Pyrrolomycins as potential anti-staphylococcal biofilms agents

Abstract

With the goal of discovering new anti-infective agents active against microbial biofilms, this investigation focused on some natural pyrrolomycins, a family of halogenated pyrrole antibiotics. In this study the anti-staphylococcal biofilm activity of pyrrolomycins C, D, F1, F2a, F2b, F3 and of the synthesized related compounds I, II, III were investigated. The susceptibility of six staphylococcal biofilms was determined by methyltiazotetrazolium staining. Most of the compounds were active at concentrations of 1.5 μg ml⁻¹ with significant inhibition percentages. A few of the compounds were active at the lowest screening concentration of 0.045 μg ml⁻¹. The population log reduction of activity against the two best biofilm forming Staphylococcus aureus strains as determined by viable plate counts is also reported. In order to adequately assess the utility of these compounds, their toxicity against human cells was evaluated. It is concluded that pyrrolomycins and synthetic derivatives are promising compounds for developing novel effective chemical countermeasures against staphylococcal biofilms.

Keywords:

• staphylococcal biofilms
• anti-biofilm agents
• pyrrolomycins

Acknowledgements

This work was supported by a grant from Università degli Studi di Palermo (Fondi di Ateneo, 2006). The authors thank Dr Talya Dayton for English language revision of the manuscript.