jingluodatacurator
commented
9 months ago Summary of expt. :
(2.1. Selection and in vitro susceptibility testing of VCZ-resistant isolates) Aspergillus flavus X26728 highly susceptible to various antifungal drugs was used. Approximately 1 × 106 conidia per plate were spread on SDA containing 0.5 micro g/mL VCZ and the plates were incubated at 35 ◦C for 4–6 days in plastic bags to maintain moisture. Colonies growing on these plates were screened for their susceptibility to VCZ using 96-well microtitre plates. Seventeen colonies that grew in the presence of 4 micro g/mL VCZ in liquid culture (frequency ca. 0.5 × 10−8) were selected and further tested for their in vitro susceptibility to various antifungal drugs. The MICs of antifungal drugs for the VCZ-susceptible parent X26728 and VCZ-resistant A. flavus isolates were determined by the broth dilution method recommended by the Clinical and Laboratory Standards Institute.
(Results 3.1. Characterisation of cyp51A and CYP51B genes) Alignment of the deduced amino acid sequences of CYP51Ap and CYP51Bp from ten VCZ-resistant isolates with that of the drug-susceptible parent X26728 showed variation in six of the ten isolates. Changes in CYP51Ap were noted at K197N (isolates Afl-VCZ6 and Afl-VCZ46), Y132N + T469S (isolate Afl-VCZ114) and K197N + D282E + M288L (isolate Afl-VCZ45). Similarly, in CYP51Bp amino acid changes were noted at positions H399P + D411N (isolate Afl-VCZ40) and T454P + T486P (isolate Afl-VCZ112) (Table 1; Fig. 4). These data suggest that drug target modification may play an important role in VCZ resistance in A. flavus. The lack of any amino acid changes in four of the ten isolates implies that other mechanism(s), e.g. efflux, might also be involved.
CuzickA
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https://canto.phi-base.org/curs/c2c86c6be23c622b