IADR Abstract Archives
Bacteriostatic Effect of Simvastatin on Selected Oral Bacteria In Vitro
Objectives: To assess the in vitro efficacy of simvastatin against selected strains of oral bacteria, as determined by minimum inhibitory concentration (MIC).
Methods: Streptococcus mutans (25175), Streptococcus anginosus (33397), Streptococcus sanguis (10556) Streptococcus salivarius (2593) and Aggregatibacter actinomycetemcomitans (29523) were purchased from the American Type Culture Collection (Manassas, Va.). All bacteria were grown in/on brain heart infusion broth/agar. Simvastatin (5 mg, Sigma Chemical Co., St. Louis, Mo.) was diluted in 100% dimethylsulfoxide (DMSO) to make stock solutions ranging from 6mM to 24.7 nM. MIC was determined by broth dilution assays.
For each bacteria, growth curves were started by adding a fixed culture of bacteria to BHI media. After 3 hrs, simvastatin was added at its MIC, and turbidity was measured for another 6 hrs. At the end of this time (9 hrs. total incubation), cells were pelleted in sterile eppendorf tubes, washed twice in sterile isotonic saline, and transferred back into sterile BHI. Turbidity was then measured for another 15 hrs (24 hrs total). Growth curves without simvastatin served as control.
Results: Determination of MIC by Broth Dilution Assay: MIC's against the selected bacteria are shown in the Table 1. The effect of 2-fold serial dilutions of simvastatin on S. mutans is shown in Fig 1. However, the minimum bactericidal activity could not be determined since aliquots (100 μl) from clear culture tubes showed bacterial growth when streaked onto agar plates and incubated for 24 hrs. This measure of antibacterial activity indicates that simvastatin is a bacteriostatic antimicrobial agent against these strains of oral bacteria.
Growth Curve Determination of Bacteriostatic vs Bactericidal Action of Simvastatin: Bacterial cultures incubated in the presence of simvastatin exhibit slowed growth rates as compared to control growth curves. However, when the bacteria were washed and transferred to growth medium lacking simvastatin, they resumed log growth. This measure of antibacterial activity confirms that simvastatin is a bacteriostatic antimicrobial agent against these strains of oral bacteria.
Conclusions: Simvastatin has bacteriostatic properties against the selected oral bacteria with MIC's in the range of 3.9 μg/ml- 15.6 μg/ml.
Methods: Streptococcus mutans (25175), Streptococcus anginosus (33397), Streptococcus sanguis (10556) Streptococcus salivarius (2593) and Aggregatibacter actinomycetemcomitans (29523) were purchased from the American Type Culture Collection (Manassas, Va.). All bacteria were grown in/on brain heart infusion broth/agar. Simvastatin (5 mg, Sigma Chemical Co., St. Louis, Mo.) was diluted in 100% dimethylsulfoxide (DMSO) to make stock solutions ranging from 6mM to 24.7 nM. MIC was determined by broth dilution assays.
For each bacteria, growth curves were started by adding a fixed culture of bacteria to BHI media. After 3 hrs, simvastatin was added at its MIC, and turbidity was measured for another 6 hrs. At the end of this time (9 hrs. total incubation), cells were pelleted in sterile eppendorf tubes, washed twice in sterile isotonic saline, and transferred back into sterile BHI. Turbidity was then measured for another 15 hrs (24 hrs total). Growth curves without simvastatin served as control.
Results: Determination of MIC by Broth Dilution Assay: MIC's against the selected bacteria are shown in the Table 1. The effect of 2-fold serial dilutions of simvastatin on S. mutans is shown in Fig 1. However, the minimum bactericidal activity could not be determined since aliquots (100 μl) from clear culture tubes showed bacterial growth when streaked onto agar plates and incubated for 24 hrs. This measure of antibacterial activity indicates that simvastatin is a bacteriostatic antimicrobial agent against these strains of oral bacteria.
Growth Curve Determination of Bacteriostatic vs Bactericidal Action of Simvastatin: Bacterial cultures incubated in the presence of simvastatin exhibit slowed growth rates as compared to control growth curves. However, when the bacteria were washed and transferred to growth medium lacking simvastatin, they resumed log growth. This measure of antibacterial activity confirms that simvastatin is a bacteriostatic antimicrobial agent against these strains of oral bacteria.
Conclusions: Simvastatin has bacteriostatic properties against the selected oral bacteria with MIC's in the range of 3.9 μg/ml- 15.6 μg/ml.
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