Vibrational spectroscopic based approach for diagnosing babesia bovis infection

Authors: RÜTHER, ANJA - Albert University Of Freiburg; PEREZ-GUAITA, DAVID - Monash University; POOLE, WILLIAM - Monash University; COOKE, BRIAN - Monash University; Suarez, Carlos; HERAUD, PHILIP - Monash University; WOOD, BAYDEN - Monash University

Submitted to: Analytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2020
Publication Date: 6/1/2020
Citation: Rüther, A., Perez-Guaita, D., Poole, W.A., Cooke, B.M., Suarez, C.E., Heraud, P., Wood, B.R. 2020. Vibrational spectroscopic based approach for diagnosing babesia bovis infection. Analytical Chemistry. 92(13):8784-8792. https://doi.org/10.1021/acs.analchem.0c00150.
DOI: https://doi.org/10.1021/acs.analchem.0c00150

Interpretive Summary: Babesia bovis parasites present a serious and significant health concern for the beef and dairy industries in many areas of the world. Difficulties associated with current diagnostic techniques are that they are prone to human error (microscopy) or expensive and time consuming (Polymerase Chain Reaction) to perform. Little is known about the biochemical changes in blood that are associated with Babesia infections. The discovery of new biomarkers will lead to improved diagnostic outcomes for the cattle industry. Vibrational spectroscopic technologies can record a chemical snapshot of the entire organism and the surrounding cell thereby providing a phenotype of the organism and the host infected cell. This study was aimed at demonstrating the applicability of sensitive and specific vibrational spectroscopic imaging techniques including Atomic Force Microscopy Infrared (AFM-IR) and confocal Raman microscopy to discover new biomarkers for the diagnosis of B. bovis infections.

Technical Abstract: Babesia bovis parasites present a serious and significant health concern for the beef and dairy industries in many areas of the world. Difficulties associated with current diagnostic techniques are that they are prone to human error (microscopy) or expensive and time consuming (Polymerase Chain Reaction) to perform. Little is known about the biochemical changes in blood that are associated with Babesia infections. The discovery of new biomarkers will lead to improved diagnostic outcomes for the cattle industry. Vibrational spectroscopic technologies can record a chemical snapshot of the entire organism and the surrounding cell thereby providing a phenotype of the organism and the host infected cell. Here, we demonstrate the applicability of vibrational spectroscopic imaging techniques including Atomic Force Microscopy Infrared (AFM-IR) and confocal Raman microscopy to discover new biomarkers for B. bovis infections. Furthermore, we applied Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) to detect B. bovis in red blood cells (RBCs). Based on changes in the IR spectral bands, ATR-FTIR in combination with Partial Least Squares-Discriminant Analysis we were able to discriminate infected samples from controls with a sensitivity and specificity of 92.0 % and 91.7%, respectively in less than two minutes, excluding sample extraction and preparation. The proposed method utilized a lysis approach to remove hemoglobin from the suspension of infected and uninfected cells, which significantly increased the sensitivity and specificity compared to measurements performed on intact infected red blood cells (iRBC, 77.3% and 79.2%.) This work represents a holistic spectroscopic study from the level of the single iRBC using AFM-IR and confocal Raman to the detection of the parasite in a cell population using ATR-FTIR for a babesiosis diagnostic.