Growth kinetics of Mycobacterium tuberculosis measured by quantitative resazurin reduction assay: a tool for fitness studies

Abstract

We standardized a method to evaluate the growth kinetics of Mycobacterium tuberculosis by measuring quantitatively the reduction of resazurin by spectrophotometry. Growth curves and the rate of growth of twenty-one M. tuberculosis clinical isolates were determined. The method showed technical simplicity and is inexpensive to assess the fitness of each isolate.

An <em>In Silico</em> Study of a Novel rpoB Insertion in a Cluster of Clinical Strains of <em>Mycobacterium tuberculosis</em> Highly-Rifampicin Resistant

“…The evolution of single drug resistant to multiple antibiotics is driven mainly by the sequential acquisition and accumulation of resistance conferring mutations on the bacterial chromosome. Biological cost has been evaluated mainly by growth rate, being one indirect evaluation of fitness (Andersson and Hughes, 2010;von Groll et al, 2010avon Groll et al, , 2010b.…”

“…The growth curve was determined by resazurin reduction method as previously reported (von Groll et al, 2010b). Briefly, the two individual clinical isolates with the insertion, three wild type clinical isolates and in one susceptible control strain (H37Rv) were freshly sub-cultured on Löwenstein-Jensen medium and kept for 3 weeks.…”

Resazurin Assay Data for Mycobacterium tuberculosis Supporting a Model of the Growth Accelerated by a Stochastic Non-Homogeneity

“…The principal protocol followed [19] with some adjustments to the actual conditions of the experiment. The suspension of M. tuberculosis was unfrozen for three weeks before the experiment and cultured on Löwenstein-Jensen medium.…”

Measuring of Mycobacterium tuberculosis growth: a correlation of the optical measurements with colony forming units

“…The method considered the most reliable for measuring the concentration of viable microorganisms in culture is the quantification of colony-forming units (cfu) per unit volume of culture (Davey et al , 2004). However, this approach is laborious, and for M. tuberculosis , requires lengthy time periods to obtain results (Damato et al , 1983; von Groll et al , 2010). The aim of this study was to define the number of viable M. tuberculosis cells equivalent to McFarland and OD 600 measurements in liquid cultures and to compare the reliability of these methods in estimating M. tuberculosis concentrations in suspension.…”

“…These data support the idea of an erroneous quantification when McFarland equivalents in E. coli are used to evaluate the growth of M. tuberculosis , which lead to a misinterpretation of results in liquid cultures. Other methods such as respiration rate (Gomez-Flores et al , 1995), resazurin reduction (Sanchotene et al , 2008; von Groll et al , 2010), as well as protein and ATP measurements (Meyers et al , 1998) have measured the growth kinetics of M. tuberculosis, but all of these methods require further incubation time and analysis resulting in a delay of additional assays. In conclusion, OD 600 measuring is the most sensible method for the evaluation of M. tuberculosis growth in liquid cultures, whereas the growth curve is more consistent using McFarland method, particularly between 9–15 days.…”