TY - JOUR
T1 - Use of the "RAM" susceptibility testing method for rapid detection of clarithromycin resistance in the Mycobacterium avium complex
AU - Flauta, Victor
AU - Osterhout, Gerard
AU - Ellis, Brandon
AU - Grayson, Michael
AU - Sasser, Myron
AU - Cohen, Sam
AU - Sander, Melissa
AU - Dionne, Kim
AU - Carroll, Karen
AU - Parrish, Nicole
PY - 2010/5/1
Y1 - 2010/5/1
N2 - Standard susceptibility testing of the Mycobacterium avium complex (MAC) can require 7 to 14 days from initial isolation. We evaluated a high-performance liquid chromatography-based susceptibility test for rapid determination of clarithromycin (CLR) resistance in MAC. This method can be completed in 72 h of incubation. A total of 110 MAC strains were tested using the following concentrations of CLR: 4, 16, and 64 μg/mL, for a total of 330 tests. Microbroth dilution was used as the reference method. Rapid analysis of mycolic acid ("RAM") concordance with the reference method for CLR susceptibility was 98% (254/258) and 100% for CLR resistance (72/72). The 4 discordant results occurred with 2 strains, which demonstrated intermediate resistance with an MIC of 16 μg/mL. This study demonstrates that "RAM"-based susceptibility testing for determination of CLR resistance in MAC is both rapid and accurate, providing a significant reduction in turn-around-time from 7 to 14 days to 72 h of incubation.
AB - Standard susceptibility testing of the Mycobacterium avium complex (MAC) can require 7 to 14 days from initial isolation. We evaluated a high-performance liquid chromatography-based susceptibility test for rapid determination of clarithromycin (CLR) resistance in MAC. This method can be completed in 72 h of incubation. A total of 110 MAC strains were tested using the following concentrations of CLR: 4, 16, and 64 μg/mL, for a total of 330 tests. Microbroth dilution was used as the reference method. Rapid analysis of mycolic acid ("RAM") concordance with the reference method for CLR susceptibility was 98% (254/258) and 100% for CLR resistance (72/72). The 4 discordant results occurred with 2 strains, which demonstrated intermediate resistance with an MIC of 16 μg/mL. This study demonstrates that "RAM"-based susceptibility testing for determination of CLR resistance in MAC is both rapid and accurate, providing a significant reduction in turn-around-time from 7 to 14 days to 72 h of incubation.
KW - Mycobacterium avium complex
KW - RAM
KW - Susceptibility testing
UR - http://www.scopus.com/inward/record.url?scp=77951498622&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77951498622&partnerID=8YFLogxK
U2 - 10.1016/j.diagmicrobio.2009.12.008
DO - 10.1016/j.diagmicrobio.2009.12.008
M3 - Article
C2 - 20226616
AN - SCOPUS:77951498622
SN - 0732-8893
VL - 67
SP - 47
EP - 51
JO - Diagnostic Microbiology and Infectious Disease
JF - Diagnostic Microbiology and Infectious Disease
IS - 1
ER -