Optimization of processing conditions for the quantification of enterococci biofilms using microtitre-plates

• Published in: Journal of microbiological methods Vol. 84; no. 2; pp. 167 - 173
• Main Authors: Extremina, C.I., Costa, L., Aguiar, A.I., Peixe, L., Fonseca, A.P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2011; Elsevier
• Subjects: Bacterial Load - methods; Bacteriological methods and techniques used in bacteriology; Bacteriology; biofilm; Biofilm quantification; Biofilms - growth & development; Biological and medical sciences; biomass; colorimetry; Dynamic model; dynamic models; Enterococcus; Enterococcus - isolation & purification; Enterococcus - physiology; Fundamental and applied biological sciences. Psychology; gentian violet; High-throughput; Microbiology; Reproducibility of Results; Screening; High-throughput; Screening; Biofilm quantification; Dynamic model; Enterococcus; Lactic acid bacteria; Optimization; Streptococcaceae; Biofilm; Bacteria; Micrococcales; Models; Quantitative analysis
• ISSN: 0167-7012; 1872-8359
• DOI: 10.1016/j.mimet.2010.11.007

We performed a comparison of four selected protocols from the literature using microtitre-plate and colorimetric biomass assay for evaluation of enterococci biofilm formation ability and optimized a protocol after the identification and stringent performance of biofilm formation steps. The optimized protocol uses a dynamic model that provided a greater discrimination of enterococci biofilm formation ability, and could better simulate
in vivo real conditions. Moreover different biofilm quantification approaches, such as the colorimetric biomass (crystal violet), the resazurin and CFU's assays could be used with the optimized protocol, with adequate reproducibility. This study also recognizes that parameters such as the biofilm formation index (BFi), the cut-off values and the Z′ factor provide greater accuracy, possibility of inter and intra laboratory comparison and quality evaluation of the biofilm screening assays, respectively.