Clinical and Bacterial Characteristics of Klebsiella pneumoniae Affecting 30-Day Mortality in Patients With Bloodstream Infection

Abstract

BackgroundThere is a paucity of studies using clinical characteristics and whole-genome sequencing together to fully identify the risk factors of patients with Klebsiella pneumoniae (KP) bloodstream infection (BSI).MethodsWe retrospectively analyzed the clinical and microbiological characteristics of patients with KP BSI. Isolates were processed using Illumina NGS, and relevant bioinformatics analysis was conducted (multi-locus sequence typing, serotype, phylogenetic reconstruction, detection of antibiotic resistance, and virulence genes). A logistic regression model was used to evaluate the risk factors of hosts and causative KP isolates associated with 30-day mortality in patients infected with KP BSI.ResultsOf the 79 eligible patients, the 30-day mortality rate of patients with KP BSI was 30.4%. Multivariate analysis showed that host-associated factors (increased APACHE II score and septic shock) were strongly associated with increased 30-day mortality. For the pathogenic factors, carriage of iutA (OR, 1.46; 95% CI, 1.11–1.81, p = 0.002) or Kvar_1549 (OR, 1.31; 95% CI, 1.02–1.69, p = 0.043) was an independent risk factor, especially when accompanied by a multidrug-resistant phenotype. In addition, ST11-K64 hypervirulent carbapenem-resistant KP co-harbored acquired blaKPC-2 together with iutA (76.5%, 13/17) and Kvar_1549 (100%, 17/17) genes. Comparative genomic analysis showed that they were clustered together based on a phylogenetic tree, and more virulence genes were observed in the group of ST11-K64 strains compared with ST11-non-K64. The patients infected with ST11-K64 strains were associated with relatively high mortality (47.2%, 7/17).ConclusionThe carriage of iutA and Kvar_1549 was seen to be an independent mortality risk factor in patients with KP BSI. The identification of hypervirulent and carbapenem-resistant KP strains associated with high mortality should prompt surveillance.

Clinical and Microbiological Characteristics of Klebsiella pneumoniae Bloodstream Infection in a Chinese Hospital: Hypervirulent and Multiclonal

“…2 Wu et al demonstrated that more than 36 STs were established in 79 BSI K. pneumoniae strains. 27 This study revealed that hvKP strains were more susceptible to tested antibiotics than cKP, consistent with previous studies. 1,8,10 The confluence of hypervirulence and multidrug resistance, especially carbapenem resistance, is extremely alarming.…”

Recurrent bacteremia with a hypermucoviscous Escherichia coli isolated from a patient with perihilar cholangiocarcinoma: insights from a comprehensive genome-based analysis

“…Interestingly, p537-20_1 also carried the iutA gene encoding the receptor of aerobactin, which is an important virulence factor for ExPEC and hypervirulent K. pneumoniae [ 52 ]. The carriage of iutA has been shown to be associated with increased mortality in E. coli , as well as K. pneumoniae bloodstream infection [ 23 , 64 ]. The possession of the iutA gene but also many other iron acquisition genes likely represents a fitness advantage in the biliary tract, due to the general iron limitation in bile [ 23 , 65 ].…”

Three Novel Sequence Types Carbapenem-Resistant Klebsiella pneumoniae Strains ST5365, ST5587, ST5647 Isolated from Two Tertiary Teaching General Hospitals in Shanxi Province, in North China: Molecular Characteristics, Resistance and Virulence Factors

“…In addition, the capsule-associated genes wabG (encoding capsule), uge (encoding capsule lipoprotein), ycfM (promoting external membrane protein), ureA (urease) are highly involved in virulence on account of their ability to evade phagocytosis and complement-mediated killing and further inhibit complement activation of the host. 39 , 40 CPS-associated genes (cps, ctrD, wcb, wzt, ureA) were detected in three strains. Moreover, the results of the serum resistance assay in our study revealed thatstrain 2 showed resistance, while strains 1 and 3 showed sensitivity.…”