Recommendations for microbiological sampling in infected hard-to-heal wounds: an Italian Association for Cutaneous Ulcers (AIUC) perspective

Abstract

Chronic and hard-to-heal wounds represent a significant and growing healthcare burden, frequently complicated by infection and impaired healing. Despite the availability of international guidelines, microbiological assessment in clinical practice remains highly heterogeneous, with substantial variability in sampling techniques, timing, and interpretation of results. This variability occurs within a broader One Health context, where antimicrobial resistance and microbial ecology are shaped by interconnected human, environmental, and healthcare factors. The present recommendations, developed by the Italian Association for Cutaneous Ulcers (AIUC), aim to provide a structured and operational framework for microbiological sampling in infected hard-to-heal wounds. A multidisciplinary expert panel conducted a structured review of the literature and developed consensus-based recommendations through iterative discussion. The resulting framework addresses key aspects of the diagnostic pathway, including indications for sampling, selection of techniques (swab, tissue biopsy, and fine needle aspiration), standard operating procedures, and principles for the interpretation of microbiological findings. The recommendations emphasise a context-driven approach to sampling, recognising the complementary roles of different techniques according to clinical presentation and depth of infection. Particular attention is given to the distinction between colonisation and infection, the limitations of quantitative thresholds, and the impact of biofilm, polymicrobial interactions, and host-related factors on diagnostic accuracy and antimicrobial response. The document also highlights the importance of integrating microbiological data with clinical assessment to support appropriate antimicrobial stewardship. By translating existing evidence into practical and reproducible procedures, these recommendations aim to reduce variability in clinical practice and improve the quality of microbiological diagnostics in wound care. Within a One Health perspective, standardised and reliable microbiological data may also support surveillance of antimicrobial resistance and inform more integrated infection control strategies. The proposed framework supports more consistent clinical decision-making and may contribute to optimising antimicrobial use and patient outcomes across diverse healthcare settings.