biostudies-literatureXu ZHigh-level Talent Research Project of Shihezi UniversityNational Natural Science Foundation of ChinaTalent Program 'Tianchi Talent (Young Doctor)' in Xinjiang Uygur Autonomous Region (CZ004336)Major Scientific and Technological Projects of Corpse70223https://www.ebi.ac.uk/biostudies/studies/S-EPMC12420658biostudies-literatureUnknown18(9)The Brucella abortus A19 attenuated live vaccine poses potential infection risks during practical applications and interferes with serological diagnostics, thereby affecting quarantine measures and the establishment of disease-free zones. Consequently, this study aimed to reduce its potential virulence, enhance its protective efficacy and differentiate it from wild-type strains by knocking out the immunosuppressive virulence gene btpB in the A19 strain. Using homologous recombination, we successfully obtained the A19ΔBtpB deletion strain. In a mouse model, the A19ΔBtpB strain demonstrated improved safety and significantly increased TLR2 and TLR4 expression levels in splenic lymphocytes, suggesting attenuated immune suppression. The A19ΔBtpB strain induced Brucella-specific IgG antibodies cMicrobial biotechnologyA BtpB-Deleted Brucella Vaccine Strain Provides Dual Advantages: Enhanced Protection and Diagnostic Differentiation Capability in Mice.PMC12420658U1803236RCZK2024562017AA003CZ004336Zhang HHe HMa ZGao HChen CYi JWu AZhang YWang YWang ZXu ZDeng XXu YfalseA BtpB-Deleted Brucella Vaccine Strain Provides Dual Advantages: Enhanced Protection and Diagnostic Differentiation Capability in Mice.The Brucella abortus A19 attenuated live vaccine poses potential infection risks during practical applications and interferes with serological diagnostics, thereby affecting quarantine measures and the establishment of disease-free zones. Consequently, this study aimed to reduce its potential virulence, enhance its protective efficacy and differentiate it from wild-type strains by knocking out the immunosuppressive virulence gene btpB in the A19 strain. Using homologous recombination, we successfully obtained the A19ΔBtpB deletion strain. In a mouse model, the A19ΔBtpB strain demonstrated improved safety and significantly increased TLR2 and TLR4 expression levels in splenic lymphocytes, suggesting attenuated immune suppression. The A19ΔBtpB strain induced Brucella-specific IgG antibodies c2025-01-01T00:00:00Z2025 Sep2026-06-03T05:42:14.956Z2026-04-25T03:17:19.272ZS-EPMC124206584092633310.1111/1751-7915.70223