Comparative Genomic Analysis of Hypervirulence Carbapenem-Resistant from Inpatients with Infection and Gut Colonization, China.

BACKGROUND

The emergence and spread of hypervirulent carbapenem-resistant (hv-CRKP) is a potential epidemiological threat that needs to be monitored. However, the transmission and pathogenic characteristics of hv-CRKP in China remain unclear. We investigated the epidemiological characteristics of gut colonized hv-CRKP in a hospital in Guangdong Province, China.

METHODS

A total of 46 gut colonized hv-CRKP isolates were collected from Sun Yat-Sen Memorial Hospital (Guangzhou, China) from August 31st to December 31st, 2021. Minimum inhibitory concentrations (MICs) were obtained for 15 antibiotics for 46 hv-CRKP isolates. BALB/C mice infection model and mucoviscosity assay was used to evaluate the virulence of the isolates. The characteristics of genome, phylogenetic relationship and the structure of the plasmid of 46 gut colonized hv-CRKP isolates were compared with pathogenic isolates from GeneBank based on whole-genome data.

RESULTS

The hv-CRKP isolation rate of all gut colonized carbapenem-resistant was 17% (46/270), and the intestinal colonization rate of hv-CRKP was irrelevant to the sex, age, department of hospitalization, and history of antibiotic use of the host. The gut colonized hv-CRKP showed pandrug resistance and hypervirulence. The gut colonized hv-CRKP and pathogenic hv-CRKP prevalent in China were mainly ST11 hv-CRKP and had two major epidemic clades. The similarities in genomic characteristics between gut colonized hv-CRKP and pathogenic hv-CRKP were consistent. The gut colonized hv-CRKP carried an incomplete structure pK2044 virulence plasmid from hypervirulent NTUH-K2044 by analyzing the virulence plasmid structure.

CONCLUSION

Our results suggest that the gut colonized ST11 hv-CRKP may serve as a reservoir for the clinical pathogenic ST11 HV-CRKP. It is necessary to further strengthen the monitoring of gut colonized hv-CRKP and research the potential mechanism of infection caused by gut colonized hv-CRKP.