Abstract
PURPOSE: Burkholderia is a conditioned pathogen in the medical setting and mainly affects patients with cystic fibrosis. We found co-infection with Burkholderia cepacia complex (Bcc) in many patients with respiratory tract infections, including H7N9 and COVID-19. However, previous studies have not focused on co-infections with BCC and respiratory viruses. Therefore, this study attempted to clarify the evolution of COVID-19-Bcc and H7N9-Bcc in terms of genetic background, antibiotic resistance, and virulence phenotypes. METHODS: This study retrospectively collected 49 Bcc isolated from patients with H7N9 and COVID-19 in a tertiary hospital of Zhejiang Province, of which 42 isolates were isolated from patients with H7N9, seven isolates were isolated from patients with COVID-19. The collected isolates were tested for antibiotic susceptibility, Galleria mellonella infection model, and whole-genome COVID-19-Bcc Characterization. RESULTS: The test results of 49 strains of Bcc showed that the strains isolated from COVID-19 patients accounted for 57.1% of multidrug-resistance resistant strains. Statistical analysis of the median lethal time of G. mellonella showed that the median fatal time for COVID-19-Bcc was shorter and more virulent than that of H7N9-Bcc (P<0.05). The results of phylogenetic analysis indicated that COVID-19-Bcc may have evolved from H7N9-Bcc. CONCLUSION: In this study, co-infection with BCC in many patients with respiratory tract infections, including H7N9 and COVID-19, was first identified and clarified that COVID-19-Bcc may have evolved from H7N9-Bcc and has the characteristics of hypervirulence and multidrug resistance.