Resistant Mechanisms of Candida albicans to Azoles / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate the resistant mechanisms of Candida albicans to azoles at molecular level.METHODS NCCLS M-27 protocols were used to test the in vitro susceptibilities of 102 C.albicans strains isolated from the patients with recurrent vulvovaginal candidiasis(RVVC) against fluconazole(FLC) and itraconazole(ITC) to screen the FLC-and ITC-resistant C.albicans isolates;six pairs of primers,A1-A2,B1-B2,C1-C2,D1-D2,E1-E2 and F1-F2 were respectively to amplify gene CYP51 of 4 strains with FLC-and ITC-resistance.The PCR products were sequenced and analyzed to identify the mutation sites by compared with the sequence of gene CYP51 of referenced C.albicans strain in NCBI site of Internet.RESULTS The analysis of full length sequence of CYP51 from 4 FLC-and ITC-resistant strains showed that from total 32 mutation sites there were 4 significant site mutations,where the mutation of GAT to GAC at 116 caused the substitution of D by E(E266D in two strains);GCC to GGT at 117 caused the substitution of A by G(A117G in 1 strain);GAA to GAC at 266 caused the substitution of E by D(E266D in 2 strains);and GTT to ATT at 488 caused the substitution of I by V(V488I in 1 strain).The site mutations of 266 and 488 were tested in 1 strain of 4 strains.CONCLUSIONS The CYP51 total gene of 4 strains has been checked out.Of FLC and ITC-resistant C.albicans alignment in this time,find out 4 significant bp mutations.Causing its amino acide change,among them,A117G has not be interrelated report still now.The details of mechanism need to be further studied.