Not sure why this was down voted because it's true. Only a few big pharma have R&D programs in the antibacterial space. As a reply above states, the current system penalizes new antibiotics by reserving them for only the most severe cases. With the cost of a new antibiotic approval in the hundreds of millions of dollars, companies put their R&D dollars into areas with better returns.

That being said, a few new legislative changes have happened and will happens (GAIN Act approved, DISARM Act being considered) that will change the economics of antibiotic research and have already prompted drug companies to get back into the field.