Effect of ciprofloxacin in the ultrastructure and development of biofilms formed by rapidly growing mycobacteria.

Background: The aim of this study was to analyze the effect of ciprofloxacin at different times on the development and behavior of intrinsic autofluorescence, covered area, thickness and cell viability in a biofilm formed by non-pigmented rapidly growing mycobacteria (NPRGM).Confocal laser scanning microscopy and image analysis were used to study the behavior of ciprofloxacin on biofilms.

Results: Thickness was the most affected parameter, although some species showed changes in other parameters. At the same time, we also measured the minimum inhibitory concentration and the minimum biofilm eradication concentration (MBEC). An increase in MBEC was observed in all the strains, M. peregrinum being the species that presented the highest increase.

Conclusions: This study help us to understand better how mycobacterial biofims can be affected by ciprofloxacin.