specimens, you can prepare an additional pre-incubation vial. First, inoculate the swab into the first vial, then transfer approximately 1 mL into a second, new pre-incubation vial. This method helps reduce the chance of turbidity warnings.

Some bacteria produce gas during growth. When the amount of gas exceeds the internal space of the container, it can force the cap open. To prevent this, during pre-incubation, you may open only the plastic outer cap without removing the aluminum seal. Then, inject the sample directly into the vial using a needle and syringe (for swab specimens, first mix in sterile saline, then draw into the syringe). This helps prevent the cap from popping open. After pre-incubation, you can also insert a sterile needle into the silicone cap to release excess gas before opening the vial, avoiding pressure-related accidents. You can then proceed with disc-based cultivation as usual.

miniAST is designed to work excellently with aerobic bacteria, providing fast and reliable results. It is specifically tailored for aerobic organisms and is not suitable for use with anaerobic bacteria, due to the system’s operational design and environmental requirements.

Currently, we do not recommend applying milk samples directly to the miniAST system. However, bacteria isolated from milk samples can be used with miniAST.

If the bacteria do not reach the specified concentration by the end of the preincubation period (currently 10 hours), the instrument will indicate no bacterial growth. This may result from the absence of bacteria in the sample or slow bacterial growth preventing the required concentration from being achieved. In such cases, the same preincubation bottle can be used for an additional round of pre-incubation.

If needed, an additional sample can be obtained and processed following a new pre-incubation step.

Under standard conditions, bacteria typically proliferate within the miniAST disc during the test phase, enabling accurate AST interpretation. However, certain samples may fail to reach the necessary bacterial concentration due to either slow bacterial growth or insufficient sample volume introduced into the disc.

Although bacterial growth rate is not easily controlled, applying the correct volume of diluted media can significantly reduce the likelihood of this issue. In cases involving slow-growing bacteria, the same disc may be reused for extended incubation and retesting.

Alternatively, a new sample may be collected and processed to ensure reliable AST results.