Distribution and antimicrobial resistance of pathogens in oral and maxillofacial infections during and Post-COVID-19 pandemic

Background: This study investigated the distribution characteristics and antimicrobial resistance patterns of pathogens isolated from patients with oral and maxillofacial infections during and after the COVID-19 pandemic. Methods: This retrospective study analyzed microbial cultures of specimens obtained from patients with odontogenic and non-odontogenic oral and maxillofacial infections during the pandemic period (January 2020-December 2022) and the post-pandemic period (January 2023-December 2024). Pathogen identification was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing was conducted using the VITEK 2 Compact automated analyzer, the Kirby-Bauer disk diffusion method, and the Etest. Data were analyzed using WHONET (version 5.6) and R software (version 4.2.1). This study was approved by the Medical Ethics Committee of West China Hospital of Stomatology, Sichuan University (Approval No.: WCHSIRB-D-2025-280). Results: (CR-AB) rose from 9.52 to 17.11%. Conclusion: Following the COVID-19 pandemic, shifts in both the pathogen spectrum and antimicrobial resistance patterns were observed in odontogenic and non-odontogenic infections. These findings reflect an evolving microbial landscape and highlight the need for tailored, etiology-specific antimicrobial strategies in the management of oral and maxillofacial infections. However, as these changes may be attributable to multiple confounding factors, further studies are warranted to establish causality.