Min-Chi Lu1, Hui-Ling Tang2, Chien-Shun Chiou3, Yao-Chen Wang4, Ming-Ko Chiang5, Yi-Chyi Lai6. 1. Division of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan. 2. Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan. 3. The Central Region Laboratory, Center for Research and Diagnostics, Centers for Disease Control, Taichung, Taiwan. 4. Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. 5. Department of Life Science, National Chung Cheng University, Chia-Yi County, Taiwan. 6. Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan; Department of Microbiology and Immunology, Chung Shan Medical University, Taichung, Taiwan. Electronic address: yclai@csmu.edu.tw.
Abstract
OBJECTIVES: The global spread of carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become a massive threat to human health. We investigated the clonal relatedness of CR-Kp strains in central Taiwan. METHODS: CR-Kp strains were prospectively collected from inpatients referred to Chung Shan Medical University Hospital (CSMUH) during September 2011 to December 2015. The presence of carbapenemase genes, including blaKPC-2, blaVIM-1, blaNDM-1, and blaOXA-48, was analysed with polymerase chain reaction (PCR) and sequence determination. Clonal relatedness was determined by pulse-field gel electrophoresis and multilocus sequence typing. Capsule synthesis loci were typed based on the variation of the wzi gene. RESULTS: A total of 174 CR-Kp strains were collected. KPC-2 and OXA-48 were present in 63 (36.2%) and 22 (12.6%) CR-Kp strains, respectively. Two strains isolated in 2014 coproduced KPC-2 and OXA-48. Nearly all (98%) carbapenemase-producing K. pneumoniae strains belonged to the ST11 clone and could be further grouped into distinct sub-lineages. Intriguingly, the first sub-lineage, designated ST11-Clade I, contained all KPC-2 strains; OXA-48 strains were mostly included in the second sub-lineage, ST11-Clade II. Furthermore, a variation on the capsule synthesis loci was detected between these two sub-lineages: KL-47 was assigned to ST11-Clade I, whereas KL-64 or KL-9 were the main types for the ST11-Clade II strains. CONCLUSIONS: Clonal expansion of ST11 was responsible for the dissemination of carbapenemase-producing K. pneumoniae. Although KPC-2 still predominates, OXA-48 has emerged rapidly. Co-existence of KPC-2 and OXA-48 in two ST11-Clade I K. pneumoniae highlights the urgency to unravel mechanisms that contribute to this highly transmissible lineage.
OBJECTIVES: The global spread of carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become a massive threat to human health. We investigated the clonal relatedness of CR-Kp strains in central Taiwan. METHODS: CR-Kp strains were prospectively collected from inpatients referred to Chung Shan Medical University Hospital (CSMUH) during September 2011 to December 2015. The presence of carbapenemase genes, including blaKPC-2, blaVIM-1, blaNDM-1, and blaOXA-48, was analysed with polymerase chain reaction (PCR) and sequence determination. Clonal relatedness was determined by pulse-field gel electrophoresis and multilocus sequence typing. Capsule synthesis loci were typed based on the variation of the wzi gene. RESULTS: A total of 174 CR-Kp strains were collected. KPC-2 and OXA-48 were present in 63 (36.2%) and 22 (12.6%) CR-Kp strains, respectively. Two strains isolated in 2014 coproduced KPC-2 and OXA-48. Nearly all (98%) carbapenemase-producing K. pneumoniae strains belonged to the ST11 clone and could be further grouped into distinct sub-lineages. Intriguingly, the first sub-lineage, designated ST11-Clade I, contained all KPC-2 strains; OXA-48 strains were mostly included in the second sub-lineage, ST11-Clade II. Furthermore, a variation on the capsule synthesis loci was detected between these two sub-lineages: KL-47 was assigned to ST11-Clade I, whereas KL-64 or KL-9 were the main types for the ST11-Clade II strains. CONCLUSIONS: Clonal expansion of ST11 was responsible for the dissemination of carbapenemase-producing K. pneumoniae. Although KPC-2 still predominates, OXA-48 has emerged rapidly. Co-existence of KPC-2 and OXA-48 in two ST11-Clade I K. pneumoniae highlights the urgency to unravel mechanisms that contribute to this highly transmissible lineage.
Authors: Wenli Liao; Na Huang; Ying Zhang; Yao Sun; Tao Chen; Weiliang Zeng; Liqiong Chen; Hong Wen; Jianming Cao; Tieli Zhou Journal: Front Public Health Date: 2021-12-03