Delivery of florfenicol in veterinary medicine through a PLGA-based nanodelivery system: improving its performance and overcoming some of its limitations.

As is the case with other veterinary antibiotics, florfenicol (FFC) faces certain limitations, such as low solubility in water, or the fact that it is reported to interfere with the immune response after some immunoprofilactic actions in livestock. Aiming to improve its efficacy and overall performance, FFC was loaded into a polymeric nanobased delivery system by succesfully using the emulsion-evaporation technique. The poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with FFC were characterized in terms of size (101 ± 0.52 nm), zeta potential (26.80 ± 1.30 mV) and poly-dispersity index (0.061 ± 0.019). The achieved loading was 2.24 µg FFC/mg of NPs, with an entrapment efficiency of 7.9%. The antimicrobial effect, the anti-biofilm formation and the cytotoxicity properties of the NPs were evaluated. The results indicated a MIC decreased by ~97.13% for S. aureus, 99.33% for E.coli and 64.1% for P. aeruginosa when compared to free FFC. The minimum inhibitory concentration (MIC) obtained indicated the potential for using a significantly lower dose of florfenicol. The delivery system produced biofilm inhibition while showing no cytotoxic effects when tested on porcine primary fibroblasts and horse mesenchymal stem cells. These findings suggest that florfenicol can be improved and formulations optimized for use in veterinary medicine through its incorporation into a nanobased delivery system designed to release in a controlled manner over time.

Serological reactivity to Borrelia burgdorferi sensu lato in dogs and horses from distinct areas in Romania.

Lyme disease is a perfect model of the complex relationship between host, vector, and the vector-borne bacteria. Both dogs and horses in Romania are exposed to infection. The aim of the present study was to assess the seroreactivity against Borrelia burgdorferi sensu lato in dogs and horses from different regions of Romania. 276 samples from dogs and 260 samples from horses located in different regions of Romania were analyzed by ELISA and IFA, respectively. The effect of several factors potentially affecting seroreactivity (location, age, gender, occupation, and vector exposition risk) was evaluated using Fisher's exact test (R 2.12.0). The overall prevalence of anti-Borrelia antibodies was 6.52% (18/276) in dogs, with a significantly higher positivity (46.15%, 6/13, p = 0.0005) recorded in a midcountry region. Seroreactivity was correlated with occupation, with working dogs being more exposed. The results may indicate that Lyme borreliosis foci are restricted to small areas, but further studies on Borrelia prevalence in tick populations are needed to confirm this hypothesis. In horses, a global seroprevalence of 11.92% (31/260) was observed. No correlations were found between positive results and age, sex, county, or occupation. This is the first serological survey on antibodies to B. burgdorferi sensu lato in Romanian dogs and horses.