BackgroundThe aim of the present study was to investigate biochemical and oxidative stress responses to experimental F. tularensis infection in European brown hares, an important source of human tularemia infections.MethodsFor these purposes we compared the development of an array of biochemical parameters measured in blood plasma using standard procedures of dry chemistry as well as electrochemical devices following a subcutaneous infection with a wild Francisella tularensis subsp. holarctica strain (a single dose of 2.6 × 109 CFU pro toto).ResultsSubcutaneous inoculation of a single dose with 2.6 × 109 colony forming units of a wild F. tularensis strain pro toto resulted in the death of two out of five hares. Plasma chemistry profiles were examined on days 2 to 35 post-infection. When compared to controls, the total protein, urea, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were increased, while albumin, glucose and amylase were decreased. Both uric and ascorbic acids and glutathione dropped on day 2 and then increased significantly on days 6 to 12 and 6 to 14 post-inoculation, respectively. There was a two-fold increase in lipid peroxidation on days 4 to 8 post-inoculation.ConclusionsContrary to all expectations, the present study demonstrates that the European brown hare shows relatively low susceptibility to tularemia. Therefore, the circumstances of tularemia in hares under natural conditions should be further studied.

Low molecular weight antioxidants (LMWAs) were assayed by square wave voltammetry (SWV) using screen printed electrodes. Standard antioxidants, i.e. uric acid, ascorbic acid, trolox and glutathione, were assayed in order to estimate the sensitivity and standard redox potentials of individual LMWAs. In another experiment, plasma from Grey Partridges was used as model real samples. Ferric reducing antioxidant power (FRAP) was used as a reference method. Two peaks in plasma samples were found by SWV and correlated to FRAP. The SWV peaks were successfully correlated to FRAP. The practical importance of SWV carried out on screen printed electrodes is discussed.