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Characterization of Hypervirulent and Carbapenem-Resistant K. pneumoniae Isolated from Neurological Patients
Qingping Zhou1, Chunyang Wu2, Peiyao Zhou3
1Department of Neurology, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, 330006, People's Republic of China.
Background:
Patients with neurological disorders were easier to develop severe intracranial infections caused by hypervirulent and carbapenem-resistant K. pneumoniae, leading to a distressing clinical outcome. In this study, eight hv-CRKP were isolated from neurological patients, to clarify the resistant and virulent features.
Methods:
We tested the susceptibility of common antibiotics in these isolates to feature the antibiotic-resistant phenotypes. We also detected the key virulence factors, including mucoviscosity, siderophores production, biofilm formation in vitro, and further evaluated the virulence potential with serum killing model. We also used whole-genome sequencing (WGS) to investigate the molecular mechanisms.
Results:
We observed that ST11-KL64 hv-CRKP (6/8) has an overwhelming epidemic dominance in these hypervirulent and carbapenem-resistant K. pneumoniae. Though the acquirement of virulence plasmid made no influence to the maintain of multidrug-resistant phenotype of these isolates, only the ST11-KL64 strains fully exhibited the hypervirulent features. Compared with ST11-KL47 and ST15-KL24 strains, ST11-KL64 hv-CRKP were more advantages in productions of capsule polysaccharide, biofilm, and siderophores. The virulence potential of ST11-KL64 hv-CRKP was further confirmed by using serum killing model. Previous studies have demonstrated that IncFII plasmid could act as a helper plasmid to mobile the non-conjugative IncFIB/IncHIB virulence plasmids. We could only observe the co-existence of IncFII resistance plasmid and IncFIB/IncHIB virulence plasmids in ST11-KL64 isolates. The co-existence of such two plasmids facilitated the formation of ST11-KL64 hv-CPKP, which then become nosocomial epidemic under the antibiotic stress.
Conclusion:
Overall, we observed the ST11-KL64 hv-CRKP dominated in the isolates from neurological patients, and required most clinical attention.
Insights
Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) strains, particularly ST11-KL64, are emerging in neurological patients. These strains exhibit enhanced virulence and antibiotic resistance, necessitating increased clinical vigilance.
Area of Science:
- Microbiology
- Infectious Diseases
- Genomics
Background:
- Neurological patients are susceptible to severe intracranial infections from hypervirulent and carbapenem-resistant Klebsiella pneumoniae (hv-CRKP).
- Eight hv-CRKP isolates were obtained from neurological patients to characterize their resistance and virulence traits.
Purpose of the Study:
- To investigate the antibiotic resistance and virulence factors of hv-CRKP strains isolated from neurological patients.
- To elucidate the molecular mechanisms underlying the emergence and dominance of specific hv-CRKP strains.
Main Methods:
- Antibiotic susceptibility testing was performed on clinical isolates.
- Key virulence factors (mucoviscosity, siderophores, biofilm) were assessed in vitro.
- Serum killing assays evaluated virulence potential, and whole-genome sequencing (WGS) identified molecular mechanisms.
Main Results:
- The ST11-KL64 sequence type demonstrated overwhelming epidemic dominance (6/8 isolates).
- ST11-KL64 strains exhibited enhanced production of capsule polysaccharide, biofilm, and siderophores compared to other strains.
- Co-existence of IncFII resistance plasmids and IncFIB/IncHIB virulence plasmids in ST11-KL64 facilitated their nosocomial epidemic spread under antibiotic pressure.
Conclusions:
- ST11-KL64 hv-CRKP is the dominant strain in neurological patients, posing a significant clinical threat.
- The combination of specific resistance and virulence plasmids drives the epidemic success of these hypervirulent strains.
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