Abstract:A patient was admitted to hospital due to umbilical pain. Gram-staining presented short, positive coccobacillus in the purulent secretions from the umbilical cord of the patient. Meanwhile, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), 16S rRNA detection, and in vitro antimicrobial susceptibility testing were performed on the isolated strains. Corynebacterium tuberculostearicum was identified by Gram-staining, MALDI-TOF MS and 16S rRNA. Antimicrobial susceptibility testing results showed that the strain was sensitive to penicillin, ceftriaxone, cefepime, meropenem, vancomycin, daptomycin, linezolid, compound sulfamethoxazole, ampicillin, gentamicin and tetracycline. Smear of microorganisms is helpful for the identification of Corynebacterium tuberculostearicum morphology, and MALDI-TOF MS is necessary for rapid identification of strains. Antimicrobial susceptibility testing can also assist the empirical treatment for infection due to this strain.