There 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).

We 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.

Of 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 bla_KPC-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).

The 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.

很少有研究结合临床特征和全基因组测序来充分识别患有 肺炎克雷伯菌 (KP) 血流感染 (BSI)。

我们回顾性分析了 KP BSI 患者的临床和微生物学特征。使用Illumina NGS处理分离物，并进行相关生物信息学分析（多位点序列分型、血清型、系统发育重建、抗生素抗性检测和毒力基因）。使用逻辑回归模型评估与感染 KP BSI 的患者 30 天死亡率相关的宿主和致病 KP 分离株的风险因素。

在 79 名符合条件的患者中，KP BSI 患者的 30 天死亡率为 30.4%。多变量分析显示宿主相关因素（APACHE II 评分增加和感染性休克）与 30 天死亡率增加密切相关。对于致病因素，携带IUTA (OR, 1.46; 95% CI, 1.11–1.81, 磷 = 0.002) 或 Kvar_1549 (OR, 1.31; 95% CI, 1.02–1.69, 磷= 0.043) 是一个独立的危险因素，特别是当伴有多重耐药表型时。此外，还获得了ST11-K64高毒力耐碳青霉烯KPbla _KPC-2 和...一起 IUTA (76.5%, 13/17) 和 Kvar_1549(100%, 17/17) 基因。比较基因组分析表明，它们基于系统发育树聚类在一起，与 ST11-非 K64 相比，在 ST11-K64 菌株组中观察到更多的毒力基因。感染 ST11-K64 菌株的患者死亡率相对较高（47.2%，7/17）。

的运输 IUTA 和 Kvar_1549被认为是 KP BSI 患者的独立死亡风险因素。与高死亡率相关的高毒力和耐碳青霉烯 KP 菌株的鉴定应立即进行监测。