Kröger Lab

@kroegerlab.bsky.social

Microbiology Lab run by Carsten Kröger at the Moyne Institute of Preventive Medicine, Trinity College Dublin, the University of Dublin.

⏰ We have two exciting opportunities to join our team in Southampton! 🚀 𝐏𝐨𝐬𝐭𝐝𝐨𝐜𝐭𝐨𝐫𝐚𝐥 𝐑𝐞𝐬𝐞𝐚𝐫𝐜𝐡𝐞𝐫 (2 𝐲𝐞𝐚𝐫𝐬) 𝘈𝘤𝘪𝘯𝘦𝘵𝘰𝘣𝘢𝘤𝘵𝘦𝘳 virulence 👉 jobs.soton.ac.uk/Vacancy.aspx... 𝐑𝐞𝐬𝐞𝐚𝐫𝐜𝐡 𝐓𝐞𝐜𝐡𝐧𝐢𝐜𝐢𝐚𝐧 (3 𝐲𝐞𝐚𝐫𝐬) Engineering Biology 👉 jobs.soton.ac.uk/Vacancy.aspx...

Job Opportunity at the University of Southampton: Research Fellow

The McCarthy Lab has an exciting opportunity for a prospective Postdoctoral Research Fellow who is interested in understanding virulence and hospital persistence in Acinetobacter baumannii. The role w...

jobs.soton.ac.uk

New pre-print from our lab looking at antibiotic resistance and sensitivity of AB5075 lacking p1AB5075 - a serendipitous isolation. We also included a full sequence of the widely used pWH1266 E.coli-Acinetobacter shuttle plasmid: GenBank accession no.: PV577797.1.

bioRxiv Microbiology@biorxiv-microbiol.bsky.social · 4mo ago

Contributions of plasmid p1AB5075-encoded antibiotic resistance genes to multidrug resistance of Acinetobacter baumannii AB5075 https://www.biorxiv.org/content/10.64898/2026.03.29.715119v1

Always good to start the year with a new preprint. We charted DNA methylation in Salmonella enterica: www.biorxiv.org/content/10.64898/2026.01.27.702048v1.

Methylome and transcriptome mapping reveal miniscule DNA methyltransferase regulons in Salmonella enterica serovar Typhimurium

DNA methylation is a regulator of bacterial gene expression and adaptation, influencing traits such as virulence and antimicrobial resistance. The dynamic nature of DNA methylation enables rapid responses to changing environments and is a source of heterogeneity in bacterial populations. However, condition-dependent DNA methylation and consequences for transcriptional output remain poorly understood. We applied Oxford Nanopore sequencing to profile DNA methylation during exponential growth and late stationary phase of Salmonella enterica serovar Typhimurium and integrated these data with transcriptomic analyses. We found that each DNA methyltransferase (MTases) exhibits a distinct activity pattern across growth stages, which could not be explained by transcriptional levels of the corresponding enzymes. As predicted, DNA methylation patterns determined by regulatory MTases were dynamic across growth conditions whereas methylation patterns of MTases belonging to R-M systems were comparatively stable. We identified growth stage–specific methylation patterns for all studied MTases and correlations between methylation states and gene expression patterns. Together, these findings chart DNA methylation networks in the epigenetic regulation of bacterial physiology. Author summary DNA methylation in bacteria is best known for its role protecting DNA from endonucleases, such as restriction–modification, and coordinating chromosome replication and mutation repair, yet DNA methylation also regulates gene expression and cell physiology. Previous studies primarily examined bacterial DNA methylation at single time points or in limited genomic regions, providing only a partial view of its biological significance. In this study, we used Oxford Nanopore sequencing to compare DNA methylation patterns in Salmonella enterica during exponential growth and late stationary phase then integrated these data with corresponding gene expression profiles. We identified numerous methylation target motifs, all of which demonstrated constitutively methylated or unmethylated regions. This systems-level analysis clarifies the role of DNA methylation in bacterial adaptation across growth stages and demonstrates the utility of Oxford Nanopore sequencing for genome-wide methylation profiling. ### Competing Interest Statement The authors have declared no competing interest. European Union, https://ror.org/019w4f821, Marie Skłodowska-Curie grant agreement No. 896441 University of Regina Fir cluster of the Digital Research Alliance of Canada

biorxiv.org

Happy International Microorganism Day! 🎉 Today, we are celebrating the tiny powerhouses that have a massive impact on our world. From the bacteria in our gut to the fungi that give us antibiotics, these incredible organisms are essential to life. Let's make some noise for the microscopic!

Bild

Publish with us and invest in the research community. Supported by income from our journals, the Microbiology Society awards hundreds of grants every year, providing opportunities and experience for microbiologists at all career levels.

Poster quoting from a reviewer saying "I have been supported by the Microbiology Society so much, so I will always support them."