Tuberculosis Gene Map Points to Stronger Antibiotic Combinations

WHO:

Phys.org - Rockefeller scientists created a map of interactions among essential genes in *Mycobacterium tuberculosis* (Mtb), the bacterium that causes tuberculosis (TB).

Nature - The research examined Mtb, generally using derivatives of the H37Rv strain, and *Mycobacterium smegmatis* (Msm), generally using derivatives of mc²155.

Nature - The study used Mtb and Msm gene-targeting libraries, with 1,493 and 1,534 guide RNAs respectively in their gene-interaction libraries.

WHAT:

Phys.org - The researchers produced what they described as the most comprehensive map to date of interactions among Mtb’s essential genes, revealing thousands of previously unknown genetic relationships.

Phys.org - The map offers a new way to investigate the inner workings of a pathogen responsible for one of the world’s deadliest diseases.

Nature - The Mtb gene-interaction library contained 1,483 targeting guide RNAs for 762 genes, plus 10 non-targeting controls, for 1,493 guides total.

Nature - The Msm gene-interaction library contained 1,524 targeting guides for 787 genes, plus 10 non-targeting controls, for 1,534 guides total.

Nature - A separate genome-wide Mtb CRISPRi library, RLC25, contained 31,143 guides: 30,306 targeting 4,005 genes and 837 non-targeting controls.

Nature - RLC25 combined libraries RLC3 and RLC14 and had 65,557 fewer guides than reference library RLC12 while maintaining genome-wide coverage.

Nature - The study assessed drug interactions using checkerboard synergy assays and kill-curve assays. Checkerboard pairs were classified as synergistic when the most synergistic area’s mean Bliss score exceeded 15, and antagonistic when the most antagonistic area’s mean score was below −15.

Nature - The kill-curve tests examined Vertex-49 with bedaquiline or ethambutol. A pair was considered synergistic when the combination produced more than 100-fold more killing than the more effective individual drug at the same concentration.

WHERE:

Phys.org - The work was conducted by Rockefeller scientists.

Nature - Mtb cultures were grown in tissue-culture flasks with 5% carbon dioxide; the described cultures were incubated at 37 °C.

WHY:

Phys.org - The map was created to reveal previously unknown gene relationships and provide insight into Mtb biology, with potential to inform better antibiotic pairings.

Nature - Researchers used gene-interaction profiling and drug screens to investigate genetic relationships and assess how drugs affect Mtb when gene targets are reduced.

HOW:

Nature - Researchers used CRISPR interference (CRISPRi) libraries to reduce gene expression and profile gene interactions, comparing combined gene-knockdown effects with expected effects from individual knockdowns.

Nature - Mtb and Msm interaction libraries used paired guide RNAs. The Mtb library targeted essential genes and 72 selected non-essential genes; the Msm library targeted essential genes and Mtb homologues classified as essential in vitro.

Nature - The RLC25 drug-profiling library combined guides targeting non-essential genes with hypomorphic guides targeting essential genes.

Nature - Drug-profile cultures were pre-depleted with anhydrotetracycline (ATc), exposed to nine drug concentrations spanning 0.03125 to two times the pre-determined MIC₉₀, and grown for 14 days before measurement.

(UPDATED November 5, 2026 02:03 UTC)

Rockefeller scientists mapped essential genes in tuberculosis bacteria, uncovering thousands of previously unknown relationships. The map offers new insight into the pathogen and potential antibiotic pairings. Researchers used gene-silencing tools and drug screens.