AUTHOR=Hu Dakang , Chen Wenjie , Zhang Qi , Li Meng , Yang Zehua , Wang Yong , Huang Yunkun , Li Gang , Tian Dongxing , Fu Pan , Wang Weiwen , Ren Ping , Mu Qing , Yu Lianhua , Jiang Xiaofei 

TITLE=Prevalence of Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae and Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae in China Determined via Mouse Lethality Tests

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.882210

DOI=10.3389/fcimb.2022.882210

ISSN=2235-2988

ABSTRACT=<sec><title>Objective</title><p>To investigate the epidemiology of carbapenem-resistant hypervirulent <italic>Klebsiella pneumoniae</italic> (CR-HvKP) and hypervirulent carbapenem-resistant <italic>Klebsiella pneumoniae</italic> (Hv-CRKP).</p></sec><sec><title>Methods</title><p>Totally 436 <italic>K. pneumoniae</italic> strains were collected from 7 hospitals in mainland China between 2017.01 and 2018.02. Sequence types, serotypes, antimicrobial-resistance and virulence genes were analyzed. Additionally, string test, capsule stain, Periodic Acid Schiff stain, fitness analysis, quantitative real-time PCR and mouse lethality test were also performed. Molecular combinations were used to screen putative <italic>bla</italic><sub>KPC</sub>(+)-HvKP and Hv-<italic>bla</italic><sub>KPC</sub>(+)-KP, followed by the confirmation of mouse lethality test.</p></sec><sec><title>Results</title><p>Diverse detection rates were found for the virulence genes, ranging from <italic>c-rmpA</italic> (0.0%) to <italic>entB</italic> (100.0%). According to the molecular criteria, 127, 186, 9 and 26 strains were putatively denoted as HvKP, <italic>bla</italic><sub>KPC</sub>(+)-KP, <italic>bla</italic><sub>KPC</sub>(+)-HvKP and Hv-<italic>bla</italic><sub>KPC</sub>(+)-KP. Mouse lethality test confirmed 2 <italic>bla</italic><sub>KPC</sub>(+)-HvKP strains (JS184 and TZ20) and no Hv-<italic>bla</italic><sub>KPC</sub>(+)-KP. JS184 showed K2 serotype, thin capsule, positive exopolysaccharid and string test. TZ20 presented K20 serotype, thin capsule, negative exopolysaccharide and string test. Compared with the positive control NTUH-K2044, equal <italic>galF</italic> expression and growth curves were confirmed for JS184 and TZ20.</p></sec><sec><title>Conclusions</title><p>Molecular determination of CR-HvKP and Hv-CRKP brings remarkable bias compared with mouse lethality test. The exact prevalence of CR-HvKP is less than 1.0%, which of Hv-CRKP is much lower.</p></sec>