Ref ID: 15149
Author:
S. KRISHNAN-NATESAN, K. JOST, P. CHANDRASEKAR
Author address:
1Wayne State Univ., Detroit, MI, 2John D. Dingell VA Med. Ctr., Detroit, MI.
Full conference title:
50th Annual ICAAC
Date: 12 September 2014
Abstract:
Background: Invasive aspergillosis remains a life threatening infection; clinical failures may be attributed to antifungal drug resistance. Research on Aspergillus efflux pumps (EPs) is scant. Aim: To develop a Rhodamine-6G based spectrophotometric assay for drug efflux and to evaluate overexpression of MDR-EPs in VCZ-R A. flavus that lack cyp51A mutation. Methods: VCZ-R A. flavus (n=10; MIC 2-16 µg/ml, laboratory-selected) were screened for ABC: ATP Binding Cassette [± CCCP (8 mcg/ml)] and MFS: Major Facilitator Superfamily MFS [± glucose (1M)] EP overexpression using a R6G-FA. Isolates that showed efflux (n=5) were selected, grown in the presence and absence of VCZ (n=10) and RNA isolated. Four novel EPs (ABC1, ATRF, MDR4 and MFS1) were identified in A flavus (NRRL 3357), amplified using Taqman-qRT-PCR; results for parent vs VCZ-R A. flavus (±VCZ) were compared. Isolates were also tested for cyp51A mutations. Results: None of VCZ-R A. flavus tested had cyp51A mutation. Inhibition (ABC-EP) or excitation (MFS-EP) of R6G efflux was demonstrated with CCCP and glucose respectively in 5/10 VCZ-R A. flavus. Constitutive overexpression (>7-fold) of ATRF (n=4), ABC1 (n=4) and MDR.4 (n=1) was demonstrated in VCZ-R A. flavus; inducible overexpression (>10-fold) of ATRF and ABC1 was seen in the VCZ-S parent; ABC1, MFS and MDR 4 were induced >100-fold in 1/5 VCZ-R A flavus; MFS was downregulated in 2/5 VCZ-R A flavus. Conclusion: Screening using R6G assay detects possible upregulation of ABC and MFS EPs; EP inhibition with CCCP suggests that A. flavus MDR4, ATRF and ABC1 belong to ABC-family of EP. VCZ is a substrate for both ABC and MFS class EPs. Multiple EPs are induced on exposure to sub-MIC of VCZ. Constitutive upregulation of several MDR-EPs in the absence cyp51A mutation may play a crucial role in phenotypic VCZ-R in A. flavus.
Abstract Number: M-626
Conference Year: 2010
Link to conference website: NULL
New link: NULL
Conference abstracts, posters & presentations
-
Title
Author
Year
Number
Poster
-
v
C Gutierrez Perez1*, S Dhingra1,2, SM Kwansy3, TJ Opperman3, RA Cramer1
2022
93
-
v
PC Chatterjee1*, WC Chiu1, EBB Burgener2, PLB Bollyky3, JH Hsu1
2022
92
-
v
AS Serris1*, FU Uhel2, GMB Martin-Blondel3, OL Lambotte4, MEB Bougnoux5, EL Litvinova6, AO Ouedrani7, CR Rouzaud1, VB Bedarida8, JHR Raphalen9, FL Lanternier1,10
2022
91
-
v
ZA Lewis1, RB Meagher2*, S Ambati2, X Lin1
2022
90
-
v
QJ Choudhury1*, S Ambati2, X Lin1, ZA Lewis1, RB Meagher2
2022
-
v
M James1*, KW Liu1, E Vesley1, T Hohl2, RA Cramer1
2022
88
-
v
D Luptakova1, RH Patil1,2, V Havlicek1,2*
2022
87
-
v
EI Matthaiou1*, W Chiu1, C Conrad2, J Hsu1
2022
86
-
v
H Kamboj*, M Vijay, L Gupta, P Vijayaraghavan
2022
85
-
v
S Hartung1,2*, TNM Hoang1,2*, Z Cseresnyes3*, N Schuck1, K Rennert4,5, F Klos6, AS Mosig5,7, MT Figge3,8, M von Lilienfeld-Toal1,2
* Authors 1, 2 and 3 contributed equally
2022
84
