Abstract
Introduction: Staphylococcus aureus was associated with more than 1 million deaths in 2019. The coronavirus disease 2019 (COVID-19) pandemic has lasted three years. In China, measures to control COVID-19 cases were adjusted in December 2022. In this study, we investigated the effects of the COVID-19 pandemic on the drug resistance of S. aureus infection.
Methodology: A retrospective analysis was performed, focusing on the clinical distribution and drug resistance of distributions of S. aureus isolated from the Fifth Affiliated Hospital of Sun Yat-sen University during the COVID-19 pandemic from January 2020 to March 2023. The effects of COVID-19 control measures on the drug resistance of S. aureus infection were further investigated.
Results: A total of 1437 strains of S. aureus were isolated, with a methicillin-resistant S. aureus (MRSA) detection rate of 19.2%. The department with the highest detection rate was the oncology department (17.0%, 244/1437), followed by the intensive care unit (11.1%, 159/1437), the dermatology department (10.7%, 154/1437), and the wound repair and burn department (9.7%, 139/1437). The most frequent specimens were secretions (42.0%, 603/1437), followed by sputum (23.3%, 335/1437), blood (10.7%, 154/1437), and pus (5.4%, 78/1437). The population distribution was primarily male (62.3%, 895/1437). S. aureus infections were most common among those aged 50–65 (32.8%, 472/1437), followed by those aged 18–49 (30.7%, 441/1437). S. aureus was most resistant to penicillin G (86.3%), followed by erythromycin (37.9%) and clindamycin (37.3%). The antibiotics with no resistance were linezolid, teicoplanin, tigecycline, and vancomycin. There was no significant difference in the drug-resistance rate between COVID-19–positive and COVID-19–negative patients.
Conclusions: The outbreak of COVID-19 in 2020 and the adjustment of control measures had no significant impact on the drug resistance of S. aureus infection.

Key words: Clinical distribution; COVID-19 infection; drug-resistance characteristics; Staphylococcus aureus