Antimicrobial Agents

Donna Henderson

Microbiology 314

September 16, 2013

Sinead M. Ni Chadhain

The questions this paper asks are what effect does Oritavancin activities have on S. aureus in slow growing and biofilm states. What causes microbes to be resistant to some antimicrobial agents? How does Oritavancin work that it has had better results than vancomycin, along with other antimicrobial agents?

The author linked his/her work to previous research by telling us what the drug Oritavancin is and how it works such as, the activity that it exhibits in certain infections that it has already been tested on. They also tell us that Oritavancin has multiple mechanisms of action, what distinguishes it from vancomycin, and the rapidity of its bactericidal activity against some bacterial infections. They also tell us about research that has been done on other bacterial infections that harbor tolerant cells.

Infections that are in certain stages such as, slow-growing, dormant, or in a biofilm create a challenge for therapy because they show tolerance toward the activity of antimicrobial agents. There has been research done on different types of infections with different antimicrobial agents to try and figure out how they work or if they do work. Oritavancin is an antimicrobial agent that has been tested and found to have multiple mechanisms of action and a rapid activity rate in a different way than Vancomycin and this is one of the major differences between the two. The conditions under which Vancomycin could work are very specific.

Oritavancin shows activity against stationary phase cells and in the exponential phase and vancomycin only shows slight activity in the exponential phase.

Only Oritavancin exerted bactericidal activity against stationary phase MSSA strain ATCC 29213 in nutrient depleted CAMHB, with Vancomycin being most affected by growth phase. Vancomycin killed more cells in the exponential phase than in the stationary phase. In another experiment with MRSA and VRSA...