Species Distribution and Antimicrobial Susceptibility of Diverse Strains Within Burkholderia cepacia Complex

The aim of the present study was to examine the clinical distribution and antibiotic susceptibility of the Burkholderia cepacia complex (BCC). The BCC clinical strains were obtained from the First Affiliated Hospital of Zhejiang University School of Medicine in China from January 2019 to January 2024, and hisA gene sequencing was employed for strain identification. The in vitro susceptibility of various antibacterials was measured through the disk diffusion method and the broth microdilution method. A total of 386 strains of BCC were collected. Among them, the most common strains were B. cenocepacia (45.9%), B. multivorans (45.1%), and B. contaminans (7.0%). B. multivorans was the main one in respiratory specimens, whereas B. cenocepacia dominated in blood specimens. B. cenocepacia, B. multivorans, and B. contaminans exhibited a susceptibility over 95% to meropenem and sulfamethoxazole-trimethoprim, whereas varying sensitivities were displayed to levofloxacin, ceftazidime, and minocycline (p < 0.05). Among tetracyclines, eravacycline exhibited the lowest minimum inhibitory concentration 90 (MIC90) values 1 µg/mL for B. cenocepacia, 1 µg/mL for B. multivorans, and 2 µg/mL for B. contaminans. This was followed by tigecycline (MIC90: 2 µg/mL, 2 µg/mL, and 4 µg/mL, respectively), minocycline (MIC90: 8 µg/mL, 2 µg/mL, and 8 µg/mL, respectively), and omadacycline (MIC90: 8 µg/mL, 4 µg/mL, and 16 µg/mL, respectively). Compared with the broth microdilution method, the category agreement (CA) of sulfamethoxazole-trimethoprim and ceftazidime was >95%, and the very major error was <1%, whereas the CA of minocycline and meropenem was <90%. Thus, there are differences in the in vitro antimicrobial susceptibility of different BCC strains, with eravacycline demonstrating lower MIC values compared with tigecycline, minocycline, and omadacycline.