Genome-Wide Comparison Analysis of Brucella Attenuated Vaccine Strain BA0711 and Brucella Wild-Type Strain M28 and Establishment of a Dual qPCR Differentiation Method.

Novel qPCR assay accurately differentiates vaccine from wild-type Brucella strains for surveillance.

This study conducted whole genome sequencing and comparative genomic analysis of the Brucella attenuated vaccine strain BA0711 against the wild-type virulent strain M28 to elucidate the genetic basis of virulence attenuation. The BA0711 vaccine strain exhibited 199 and 144 mutations, deletions, and unique gene fragments on chromosomes I and II respectively compared to M28. Key findings revealed that BA0711 lacks genes encoding cold shock proteins and glutamine transferases, with functional impairments in energy metabolism, stress defense, drug resistance, virulence expression, and genomic plasticity. Despite these genomic alterations, the vaccine strain maintained strong host adaptability, viability, and immunogenicity. The researchers developed a sensitive and specific dual TaqMan qPCR assay targeting BA0711-specific gene fragments, achieving 1×10¹ copies/μL sensitivity with intra- and inter-assay coefficients of variation below 0.5%. Validation on 100 samples confirmed accurate differentiation between BA0711, other Brucella serotypes, and mixed infections. This work provides crucial tools for epidemic surveillance and clinical diagnosis of brucellosis.

This summary was distilled by AI and may occasionally misinterpret data. Confirm critical details with the primary literature before clinical application.