A requirement for flow to enable the development of Ureaplasma parvum biofilms in vitro.

AIMS

To use a flow-based method to establish, quantify and visualize biofilms of Ureaplasma parvum.

METHODS AND RESULTS

Absorbance readings of a U. parvum HPA5 culture were taken at 550 nm every 3 h for 30 h in order to establish a growth curve, with viability determined by the number of colour changing units (CCUs). Biofilms were established using the DTU flow-cell with a flow rate of 0·01 ml min and compared to the static control. Titres of bacteria were determined by CCU and biofilm biomass was quantified by Syto9 staining and COMSTAT analysis. High-resolution images were obtained by scanning electron microscopy (SEM). Flow resulted in significantly more biofilm and higher cell titre (0·599 µm /µm  ± 0·152 and 4 × 10  CCU per ml, respectively) compared with static conditions (0·008 µm /µm  ± 0·010 and no recoverable cells, respectively). SEM revealed pleomorphic cells, with signs of budding and possible membrane vesicle formation.

CONCLUSIONS

Flow is an essential requirement for the establishment of U. parvum biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first quantification of biofilm biomass formed by U. parvum. It is now possible to establish viable biofilms of U. parvum which will allow for future testing of antimicrobial agents and understanding of virulence-associated with adhesion.