In vivo inflammatory cytokine responses in mice infected with Klebsiella pneumoniae FK6741, Δhns mutant, and complemented strains in an intraperitoneal infection model

This dataset contains experimental data on serum inflammatory cytokines in mice infected with Klebsiella pneumoniae(K. pneumoniae) FK6741, its Δhns mutant, and the complemented strain (Δhns+phns), aimed at investigating the role of the global regulator H-NS in bacterial virulence in vivo. A total of 60 male ICR mice (Charles River, Zhejiang, China), aged 4–5 weeks and weighing 22–25 g, were randomly assigned to three groups corresponding to the three bacterial strains. Bacteria were cultured in LB broth for 6 h, and bacterial concentrations were determined by the plate colony counting method. Each mouse received an intraperitoneal injection of 200 µL bacterial suspension containing 3 × 10⁷ CFU. Mouse survival and body weight were recorded over 24 h at 6 h intervals. At the end of the experiment, all mice were euthanized, and peritoneal lavage was performed for colony enumeration. Serum samples were collected from the orbital sinus of each mouse. Levels of TNF-α, IL-1β, and IL-6 were quantified using commercially available ELISA kits(RayBio® Sandwich-based ELISA Kits) based on the double-antibody sandwich method. Absorbance measurements were taken using a microplate reader (ELX-800, Bio-Tek, Winooski, USA). The dataset contains a single Excel (.xlsx) file, which includes three separate worksheets corresponding to three different inflammatory cytokine measurements (TNF-α, IL-1β, and IL-6). Each worksheet records the optical density (OD) values of the three biological replicates for each of the three bacterial strains (FK6741, Δhns mutant, and complemented strain), along with the corresponding standard curves used for quantification. The tables also include bacterial strain information for each sample. Rows correspond to individual mice, and columns represent measured parameters and experimental replicates. Metadata specifying experimental conditions, mouse age, weight, bacterial concentration, and ELISA kit details. Strain: Code indicating bacterial strain used in the experiment (W = wild-type, H = Δhns mutant, Hp = complemented strain, Wp = empty plasmid control). Data are presented as mean ± standard deviation (SD) from biological replicates. P values indicate the statistical significance of differences between groups and were calculated using appropriate tests (e.g., Student’s t-test or one-way ANOVA), with P < 0.05 considered statistically significant，**P < 0.01, ***P < 0.001, ****P < 0.0001. Sources of error include biological variability among mice and technical variation in ELISA measurements, which are reflected in the SD values. No missing data are present for cytokine measurements or survival data. All in vivo experiments were conducted between April and May 2024. Body weight and survival were recorded every 6 h over a 24 h period. All experiments were performed in the animal facility of The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China (28.0042 N, 120.6358 E). This dataset provides key in vivo phenotypic measurements to support the analysis of H-NS-mediated virulence regulation in K. pneumoniae and can be reused for comparative studies or meta-analyses of bacterial pathogenicity