Comparative and combinatorial study of Biogenic Bismuth nanoparticles with Silver Nanoparticles and Doxycycline against Multidrug Resistant Staphylococcus aureus BTCB02 and Salmonella typhi BTCB06

At the present time world is facing a turmoil due to emergence of diseases caused by antibiotic resistant pathogens. The current need is to find alternative ways of curing diseases led by these pathogens. In this context the current study was steered towards finding the potential of extracellularly synthesized biogenic bismuth nanoparticles BiNPs in combination with biogenic silver nanoparticles AgNPs and doxycycline hydrochloride against multidrug resistant pathogens. MIC value for BiNPs was 6 and 10mg/l and for biogenic AgNPs it was 16 and 18ug/l against Salmonella typhi BTCB06 and Staphylococcus aureus BTCB02, respectively. Whereas combination of BiNPs and doxycycline MIC was 3 and 5mg/l and for BiNPs and AgNPs it was 8 and 9ug/l for S. typhi and S. aureus, respectively. FICI value for the combination of BiNPs and Doxycycline was 0.75 against Salmonella typhi and Staphylococcus aureus, respectively. However the combination of AgNPs and BiNPs had FICI value 1 against both the test strains. Bismuth nanoparticles and doxycycline showed synergistic effect against both pathogens. BiNPs and AgNPs showed additive effect against both pathogens. Conclusively, biogenic BiNPs can be used as an excellent alternative alone or in combination in combating diseases caused by resistant pathogens.

Keywords: Bismuth, Silver, Nanoparticles, Minimum Inhibitory Concentration, Synergistic Effect.