Identification of the Burkholderia cepacia complex genomovars and their virulence in an alfalfa infection model

Abstract:

Abstract: [Objective] To confirm Burkholderia cepacia complex (Bcc) genomovars from agricultural niches and clinical samples, and to evaluate their possible virulence to human body on alfalfa infection model in China. [Methods] A total of 57 Bcc strains were isolated and collected from the rhizosphere, soil and clinical samples in China. The genomovars composition of the Bcc strains was analyzed by species-specific PCR tests, and the virulence of the Bcc strains was tested on alfalfa seedlings. [Results] Four genomovars of the ten genomovars were detected among the Bcc strains, including B. cepacia (genomovarⅠ), B. cenocepacia (genomovarⅢ), B. vietnamiensis (genomovarⅤ) and B. pyrrocinia (genomovar Ⅸ). Bcc genomovarsⅠandⅢA from clinic, and genomovarⅢB from rhizosphere were the most virulent in the alfalfa infection model, and caused symptoms in 69%, 68% and 55% of seedlings, respectively. There were significant variances in the mean percentage of seedlings with symptoms for genomovarsⅠ,ⅢA andⅢB compared to those for genomovarⅤandⅨ. [Conclusion] There was difference in the ability to cause disease in alfalfa for different genomovar strains from agricultural inches. The strains of Bcc genomovarⅢB from rhizosphere were more virulent similar to those of Bcc geno-movarⅢA from clinic.