Objective To investigate the antimicrobial susceptibility of clinical isolates of Corynebacterium striatum and the clinical characteristics of the patients infected or colonized with these strains.Methods The C.striatum strains isolated from clinical specimens were collected in Quanzhou First Hospital Affiliated to Fujian Medical University from July 2020 to September 2022.The clinical data were analyzed to examine the clinical characteristics of patients with C.striatum colonization or infection.The susceptibility of these strains to 18 antimicrobial agents were tested by broth microdilution method.The gyrA gene related to quinolone resistance determining region was amplified and sequenced to analyze the position of amino acid mutations.The ribosomal methylase gene ermX and aminoglycoside enzyme gene aphA1 were amplified by PCR and sequenced.Results Antimicrobial susceptibility testing indicated that all of the 72 strains were susceptible to vancomycin,linezolid and daptomycin.All stains were resistant to ceftriaxone,ciprofloxacin and moxifloxacin.The C.striatum strains showed high resistance rate to penicillin(87.5％),cefepime(95.8％),meropenem(95.8％),trimethoprim-sulfamethoxazole(90.3％),erythromycin(98.6％)and clindamycin(98.6％),but relatively lower resistance rate to gentamycin(25.0％),tetracycline(30.6％)and rifampicin(23.6％).Sequencing analysis indicated that 3 strains of C.striatum had single mutation of gyrA gene(Ser87Val),67 strains had double mutations(Ser87Phe,Asp91Ala or Ser87Tyr,Asp91Ala)and 2 strains had three point mutations(Ser87Phe,Ala88Pro and Asp91 Ala),which was newly identified in this study.The ermXgene was detected in all of the isolates and the prevalence of aphA1 gene was 43.1％.The 72 strains of C.striatum were mainly isolated from ICU(65.2％)and lower respiratory tract specimen(91.6％).The average age of patients was 68.0±15.3 years old.About 72.2％(52/72)of the C.striatum strains were isolated from the patients with infection and 27.8％(20/72)were colonizers.Compared to the patients colonized with C.striatum,the patients with C.striatum infection had statistically significant higher percentages of hospital stay ≥ 28 days,cerebral hemorrhage,disturbance of consciousness and disease deterioration(P＜0.05).Conclusions All of the 72 C.striatum isolates were multidrug resistant,and the outcome of patients with C.striatum infection was relatively poor.