Original article Extract nature influences the effects of Melissa officinalis L. on the milk microbiome in cows with subclinical mastitis

Abstract

Ma stitis in da iry cows represents one of the most economically impa cting pathology, the managment costs being augmented by difficulties in diagnosing the subclinical form of the disease. The bia sed and non-discriminatory use of antibiotics led to their lesser efficacy, therefore therapeutic alternatives are looked for. In this study, the influence of the extraction solvent on the antimicrobial effectiveness of Melissa officinalis L. was assessed on subclinical mastitis microbiome.Milk and blood samples were harvested from dairy cows at the peak of the lactation. N/L ratios from the blood (Panoptic stain) were calculated as indicators of the degree of stress/immune suppression in subclinical disease. The microbiome components were identified by use of classical bacteriological methods and cultivated against M. officinalis alcoholic extract and essential oil (Kirby-Bauer method). Minitab 16.0 was used for the statistical interpretation of the data while the significance of the differences between the groups was interpreted by Student's t test.N/L ratios indicated significantly increased stress (p < 0.01) in subclinically affected animals (1.24 ± 0.69) when compared to healthy ones (0.56 ± 0.12). In bacteria from mastitic milk, M. officinalis alcoholic extract was less effective than the essential oil (inhibition zone of 11.3 ± 3.6 mm versus 12.3 ± 4.3 mm), but comparable to amoxicillin, amoxicillin/clavulanic acid and higher than cefoperazone (total resistance). Similarly, in healthy milk isolates, the effects were more pronounced for the essential oil than for the tincture (18.67 ± 7.0 mm versus 13.0 ± 8.2 mm) and higher than in cefoperazone (15.67 ± 3.2 mm).The results suggested that the therapeutic use of M. officinalis essential oil rather than the alcoholic extract could prove to be efficient against mastitic milk bacteriome, depending on the bacteria genus more than on the extract type.

Multidrug Resistance in Zoonotic Pathogens: Are Medicinal Plants a Therapeuthic Alternative?

“…The lesser antibiotic efficacy, therefore, demands for therapeutic alternatives. In a study on the antimicrobial effectiveness of Melissa officinalis on the subclinical mastitis, microbiome carried out on several Romanian dairy farms ( [93]), a variety of bacteria (S. sciuri, Shigella spp. S. lentus, Acinetobacter baumannii, Chryseomonas luteola, Enterobacter cloacae, Escherichia vulneris, etc.)…”