Abstract
Background:Carbapenem-resistant and hypervirulent Klebsiella pneumoniae (CR-hvKP) caused infections of high mortality and brought a serious impact on public health. This study evaluated the transmissibility of CR-hvKP among different regions to provide corresponding advice for cross-regional prevention.
Methods: Clinical K. pneumoniae strains were collected from Jiujiang region and Nanchang region in Jiangxi province from November 2021 to June 2022. We characterized these strains for their genetic relatedness, virulence phenotype, and dissimilarities in virulence plasmid structures using PFGE, Galleria mellonella, Whole-genome sequencing.
Results: Among 609 strains, 45 (7.4%) CR-hvKP were identified, while the strains
isolated from Nanchang and Jiujiang accounted for 10.05% (36/358) and 3.59% (9/251). We observed that ST11-KL64 CR-hvKP had an overwhelming epidemic dominance in these two regions. Significant genetic diversity was identified among all ST11-KL64 CR-hvKP cross-regional transmission between Nanchang and Jiujiang serving as major drivers of clonal clusters. Virulence genes profile revealed that ST11-KL64 CR-hvKP might harbour incomplete pLVPK-like plasmids and primarily evolved from CRKP by acquiring the hypervirulence plasmid. We found the predominance of truncated-IncFIB/IncHI1B type virulence plasmids with a 25kb fragment deletion that encoded iroBCDN clusters.
Conclusion: ST11-KL64 is the most cross-regional prevalent type CR-hvKPs in Jiangxi province, which mainly evolved from CRKPs by acquiring a truncated-IncHI1B/IncFIB virulence plasmid with the deletion of iroBCDN. Stricter surveillance and control measures are urgently needed to prevent the epidemic transmission of ST11-KL64 CR-hvKP.