Drug sensitivity spectrum and pathogenic characteristics of human Brucella strains in Hubei Province from 2012 to 2023
This study was aimed at investigating the antimicrobial susceptibility spectrum and pathogenic characteristics of human brucellosis in Hubei Province.A retrospective analysis was performed on 122 brucellosis cases reported in Hubei Prov-ince from 2012 to 2023.Isolation and culture,biochemical identification,molecular biology methods,and serological identifica-tion were used for pathogen identification;the E-test method was used for in vitro drug susceptibility testing;and whole ge-nome sequencing was used to perform MLST typing and phylogenetic developmental tree analysis of 25 strains of Brucella.All Brucella isolates in Hubei Province were Brucella melitensis bv.3 str.The drug susceptibility results for 122 Brucella isolates indicated that 109 Brucella isolates were generally sensitive to 12 drugs,among which 13 Brucella isolates were sensitive to 11 drugs,and were intermediate to sulfamethoxazole.MLST 9-site sequence typing indicated that all 25 strains of Brucella isolates were ST8 type,with similar virulence gene characteristics,but different strains carried slightly different virulence genes.Phylogenetic tree analysis demonstrated that the 25 strains of Brucella isolates could be divided into two major evolu-tionary branches and multiple subbranches,and exhibited polymorphism.The dominant clone group of human Brucella in Hu-bei Province was ST8 type,which carried multiple virulence genes associated with immune escape.The MIC for sulfamethox-azole has increased,and surveillance should be strengthened.
Brucellaspecies identificationdrug sensitivity testMLST typinggenetic and evolutionary analysis