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

Abstract

ObjectiveTo investigate the epidemiology of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-HvKP) and hypervirulent carbapenem-resistant Klebsiella pneumoniae (Hv-CRKP).MethodsTotally 436 K. pneumoniae 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 blaKPC(+)-HvKP and Hv-blaKPC(+)-KP, followed by the confirmation of mouse lethality test.ResultsDiverse detection rates were found for the virulence genes, ranging from c-rmpA (0.0%) to entB (100.0%). According to the molecular criteria, 127, 186, 9 and 26 strains were putatively denoted as HvKP, blaKPC(+)-KP, blaKPC(+)-HvKP and Hv-blaKPC(+)-KP. Mouse lethality test confirmed 2 blaKPC(+)-HvKP strains (JS184 and TZ20) and no Hv-blaKPC(+)-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 galF expression and growth curves were confirmed for JS184 and TZ20.ConclusionsMolecular 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.

RETRACTED: Drug Resistance and Molecular Characteristics of Carbapenem-Resistant OXA-48-Producing Klebsiella pneumoniae Strains in Hainan, China

“…A strain was considered genetically hypervirulent if it contained the rmpA / rmpA2 and iutA genes as previously described [ 15 ]. Capsular genotyping, detection of the rmpA / rmpA2 genes, and genes encoding for carbapenemases, bla OXA-48 , bla IMP , bla VIM , bla KPC , and bla NDM were detected by PCR as previously described [ 15 , 16 ].…”

“…All animal care procedures and protocols were approved by the Institutional Animal Care and Use Committee of the First Affiliated Hospital of Hainan Medical University. Female C57BL/6 mice aged 6–8 weeks were given intraperitoneal injections of KP strains at various concentrations, according to previous studies [ 9 , 14 , 15 , 16 ]. Survival was determined by Kaplan-Meier analysis with a log-rank test using the Prism software package (GraphPad, Prism 9.0).…”

Prevalence of multidrug-resistant hypervirulent Klebsiella pneumoniae without defined hypervirulent biomarkers in Anhui, China: a new dimension of hypervirulence

“…Indeed, some string test-positive isolates were previously shown to be cKP, while string test negative K. pneumoniae strains were hvKp (Li et al, 2019). In growth curve, all the clinical MDR-hvKp isolates showed hypervirulent growth patterns similar to NTUH-K2044 (Hu et al, 2022).…”

“…K. pneumoniae isolates that resisted at least three antibiotic groups was considered MDR-Kp ( Magiorakos et al, 2012 ). Furthermore, MDR-Kp isolates that showed and/or any of the following phenotypes, such as hyper mucoid phenotype (carried rmpA and/or rmpA2 ) ( Yu et al, 2006 ; Russo and Marr, 2019 ), similar growth pattern with hypervirulent isolate NTUH-K2044 ( Hu et al, 2022 ), hypervirulence phenotype in Galleria mellonella infection model ( Shen et al, 2019 ), were considered as MDR-hvKps.…”