A Seven-Year Surveillance of Epidemiological Trends of Serratia marcescens with Different Infection Types in a Tertiary Hospital in China

Objective: To explore the trend of detection and antimicrobial resistance of Serratia marcescens with different infection types for 7 consecutive years, to provide a reference for future studies for the control of S. marcescens infections and a rational selection of antibiotics. Methods: S. marcescens isolates were collected from 2014 to 2020, and the trend of detection and antimicrobial resistance were analyzed according to different types of infection. Results: For 7 consecutive years, the data showed that patients with S. marcescens infections were mainly from the intensive care unit (ICU) (384 isolates, 40.98%), and the isolates recovered were mainly from sputum samples (743 isolates, 79.30%). The number of isolated strains increased every year, and the average rate of detection ranged from 0.60% to 0.80%. The detection rate of S. marcescens with hospital-acquired infections (HAI) showed a downward trend and that of S. marcescens with colonization showed an upward trend. The detection rate of multidrug-resistant S. marcescens fluctuated between 8.33%–16.89%. The resistance rate of S. marcescens to piperacillin was 17.0%–29.06% and the resistance rate to piperacillin tazobactam was 2.95%–13.13%. For cephalosporin antibiotics, the resistance rates of S. marcescens to cefuroxime and cefazolin were > 99% and the resistance rates to ceftazidime and cefepime were < 13%. The resistance rate of S. marcescens to aminoglycoside antibiotics, especially amikacin, was the lowest. The resistance rate of S. marcescens with community-acquired infections (CAI) to carbapenems was higher than that with HAI and colonization. Conclusion: The different infection types of S. marcescens have different detection and epidemic trends. In addition, resistance to carbapenems is different across the strains.