Activity and free radical generation in Staphylococcus aureus induced by N-Benzenesulfonyl 1,2,3,4- tetrahydroquinoline

MARTINEZ SR ; MIANA GE; VILLEGAS VENENCIA NV ; ALBESA I; MAZZIERI MR; BECERRA MC

Congreso; VIII Meeting of the Society for Free Radical Biology and Medicine-South American Group (VIII SFRBM-SAG); 2013

Staphylococcus aureus is a pathogen of the community and nosocomial infections. The continous appearance of resistant strains requires an urgent search for new compounds. The generation of reactive oxygen species (ROS) could be an effect associated to the mechanism of antibacterial action. The objective was to investigate the antibacterial activity of N-Benzenesulfonyl- 1,2,3,4- tetrahydroquinoline (BSTHQ) and ROS generation. The Minimun Inhibitory Concentration (MIC) was determined in S.aureus ATCC 29213 and in a Methicillin-resistant clinical strain (SAMR) by macrodilution method. A stock solution of BSTHQ in polyethyleneglycol 400 and dimethyl sulfoxide was prepared. Serial dilutions in the range of 25 to 200 µg/mL were taken. The generation of ROS was assayed in bacterial suspension (OD600 1.0) incubated without (basal) or with different concentrations of BSTHQ. Then, Nitro Blue Tetrazolium was added for 30 min at 37ºC. The results were expressed as a percentage of the increase with respect to the basal values. The MICs for BSTHQ of both strains were 200 µg/mL. The increase of ROS was 58.29% in SAMR at the MIC, and 55.04 % in S. aureus ATCC at the same concentration. It was showed that BSTHQ exhibits antibacterial activity, which could be related to the generation of ROS.