DNA Typing of Trichophyton Mentagrophytes

Objective To explore the DNA typing of Trichophyton mentagrophytes by Southern blotting,analyze the relationship between genotype and different geographical areas.Methods Thirty five strains of T.Mentagrophytes(14fromDalian,3fromShenyang,5fromshanghai,5frombeijing,3fromnanjing,2fromhebei,2fromkunming,and1fromhangzhou)were studied.DNA was extracted using cetyltrimethyl ammonium bromide(CTAB).The polymorphisms were detected by hybridization of EcoR1-digested T.Mentagrophyes genomic DNA with a probe amplified from the small-subunit rDNA and adjacent internal transcribed spacer(ITS) regions.The probe was made using a pair of primers NS5[5′-AACTTAAAGGAATTGACGGAAG-3′]and ITS4[5′-TCCTCCGCTTATTGATATGC-3′] and was labeled by ECL.The band patterns obtained by Southern blotting were used as the basis of the genotyping of T.Mentagrophytes.Results Fifteen individual patterns(DNA type A to N) were recognized among 35 strains of T.mentagrophytes.Type A to D accounted for 62.86% of all strains.The DNA patterns of Southern strains were represented by type A and C,those of northern strains were represented by type B and D.Conclusion The DNA typing of T.Mentagrophytes using Southern blotting was sensitive,highly distinguishable.The DNA patterns of southern strains are obviously different from those of northern strains.