PhD project

PhD project

Host adapted plasmids in human bacterial pathogens

Supervisor: Christoph Tang


Many bacteria have evolved as pathogens or become resistant to antimicrobial drugs through the acquisition of mobile genetic elements called plasmids. In some instances, plasmids disseminate widely among bacterial species, and mediating the spread of AMR. Other plasmids develop long term evolutionarily stable relationships with certain bacterial hosts.

The laboratory studies the human-adapted pathogens, Shigella and Neisseria gonorrhoeae. Shigella are an important cause of childhood diarrhoea, and emerged from commensal E. coli by acquiring a large virulence plasmid. Additionally, treatment options for Shigella sonnei are becoming more limited due to plasmid-mediated AMR. We also have been dissecting the maintenance and spread of resistance plasmids which are largely only found in pathogenic Neisseria.

The project will entail defining the molecular relationships between plasmids and their host, and designing interventions to eliminate plasmids from bacteria. We employ a range of methods to derive mechanistic understanding of long term plasmid:host relationships.



  • Yee WX, Yasir M, Turner AK, Baker DJ, Cehovin A, Tang CM (2023) Evolution, persistence, and host adaption of a gonococcal AMR plasmid that emerged in the pre-antibiotic era.  PLoS Genet. 2023 May 15;19(5):e1010743. doi: 10.1371/journal.pgen.1010743. eCollection 2023 May.
  • Pilla G, Arcari G, Tang CM, Carattoli A (2022). Virulence plasmid pINV as a genetic signature for Shigella flexneri phylogeny. Microb. Genom. 8(6). doi: 10.1099/mgen.0.000846.
  • Martyn JE, Pilla G, Hollingshead S, Winther KS, Lea S, McVicker G, Tang CM (2022). Maintenance of the Shigella sonnei virulence plasmid is dependent on its repertoire and amino acid sequence of toxin:antitoxin systems. J Bacteriol. JB0051921. doi: 10.1128/JB.00519-21

Tang lab

Understanding how pathogens colonise specific niches in the body, evade elimination by the immune system, and cause disease

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