Diagnóstico de vírus de impacto reprodutivo em suínos: aplicabilidade da espectroscopia raman

Abstract

Of great relevance for preventive veterinary medicine, porcine parvovirus (PPV) is one of the major infectious causes of reproductive failure in swine, responsible for important economic losses, specially along with Porcine Circovirus type 2 (PCV2). To date, the most useful detection tool is PCR-based, which is quite sensitive and specific, but laborious, costly and time-demanding. Moreover, the recent pandemic has shown how much public health demands innovative and simple diagnostic strategies that are more suitable for large scale applications. Our goal was to identify molecular biomarkers of PPV or PCV2 infection by Raman Microspectroscopy (RMS), in order to strength the Raman database and to contribute to its application on viral diagnostic worldwide. For this intent, swine testis (ST) cells were inoculated with PPV or PCV2 and in vitro cultured (37 ºC, 5% CO2) for four days. Fixed cells were then subdjected to RMS investigation using a 633 nm laser. A total of 225 spectra was obtained for each experimental group (PPV+, PCV2+ and negative control). Theoretical fitting of obtained spectra was performed for Peak Intensity Ratios (PIR) calculation, from which biomarkers were derived. Biomarkers which accurately separated all three groups were, from the most to the least impactful: nucleic acids, proteins and Arginine, while infection biomarkers, i. e., peaks able to differentiate negative control (NC) against other groups were mostly proteins. Interestingly, PPV show specific biomarkers assignments, being lipids and nucleic acids the most impactful ones, although proteins too. These results built a promising bases for RMS, as an alternative diagnostic approach for biomedical applications.