-This study was conducted to measure the antibacterial activity of grape (Vitis vinifera L; Vitaceae) seed extract against methicillin-resistant Staphylococcus aureus (MRSA). Grape seed and skin extracts were tested for antibacterial activity against forty-three strains of MRSA by gel diffusion, growth and respirometric studies. All MRSA strains were found to be sensitive to grape seed extract. Complete inhibition of all bacterial strains tested was observed at a concentration of 3 mg/ml crude grape seed proanthocyanidins extract (GPSE), equivalent of 20.7 µg/ml flavonoid content. Antibacterial activity was bactericidal as shown by a disruption of the bacterial cell wall in scanning and transmission electron microscopy. Grape seed extract is known to be rich in potent antioxidant polyphenolics that could show antibacterial activity. Phenolic compounds in the grape seed extract were assayed by Folin-Ciocalteu's reagent. The considerable antibacterial activity of commonly available grape seed extract could signify a major advancement in the treatment of MRSA diseases.

Gravel particles from four sites along the Arabian Gulf coast in autumn, winter, and spring were naturally colonized with microbial consortia containing between 7 and 400 × 10(2) cm(-2) of cultivable oil-utilizing bacteria. The 16S rRNA gene sequences of 70 representatives of oil-utilizing bacteria revealed that they were predominantly affiliated with the Gammaproteobacteria and the Actinobacteria. The Gammaproteobacteria comprised among others, the genera Pseudomonas, Pseudoalteromonas, Shewanella, Marinobacter, Psychrobacter, Idiomarina, Alcanivorax, Cobetia, and others. Actinobacteria comprised the genera Dietzia, Kocuria, Isoptericola, Rhodococcus, Microbacterium, and others. In autumn, Firmicutes members were isolated from bay and nonbay stations while Alphaproteobacteria were detected only during winter from Anjefa bay station. Fingerprinting by denaturing gradient gel electrophoresis of amplified 16S rRNA genes of whole microbial consortia confirmed the culture-based bacterial diversities in the various epilithons in various sites and seasons. Most of the representative oil-utilizing bacteria isolated from the epilithons were diazotrophic and could attenuate oil also in nitrogen-rich (7.9-62%) and nitrogen-free (4-54%) cultures, which, makes the microbial consortia suitable for oil bioremediation in situ, without need for nitrogen supplementation. This was confirmed in bench-scale experiments in which unfertilized oily seawater was bioremediated by epilithon-coated gravel particles.