Molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae in China, 2016–20

Abstract

We read with interest the work of Minggui Wang and colleagues in comparing the clinical outcomes and molecular epidemiological features of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections reported globally, where a total of 485 CRKP strains collected from China between June 13, 2017, and Nov 30, 2018, were included.1Wang M Earley M Chen L et al.Clinical outcomes and bacterial characteristics of carbapenem-resistant Klebsiella pneumoniae complex among patients from different global regions (CRACKLE-2): a prospective, multicentre, cohort study.Lancet Infect Dis. 2021; (published online Nov 9.)https://doi.org/10.1016/S1473-3099(21)00399-6Summary Full Text Full Text PDF Scopus (12) Google Scholar Here, we provide relevant data on 2594 CRKP strains collected in 27 provinces and municipalities in China during 2016–20 from our own surveillance programme. Among these strains, KPC-2 was the most prevalent enzyme detected, followed by NDM-1 and NDM-5. CTX-M-65 was the most dominant extended-spectrum β-lactamase (prevalence 37·3–59·6% across the years), followed by SHV-12 (14·6–34·2%), which exhibited a decreasing trend from 2016 to 2020. Prevalence of acquired fosfomycin and fluoroquinolone resistance genes over the period were 25·1% and 48·8%, respectively (appendix). Consistently, ST11 was the main sequence type in China, accounting for 64·2% of all CRKP strains in the period (appendix). Notably, a drastic increase in the prevalence of ST15 CRKP strains was observed over the years. Other sequence types were also detectable but were mostly region-specific. For instance, ST290 CRKP strains were mainly found in Zhejiang province and Tianjin city. KL64 (30·1%) and KL47 (28·2%), belonging to ST11, were the most common serotypes, followed by KL19 (6·4%), belonging to ST15 (appendix). Carriage of virulence genes that are specific for hypervirulent K pneumoniae (HvKP) was also common among the CRKP strains. Yersiniabactin was the virulence factor that was most commonly expressed by CRKP strains, with an average detection rate of 83·7%. Production of colibactin was relatively rare among these CRKP strains; this observation is consistent with a report by Holt and colleagues.2Holt KE Wertheim H Zadoks RN et al.Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health.Proc Natl Acad Sci USA. 2015; 112: e3574-81Crossref PubMed Scopus (570) Google Scholar Production of yersiniabactin has been reported to be strongly correlated with human infections and might precede acquisition of the other siderophores in CRKP;2Holt KE Wertheim H Zadoks RN et al.Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health.Proc Natl Acad Sci USA. 2015; 112: e3574-81Crossref PubMed Scopus (570) Google Scholar hence, surveillance of carriage of this virulence factor among clinical CRKP strains is necessary. RmpA2 and aerobactin were also commonly detected, accounting for 32·5% and 35·6% of the test strains, respectively. These findings suggest that these strains have already evolved into carbapenem-resistant HvKP. The high rate of carriage of virulence genes in CRKP strains in China might account for the difference in the severity of infection and clinical outcome when compared with CRKP infections in other countries. The χ2 test was used to compare the genetic features among CRKP strains isolated from 2016, 2017, 2018, 2019, and 2020, and significant differences were observed in most of the genetic features among these strains (appendix). All in all, this 5-year, continuous, nationwide surveillance study on the prevalence of CRKP strains further revealed that a substantial shift in genetic characteristics of CRKP isolates towards those of HvKP has occurred in China, and so a major proportion of CRKP strains in China should now be regarded as hypervirulent CRKP. These findings provide important insight into development of more effective approaches to control CRKP and hypervirulent CRKP infections in China. We declare no competing interests. This work was supported by the National Natural Science Foundation of China (grant numbers 81772250, 81861138052). Download .pdf (.43 MB) Help with pdf files Supplementary appendix Clinical outcomes and bacterial characteristics of carbapenem-resistant Klebsiella pneumoniae complex among patients from different global regions (CRACKLE-2): a prospective, multicentre, cohort studyGlobal CRKP epidemics have important regional differences in patients’ baseline characteristics and clinical outcomes, and in bacterial characteristics. Research findings from one region might not be generalisable to other regions. Full-Text PDF