Chapter 27
A Multistress Model for High Throughput Screening Against
Nonreplicating Mycobacterium tuberculosis
Ben Gold, Thulasi Warrier, and Carl Nathan
Abstract
Models of nonreplication help us understand the biology of persistent Mycobacterium tuberculosis. High
throughput screening (HTS) against nonreplicating M. tuberculosis may lead to identification of tool
compounds that affect pathways on which bacterial survival depends in such states and to development
of drugs that can overcome phenotypic resistance to conventional antimycobacterial agents, which are
mostly active against replicating M. tuberculosis. We describe a multistress model of nonreplication that
mimics some of the microenvironmental conditions that M. tuberculosis faces in the host as adapted for
HTS. The model includes acidic pH, mild hypoxia, a flux of nitric oxide, and other reactive nitrogen
intermediates arising from nitrite at low pH and low concentrations of a fatty acid (butyrate) as a carbon
source.
Key words Mycobacterium tuberculosis, Nonreplication, Hypoxia, Acidic pH, Fatty acids, Nitric oxide,
Reactive nitrogen species, Phenotypic tolerance, Antibiotics, High-throughput screening
1 Introduction
Multiple lines of evidence indicate that in murine or human tuberculosis (TB), populations of Mycobacterium tuberculosis persist in
physiologic states that render them phenotypically resistant to most
existing chemotherapeutics. Unlike genetically resistant
M. tuberculosis, progeny of phenotypically resistant bacilli that are
refractory to in vivo antibiotic treatment are drug-sensitive when
tested in vitro under conditions that sustain replication [1–4].
Identification of compounds that kill nonreplicating
M. tuberculosis and their targets may shed light on how
M. tuberculosis survives in a nonreplicating state [1, 5–
12]. Although there are many ways to put M. tuberculosis into a
nonreplicating state, there is little validation as to which model(s) of
nonreplication lead(s) to identification of compounds that kill persistent M. tuberculosis in an experimental host or in humans [2]. At
Tanya Parish and Anuradha Kumar (eds.), Mycobacteria Protocols, Methods in Molecular Biology, vol. 2314,
https://doi.org/10.1007/978-1-0716-1460-0_27, © Springer Science+Business Media, LLC, part of Springer Nature 2021
611
A Multistress Model for High Throughput Screening Against
Nonreplicating Mycobacterium tuberculosis
Ben Gold, Thulasi Warrier, and Carl Nathan
Abstract
Models of nonreplication help us understand the biology of persistent Mycobacterium tuberculosis. High
throughput screening (HTS) against nonreplicating M. tuberculosis may lead to identification of tool
compounds that affect pathways on which bacterial survival depends in such states and to development
of drugs that can overcome phenotypic resistance to conventional antimycobacterial agents, which are
mostly active against replicating M. tuberculosis. We describe a multistress model of nonreplication that
mimics some of the microenvironmental conditions that M. tuberculosis faces in the host as adapted for
HTS. The model includes acidic pH, mild hypoxia, a flux of nitric oxide, and other reactive nitrogen
intermediates arising from nitrite at low pH and low concentrations of a fatty acid (butyrate) as a carbon
source.
Key words Mycobacterium tuberculosis, Nonreplication, Hypoxia, Acidic pH, Fatty acids, Nitric oxide,
Reactive nitrogen species, Phenotypic tolerance, Antibiotics, High-throughput screening
1 Introduction
Multiple lines of evidence indicate that in murine or human tuberculosis (TB), populations of Mycobacterium tuberculosis persist in
physiologic states that render them phenotypically resistant to most
existing chemotherapeutics. Unlike genetically resistant
M. tuberculosis, progeny of phenotypically resistant bacilli that are
refractory to in vivo antibiotic treatment are drug-sensitive when
tested in vitro under conditions that sustain replication [1–4].
Identification of compounds that kill nonreplicating
M. tuberculosis and their targets may shed light on how
M. tuberculosis survives in a nonreplicating state [1, 5–
12]. Although there are many ways to put M. tuberculosis into a
nonreplicating state, there is little validation as to which model(s) of
nonreplication lead(s) to identification of compounds that kill persistent M. tuberculosis in an experimental host or in humans [2]. At
Tanya Parish and Anuradha Kumar (eds.), Mycobacteria Protocols, Methods in Molecular Biology, vol. 2314,
https://doi.org/10.1007/978-1-0716-1460-0_27, © Springer Science+Business Media, LLC, part of Springer Nature 2021
611