Proposal of protocols using D-glutamine to optimize the 2,3-bis(2-methoxy-4-nitro-5-sulfophenly)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay for indirect estimation of microbial loads in biofilms of medical importance.

Autor: Gobor T; Xenobiotics Research Unit, Biological and Health Sciences Centre, The Pontifical Catholic University of Paraná, Curitiba, Brazil., Corol G, Ferreira LE, Rymovicz AU, Rosa RT, Campelo PM, Rosa EA
Jazyk: angličtina
Zdroj: Journal of microbiological methods [J Microbiol Methods] 2011 Feb; Vol. 84 (2), pp. 299-306. Date of Electronic Publication: 2010 Dec 20.
DOI: 10.1016/j.mimet.2010.12.018
Abstrakt: Due to technical problems, biofilm biomasses are difficult to be precisely determined. One reliable strategy is based on the colorimetry of formazan compounds derived from tetrazolium salt reduction. XTT presents some desirable properties that make the biofilm measurements easier. However, cells entrapped within the extracellular matrixes normally do not metabolize the tetrazolium equally, leading to underestimation of cell contents. This study evaluated the effectiveness of D-glutamine, a plerotic substrate of tricarboxilic acid cycle (TAC), as inducer of XTT reduction. The metabolic activities of aerobic and anaerobic 48 h-old monospecific biofilms of Pseudomonas aeruginosa ATCC®27853™, Klebsiella pneumoniae ATCC®13883™, Staphylococcus epidermidis ATCC®12228™, Streptococcus mutans ATCC®25175™, and Candida albicans SC5314 were evaluated. Results showed that D-glutamine 50 mM (for P. aeruginosa, K. pneumoniae, and S. epidermidis) and 25 mM (for S. mutans and C. albicans) may enhance the detection of soluble formazan in a significant manner, what becomes the XTT reduction assay more robust.
(Copyright © 2011 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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