Volatile Organic Compounds Induced upon Viral Infection in Cell Culture: Uniform Background Study with Use of Viruses from Different Families

This study investigates the production of volatile organic compounds (VOCs) in RK-13 cells infected with three equine viruses representing different families: equine arteritis virus (EAV) (<i>Arteriviridae</i>), equine herpesvirus 1 (EHV-1) (<i>Herpesviridae</i>), and equine rhinitis B virus (ERBV) (<i>Picornaviridae</i>). VOCs, which are byproducts of cellular metabolism and potential non-invasive diagnostic markers, were analyzed using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Since viruses do not possess intrinsic metabolic activity, the observed changes in the VOC profiles were attributed to host responses, such as metabolic reprogramming, oxidative stress, and apoptosis. We hypothesized that each viral infection induces distinct metabolic changes, resulting in characteristic VOC signatures that mirror the virus type, replication kinetics, and cytopathic effects. Notably, viruses with rapid cytopathic effects (e.g., EHV-1) were anticipated to trigger more pronounced VOC alterations. In our experimental design, RK-13 cells were infected at a multiplicity of infection of 1 and incubated for 24 h, 48 h, or 72 h. Distinct VOC profiles emerged, with significant elevations in compounds like 2-ethyl-1-hexanol, particularly in EHV-1 infections, and selective increases in acetophenone and benzaldehyde. Principal component analysis (PCA) of the VOC concentration data showed the clear separation of data from viruses from different families. These findings support the potential of VOC profiling as a rapid diagnostic tool for viral infections.