Effect of Sulfur Hexafluoride Gas on Antibacterial Activity of Antibiotics in vitro against Agents Causing Endophthalmitis

Abstract

Background: We conducted a study to evaluate the effect of sulfur hexafluoride gas (SF₆) on the antibacterial activity of antibiotics in vitro against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa, which are common endophthalmitis-causing agents. Methods: In this experimental study, antibiotic susceptibility tests were prepared according to the National Committee for Clinical Laboratory Standards macrobroth dilution method. Müller-Hinton broth was the test medium. Standard P. aeruginosa (ATCC 27853), S. epidermidis (ATCC 12228) and S. aureus (ATCC 29213) strains were studied. For P. aeruginosa ceftazidime, ofloxacin and tobramycin dilutions, and for S. epidermidis and S. aureus, cefazolin, ofloxacin and tobramycin dilutions were prepared identically in two sets of tubes. One set of tubes, into which pure SF₆ was injected, was defined as the SF₆ group. The other set of tubes, into which no SF₆ was injected, was taken as the control group. To determine the minimal bactericidal concentrations of the antibiotics, subcultures were made onto Müller-Hinton agar, and the colonies were counted after 18 h of incubation at 37°C. Results: The minimal inhibitory concentrations of the antibiotics in the SF₆ group were found to be identical with those of the control group. However, the minimal bactericidal concentrations of the antibiotics were found to be at least two dilutions lower in the SF₆ group than in the control group, except for the minimal bactericidal concentration of cefazolin for S. aureus, which was found to be one dilution lower in the SF₆ group. Conclusion: SF₆ was found to potentiate the in vitro antibacterial activity of ofloxacin and tobramycin against S. aureus, S. epidermidis and P. aeruginosa, ceftazidime against P. aeruginosa, and cefazolin against S. epidermidis. Experimental animal studies are required to determine the role of SF₆ in the management of endophthalmitis.

Anti-bacterial properties and GC-MS analysis of extracts and essential oils of selected plant product

“…The bioactive parts against bacteria in these conventional antibiotics include structural moieties that include-Cl,-F,-N,-NH 2, -S,-COOH and-OH, which are also found in many herbs used traditionally against bacterial infections. Studies have shown that sulfur-containing compounds have strong inhibitory antibacterial activities (Julia and Ann 1947;Kyung and Fleming 1996;Yanyali et al 2001). Nitrite exhibits toxic properties while nitrous acid is bactericidal, chlorine releasing compounds such as chlorine dioxide (ClO 2 ), acidic and alcoholic compounds act as antibacterial agents (Gerald and Russell 1999).…”