Summary: Antimicrobial susceptibility testing (AST) via disk diffusion remains a globally adopted, cost-effective method in veterinary diagnostics, particularly in livestock health. This white paper explores current global and domestic trends, challenges, and innovations in the field, emphasizing the ongoing relevance of disk diffusion and the transformative potential of AI-powered tools. It highlights the emergence of AI-powered tools aimed at standardizing and enhancing AST practices in veterinary settings, including innovations designed specifically for livestock applications.

1. Introduction: Why This Topic Matters

Antimicrobial resistance (AMR) is a critical issue affecting both human and animal health. In the livestock sector, the responsible use of antimicrobials is vital to ensure food safety, animal welfare, and public health. Disk diffusion AST (Kirby-Bauer method) remains one of the most accessible and widely used methods for selecting appropriate antibiotics in veterinary medicine. Despite being a traditional technique, it plays a pivotal role in informing treatment decisions and resistance monitoring.

With increasing global efforts to combat AMR, accurate, standardized, and efficient AST in animals is gaining urgency. From rural conventional farms to contemporary large-scale farms, disk diffusion remains a central tool—but one that requires modernization. As diagnostic infrastructures evolve, the integration of AI technologies like CarbConnect’s upcoming ZOI VET platform promises to revolutionize how AST is conducted, interpreted, and shared across veterinary networks.

2. Technological Deep Dive: Disk Diffusion and the Role of AI

Disk diffusion AST is straightforward: antimicrobial-impregnated paper disks are placed on an agar plate inoculated with a bacterial isolate. After incubation, the inhibition zones are measured to determine susceptibility. Its simplicity, affordability, and compatibility with various bacterial species have made it indispensable in both clinical and research settings.

However, challenges persist:

• Time-consuming cross-referencing between inhibition zone diameters and interpretive criteria (e.g., CLSI tables) to determine S/I/R categories Manual variability in zone measurements
• Variability in measurement results depending on the individual performing the test,
• Time-consuming manual processes that make it difficult to handle large sample volumes efficiently
• Limited access to skilled personnel and infrastructure in rural or under-resourced areas, complicating timely testing and reporting

AI-based image analysis, as pioneered in human AST with CarbConnect’s ZOI VET, offers solutions:

• Automated zone detection with consistent measurements
• Real-time result sharing for remote diagnosis and support
• Data integration for resistance pattern monitoring
• Training and standardization across veterinary labs

ZOI VET builds on this legacy by exploring a tailored interface, veterinary-specific drug panels, and animal health-focused analytics. While currently in an early development phase, it is designed with the long-term goal of enhancing AST reliability and accessibility in livestock practices worldwide.

3. Expected Use Cases: From Farm to Lab

ZOI VET addresses pain points across veterinary diagnostics:

Clinical Diagnosis in Livestock

• On-site or near-site susceptibility testing for dairy cows, pigs, poultry, and more
• AI-assisted zone measurement reduces error and saves labor
• Enables more informed antimicrobial use, enhancing animal recovery and reducing resistance spread

Veterinary Research and Pharma

• Streamlined data generation for new veterinary antimicrobial development
• Enhances reproducibility in academic studies and regulatory submissions

Education and Lab Quality Control

• Training veterinary students and lab technicians in standardized AST procedures
• Supporting QC programs with traceable, AI-verified data

4. Future Outlook: ZOI VET in a Changing Landscape

Surveillance and Public Health

• Integration with national AMR monitoring programs (e.g., JVARM, NARMS)
• Standardized data collection across labs in different regions
• Facilitates early detection of resistance trends and supports One Health initiatives

As regulatory bodies tighten control on antimicrobial use in animals, and new diagnostics emerge, ZOI VET positions itself as a timely solution:

• AI-enhanced AST will likely become a standard in disk diffusion test practices
• Global harmonization of interpretation standards (e.g., CLSI VET01, EUCAST VetCAST)
• Increased digitization of veterinary diagnostics will require scalable, cloud-based tools like ZOI VET

In particular, ZOI VET supports the global push to expand AST access in resource-limited areas. By lowering the technical and economic barriers to quality testing, it contributes to global AMR control and sustainable livestock health management.

5. References

• CLSI. Performance Standards for Antimicrobial Disk and Dilution Susceptibility Tests for Bacteria Isolated From Animals; Approved Standard – VET01.
• EUCAST VetCAST Position Papers. https://www.eucast.org
• OIE (WOAH). Terrestrial Animal Health Code. https://www.woah.org
• “Antimicrobial Usage and Antimicrobial Resistance in Animal Production in Southeast Asia: A Review,” Animals, MDPI
• “Antimicrobial susceptibility testing in veterinary medicine,” One Health Advances, Springer
• CarbConnect White Paper: Revolutionizing AST with AI and Automation. https://carb-connect.com

6. Conclusion & Call to Action

Key Takeaways:

• Disk diffusion remains the backbone of AST in veterinary settings.
• AI and automation can overcome longstanding limitations in zone measurement and standardization.
• ZOI VET introduces a future-ready platform to support better treatment decisions, AMR surveillance, and One Health objectives.

Call to Action: 

We encourage you to try out ZOI VET in your clinic, lab, or research setting. Your honest feedback will help us refine and improve the tool further—together, we can advance veterinary diagnostics and support stronger AMR countermeasures.

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Let’s build a better future for veterinary microbiology, hand in hand.