Background: In view of the ever‐increasing representation of Staphylococcus spp. strains resistant to various antibiotics, the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.Methods: In this article, we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical antimicrobial agents that matches the real clinical situation. The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.Results: In the final model, 10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia, with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension. One pig was not inoculated and used as the negative control. Subsequently, the bandages were changed on Days 4, 8, 11, and 15. At these time points, a filter paper imprint technique (FPIT) was made from each wound for semi‐quantitative microbiological evaluation. Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological, histopathological, and molecular‐biological examination. The infection with the inoculated S. aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples. The dynamics of the inflammatory markers and clinical signs of infection are also described.Conclusions: A successfully developed porcine model is suitable for in vivo testing of novel short‐acting topical antimicrobial agents.

Aminophylline, a bronchodilator mainly used to treat severe asthma attacks, may induce arrhythmias. Unfortunately, the underlying mechanism is not well understood. We have recently described a significant, on average inhibitory effect of aminophylline on inward rectifier potassium current I_K1, known to substantially contribute to arrhythmogenesis, in rat ventricular myocytes at room temperature. This study was aimed to examine whether a similar effect may be observed under clinically relevant conditions. Experiments were performed using the whole cell patch clamp technique at 37°C on enzymatically isolated healthy porcine and failing human ventricular myocytes. The effect of clinically relevant concentrations of aminophylline (10-100 µM) on I_K1 did not significantly differ in healthy porcine and failing human ventricular myocytes. I_K1 was reversibly inhibited by ∼20 and 30 % in the presence of 30 and 100 µM aminophylline, respectively, at -110 mV; an analogical effect was observed at -50 mV. To separate the impact of I_K1 changes on AP configuration, potentially interfering ionic currents were blocked (L-type calcium and delayed rectifier potassium currents). A significant prolongation of AP duration was observed in the presence of 100 µM aminophylline in porcine cardiomyocytes which well agreed with the effect of a specific I_K1 inhibitor Ba²⁺ (10 µM) and with the result of simulations using a porcine ventricular cell model. We conclude that the observed effect of aminophylline on healthy porcine and failing human I_K1 might be involved in its proarrhythmic action. To fully understand the underlying mechanism, potential aminophylline impact on other ionic currents should be explored.

Members of the microsporidial genus Encephalitozoon have the capacity to infect both mammals and birds, and E. cuniculi is most commonly found in rabbits. With a seroprevalence ranging up to 85%, E. cuniculi can be a problem in pet rabbits as well as in food production and laboratory animal science. While most infections are likely subclinical, there are three main clinical presentations: neurological, renal, and ocular. Typical clinical signs including vestibular disease and phacoclastic uveitis may develop with initial or relapsing infection, while renal infection is usually progressive and associated with non-specific clinical signs. High-sensitivity/specificity ante mortem diagnostic options are lacking, and serological testing most often provides adjunct rather than definitive information such that physical examination and other diagnostics are used more so for ruling out other differentials and comorbidities, rather than confirming infection. In the veterinary community, treatment regimens are variable given the lack of thorough studies and a consensus. The aim of this document is to present the available literature to give a concise review of this organism and its infection of rabbits as well as to propose guidelines and protocols for diagnostics and treatment regimens. In addition, the current challenges and recommendations for further studies are discussed.

Given the global rise in antibiotic resistance, this study focuses on developing an alternative treatment for deep skin and soft tissue infections (SSTIs) caused by a carbapenem-resistant Pseudomonas aeruginosa. An injectable hydrogel composed of polyvinyl alcohol and chitosan was developed as a stable carrier for the porcine cathelicidins PR-39 and Protegrin-1. In vitro tests demonstrated that the addition of 8 mM EDTA fully restores the activity of antibacterial peptides in fetal bovine serum and eliminates the influence of divalent cations. In a porcine model, the application of this hydrogel resulted in a significant reduction in bacterial load after only two doses, with levels dropping below 10⁵ CFU/g of tissue. In addition to eliminating the infection, the treated group showed early granulation tissue formation, reduced necrosis and inflammation, and the development of a continuous epidermis, all of which were completely absent in the untreated group. The research confirms that the combination of cathelicidins and EDTA in a hydrogel carrier represents a highly effective approach for treating complicated bacterial infections.