Optimization of techniques using urine as biological material in the diagnosis of schistosomiasis
Name: JULIANA DE MELLO DO CARMO
Publication date: 20/08/2024
Examining board:
Name |
Role |
|---|---|
| CARLOS GRAEFF TEIXEIRA | Presidente |
| MOISES PALACI | Examinador Interno |
| SILVIO DOLABELLA | Examinador Externo |
Summary: Human infections by helminths, particularly in regions with inadequate sanitation, represent a serious public health issue. Schistosoma mansoni, the causative agent of schistosomiasis, is transmitted through contact with contaminated water. Control measures have been prioritized by the Brazilian Ministry of Health and the World Health Organization to reduce schistosomiasis transmission, highlighting the need for more specific and sensitive diagnostic methods for infection detection. The primary aim of this study was to optimize parameters for using urine as a biological material in the diagnosis of schistosomiasis. To achieve this goal, urine samples were collected from different locations (Estância/SE and Afonso Cláudio/ES), and urine from volunteers at the Infectious Diseases Nucleus (NDI) was evaluated for spectral differences before and after freezing using near-infrared spectroscopy (NIRS). In addition to these samples, urine from a previous study in Marau/RS and urine from NDI volunteers were lyophilized for protein pattern detection by electrophoresis. Among the 34 lyophilized urine samples from NDI volunteers analyzed after different freezing conditions (first at -20 °C for two hours, followed by -80 °C for 48 hours, and the other group directly at -80 °C for 48 hours), it was observed that the group subjected to initial freezing at -20 °C had a higher rate of samples completing the drying process. The limited protein separation capacity of SDS-PAGE electrophoresis may have prevented the observation of differences in protein profiles between negative urine samples from NDI volunteers and negative and false-positive samples from Marau. Analysis of spectra from 312 samples from different regions showed that storing urine at -20 °C for several days can cause changes in post-freezing spectral patterns. Urine proves to be a promising biological material for diagnosis due to its ease of collection and low cost. Furthermore, the use of the Nano-NIRS spectrometer is a promising approach that could be integrated into surveillance programs as a screening technique for schistosomiasis. However, the results indicate the need for further investigations to validate new diagnostic methods with larger sample sizes and improved methodologies. Thus, ongoing research is essential to identify and validate new urinary biomarkers.
