Investigation of the in Vitro Antibacterial Effects of Statins

Abstract

It was previously shown that statins have anti-inflammatory, immunomodulatory and anti-oxidant effects. This study was aimed to investigate the in-vitro antibacterial effects of simvastatin and atorvastatin. In this study antibacterial activity of the statins were tested against 16 methicillin-susceptible Staphylococcus aureus (MSSA), 16 methicillin-resistant S.aureus (MRSA), 16 methicillin-resistant coagulase-negative Staphylococcus (MRCoNS), 9 vancomycin-susceptible Enterococcus faecium, 7 vancomycin- susceptible Enterococcus faecalis, 13 vancomycin-resistant E.faecium, 16 extended spectrum beta-lactamase (ESBL) positive Escherichia coli, 16 Pseudomonas aeruginosa, 16 Acinetobacter baumannii, 15 ESBL positive Klebsiella pneumoniae, 6 Stenotrophomonas maltophilia by broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) performance and interpretive guidelines. S.aureus ATCC 29213, S.aureus ATCC 25923, S.aureus ATCC 43300, Enterococcus faecalis ATCC 29212, K.pneumoniae ATCC 700603 and E.coli ATCC 35218 were tested as control strains. The results showed that minimum inhibitory concentration (MIC) values for all isolates were > 128 μg/ml for the two statins tested. However, MIC of simvastatin was 32 μg/ml for S.aureus ATCC 29213 and was 64 μg/ml for S.aureus ATCC 25923 and E.faecalis ATCC 29212 and was > 128 μg/ml for others, but MIC of atorvastatin was > 128 μg/ml for all standard strains. According to these results, we observed that simvastatin and atorvastain had no significant antibacterial effect in vitro. In this study, although no antibacterial effect of statins were determined in vitro, further studies are needed to investigate the combined effect of statins with antibacterial agents in the living organism.