Abstract
BACKGROUND: The transmission of carbapenem-resistant Pseudomonas aeruginosa (CRPA) between hospital environment and patients poses significant challenges for clinical management. The COVID-19 pandemic may have influenced bacterial transmission dynamics in intensive care units (ICU). This study aimed to prospectively investigate the temporal and spatial spread of P. aeruginosa after a COVID-19 upsurge period in China. METHODS: We routinely screened for P. aeruginosa in both the environment and patients in a newly-opened 21-bed tertiary teaching hospital ICU in eastern China from October 2022 to April 2023, during which a COVID-19 upsurge occurred from December 2022 to January 2023. Whole-genome sequencing and antibiotic susceptibility testing were performed on all non-repetitive P. aeruginosa isolates. RESULTS: Among 1694 environmental samples, 40 (2.36%) samples were CRPA. In 1576 nasopharyngeal and rectal samples (from 353 patients), 108 samples (6.86%) were CRPA. Sequence type (ST) 463 was the most prevalent clone in both patient and environmental samples. Spatiotemporal distribution and genomic data revealed sporadic patients-related transmission before COVID-19 upsurge period, while high-risk ST463 clone transmission was detected during COVID-19 upsurge period. However, there was no strong evidence to show that antibiotic consumption significantly influenced CRPA transmission in this study. Additionally, the evolution events of bla (KPC) (from bla (KPC-2) to bla (KPC-71)) were observed, resulting in multi-sites CRPA colonization in one patient. CONCLUSION: Our prospective study demonstrates that COVID-19 upsurge is associated with increased P. aeruginosa transmission. These findings provide valuable insights into nosocomial infection management during future public health crisis. We also reported carbapenemase mutation from bla (KPC-2) to bla (KPC-71) in P. aeruginosa, which provides reference for further antibiotic usage.