Spray-drying-microencapsulated Minthostachys verticillata essential oil and limonene as innovative adjuvant strategy to bovine mastitis vaccines

Effects of intramammary infusion of Minthostachys verticillata essential oil in cows at drying-off on microbiological and immunological parameters, and milk quality during the subsequent lactation

This study evaluated the effects of EO administered via intramammary inoculation in dairy cows during the drying-off period and its impact on milk quality in the subsequent lactation. Ten pregnant Holstein cows, free of mastitis, were selected from an organic dairy farm in Córdoba, Argentina. Twenty-four quarters were inoculated with EO: eight received 0.25 g, eight received 0.50 g, and eight received 1.00 g. Control groups included uninoculated quarters and quarters treated with cephapirin. Milk samples were collected before treatment and within 4 days after calving to assess microbial count and somatic cell counts (SCC). The expression of TNF-α, IL-6, and IL-10 was quantified using qPCR and malondialdehyde (MDA) levels were also measured. Blood samples were collected before treatment and within 4 days after calving to determine serum IL-6 and IL-4 levels using ELISA. No significant effects were observed on milk's physical-chemical properties following EO or cephapirin treatment. EO at 1.00 g significantly reduced microbial load (p < 0.05), comparable to cephapirin. SCC increased with all EO doses (p < 0.01, p < 0.05, p < 0.05, respectively). Differential cell counts showed an increase in macrophages after 1.00 g EO treatment. The relative expression of TNF-α, IL-6, and IL-10 decreased without statistical significance. MDA levels significantly increased with cephapirin (p < 0.001), but EO had no effect. Serum IL-6 and IL-4 levels remained unchanged. In conclusion, intramammary EO inoculation enhanced immune response, reduced microbial load, and did not induce lipid peroxidation, suggesting its potential as a preventive treatment for mastitis.

Harnessing Plant-Derived Terpenoids for Novel Approaches in Combating Bacterial and Parasite Infections in Veterinary and Agricultural Settings

The rising resistance to conventional antimicrobial therapies in veterinary contexts poses a formidable challenge. While various innovative treatment strategies for pathogenic infections have emerged, their success still needs to be improved, warranting continued research. Recent investigations into natural products as potential sources for biologically active therapeutics have gained traction. Phytochemicals present a promising alternative in combating a spectrum of pathogens, including bacteria, fungi and parasites. One such class of phytochemicals with mounting potential is the structurally diverse terpenes. These chemicals contribute to plants' characteristic odour and medicinal effects and have been widely investigated in the scientific literature for their exceptional antibacterial activity. Their efficacy is demonstrated through diverse mechanisms, encompassing damage to bacterial membranes, suppression of virulence factors, and interference with enzymes, toxins, and biofilm formation. This review comprehensively examines terpenes' in vitro and in vivo activity and their derivatives against pathogens, elucidating their potential against antimicrobial resistance (AMR) and the underlying mechanisms specific to each terpene class. The findings underscore the burgeoning potential of terpene therapy as a viable alternative or supplementary approach to conventional antibiotics in addressing bacterial and parasitic infections in livestock and companion animals.

Minthostachys verticillata essential oil modulates cytokine synthesis and Staphylococcus aureus internalization in MAC-T cells at least through TLR4/MyD88/NFkB pathway

The aim of this study was to evaluate the activation pathway(s) triggered by Minthostachys verticillata essential oil (EO) in bovine mammary epithelial cells (MAC-T) challenged with a strain of bovine Staphylococcus aureus. MAC-T cells were stimulated with EO, S. aureus or pre-treated with EO and then challenged with S. aureus. Cytokine's release was measured by ELISA. The mRNA for TLR2, TLR4, NOD2, MyD88 and NFκB was quantified by RT-qPCR. S. aureus adherence and internalization was also evaluated. MAC-T cells stimulated with S. aureus synthesized high levels of IL-1ß and IL-6 were kept up to 48 h, while IL-4 levels were not altered. Cells pre-treated with EO for 2 and 6 h and then challenged with S. aureus showed a significant increase of IL-1β and IL-6. However, in these cells, a decrease in IL-1ß and IL-6 levels and an increase of IL-4 values was observed from 24 h. No significant increase in the expression levels of TLR2 or NOD2 was detected in all stimulated cells. However, the expression of TLR4, MyD88 and NFκB was increased in cells stimulated with S. aureus at 2 and 6 h as well as in cells pre-treated with EO between 2 and 6 h and then challenged with S. aureus. The NFκB expression levels was similar to control at 24 h in all stimulated cells, although pro-inflammatory cytokine levels and TLR4 and MyD88 expression levels remained high in cells stimulated with S. aureus. This results suggested the activation of other pathways independent of MyD88 by the pathogen that involucrated the activation of others transcription factors. Pre-treatment with EO during 2, 6 and 24 h did not affect S. aureus adherence but decreased its internalization. In conclusion, pre-treatment with EO increased the IL-1β and IL-6 synthesis during the first hours post-challenged with S. aureus up-regulating TLR4/MyD88/NFκB pathway. Furthermore, EO increased the IL-4 levels from 6 to 24 h down-regulating the NFκB and possibly other transcription factors activated by the pathogen, which decreased its internalization into MAC-T cells.

