In vitro antimicrobial susceptibility testing methods: agar dilution to 3D tissue-engineered models.

Area of Science:

• Orthopaedic Surgery
• Microbiology
• Biomaterials Science

Background:

• Periprosthetic infections are a significant challenge in orthopaedic surgery.
• Antimicrobial susceptibility testing (AST) is vital for guiding treatment and combating resistance.

Purpose of the Study:

• To review established and emerging antimicrobial susceptibility testing methods for orthopaedic infections.
• To assess the clinical applicability and future potential of various AST techniques.

Main Methods:

• Discussion of conventional gold-standard methods (e.g., broth microdilution).
• Analysis of recently developed techniques including microfluidics, microdroplets, optical, and mechanical methods.
• Evaluation of novel in vivo-like models such as osteoblast infection and tissue models.

Main Results:

• Conventional methods remain standard in clinical practice.
• Emerging microfluidic and microdroplet methods show promise for speed and insight but need validation.
• Optical, mechanical, and advanced tissue models face challenges in cost, complexity, and clinical integration.

Conclusions:

• There is an urgent need for validated AST methods applicable to both clinical and research settings.
• Developing rapid and reliable AST is essential to address increasing antimicrobial resistance in recurrent periprosthetic infections.