An outbreak of extensively drug-resistant and hypervirulent Klebsiella pneumoniae in an intensive care unit of a teaching hospital in Southwest China

Abstract

Extensively drug-resistant and hypervirulent Klebsiella pneumoniae (XDR-hvKp) is a new problem for patients in Intensive Care Unit (ICU) and can become an even more severe threat if resistant to tigecycline, considered one of the ‘last lines of defense’ drugs. This study collected seven non-replicated tigecycline-resistant XDR-hvKp from seven patients and performed genome analysis and epidemiological investigation using whole genome equencing (WGS) and other methods. All strains in this study were identified as ST11-KL64 and showed high resistance to antibiotics such as β-lactams, aminoglycosides, quinolones, and tigecycline, and one strain was also resistant to colistin. All strains were determined to be hvKp by the results of serum resistance assay and Galleria mellonella infection models. All strains had resistance genes blaCTX-M-65,blaKPC-2,blaLAP-2,blaTEM-1B, rmtB, and qnrS1 and virulence factors such as rmpA, rmpA2, and aerobactin (iucABCD, iutA). The expression of the AcrAB-TolC efflux pump was upregulated in all strains, and the expression levels of the gene pmrK was significantly upregulated in colistin-resistant strain DP compared to colistin-sensitive strain WT in this study. In conclusion, we described an outbreak caused by tigecycline-resistant XDR-hvKp in the ICU of a teaching hospital in southwest China. The spread of these superbugs poses a great threat to patients and therefore requires us to closely monitor these XDR-hvKp and develop relevant strategies to combat them.

Molecular epidemiology and clinical characteristics of the type VI secretion system in Klebsiella pneumoniae causing abscesses

“…We investigated 11 virulence-associated and nine drug resistance-associated genes and found that the positive rates of rmpA , rmpA2 , aerobactin, iroB , wcaG , alls , and Kfu were relatively higher for T6SS-positive isolates than for T6SS-negative isolates ( p < 0.001). These seven virulence factors are associated with high pathogenicity: rmpA and rmpA2 are involved in the hypermucoviscosity phenotype and capsular polysaccharide synthesis; aerobactin and iroB are siderophores, and aerobactin plays a critical role in hvKp virulence; and wcaG regulates fucose biosynthesis and enhances the ability of K. pneumoniae to resist neutrophil phagocytosis ( Zheng et al, 2018 ; Russo and Gulick, 2019 ; Liu et al, 2022 ; Xu et al, 2022 ). These results further indicate that the T6SS-positive isolates were hypervirulent; however, the specific virulence mechanism involved in this process requires further study.…”

Whole-Genome Sequencing Revealed the Fusion Plasmids Capable of Transmission and Acquisition of Both Antimicrobial Resistance and Hypervirulence Determinants in Multidrug-Resistant Klebsiella pneumoniae Isolates

“…The best-characterized of these K. pneumoniae clones include, among others, ST147 and ST512 [ 3 , 42 ], to which the isolates described in our study belong. Although previously high-risk clones and hypervirulent clones of K. pneumoniae were considered to be separate evolutional groups, an increasing number of reports worldwide, especially in the last 5 years, have described the convergence of hypervirulence and MDR properties in single isolates of this species [ 17 , 19 , 43 , 44 , 45 ].…”

MgrB mutations causing colistin resistance in ST11 and ST15 Klebsiella pneumoniaes in a tertiary teaching hospital in China

“…The PFGE assay has been considered as a reference method for homology investigation of clinical infectious disease strains, especially in hospital outbreaks [25]. Compared to PFGE, MLST is more convenient to operate but less accurate.…”