Resonancia magnética nuclear como técnica alternativa para estudios de susceptibilidad a antimicrobianos y del metabolismo de microorganismos difíciles de cultivar

Abstract

Many standardized methods are used to determine antimicrobial susceptibility. They often slow and laborious and frequently show problems in both accuracy and reproducibility. The emergence of resistances and the possibility of using less toxic drugs, in addition to the difficulty of handling certain fastidious bacteria, make necessary to develop new procedures to better understand bacterial metabolism, their susceptibility to antibiotics and their potential therapeutical management. This work focuses on the use of nuclear magnetic resonance (NMR) spectroscopy for the study of bacterial metabolism and its application to determine the susceptibility of certain bacteria to antimicrobial drugs. This work sets up the NMR to study the susceptibility of two strains of Escherichia coli (ATCC 25922 and C1550) and Pseudomonas aeruginosa (ATCC 27853 and W30) against several antimicrobials (gentamicin, ciprofloxacin and levofloxacin). For this aim, the results obtained by NMR were compared with the minimum inhibitory concentrations (MIC) already established in the literature and by the pertinent Committees. In addition, and in order to better understand the metabolism of bacteria that are difficult to grow, experiments have been carried out on Rickettsia slovaca. These analyzes have allowed to detect metabolic markers that could be used for susceptibility studies and they contribute to the knowledge of the metabolism of these fastidious bacteria.