Biofilm formation by multidrug resistant Escherichia coli ST131 is dependent on type 1 fimbriae and assay conditions

  • Sohinee Sarkar, Dimitrios Vagenas, Mark A. Schembri, Makrina Totsika
  • Pathogens and Disease, March 2016, Oxford University Press (OUP)
  • DOI: 10.1093/femspd/ftw013

Sticky fingers make icky biofilms in E. coli superbugs

What is it about?

Superbug E.coli ST131 has emerged as a pandemic lineage of important multidrug resistant pathogens worldwide. It has become a major cause of antibiotic-resistant urinary tract and bloodstream infections. Despite many epidemiological studies, no has reported specific ST131 biofilm-promoting factors. Here we have shown biofilm formation by diverse ST131 isolates under different biologically-relevant conditions, including urine from healthy adult women. We have identified type 1 fimbriae as the critical determinant for biofilm formation by ST131. Type 1 fimbriae are finger-like projections on E. coli surface and are essential for sticking to human tissues to initiate infection. We also found that if we block the fimbriae with specific inhibitors, ST131 can no longer form biofilms.

Why is it important?

Superbugs are becoming extremely difficult to treat clinically due to their growing repertoire of antibiotic-resistance factors. This problem is further compounded in biofilms where these pathogens form tightly-knit communities that are hard to eliminate even in antibiotic-susceptible populations. Biofilms can form within the body and also on invasive surgical instruments, in-dwelling medical implants and diagnostic devices. This is the first study of superbug ST131 biofilm formation under biologically relevant conditions and paves the way for the application of specific adhesion-inhibitors in treating drug resistant ST131 biofilm infections.

Perspectives

Dr Sohinee Sarkar
Queensland University of Technology

Bacterial pathogens residing within biofilms are difficult to eradicate and often lead to recurrent and persistent infections. Superbugs, already resistant to multiple antibiotics, forming biofilms is of particular concern given the few options available for treatment. This paper shows that the ST131 superbug, a major cause of pandemic urinary tract and blood stream infections, is able to form good biofilms. We have also identified the single-most critical factor for biofilm formation in this pathogen and also demonstrated that blocking this factor abrogates biofilm formation.

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http://dx.doi.org/10.1093/femspd/ftw013

The following have contributed to this page: Dr Sohinee Sarkar