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Droplet digital PCR quantification of selected microRNAs in raw mastitic cow’s milk from the west of Poland
Abstract Introduction MicroRNAs (miRNAs), a class of noncoding small RNAs, have been recognised as potential biomarkers of mammary gland conditions, including bovine mastitis diagnosis. The aim of this study was to quantify selected miRNAs in the milk of mastitic cows. Material and Methods Milk samples (n = 90) were collected from healthy and mastitic dairy cows originating from local dairy cattle farms located in the west of Poland. MicroRNAs of the miR-21a, miR-92a, miR-146a and miR-383 species were quantified using the highly sensitive droplet digital PCR method. Direct measurement of somatic cell count (SCC) was performed using a cell counter. Cows were divided into three groups: those with an SCC below 200,000/mL were designated Low (n = 25), those with an SCC between 200,000 and 999,999 were Medium (n = 34), and those with an SCC of 1,000,000 or higher were High (n = 31). Microbiological analyses were performed using standard culture testing. Results The level of miR-383 was very low and this miRNA was excluded from analysis. The miR-92a was used to normalise miR-21a and miR-146a expression levels. The obtained results of expression of miR-21a and miR-146a correlated with somatic cell number (R = 0.53 and 0.79, respectively). Conclusion These results show that ddPCR is a useful method for quantifying miRNAs in raw cow milk. It seems that miR-146a is a promising marker for bovine mastitis, although further studies are needed to select a panel of miRNAs that can be used in mastitis monitoring in Poland.
In Vitro Studies of Nanoparticles as a Potentially New Antimicrobial Agent for the Prevention and Treatment of Lameness and Digital Dermatitis in Cattle
Digital dermatitis (DD) is the second most prevalent disease in dairy cattle. It causes significant losses for dairy breeders and negatively impacts cows’ welfare and milk yield. Despite this, its etiology has not been entirely identified, and available data are limited. Antibiotic therapy is a practical method for managing animal health, but overuse has caused the evolution of antibiotic-resistant bacteria, leading to a loss in antimicrobial efficacy. The antimicrobial properties of metal nanoparticles (NPs) may be a potential alternative to antibiotics. The aim of this study was to determine the biocidal properties of AgNPs, CuNPs, AuNPs, PtNPs, FeNPs, and their nanocomposites against pathogens isolated from cows suffering from hoof diseases, especially DD. The isolated pathogens included Sphingomonas paucimobilis, Ochrobactrum intermedium I, Ochrobactrum intermedium II, Ochrobactrum gallinifaecis, and Actinomyces odontolyticus. Cultures were prepared in aerobic and anaerobic environments. The viability of the pathogens was then determined after applying nanoparticles at various concentrations. The in vitro experiment showed that AgNPs and CuNPs, and their complexes, had the highest biocidal effect on pathogens. The NPs’ biocidal properties and their synergistic effects were confirmed, which may forecast their use in the future treatment and the prevention of lameness in cows, especially DD.
Silver and Copper Nanoparticles as the New Biocidal Agents Used in Pre- and Post-Milking Disinfectants with the Addition of Cosmetic Substrates in Dairy Cows
Mastitis is one of the most common issues for milk producers around the world. Antibiotic therapy is often ineffective, and therefore, scientists must find a new solution. The aim of this paper is to estimate the influence of common and well-known cosmetic substrates and mixtures of nanoparticles (NPs) and cosmetic substrates on the viability of frequently occurring mastitis pathogens, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The obtained results suggest that only collagen + elastin and glycerine influenced and increased bacteria viability. In case of the rest of the cosmetic substrates, the viability of E. coli and S. aureus was decreased, and the results were statistically significant (p ≤ 0.01). Prepared pre-dipping and dipping mixtures decrease (p ≤ 0.01) the viability of the mentioned pathogens. The obtained results of the in vitro analysis are very promising. In the next step, prepared mixtures should be tested in different herd conditions if they can be used in mastitis prevention or decrease the number of subclinical mastitis cases. Furthermore, these mixtures could become an interesting alternative for organic milk production where conventional preparations and antibiotics are forbidden. However, further analysis, especially on the influence of prepared mixtures on other bacteria species and, algae, fungi, are necessary.