TY - JOUR
T1 - Evaluation of a semi-automated reporter phage assay for susceptibility testing of Mycobacterium tuberculosis isolates in South Africa
AU - Banaiee, Niaz
AU - January, Vanessa
AU - Barthus, Charmaine
AU - Lambrick, Maureen
AU - RoDiti, Denise
AU - Behr, Marcel A.
AU - Jacobs, William R.
AU - Steyn, Lafras M.
N1 - Funding Information:
This work was supported by grants from National Institutes of Health K08 AI061105 (NB), R01 AI26170 and AI43268 (WRJ), and Howard Hughes Medical Institute.
PY - 2008/1
Y1 - 2008/1
N2 - In a prospective study conducted by laboratory technologists in a diagnostic laboratory in Cape Town, South Africa, a semi-automated phage-based antibiotic susceptibility assay was implemented and the performance of the luciferase reporter mycobacteriophage (LRP) system for susceptibility testing of clinical Mycobacterium tuberculosis complex (MTC) isolates against rifampin and isoniazid was evaluated. Two hundred consecutive clinical MGIT cultures of MTC species were included in this study. Antibiotic susceptibility assays were set up manually for the LRP and BACTEC radiometric systems (BACTEC) and read in a plate luminometer and the BACTEC 460 instrument, respectively. Discrepant susceptibility results were resolved by the conventional agar proportion method. Of the 200 secondary cultures prepared for this study, 9 (4.5%) were lost to contamination (LRP 4, BACTEC 1, both 4). All of the remaining 191 cultures underwent susceptibility testing by both methods and the overall agreement between the LRP and BACTEC was 98.4% (rifampin 100%; isoniazid 96.9%). Of the 6 discrepant cultures tested by the agar proportion method, 2 gave results in agreement with the LRP. The sensitivity of the LRP for detection of drug-resistant isolates was 100% for both rifampin (n=9) and isoniazid (n=12). The median turnaround time for susceptibility testing was 2 days with the LRP and 9 days with BACTEC. In conclusion, the semi-automated LRP-based assay offers a rapid and practical approach for accurate susceptibility testing of M. tuberculosis cultures in diagnostic laboratories with limited financial resources, but with competent technologists.
AB - In a prospective study conducted by laboratory technologists in a diagnostic laboratory in Cape Town, South Africa, a semi-automated phage-based antibiotic susceptibility assay was implemented and the performance of the luciferase reporter mycobacteriophage (LRP) system for susceptibility testing of clinical Mycobacterium tuberculosis complex (MTC) isolates against rifampin and isoniazid was evaluated. Two hundred consecutive clinical MGIT cultures of MTC species were included in this study. Antibiotic susceptibility assays were set up manually for the LRP and BACTEC radiometric systems (BACTEC) and read in a plate luminometer and the BACTEC 460 instrument, respectively. Discrepant susceptibility results were resolved by the conventional agar proportion method. Of the 200 secondary cultures prepared for this study, 9 (4.5%) were lost to contamination (LRP 4, BACTEC 1, both 4). All of the remaining 191 cultures underwent susceptibility testing by both methods and the overall agreement between the LRP and BACTEC was 98.4% (rifampin 100%; isoniazid 96.9%). Of the 6 discrepant cultures tested by the agar proportion method, 2 gave results in agreement with the LRP. The sensitivity of the LRP for detection of drug-resistant isolates was 100% for both rifampin (n=9) and isoniazid (n=12). The median turnaround time for susceptibility testing was 2 days with the LRP and 9 days with BACTEC. In conclusion, the semi-automated LRP-based assay offers a rapid and practical approach for accurate susceptibility testing of M. tuberculosis cultures in diagnostic laboratories with limited financial resources, but with competent technologists.
KW - Drug resistance
KW - Drug susceptibility testing
KW - Luciferase reporter mycobacteriophages
KW - Mycobacterium tuberculosis
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U2 - 10.1016/j.tube.2007.08.006
DO - 10.1016/j.tube.2007.08.006
M3 - Article
C2 - 17980664
AN - SCOPUS:37249080649
VL - 88
SP - 64
EP - 68
JO - Bulletin of the International Union Against Tuberculosis and Lung Disease
JF - Bulletin of the International Union Against Tuberculosis and Lung Disease
SN - 1472-9792
IS - 1
ER -