NMR metabolome of Borrelia burgdorferi in vitro and in vivo in mice

Abstract

<p>Lyme borreliosis (LB), caused by bacteria of the Borrelia burgdorferi sensu lato (Borrelia) species, is<br />the most common tick-borne infection in the northern hemisphere. LB diagnostics is based on clinical<br />evaluation of the patient and on laboratory testing, where the main method is the detection of Borrelia<br />specific antibodies in patient samples. There are, however, shortcomings in the current serology based<br />LB diagnostics, especially its inability to differentiate ongoing infection from a previously treated one.<br />Identification of specific biomarkers of diseases is a growing application of metabolomics. One of the<br />main methods of metabolomics is nuclear magnetic resonance (NMR) spectroscopy. In the present<br />study, our aim was to analyze whether Borrelia growth in vitro and infection in vivo in mice causes<br />specific metabolite differences, and whether NMR can be used to detect them. For this purpose,<br />we performed NMR analyses of in vitro culture medium samples, and of serum and urine samples of<br />Borrelia infected and control mice. The results show, that there were significant differences in the<br />concentrations of several amino acids, energy metabolites and aromatic compounds between Borrelia<br />culture and control media, and between infected and control mouse serum and urine samples. For<br />example, the concentration of L-phenylalanine increases in the Borrelia growth medium and in serum of<br />infected mice, whereas the concentrations of allantoin and trigonelline decrease in the urine of infected<br />mice. Therefore, we conclude that Borrelia infection causes measurable metabolome differences in vitro<br />and in Borrelia infected mouse serum and urine samples, and that these can be detected with NMR.<br /></p>