Abstract Background Bloodstream infection (BSI) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is a serious and urgent threat for hospitalized patients. This study aims to describe the clinical and molecular characteristics of CRKP causing BSI in a tertiary care hospital in Chengdu, China. Methods In total, 123 nonconsecutive CRKP strains were collected in the hospital from 2020 to 2022 and sent for whole genome sequencing. String tests were performed of all CRKP strains, and clinical information of relevant cases was collected. Results Among the 123 CRKP strains collected, the median age of the patients was 53 years, 77.2% of patients with CRKP BSI were elderly men, 62.6% were admitted to the intensive care unit, 80.5% underwent intravascular catheters procedures, and 86.7% had underlying lung diseases. The rate of 30-day mortality was 21.1%. Microbiological characteristics showed that carbapenem resistance was primarily mediated by carbapenemase acquisition, predominantly blaKPC-2 (93.5%). The 123 CRKP isolates comprised 9 sequence types (STs) and 10 serotypes, with ST11 being dominant (84.6%). The serotype KL64 accounted for 73.2%, followed by KL47 at 7.3%. The positive rate of the string test was 13.8%, and virulence genes (rmpA2, iuc-iutA) were detected in 48.8% of ST11-KL64 strains. Phylogenetic analysis indicated that most ST11 strains were closely related. Genomic transmission analyses revealed that 6.7% of pairs had ≤20 pairwise single-nucleotide polymorphisms and were thus designated as “highly likely” transmission. Conclusions This study poses an urgent need for enhancing infection control measures in the hospital, especially CRKP strains with hypervirulent genes.
Liao et al. (Fri,) studied this question.