Characterization of a vancomycin intermediate-resistant Staphylococcus aureus isolated from a hospital.

A Vancomycin intermediate resistant strain of Staphylococcus aureus (S. aureus) labeled as CP2 (MIC 16 microg/ml) was isolated from an in-patient of local Cardiac Hospital of Karachi. CP2 showed typical characters of Vancomycin intermediate resistant S. aureus (VISA) i.e. high level of oxacillin resistance, thickened cell wall with rough surface and reduced autolytic activities associated with murein hydrolase (MH) enzyme. This strain may have acquired vancomycin resistance due to long term exposure to antibiotic during the treatment of the patient. Therefore, it implicates the importance of monitoring the usage and also to control of the abuse of antibiotics for prevention of any further proliferation of this type of notorious bugs.