Bovine mastitis is an inflammation of the mammary gland caused by physical trauma or pathogenic organisms, as specified by DairyGlobal.

Alternatives

New alternatives to antibiotics are necessary, such as plant extracts or essential oils that show antibacterial activity against both antibiotic-resistant and non-resistant pathogens.

Bovine mastitis results in changes in milk quality, increased labor and treatment costs, premature culling of cows, and global annual losses of approximately 35 billion USD.

Antibiotics have been the primary approach for mastitis treatment; however, their effectiveness is limited, leading to antibiotic-resistant strains of pathogens.

Several alternatives to antibiotics, such as plant extracts or essential oils, show antibacterial activity.

Cinnamon

Cinnamon is obtained from the inner bark of various trees belonging to the Cinnamomum genus. Essential oils from cinnamon have antibacterial effects due to secondary metabolites such as trans-cinnamaldehyde, cinnamyl acetate, eugenol, L-borneol, camphor, caryophyllene oxide, β-caryophyllene, and L-bornyl acetate.

Essential oils from Cinnamomum aromaticum, Cinnamomum cassia, and Cinnamomum zeylanicum exhibit antibacterial effects against Staphylococcus species associated with mastitis.

Moreover, cinnamon oil is more effective against Gram-positive bacteria than Gram-negative ones due to the outer membrane of Gram-negative bacteria acting as a barrier, preventing cinnamon oil from penetrating the cells.

A combination of cinnamon oil and silver nanoparticles causes 100% inhibition of Staphylococcus agalactiae cells within 4 hours.

Cinnamomum cassia oil disrupts the membranes of Staphylococcus aureus and E. coli, reduces biofilm formation, and provides an additional layer of protection against mastitis. Additionally, cinnamon alleviates both inflammation and mammary tissue damage associated with mastitis.

Origanum

Essential oils from oregano include terpenes, phenols, phenolic acids, flavonoids, carvacrol, thymol, linalool, and sabinene hydrate. Carvacrol is a phenolic monoterpene that causes structural and functional damage to microbial cell membranes, such as Staphylococcus aureus and E. coli, resulting in increased fluidity and permeability.

Origanum vulgare, commonly known as oregano, is effective against major mastitis-causing pathogens, including E. coli, Cronobacter sakazakii, Klebsiella oxytoca, Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis, Serratia marcescens, and Prototheca zopfii. Origanum majorana significantly reduces bacterial populations of Staphylococcus aureus, Streptococcus agalactiae, and E. coli.

Thymus

The main components of thyme essential oils include thymol, p-cymene, and γ-terpinene. Thymol belongs to phenolic monoterpene with antimicrobial activity that results in structural and functional changes in the cytoplasmic membrane, affecting permeability. Thyme species have been successfully tested against contagious and environmental mastitis-causing bacteria.

Thymus vulgaris L. essential oil demonstrates strong antibacterial potential against β-hemolytic Streptococcus, Enterobacter sakazakii, E. coli, and Klebsiella oxytoca.

Thymus serpyllum L. essential oil exhibits strong antibacterial activity against coagulase-negative staphylococci. Thymus fontanesii essential oil shows high antibacterial activity against E. coli and Staphylococcus aureus.

Melaleuca

Melaleuca essential oil, commonly known as tea tree oil, contains more than 100 components, including various monoterpenes, sesquiterpenes, and aromatic compounds. Tea tree oil exerts antibacterial action against E. coli and Staphylococcus aureus, destabilizing potassium ion gradients, inhibiting respiration, and promoting membrane leakage.

Tea tree oil also exhibits bactericidal activity against Staphylococcus species, Streptococcus species, Klebsiella pneumoniae, Candida albicans, and provides efficient protection to the organism by reducing the proliferation of inflammatory cells without affecting their ability to secrete anti-inflammatory cytokines. Melaleuca armillaris essential oil has a synergistic effect with rifaximin and erythromycin against Staphylococcus aureus.

Lavender

The main components of lavender essential oils are linalool, linalyl acetate, terpenes, and non-terpenoid aliphatic components. Lavandula angustifolia is efficient against pathogenic isolates such as Staphylococcus species, Bacillus cereus, and Kytococcus sedentarius. Lavandula stoechas reduces the bacterial population of Staphylococcus aureus, Streptococcus agalactiae, and E. coli.

Minthostachys verticillata

The chemical composition of Minthostachys verticillate essential oil includes monoterpene pulegone, menthone, isomenthone, limonene, menthol, and α-pinene. Limonene inhibits the growth of Streptococcus uberis, E. coli, Bacillus pumilus, and Enterococcus faecium.

Conclusion

Mastitis is a major disease in the dairy industry, leading to reduced milk production, poor milk quality, and economic losses.