Fig. 1

Isolation and identification of KP and CRKP. A Colony morphology of KP and CRKP strains on LB agar plates. B Colony morphology of KP and CRKP strains on MacConkey agar. C Detection of high viscosity phenotype in KP and CRKP strains. D Gram staining results of KP and CRKP strains (1000 × magnification). E PCR gel electrophoresis detection of 16S rRNA gene amplification products in KP and CRKP strains (Lane M: DNA molecular weight marker; Lanes 1, 2, 3: amplification products of KP 16S rRNA gene; Lanes 4, 5, 6: amplification products of CRKP 16S rRNA gene). F Phylogenetic tree analysis of 16S rRNA gene in KP and CRKP strains. G Kirby-Bauer paper disk diffusion method for detecting the inhibition zones of KP and CRKP strains against 10 antibiotics (ertapenem, IM, meropenem, chloramphenicol, ciprofloxacin, levofloxacin, ceftazidime, ceftriaxone, cefotaxime, and amikacin). H Broth microdilution method for detecting the MICs of KP and CRKP strains against 10 antibiotics (ertapenem, IM, meropenem, chloramphenicol, ciprofloxacin, levofloxacin, ceftazidime, ceftriaxone, cefotaxime, and amikacin). I Modified carbapenem inactivation method (mCIM) for detecting carbapenemase phenotype in KP and CRKP strains, and ethylenediaminetetraacetic acid-carbapenem inactivation method (eCIM) for detecting metallo-β-lactamase phenotype in KP and CRKP strains. J PCR gel electrophoresis detection of carbapenemase genes in KP and CRKP strains (Lane M: DNA molecular weight marker; Lane 1: negative control; Lane 2: positive control; Lane 3: KP strain; Lane 4: CRKP strain). K Western blot experiment to detect the expression levels of NDM1 protein in KP and CRKP strains (upper figure), as well as the statistical results (lower figure). Quantitative data in the figure are represented as mean ± SD, and each experiment group was repeated three times. *P < 0.05 compared to the KP group