Epidemiological and pathogenic analyses of three cases of imported Corynebacterium diphtheriae infection in Fujian Province
The epidemiology and etiology of three suspected cases of imported skin diphtheria infection in Fujian Province were investigated.Secretion samples of patients with skin damage were collected for isolation and culture of Corynebacterium diphtheriae.Biochemical identification and mass spectrum analysis of pure cultures of suspected C.diphtheriae were conduc-ted,the virulence-related genes,including diphtheria toxin reporter(dtxR),toxin A(toxA),and toxin B(toxB)were detec-ted,and multilocus sequence typing(MLST)was performed.All three cases had typical clinical manifestations of cutaneous diphtheria,and C.diphtheriae was isolated from the damaged skin.The virulence genes of two C.diphtheriae strains isolated from two cases were identified as dtxR(+),toxA(-),and toxB(-),and the MLST type was ST-703.The virulence genes of C.diphtheriae isolated from one case were identified as dtxR(+),toxA(+),toxB(+),and the MLST type was ST-248.There is an increased risk of diphtheria in Fujian Province.C.diphtheriae without diphtheria toxin genes can also cause skin diphtheria.