Antibacterial Activity of Mulinum spinosum Extracts against Slime-producing Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus Isolated from Nasal Carriers: An Overview

Nasal carriers of Staphylococcus aureus are important reservoirs with risk of developing endogenous
infections or transmitting infections to susceptible individuals. Methicillin-resistant S. aureus (MRSA)
are associated with higher rates of treatment failure. Some strains of S. aureus produce slime which is
believed to make the microorganisms more resistant to antibiotics and host defenses. The
antibacterial activity of ethyl acetate: n-hexane (EtOAc:HEX) extracts of Mulinum spinosum (5:95%
EtOAc:HEX, 50:50% EtOAc:HEX, 70:30% EtOAc:HEX and mix 20:80/30:70% EtOAc:HEX,
50:50/70:30/100:0% EtOAc:HEX) were assayed against 3 slime-producing S. aureus strains and 2
MRSA strains isolated from nasal carriers. S.aureus ATCC 35556 slime-producing strain and MRSA
ATCC 43300 strain were used as controls. The extracts were prepared using flash chromatography.
M. spinosum 5:95% AcOEt:HEX showed antibacterial effect against all slime-producing strains
(MIC:500 μg/ml) and the highest activity against MRSA strains (MIC:500 to 1000 μg/ml). All
M.spinosum extracts assayed were active against slime-producing S. aureus and MRSA at doses
between 500 and 4000 μg/ml. Both, slime-producing S. aureus and MRSA are highly contagious and
hardly eradicated by antibiotic therapies. So, there is an increasing need to find new substances with
the ability to inhibit these strains.