Enhancing the Functional Properties of Tea Tree Oil: In Vitro Antimicrobial Activity and Microencapsulation Strategy

In the context of addressing antimicrobial drug resistance in periocular infections, Tea Tree Oil (TTO) has emerged as a promising therapeutic option. This study aimed to assess the efficacy of TTO against bacterial strains isolated from ocular infections, with a particular focus on its ability to inhibit biofilm formation. Additionally, we designed and analyzed microcapsules containing TTO to overcome certain unfavorable physicochemical properties and enhance its inherent biological attributes. The quality of TTO was confirmed through rigorous analysis using GC-MS and UV-Vis techniques. Our agar diffusion assay demonstrated the effectiveness of Tea Tree Oil (TTO) against ocular bacterial strains, including Corynebacterium spp., coagulase-negative Staphylococcus spp., and Staphylococcus aureus, as well as a reference strain of Staphylococcus aureus (ATCC 25923). Notably, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for all tested microorganisms were found to be 0.2% and 0.4%, respectively, with the exception of Corynebacterium spp., which exhibited resistance to TTO. Furthermore, TTO exhibited a substantial reduction in biofilm biomass, ranging from 30% to 70%, as determined by the MTT method. Through the spray-drying technique, we successfully prepared two TTO-containing formulations with high encapsulation yields (80-85%), microencapsulation efficiency (90-95%), and embedding rates (approximately 40%). These formulations yielded microcapsules with diameters of 6-12 μm, as determined by laser scattering particle size distribution analysis, and exhibited regular, spherical morphologies under scanning electron microscopy. Importantly, UV-Vis analysis post-encapsulation confirmed the presence of TTO within the capsules, with preserved antioxidant and antimicrobial activities. In summary, our findings underscore the substantial therapeutic potential of TTO and its microcapsules for treating ocular infections.

The combination of vaccines and adjuvants to prevent the occurrence of high incidence of infectious diseases in bovine

As the global population grows, the demand for beef and dairy products is also increasing. The cattle industry is facing tremendous pressures and challenges. The expanding cattle industry has led to an increased risk of disease in cattle. These diseases not only cause economic losses but also pose threats to public health and safety. Hence, ensuring the health of cattle is crucial. Vaccination is one of the most economical and effective methods of preventing bovine infectious diseases. However, there are fewer comprehensive reviews of bovine vaccines available. In addition, the variable nature of bovine infectious diseases will result in weakened or even ineffective immune protection from existing vaccines. This shows that it is crucial to improve overall awareness of bovine vaccines. Adjuvants, which are crucial constituents of vaccines, have a significant role in enhancing vaccine response. This review aims to present the latest advances in bovine vaccines mainly including types of bovine vaccines, current status of development of commonly used vaccines, and vaccine adjuvants. In addition, this review highlights the main challenges and outstanding problems of bovine vaccines and adjuvants in the field of research and applications. This review provides a theoretical and practical basis for the eradication of global bovine infectious diseases.

Plant Essential Oils as a Tool in the Control of Bovine Mastitis: An Update

Bovine mastitis is a major concern for the dairy cattle community worldwide. Mastitis, subclinical or clinical, can be caused by contagious or environmental pathogens. Costs related to mastitis include direct and indirect losses, leading to global annual losses of USD 35 billion. The primary treatment of mastitis is represented by antibiotics, even if that results in the presence of residues in milk. The overuse and misuse of antibiotics in livestock is contributing to the development of antimicrobial resistance (AMR), resulting in a limited resolution of mastitis treatments, as well as a serious threat for public health. Novel alternatives, like the use of plant essential oils (EOs), are needed to replace antibiotic therapy when facing multidrug-resistant bacteria. This review aims to provide an updated overview of the in vitro and in vivo studies available on EOs and their main components as an antibacterial treatment against a variety of mastitis causing pathogens. There are many in vitro studies, but only several in vivo. Given the promising results of treatments with EOs, further clinical trials are needed.

Emerging roles of noncoding micro RNAs and circular RNAs in bovine mastitis: Regulation, breeding, diagnosis, and therapy

Bovine mastitis is one of the most troublesome and costly problems in the modern dairy industry, which is not only difficult to monitor, but can also cause economic losses while having significant implications on public health. However, efficacious preventative methods and therapy are still lacking. Moreover, new drugs and therapeutic targets are in increasing demand due to antibiotic restrictions. In recent years, noncoding RNAs have gained popularity as a topic in pathological and genetic studies. Meanwhile, there is growing evidence that they play a role in regulating various biological processes and developing novel treatment platforms. In light of this, this review focuses on two types of noncoding RNAs, micro RNAs and circular RNAs, and summarizes their characterizations, relationships, potential applications as selection markers, diagnostic or treatment targets and potential applications in RNA-based therapy, in order to shed new light on further research.