Near-infrared Raman spectroscopy to detect anti-Toxoplasma gondii antibody in blood sera of domestic cats: quantitative analysis based on partial least-squares multivariate statistics

Abstract

Abstract. Toxoplasmosis is an important zoonosis in public health because domestic cats are the main agents responsible for the transmission of this disease in Brazil. We investigate a method for diagnosing toxoplasmosis based on Raman spectroscopy. Dispersive nearinfrared Raman spectra are used to quantify anti-Toxoplasma gondii ͑IgG͒ antibodies in blood sera from domestic cats. An 830-nm laser is used for sample excitation, and a dispersive spectrometer is used to detect the Raman scattering. A serological test is performed in all serum samples by the enzyme-linked immunosorbent assay ͑ELISA͒ for validation. Raman spectra are taken from 59 blood serum samples and a quantification model is implemented based on partial least squares ͑PLS͒ to quantify the sample's serology by Raman spectra compared to the results provided by the ELISA test. Based on the serological values provided by the Raman/PLS model, diagnostic parameters such as sensitivity, specificity, accuracy, positive prediction values, and negative prediction values are calculated to discriminate negative from positive samples, obtaining 100, 80, 90, 83.3, and 100%, respectively. Raman spectroscopy, associated with the PLS, is promising as a serological assay for toxoplasmosis, enabling fast and sensitive diagnosis.

Correlating the amount of urea, creatinine, and glucose in urine from patients with diabetes mellitus and hypertension with the risk of developing renal lesions by means of Raman spectroscopy and principal component analysis

“…[11][12][13][14] Using dispersive or FourierTransform Raman techniques in the near-infrared spectrum, there is no need for additional chemical steps for analysis (separation, dilution, or mixture of other reagents) and may prove superior to current methods of testing urine, 11,12 nondestructively. Biochemical assays based on Raman spectroscopy could be used for testing body fluids such as blood, blood components, and metabolites in the serum for doping control, 15 detecting antibodies in cat's serum, 16 and even monitoring heparin levels in blood during surgeries. 17 Optical techniques may become a future alternative or even replace existing laboratory methods.…”

Diagnosing COVID-19 in human serum using Raman spectroscopy: a preliminary study

“…Previous studies showed that Raman spectroscopy could be used to detect and quantify anti-Toxoplasma gondii IgG antibodies in sera of cats [52] and to detect dengue antibody IgM antibodies in human sera [53]. The Raman spectra were also used to detect hepatitis (B and C) virus infection in sera [54,55] as well as dengue virus infection also in sera [56].…”

Diagnosing COVID-19 in human serum using Raman spectroscopy

“…Previous studies showed that Raman spectroscopy could be used to detect and quantify anti-Toxoplasma gondii IgG antibodies in sera of cats [58], to detect IgM antibody in dengue infection in human sera [59], and to detect IgM and IgG in sera of COVID-19 positive patients aiming diagnosis [29]. The Raman spectra were also used to detect hepatitis (B and C) virus infection in sera [60,61] as well as dengue virus infection also in sera [62].…”