It should be noted that while promising new antibiotics are under development, they do not represent a complete or permanent answer to the resistance problem. Few new antibiotics are expected to reach the market soon. Those that are closest to market readiness are structurally similar to existing antibiotics, which means that some bacteria may already possess defenses against them. The development of new antibiotics with truly novel mechanisms of action has become a long and expensive process that may require almost 10 years of clinical trials and hundreds of millions of dollars. Nosocomial infections are hospital-acquired infections, usually discovered during hospitalization.
Recent organisms compound the complexity of treating nosocomial infections.
For example, nosocomial enterococcal infections are increasing in frequency, and enterococci have displayed resistance to virtually every antibiotic used to treat them. As an example of the impact of resistance on prescribing practices, the CDC has issued guidelines to reduce the use of vancomycin and, hence, the selection of vancomycin-resistant enterococci and Staphylococcus aureus. Also, methicillin-resistant staphylococci are appearing more frequently as a cause of nosocomial infections, and these strains are increasingly resistant to a number of other agents, including rifampin and fluoroquinolones. When prescribing antibiotics for the treatment of nosocomial infections, hospital physicians should take into account the likelihood of resistant pathogens causing the infections, as well as selection of a treatment that does not cause further resistance to develop. Also, physicians in hospitals may choose to reduce their usage of antibiotics altogether or alternate among various antibiotics to reduce overexposure to one particular agent.