• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.500-506
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• 2023

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is emerging as a worldwide public health threat. Recently, Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing sequence type (ST) 307 was identified main clone of CRKP, and dissemination of ST307 was reported in South Korea. This study examined the molecular characteristic and antimicrobial resistance pattern of 50 CRKP isolated from a tertiary hospital in Daejeon, from March 2020 to December 2021. Epidemiological relationship was analyzed by Multilocus sequence typing (MLST) and antimicrobial susceptibility test was determined using disk-diffusion method. PCR and DNA sequence analysis were performed to identify carbapenemase genes. CRKP infections were significantly more frequent in males and the patients aged ≥ 60 years. Among the 50 CRKP isolates, 46 isolates (92.0%) were multidrug-resistant (MDR), and 44 isolates (88.0%) were carbapenemase-producing K. pneumoniae (CPKP). The major carbapenemase type was KPC-2 (36 isolates, 72.0%) and New Delhi metalloenzyme-1 (NDM-1) and NDM-5 were identified in 7 isolates (14.0%) and 1 isolate (2.0%), respectively. In particular, 88.9% (32/36) of KPC-2-producing K. pneumoniae belonged to ST307, whereas 87.5% (7/8) of NDM-1,-5-producing K. pneumoniae belonged to non-ST307. These results suggest that proper infection control and effective surveillance network need to prevent not olny the spread of ST307, but also the development of non-ST307.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.265-272
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• 2022

The emergence and dissemination of carbapenemase-producing Enterobacteriaceae (CPE), particularly the Klebsiella pneumoniae carbapenemase-2 (KPC-2) producing Klebsiella pneumoniae, has been rapidly increasing worldwide and is becoming a serious public health threat. Since the epidemiology and characteristics of these KPC-2-producing K. pneumoniae vary according to the region and period under consideration, this study investigated the prevalence of carbapenemases and the epidemiological relationship of 78 carbapenem-resistant K. pneumoniae (CRKP) isolated from a tertiary hospital in Daejeon, from March 2017 to December 2020. The antimicrobial susceptibility tests were identified using the disk-diffusion method. PCR and DNA sequencing were used to determine the carbapenemase genes. In addition, molecular epidemiology was performed by multilocus sequence typing (MLST). Among the 78 CRKP isolates, 35 isolates (44.9%) were carbapenemase-producing K. pneumoniae (CPKP) and the major carbapenemase type was KPC-2 (30 isolates, 85.7%). The New Delhi metallo-enzyme-1 (NDM-1) and NDM-5 were identified in 4 isolates (11.4%) and 1 isolate (2.9%), respectively. Multilocus sequence typing (MLST) analysis showed 10 sequence types (STs) and the most prevalent ST was ST307 (51.4%, 18/35). All the ST307 isolates were KPC-2-producing K. pneumoniae and were multidrug-resistant (MDR). In addition, ST307 has gradually emerged during a four-year period. These findings indicate that continuous monitoring and proper infection control are needed to prevent the spread of KPC-2-producing K. pneumoniae ST307.