Sinergicity test of silver nanoparticles and clindamycin against Staphylococcus aureus

Acne is a chronic inflammatory disease. The pathogenesis of acne is multifactorial; one of them is caused by an overgrowth of microbes like S. aureus. Clindamycin is one of the antibiotics recommended for acne therapy. Still, the use of clindamycin causes various side effects such as changes in intestinal function associated with intestinal flora, pseudomembranous colitis, and increases the risk of resistance. Silver nanoparticles are potent antimicrobials, have broad-spectrum activity, and can reduce the development of resistance. Despite having potent activity, the long-term use of silver nanoparticles is reported to have side effects argyria. The use of antimicrobial combinations is a strategy to reduce side effects and increase the effectiveness of therapy. Antimicrobial combinations can use low concentrations but still have the potential to inhibit microbial growth. This research aim is to determine the antibacterial synergism of a combination of silver nanoparticles and clindamycin against S. aureus. Determination of the minimum inhibitory concentration (MIC) of silver nanoparticles, clindamycin, and synergism test was carried out by microdilution using 96-well microplates. Synergy test is carried out using the Checkerboard method by calculating the value of the Fractional Index Concentration (FIC). The results showed the MIC values ​​of silver nanoparticles and clindamycin were 16 µg/ml and 64 µg/ml, respectively. The synergy test of the combination of silver nanoparticles yielding an FIC value of 0.75. Based on the result of the study, it was concluded that the combination of silver nanoparticles and clindamycin had partial synergy properties. The Minimum bactericidal Concentration (MBC) value clindamycin alone compared in combination with silver nanoparticles 16 µg/ml reduces from 256 µg/ml to 128 µg/ml. Combinations of silver nanoparticle and clindamycin are the potential to reduce side effects and overcome resistance.