A pilot study on fingerprinting Leishmania species from the Old World using Fourier transform infrared spectroscopy

Abstract

Leishmania species are protozoan parasites and the causative agents of leishmaniasis, a vector borne disease that imposes a large health burden on individuals living mainly in tropical and subtropical regions. Different Leishmania species are responsible for the distinct clinical patterns, such as cutaneous, mucocutaneous, and visceral leishmaniasis, with the latter being potentially fatal if left untreated. For this reason, it is important to perform correct species identification and differentiation. Fourier transform infrared spectroscopy (FTIR) is an analytical spectroscopic technique increasingly being used as a potential tool for identification of microorganisms for diagnostic purposes. By employing mid-infrared (MIR) spectral data, it is not only possible to assess the chemical structures but also to achieve differentiation supported by multivariate statistic analysis. This work comprises a pilot study on differentiation of Leishmania species of the Old World (L. major, L. tropica, L. infantum, and L. donovani) as well as hybrids of distinct species by using vibrational spectroscopic fingerprints. Films of intact Leishmania parasites and their deoxyribonucleic acid (DNA) were characterized comparatively with respect to their biochemical nature and MIR spectral patterns. The strains’ hyperspectral datasets were multivariately examined by means of variance-based principal components analysis (PCA) and distance-based hierarchical cluster analysis (HCA). With the implementation of MIR spectral datasets we show that a phenotypic differentiation of Leishmania at species and intra-species level is feasible. Thus, FTIR spectroscopy can be further exploited for building up spectral databases of Leishmania parasites in view of high-throughput analysis of clinical specimens. Graphical abstractFor Leishmania species discrimination, sample films of intact parasites and their extracted DNA were analyzed by FTIR micro-spectroscopy. Hyperspectral datasets that comprise mid-infrared fingerprints were submitted to multivariate analysis tools such as principal components analysis (PCA) and hierarchical cluster analysis (HCA). Electronic supplementary materialThe online version of this article (10.1007/s00216-017-0655-5) contains supplementary material, which is available to authorized users.

Infrared Spectroscopy of Blood

“…129 However, some successful attempts have been made to rapidly detect the promastigotes of different leishmaniasis species maintained in cell culture with FT-IR spectroscopy. 125,126,130 ATR FT-IR combined with PLS-DA was also demonstrated to successfully detect the presence of Babesia bovis in RBCs. 26 Moreover, the sensitivity was improved by lysing the red blood cells and pelleting the parasites.…”

Compressed sensing FTIR nano-spectroscopy and nano-imaging

“…In particular, infrared (IR) photons in the energy range between 400 cm −1 and 4000 cm −1 (corresponding to wavelengths from 2.5 to 25 μm) allow the investigation of fundamental vibrations and the associated rotational-vibrational structure. Since chemical bonds have unique spectral signatures, 2D chemical mapping of the dense spectral content allows to identify and localize unknown constituents [2], as desired in different fields of chemistry [3,4], biology [5,6], and medicine [7]. The achievable spatial resolution of conventional IR microscopy is, however, limited to several micrometers owing to diffraction [8].…”

Lactococcus lactis expressing sand fly PpSP15 salivary protein confers long-term protection against Leishmania major in BALB/c mice

“…To study any harmful effects or toxicity of the genetically modified bacteria, different groups of BALB/c mice were infected with different lines of recombinant or wild type L. lactis. At few hours after the injection (1,3,5,7,9,24, 72 and 120 h), all groups showed a slightly decreasing weight, and after 24 h regained the normal weight. After 24 h, there was no significant difference between groups in weight, body temperature, or behavior of mice (S2 Fig).…”

“…Leishmaniasis are high-prevalence parasitic diseases with a long history in the world [1]. Theses group of diseases are exhibited in different forms including cutaneous (CL), mucocutaneous (MCL) and visceral (VL) leishmaniasis [2].…”