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

Background: 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). Methods: 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. Results: 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 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). Conclusion: 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.

MiR-520f acts as a biomarker for the diagnosis of lung cancer.

Lung cancer is a malignant tumor with high morbidity and mortality. Early diagnosis remains a great challenge for the cancer. In this study, we aimed to explore diagnostic performance of serum microRNA-520f (miR-520f) in lung cancer.Serum specimens were collected from 139 lung cancer patients and 76 healthy volunteers. Relative expression level of serum miR-520f was detected adopting quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was applied to evaluate the association of miR-520f with clinical parameters of the patients. Additionally, receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic value of miR-520f in lung cancer.Serum miR-520f was down-regulated in lung cancer patients compared with healthy group (P <.001). Moreover, the expression of miR-520f was significantly associated with advanced TNM stage (P = .031) and metastasis (P = .002). The area under the curve (AUC) value of ROC curve was 0.888, suggesting that miR-520f could be a diagnostic biomarker for lung cancer. The cut-off value of serum miR-520f for lung cancer diagnosis was 1.815, with a sensitivity of 79.9% and a specificity of 84.2%.Serum miR-520f was down-regulated in lung cancer patients, and may be a candidate biomarker for non-invasive screening of the disease.