Title: Susceptibility of Methicillin Resistant Staphylococcus aureus to Vancomycin using Liposomal Drug Delivery System,
Abstract: Staphylococcus aureus responsible for nosocomial infections is a significant
threat to the public health. The increasing resistance of S.aureus to various
antibiotics has drawn it to a prime focus for research on designing an
appropriate drug delivery system. Emergence of Methicillin Resistant
Staphylococcus aureus (MRSA) in 1961, necessitated the use of vancomycin "the
drug of last resort" to treat these infections. Unfortunately, S.aureus has
already started gaining resistances to vancomycin. Liposome encapsulation of
drugs have been earlier shown to provide an efficient method of microbial
inhibition in many cases. We have studied the effect of liposome encapsulated
vancomycin on MRSA and evaluated the antibacterial activity of the
liposome-entrapped drug in comparison to that of the free drug based on the
minimum inhibitory concentration (MIC) of the drug. The MIC for liposomal
vancomycin was found to be about half of that of free vancomycin. The growth
response of MRSA showed that the liposomal vancomycin induced the culture to go
into bacteriostatic state and phagocytic killing was enhanced. Administration
of the antibiotic encapsulated in liposome thus was shown to greatly improve
the drug delivery as well as the drug resistance caused by MRSA.