Chemical Composition and Acaricidal Activity of the Essential Oils of Some Plant Species of Lamiaceae and Myrtaceae against the Vector of Tropical Bovine Theileriosis: Hyalomma scupense (syn. Hyalomma detritum).

The present study aimed to investigate the acaricidal properties of six essential oils. They were extracted from some plant species (Lamiaceae and Myrtaceae) using the technique of hydrodistillation with the Clevenger apparatus. The chemical compositions of the essential oils under study were determined by gas chromatography-mass spectrometer (GC-MS). An Adult Immersion Test (AIT) and a Larval Immersion Test (LIT) were used to evaluate the acaricidal activity of these essential oils against the adults and larvae of Hyalomma scupense. GC-MS analysis showed the major constituents of each essential oil: 25.49% of α-thujone (lavender); 46.82% of carvacrol (oregano); 78.78% of carvacrol (thyme); 40.27% of 1,8-cineole (blue gum); 17.45% of p-cymene (river red gum); and 26.96% of 1,8-cineole (rosemary). The biotests on the essential oils revealed that they inhibit the reproduction of H. scupense engorged females at a rate of 100 % with doses of 0.781 µl/ml of rosemary, 1.562 µl/ml of thyme, 3.125 µl/ml of lavender and oregano, and 6.250 µl/ml of blue gum and river red gum. After a treatment that lasted for 24 hours, essential oils showed a larvicidal activity with respective values of lethal concentrations (LC): LC50, LC90, and LC95 (0.058, 0.358, and 0.600 µl/ml for thyme; 0.108, 0.495, and 0.761 µl/ml for rosemary; 0.131, 0.982, and 1.740 µl/ml for oregano; 0.155, 2.387, and 5.183 µl/ml for blue gum; 0.207, 1.653, and 2.978 µl/ml for river red gum; and 0.253, 2.212, and 4.092 µl/ml for lavender). This is the first report on the acaricidal activity of these essential oils against H. scupense. The results obtained showed that the essential oils with chemotype carvacrol, 1,8-cineole, α-thujone, and p-cymene are highly acaricidal, and they can be used for ticks control. However, further studies on their toxicity in nontarget organisms are required.

Survey of bovine mycotic mastitis in different mammary gland statuses in two north-eastern regions of Algeria.

The aim of this study was to evaluate the prevalence of mycotic mastitis in different mammary gland statuses. The study was conducted on 304 dairy cows from ten farms in two north-eastern regions in Algeria; Guelma and Souk Ahras with 922 and 199 samples, respectively, forming thus a total number of 1,121 milk samples. A total of 321 milk samples were collected from clinical mastitis, 544 milk samples from subclinical mastitis and 256 milk samples from healthy mammary glands. Mycological analyses revealed that 10.17% of the treated samples were positive recording 114 species of fungi including 88 yeasts and 26 moulds. The most frequent species was Candida kefyr followed by C. albicans, C. guilliermondii, C. famata, C. tropicalis, C. colliculosa, C. krusei, C. rugosa, C. glabrata, C. parapsilosis, C. inconspicua, Trichosporon sp., Rhodotorula glutinis and Saccharomyces fragilis. Mould species have also been isolated from samples of both healthy milk and clinical mastitis milk. Aspergillus amstelodami (from glaucus group), A. fumigatus and Geotrichum candidum were identified, while the other species including Penicillium sp. and Cladosporium sp. were not identified.