Molecular Epidemiology of Hypervirulent Carbapenemase-Producing .

OBJECTIVE

To investigate the overall distributions of key virulence genes in , especially the hypervirulent -positive (Hv-(+)-KP).

METHODS

A total of 521 complete genomes of from GenBank were collected and analyzed. Multilocus sequence typing, molecular serotyping, antibiotic-resistance, virulence genes and plasmid replicon typing were investigated.

RESULTS

Positive rates of virulence genes highly varied, ranging from 2.9 () to 99.6% (). Totally 207 strains presented positive , , and and 190 showed positive , , , and , which were the two primary modes. A total of 94, 165 and 29 strains were denoted as hypervirulent (HvKP), (+)-KP and Hv-(+)-KP. ST11 accounted for 17 among the 29 Hv-(+)-KP strains; Genes , and were positive in 28, 26 and 18 Hv-(+)-KP strains respectively. Among the 29 Hv-(+)-KP strains exhibiting four super clusters from GenBank, IncHI1B plasmids carrying virulence genes and IncFII ones with were responsible for both 23 strains respectively.

CONCLUSIONS

Positive rates of virulence genes vary remarkably in . Genes , and were primary ones inducing Hv-(+)-KP. IncHI1B plasmids carrying virulence genes and IncFII ones with constitute the primary combination responsible for Hv-(+)-KP. The making of Hv-(+)-KP is mostly (+)-KP acquiring another plasmid harboring virulence genes.