Anti-Staphylococcal Activities of <i>Rosmarinus officinalis</i> and <i>Myrtus communis</i> Essential Oils through ROS-Mediated Oxidative Stress

Rosmarinus officinalis and Myrtus communis essential oils (EOs) are well-known for their ethno-pharmaceutical properties. In the present study, we have analyzed the chemical composition of both EOs by gas chromatography-mass spectrometry. Then we assessed their antibacterial, antibiofilm, and anti-virulence actions against the opportunistic pathogen Staphylococcus aureus. The cytotoxic effect of agents tested against this bacterium was investigated by monitoring reactive oxygen-species (ROS) generation and antioxidant-enzyme (catalase) production. Regarding the antistaphylococcal effects, our results showed antibacterial efficacy of both Eos and their combination, where the minimum inhibitory concentrations ranged between 0.7 and 11.25 mg/mL. A combination of tested agents showed the highest anti-hemolytic and anti-protease effects. Additionally, association between EOs displayed more potency against the development of biofilm performed by S. aureus, with percentage of removal reaching 74%. The inhibitory impacts of EOs on S. aureus virulence factors were discovered to be concentration-dependent. Furthermore, our results provide insight on the abilities of R. officinalis and M. communis EOs, as well as their potential in combination, to generate ROS and affect oxidative stress enzyme catalase in S. aureus, leading to their antagonistic effect against this pathogen

Chemical composition of essential oils of eight Tunisian Eucalyptus species and their antibacterial activity against strains responsible for otitis

Background The chemical composition and biological activity of Eucalyptus essential oils have been studied extensively (EOs). A few of them were tested for antibacterial effectiveness against otitis strains. The chemical composition and antibacterial activity of the EOs of eight Tunisian Eucalyptus species were assessed in the present study. Methods Hydrodistillation was used to extract EOs from the dried leaves of eight Eucalyptus species: Eucalyptus accedens, Eucalyptus punctata, Eucalyptus robusta, Eucalyptus bosistoana, Eucalyptus cladocalyx, Eucalyptus lesouefii, Eucalyptus melliodora and Eucalyptus wandoo. They are assessed by GC/MS and GC/FID and evaluated for antibacterial activity using agar diffusion and broth microdilution techniques against three bacterial isolates (Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae) and three reference bacteria strains (Pseudomonas aeruginosa, ATTC 9027; Staphylococcus aureus, ATCC 6538; and Escherichia coli, ATCC 8739). Furthermore, the selected twenty-one major compounds and all values of the inhibition zone diameters were subjected to further statistical analysis using PCA and HCA. Results The EO yields of the studied Eucalyptus species range from 1.4 +/- 0.4% to 5.2 +/- 0.3%. Among all the species studied, E. lesouefii had the greatest mean percentage of EOs. The identification of 128 components by GC (RI) and GC/MS allowed for 93.6% - 97.7% of the total oil to be identified. 1,8-cineole was the most abundant component found, followed by alpha-pinene, p-cymene, and globulol. The chemical components of the eight EOs, extracted from the leaves of Eucalyptus species, were clustered into seven groups using PCA and HCA analyses, with each group forming a chemotype. The PCA and HCA analyses of antibacterial activity, on the other hand, identified five groups. Conclusion The oils of E. melliodora, E. bosistoana, and E. robusta show promise as antibiotic alternatives in the treatment of otitis media

Chemical composition of five Tunisian Pinus Species' essential oils and effect of their blends on Otitis infection

Many studies reported the chemical composition and the biological activities of Pinus Essential oils (EOs). A few of them were investigated for their antibacterial activity against strains responsible for otitis. The present paper investigated the variation of the chemical composition and the antibacterial activity of the EOs of five Tunisian Pinus species and of their combinations against six bacterial strains responsible for otitis. The EOs' yields varied from 0.3 +/- 0.1% for P. pinea to 1.8 +/- 0.4% for P. halepensis. Their chromatographic analyses by GC and GC-MS identified 139 components varying according to the species. The main components were beta-pinene followed by trans-caryophyllene, germacrene D, alpha-pinene, beta-myrcene, palustradiene, abieta-7,13-triene, levopimaradiene, thunbergol, and caryophyllene oxide. Four chemical groups were identified basing on the PCA and the HCA of the 25major's components of the studied EOs. However, three subgroups were identified within the antibacterial-based PCA and HCA analyses. The highest antibacterial activity was observed with the blends of oils extracted from P. halepensis and P. canariensis and mixture of oils extracted from P. brutia and P. canariensis. These EOs blends may constitute promising antibiotic alternatives for the treatment of the otitis media

Haplotype Map of Sickle Cell Anemia in Tunisia

-Globin haplotypes are important to establish the ethnic origin and predict the clinical development of sickle cell disease patients (SCD). To determine the chromosomal background of Tunisian sickle cell patients, in this first study in Tunisia, we have explored four polymorphic regions of -globin cluster on chromosome 11. It is the 5 region of -LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal ( G and A ) genes and the 5 region of -globin gene. The results reveal a high molecular diversity of a microsatellite configuration describing the sequences haplotypes. The linkage disequilibrium analysis showed various haplotype combinations giving 22 &quot;extended haplotypes&quot;. These results confirm the utility of the -globin haplotypes for population studies and contribute to knowledge of the Tunisian gene pool, as well as establishing the role of genetic markers in physiopathology of SCD