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Kühn, C.

Publications and source records attributed to Kühn, C..

3 recordsLinked to original sources

Buffaloed in Brandenburg: Germany's first Brush with Foot-and-Mouth Disease after four Decades of Freedom

Foot-and-mouth disease (FMD) virus is one of the most feared and most consequential pathogens of livestock worldwide. It can be spread rapidly by the transboundary movement of animals, animal products and byproducts. In January 2025, Germany detected its first FMD outbreak since 1988 in extensively reared water buffalo on a small farm in the state of Brandenburg, directly outside Berlin, the federal capital. Immediate control measures including a standstill for movements of susceptible animals and pre-emptive culling were implemented by the veterinary authorities. Whole-genome sequencing identified the virus as serotype O, topotype ME-SA, lineage SA-2018 and revealed extensive recombination, but cross-neutralization assays suggested good heterologous protection by an O/PanAsia-2 vaccine strain. Epidemiological back-calculation placed the time of virus introduction in late December 2024. Although the entry route remains unresolved, human-associated introduction is most likely. Network analysis revealed minimal farm connectivity, and simulations predicted low potential for onward transmission, which is consistent with the outbreak being ultimately restricted to a single herd. This event underscores the constant and unpredictable risk of introduction of the virus. Early detection through increased awareness and comprehensive differential diagnostics as well as the international collaboration of veterinary services, laboratories and experts are essential in the face of the global presence of FMD.

microbiology↗

Triosephosphate export from chloroplasts regulates flavonoid biosynthesis and permits high light acclimation through the inactivation of SnRK1

Plants evolved multiple strategies to cope with rapid changes in the environment. During high light acclimation, biosynthesis of photoprotective flavonoids, such as anthocyanins, is induced. However, the exact nature of the signal and downstream factors for high light induction of flavonoid biosynthesis (FB) are still under debate. Here we show that carbon-fixation in chloroplasts, subsequent export of photosynthates by TRIOSEPHOSPHATE/PHOSPHATE TRANSLOCATOR (TPT), and the rapid increase in cellular sugar contents permit the transcriptional activation of FB during high light acclimation. In combination with genetic and physiological analysis, targeted and whole transcriptome gene expression studies showed that reactive oxygen species and phytohormones play only a minor role for rapid HL-induction of the anthocyanin branch of FB. In addition to FB, sugar-responsive genes were late-repressed or induced in tpt-2 in the course of the high light treatment and a significant overlap with transcripts regulated by SNF1-RELATED PROTEIN KINASE 1 (SnRK1) was found. Analysis of mutants with increased and repressed SnRK1 activity revealed that inactivation of SnRK1 is required for the rapid induction of FB during high light acclimation. Our study underlines the central role of chloroplasts as sensors for environmental changes and emphasizes the vital function of sugar-signalling in plant acclimation, even beyond the regulation of FB.

plant biology↗

Two parallel pathways implement robust propionate catabolism and detoxification in mycobacteria

Tuberculosis remains a major global health threat with over 1.5 million deaths each year. Mycobacterium tuberculosis success story is related to a flexible metabolism, allowing growth despite restrictive conditions within the human host.\n\nHost lipids stores are a major carbon source in vivo. Their catabolism yields propionyl-CoA, which is processed by two parallel pathways, the methylmalonyl CoA pathway and the methylcitrate pathway. Both pathways are considered potential drug targets. The methylcitrate pathway is upregulated in the pathological context. However, intermediates of this pathway can be cytotoxic and Mtbs preference for its usage remains unclear.\n\nWe combine thermodynamic kinetic modeling, quantitative proteomics and time-resolved metabolomics to characterize the interplay between the two pathways and to show their functionalities in an efficient and fast propionate catabolism.\n\nWe find that the methylcitrate pathway acts as a transcriptionally regulated, high capacity catabolic pathway due to its favorable thermodynamics and metabolic control distribution. In contrast, the methylmalonyl pathway is constitutively fulfilling biosynthetic tasks and can quickly detoxify propionate pulses, but is thermodynamically restricted to lower capacity.

systems biology↗