New Perspective of Origanum vulgare L. and Satureja montana L. Essential Oils as Bovine Mastitis Treatment Alternatives

Abstract

Mastitis represents a heavy burden for the dairy sector worldwide with high economic and animal welfare impact. Antibiotic treatment is an important component of mastitis control programs. However, emergence and transfer of antimicrobial-resistant (AMR) bacteria is becoming a growing concern. Therefore, the development of novel agents is required for prevention and treatment of mastitis. Hence, our aim was to assess the antibacterial properties of two essential oils (EOs) obtained from oregano (Origanum vulgare L., Lamiaceae) and mountain savory (Satureja montana L., Lamiaceae) against mastitis-associated bacteria in Serbia. The chemical composition and antioxidant potential of these EOs were also evaluated. The present study was conducted on strains derived from aseptic milk samples collected from Holstein-Friesian cows with clinical or subclinical mastitis, during the morning milking. Clinical mastitis was assessed by clinical examination, while subclinical mastitis was confirmed using somatic cell count in the milk samples. The microdilution method was used to determine the antibacterial activity, while antioxidant potential of the EOs was evaluated in several in vitro assays. The values of minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) were used to quantitatively measure the antibacterial activity of each EO. MIC/MBC ranged from 0.78/6.25 and 0.39/0.78 mg/mL for oregano and mountain savory, respectively. A total of 25 compounds were identified in the oregano EO, while 47 were identified in winter savory EO, among which aromatic oxygenated monoterpenes were the most abundant compounds. The tested EOs have shown promising antimicrobial activity and could be considered as one of the treatment approaches in mastitis-affected cows.

Environmental Bovine Mastitis Pathogens: Prevalence, Antimicrobial Susceptibility, and Sensitivity to Thymus vulgaris L., Thymus serpyllum L., and Origanum vulgare L. Essential Oils

“…The results obtained in this study regarding oregano EOs’ chemical composition point out carvacrol as a dominant compound, which is in agreement with the previously published data [ 22 , 43 , 44 ]. Analysis of common and wild thyme EOs’ chemical composition in this study revealed that the content of thymol in the wild thyme EO is higher (55.11%) than in the common thyme EO (46.37%).…”

“…Although the evaluated EOs of the same manufacturer were used in previous studies [ 21 , 22 ], their chemical composition was evaluated once more, since there could be differences recorded among different series of production. The eventually presented differences could be caused by the origin of raw plant material, place of cultivation or collection (if the plant is collected from nature), as well as a range of ecological factors influencing the content of the main compounds [ 41 , 42 ].…”

“…Along with other advantages as an alternative to antibiotics, EOs show antibacterial properties and no resistance has been reported after prolonged exposure [ 19 ]. There are many in vitro studies for evaluating the antimicrobial efficacy of EOs against common mastitis-associated pathogens [ 20 , 21 , 22 , 23 , 24 ]. The greatest antimicrobial effect is exerted by EOs with thymol and carvacrol as main components [ 25 , 26 ].…”

Farm Animal Veterinarians’ Knowledge and Attitudes toward Antimicrobial Resistance and Antimicrobial Use in the Republic of Serbia

“…Previous research suggests that the most commonly used antibiotics in mastitis therapy in Serbia were penicillin, streptomycin, gentamicin, tetracycline, cephalexin, sulfonamides, and enrofloxacin [ 79 , 80 ]. Furthermore, according to recent data [ 81 , 82 ], the most common mastitis pathogens in dairy cows from Serbia were resistant to penicillin. In the current study, the seven most commonly used antibiotics for cow mastitis therapy were enrofloxacin (17.4%), amoxicillin (14.9%), amoxicillin + clavulanic acid (14.9%), penicillin (10.3%), ceftriaxone (9.3%), tetracycline (8.4%), and gentamicin (7.2%), which is partially consistent with older studies.…”

Use of Thymol in Nosema ceranae Control and Health Improvement of Infected Honey Bees

“…Thymol (3-hydroxy-p-cymene) is a natural compound as it is a component of essential oil, derived from Thymus vulgaris L., Lamiaceae, and many other plant species. The inhibitory effect of thymol on the growth of pathogenic bacteria and fungi, such as Escherichia coli, Streptococcus spp., Salmonella typhimurium, Staphylococcus aureus, Aspergillus flavus, and Cryptococcus neoformans, has been known for many years [28,29]. In beekeeping, thymol has been used for decades to control the honey bee mite Varroa destructor [30,31] with variable success [32].…”