The Antimicrobial Applications of Nanoparticles in Veterinary Medicine: A Comprehensive Review.

Nanoparticles (NPs) are nanoscaled particles sized from 1-100 nm, which can be composed of inorganic or organic compounds. NPs have distinctive morphology, size, structure, and surface features, which give them specific properties. These particular attributes make them interesting for biological and medical applications. Due to these characteristics, researchers are studying the possible aptness of numerous nanoparticles in veterinary medicine, such as the capacity to act as a drug delivery system. The use of these NPs as a possible bactericidal or bacteriostatic medication has been studied against different bacteria, especially multiresistant strains and the ones that cause mastitis disease. The antibiofilm property of these nanostructures has also already been proved. The antiviral activity has also been shown for some important viral animal diseases; the antifungal activity had been demonstrated against both pathogenic and mycotoxigenic species. Therefore, this review aimed to elucidate the main clinical and preventive veterinary applications of inorganic and organic nanoparticles.

Topical hydrophilic gel with itraconazole-loaded polymeric nanomicelles improves wound healing in the treatment of feline sporotrichosis.

Sporotrichosis is a superficial fungal disease that can affect animals and humans. The high number of infected cats has been associated with zoonotic transmission and contributed to sporotrichosis being considered by the World Health Organization as one of the main neglected tropical fungal diseases for 2021-2030. Oral administration of itraconazole (ITZ) is the first choice for treatment, but it is expensive, time-consuming, and often related to serious adverse effects. As a strategy to optimize the treatment, we proposed the development of a hydrophilic gel with nanomicelles loaded with ITZ (HGN-ITZ). The HGN-ITZ was developed using an I-optimal design and characterized for particle size, Zeta potential, drug content, microscopic aspects, viscosity, spreadability, in vitro drug release, in vitro antifungal activity, and clinical evaluation in cats. The HGN-ITZ showed a high content of ITZ (97.3 ± 2.1 mg/g); and characteristics suitable for topical application (viscosity, spreadability, globules size, Zeta potential, controlled drug release). In a pilot clinical study, cats with disseminated sporotrichosis were treated with oral ITZ or HGN-ITZ + oral ITZ. A mortality rate of 21.3% was observed for the oral ITZ group compared to 5.3% for the HGN-ITZ + oral ITZ group. In a cat with a single lesion, topical treatment alone (HGN-ITZ) provided complete healing of the lesion in 45 days. No signs of topical irritation were observed during the treatments, suggesting that HGN-ITZ can be a promising strategy in the treatment of sporotrichosis.

Inhibitory Effect of GRAS Essential Oils and Plant Extracts on the Growth of Aspergillus westerdijkiae and Aspergillus carbonarius Strains.

The effect of essential oils (obtained using hydrodistillation) and plant extracts (ethanolic, aqueous, and hexanic extractions) of 10 different plants cultivated in Brazil were tested using the diffusion agar method, with the objective of evaluating the inhibitory effect of the oils and extracts on the mycelial growth of Aspergillus westerdijkiae NRRL 3174 and A. carbonarius RC 2054 (UNRC). Of the 40 essential oils and plant extracts analyzed, oregano essential oil and plant extract, rosemary essential oil, and the clove ethanolic extract were the best choice to obtain the growth parameters (radial growth rates (mm day-1) and lag phase (h)) due the good results presented and the volume of oil/extract obtained. Comparing all the essential oils and plant extracts that were tested for growth parameters, the best results were obtained for the clove ethanolic extract for both strains assayed. These results demonstrated an outstanding potential use of some of these products in prevention of fungal contamination in food. However, further studies need to be conducted to determine the ability of these oils and extracts to inhibit or reduce ochratoxin A production.