Molecular Profiling of a Multi-Strain Hypervirulent Infection Within a Single Patient.

BACKGROUND

The rising prevalence of infections caused by carbapenem-resistant and hypervirulent (CR-hvKP) has outpaced our understanding of their evolutionary diversity. By straining the antimicrobial options and constant horizontal gene transfer of various pathogenic elements, CR-hvKP poses a global health threat.

METHODS

Six isolates (KP1~KP6) from urine, sputum and groin infection secretion of a single patient were characterized phenotypically and genotypically. The antimicrobial susceptibility, carbapenemase production, hypermucoviscosity, serum resistance, virulence factors, MLST and serotypes were profiled. Genomic variations were identified by whole-genome sequencing and the phylogenetic differentiation was analyzed by Enterobacterial repetitive intergenic consensus (ERIC)-PCR.

RESULTS

All strains were multi-drug resistant. Four of them (KP1, KP3, KP5 and KP6) belonged to ST11-K64, with high genetic closeness (relatedness coefficient above 0.96), sharing most resistance and virulence genes. Compared with KP1, the later isolates KP3, KP5 and KP6 acquired and lost genes. KP2 and KP4 had the same clonal origin of ST35-K16 (relatedness coefficient 0.98), containing almost identical genes for resistance and virulence. They were non-mucoid and carried gene.

CONCLUSION

A co-infection with two types of CR-hvKP affiliated with different clades within a single patient amplified the treatment difficulties. In addition to source control and epidemiological surveillance, investigation of the in-host interactions between CR-hvKP variants may provide valuable treatment solutions.