Centre for Bacterial Cell Biology

Staff Profile

Dr Katarzyna Mickiewicz

Lecturer in Microbiology


Our research focuses on an understudied mechanism of antibiotic evasion, called L-form switching. Almost all bacteria are surrounded by a structure called the cell wall, which protects them against environmental stresses and helps with regular division. Many of our most commonly used antibiotics, such as penicillin, target this structure. During treatment with these antibiotics, bacteria usually burst and die, but some can survive in a wall-less state referred to as an L-form, if the surrounding environment provides sufficient osmoprotection. Without the wall, bacteria are fragile and slow growing, but resistant to all types of antibiotics that target this structure. Once antibiotic treatment is concluded, bacteria that survived in an L-form state can rebuild the wall and start dividing rapidly, potentially contributing to recurrent infections.

Importantly, many pathogens, including E. coli and S. aureus, can undergo L-form switching and over the years it has been speculated that the host can provide a supportive environment for the process. L-form switching has been implicated in several recurrent diseases in human and animals, such as sepsis, mastitis, urinary tract and gastrointestinal infections. However, the fragile nature of L-forms and their low numbers in the host's body make them difficult to study and convincing evidence for their role in disease was historically slow to emerge. We use modern molecular methods, advanced fluorescence microscopy and genetic engineering to study the role of L-form switching in bacterial recurrence and antibiotic evasion.


Current Research Project

  • Potential role of L-form bacteria in infectious disease recurrence


Current Postgraduate Research Supervision

  • Jon Chapman
  • Stephen Garrett