Evidence map›Paper›PMID 42533047›Full record

ArticleScientific reports2026

Constrained RNA polymerase mutational pathways distinguish corallopyronin A resistance from rifampicin resistance in staphylococci.

Jesenko Karačić, Sabina Karačić, Miriam Grosse, Andrea Schiefer, Kenneth Pfarr, Tanja Schneider, Achim Hoerauf, Gabriele Bierbaum

Abstract read
In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Jesenko KaračićInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany. karacicjesenko@gmail.com.ORCID 0009-0001-3642-6252
Sabina KaračićInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.ORCID 0000-0003-0440-2456
Miriam GrosseDepartment of Microbial Drugs, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany.ORCID 0000-0001-5972-639X
Andrea SchieferInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
Kenneth PfarrInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.ORCID 0000-0003-3096-2465
Tanja SchneiderGerman Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.ORCID 0000-0002-9823-2090
Achim HoeraufInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.ORCID 0000-0002-8671-3831
Gabriele BierbaumInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.ORCID 0000-0002-2933-8473

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Corallopyronin A (CorA) is a natural RNA polymerase (RNAP) inhibitor active against Gram-positive pathogens, including Staphylococcus aureus. Although spontaneous resistance to CorA occurs less frequently than to rifampicin, the genetic basis and evolutionary constraints of CorA resistance remain incompletely defined. Spontaneous mutation frequencies to CorA and rifampicin were determined by fluctuation analysis in three S. aureus strains and two coagulase-negative staphylococci (CNS). Resistant mutants were phenotypically characterized and subjected to whole-genome sequencing. Double-resistant mutants were generated under rifampicin selection. Fitness costs were assessed by direct competition assays. Mutation frequencies to CorA were consistently lower than to rifampicin across all tested strains (Rif/CorA ratios 2.3-2.7). Whole-genome sequencing of 41 independently derived CorA-resistant mutants revealed resistance-associated substitutions confined to the RNAP subunits RpoB and RpoC. The mutational landscape was highly restricted, with recurrent hotspots at RpoC K334 and RpoB S1127. In coagulase-negative staphylococci (CNS), resistance remained RNAP-centred but displayed broader allelic diversity, including substitutions previously described in S. aureus but identified here for the first time in CNS species, as well as the previously undescribed RpoC D810Y substitution. Ten mutants with resistance to CorA and rifampicin retained the CorA-associated mutation and acquired additional rifampicin resistance substitutions at non-overlapping RNAP residues. CorA resistance imposed a moderate fitness cost (12-15%), while additional rifampicin resistance resulted in mutation-dependent increases in the fitness burden. CorA resistance in staphylococci arises at lower spontaneous frequencies than rifampicin resistance and is mediated by a constrained set of RNAP mutations. The restricted mutational landscape and associated fitness costs indicate that, under the in vitro conditions examined, CorA resistance arises through more constrained evolutionary pathways than rifampicin resistance. These findings provide a foundation for further evaluation of CorA as an RNA polymerase-targeting antimicrobial.

Indexed as

Anti-Bacterial AgentsDiterpenesDNA-Directed RNA PolymerasesDrug Resistance, BacterialMutationRifampinStaphylococcusStaphylococcus aureusBacterial ProteinsLactonesMicrobial Sensitivity TestsWhole Genome SequencingAnti-Bacterial AgentsBacterial Proteinscorallopyronin ADiterpenesDNA-Directed RNA PolymerasesLactonesRifampinCorallopyronin AMutationsRifampicinStaphylococci

Identifiers

PMID42533047
PMCPMC13424638

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.