Metabolic Profiling of an Echinostoma caproni Infection in the Mouse for Biomarker Discovery

Abstract

BackgroundMetabolic profiling holds promise with regard to deepening our understanding of infection biology and disease states. The objectives of our study were to assess the global metabolic responses to an Echinostoma caproni infection in the mouse, and to compare the biomarkers extracted from different biofluids (plasma, stool, and urine) in terms of characterizing acute and chronic stages of this intestinal fluke infection.Methodology/Principal FindingsTwelve female NMRI mice were infected with 30 E. caproni metacercariae each. Plasma, stool, and urine samples were collected at 7 time points up to day 33 post-infection. Samples were also obtained from non-infected control mice at the same time points and measured using 1H nuclear magnetic resonance (NMR) spectroscopy. Spectral data were subjected to multivariate statistical analyses. In plasma and urine, an altered metabolic profile was already evident 1 day post-infection, characterized by reduced levels of plasma choline, acetate, formate, and lactate, coupled with increased levels of plasma glucose, and relatively lower concentrations of urinary creatine. The main changes in the urine metabolic profile started at day 8 post-infection, characterized by increased relative concentrations of trimethylamine and phenylacetylglycine and lower levels of 2-ketoisocaproate and showed differentiation over the course of the infection.Conclusion/SignificanceThe current investigation is part of a broader NMR-based metabonomics profiling strategy and confirms the utility of this approach for biomarker discovery. In the case of E. caproni, a diagnosis based on all three biofluids would deliver the most comprehensive fingerprint of an infection. For practical purposes, however, future diagnosis might aim at a single biofluid, in which case urine would be chosen for further investigation, based on quantity of biomarkers, ease of sampling, and the degree of differentiation from the non-infected control group.

Metabolic profiling of Echinostoma caproni and Schistosoma mansoni in their definitive and intermediate hosts

“…Vasta et al (2009) found that taurine, alanine, threonine, and lysine were present in mouse urine and that alanine and taurine were present in significantly different amounts in infected and uninfected mice. Some of these findings correlated with the spectroscopic findings of Saric et al (2008) who suggested that taurine levels in urine may serve as a biological marker for mice infected with E. caproni using spectroscopic methods. Counihan et al (2010) examined the neutral and polar lipids in intestinal and non-intestinal organs of mice infected with E. caproni.…”

Metabolic, Immune, and Gut Microbial Signals Mount a Systems Response to Leishmania major Infection

“…Spectral assignments of metabolite peaks were performed based on Chenomx NMR suite profiler 7.0 software and using known assignments from in-house NMR databases and literature. 21 The differences in individual cytokines and class microbiota levels were analysed using nonparametric univariate tests: Kruskal-Wallis ANOVA and pair-wise Mann-Whitney U-test for timematched strain comparisons, and Friedman tests and Wilcoxon matched-pair tests, for comparative analyses between time-points for each mouse model. Bonferroni correction was applied to account for multiple testing.…”

“…20 A recurrent theme across a range of these parasite-rodent models characterised by metabolic profiling is the association between parasitic infection and an altered host microbiome, as indicated by a set of microbiota-associated metabolites detected in the urine and plasma. 16,17,21 Additionally, results from L. major infection models have demonstrated that germ-free mice failed to heal lesions as compared with their conventional counterparts, despite generating a strong Th1 immune response 22 , which strongly implicates the microbiota in mounting a successful host response to the parasite.…”

Food-Borne Trematodiases

“…A metabolic profiling strategy has been successfully employed for biomarker discovery of the two blood flukes Schistosoma mansoni and Schistosoma japonicum (114,115). Recently, the metabolic fingerprint of an E. caproni infection in different biofluids obtained from mice has been characterized (87). Changes in the metabolic profiles of blood plasma, fecal water, and urine samples from mice were already apparent 1 day after experimental infection with 35 metacercariae.…”

“…For example, concen-VOL. 22,2009 FOOD-BORNE TREMATODIASES 475 trations of plasma choline, acetate, formate, lactate, and urinary creatine were decreased, while the concentration of plasma glucose was upregulated (87). A study that examined the urine of E. caproni-infected mice by high-performance thin-layer chromatography-densitometry revealed qualitative and quantitative differences in concentrations of alanine and taurine (112).…”