Affiliation:
1. Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
Abstract
Staphylococcus epidermidis is one of the major opportunistic bacterial pathogens in healthcare facilities, mainly due to its strong ability to form biofilms in the surface of indwelling medical devices. To study biofilms under in vitro conditions, both fed-batch and flow systems are widely used, with the first being the most frequent due to their low cost and ease of use.
Aim
To assess if a fed-batch system previously developed to obtain biofilm released cells (Brc) from strong biofilm producing S. epidermidis isolates could also be used to obtain and characterize Brc from isolates with lower abilities to form biofilms.
Methodology
The applicability of a fed-batch system to obtain Brc from biofilms of 3 ica+ and 3 ica− isolates was assessed by quantifying the biofilm and Brc biomass by optical density (OD) and colony-forming units (CFU) measurements. The effect of media replacement procedures of fed-batch systems on the amount of biofilm was determined by quantifying the biofilm and biofilm bulk fluid, by CFU, after consecutive washing steps.
Results
The fed-batch model was appropriate to obtain Brc from ica+ isolates, that presented a greater ability to form biofilms and release cells. However, the same was not true for ica− isolates, mainly because the washing procedure would physically remove a significant number of cells from the biofilm.
Conclusions
This study demonstrates that a fed-batch system is only feasible to be used to obtain Brc from S. epidermidis when studying strong and cohesive biofilm-forming isolates.
Funder
Portuguese Foundation for Science and Technology
BioTecNorte operation
Norte2020 - Programa Operacional Regional do Norte
Subject
General Agricultural and Biological Sciences,General Biochemistry, Genetics and Molecular Biology,General Medicine,General Neuroscience