Determination of ethambutol MICs for Mycobacterium tuberculosis and Mycobacterium avium isolates by resazurin microtitre assay

Department of Microbiology and Molecular Biology, National JALMA Institute for Leprosy and Other Mycobacterial Diseases (Indian Council of Medical Research), PO Box 1101, Dr M. Miyazaki Marg, Tajganj, Agra 282001, India.
Journal of Antimicrobial Chemotherapy (Impact Factor: 5.31). 08/2007; 60(1):152-5. DOI: 10.1093/jac/dkm117
Source: PubMed

ABSTRACT To test susceptibilities of Mycobacterium tuberculosis (MTB) isolates to ethambutol by the Löwenstein-Jensen (LJ) proportion method and resazurin microtitre assay (REMA) and to evaluate REMA for the determination of ethambutol MICs for MTB and Mycobacterium avium isolates.
A total of 50 MTB and 20 M. avium isolates were tested to determine the MICs of ethambutol by REMA and agar dilution method. MTB isolates were also tested by the LJ proportion method.
REMA provided ethambutol susceptibility results for all the isolates within 8-9 days. For MTB isolates, REMA showed 96.7% sensitivity, 100.0% specificity and 98.0% accuracy when LJ proportion results were taken as 'gold standard'. For both MTB and M. avium isolates, the MICs determined by REMA were lower than those determined in agar medium, indicating that MIC values determined by REMA are closer to the actual MICs for the isolates.
REMA can be used as a rapid and inexpensive method for mycobacterial drug susceptibility testing against ethambutol. In comparison with the agar method, the MICs determined by REMA can more accurately be correlated with achievable plasma concentrations of antimycobacterial agents.

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Available from: Vishnu dutt Sharma, Sep 26, 2015
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    • "Five total sensitive (rifampicin, isoniazid, ethambutol, pyrazinamide, streptomycin, kanamycin and amikacin) and six amikacin as well as kanamycin resistant (sensitive to other first line and second line drugs) M. tuberculosis isolates were obtained from the Mycobacterial Repository Centre of National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India. Susceptibility testing for all the drugs was performed by LJ proportion [16] and REMA methods [17] [18] "
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    Journal of proteomics 09/2013; 94. DOI:10.1016/j.jprot.2013.08.025 · 3.89 Impact Factor
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    • "scordant results ( 3 false resistant and 23 false sensi - tive ) ( Table 2 ) , resulting in a lower value of sensitivity , low value of specificity ( Montoro et al . , 2005 ) and reasonable correlation ; previous sensitivity results ranged between 92 and 98% ( 6 , 8 , 13 ) , specificity results between 98 and 100% ( Luna - Herrera et al . , 2003 , Jadaun et al . , 2007 ) and correla - tion was reasonable ( Madison et al . , 2002 ) . According to the literature , the INH high - resistance isolates showed sim - ilar results to those of Palomino et al . ( Palomino et al . , 2002 ) , RMP and STR high - resistance isolates showed worse results than Palomino et al . ( 2002 ) and Tudó et al . ( 2010 ) , resp"
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    Brazilian Journal of Microbiology 05/2013; 44(1):281-5. DOI:10.1590/S1517-83822013005000028 · 0.59 Impact Factor
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    • "The minimum inhibitory concentrations (MIC) of plant extracts were determined using the broth microdilution method in 96-well microtitre plates for S. aureus and K. pneumoniae as described by Eloff [41] and Jadaun et al. [42] for M. aurum A+. The extracts were dissolved in 10% DMSO except for aqueous extracts which were dissolved in sterile distilled water. "
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