The Office of Health Economics just released a report on incentives to stimulate antibiotic research and development( I was unable to connect to their website to provide you a link to the report - but you may have better luck at ohe.org). They focused on pull incentives in particular, and they focused on what would work in Europe while noting that the European contribution to any incentive should align with Europe’s contribution to the antibiotic marketplace in general. The report is very well done and well considered. I recommend a careful read of this work.
What about companies that recently departed the area but are having second thoughts like J&J? Then there is Pfizer that seems committed to antibiotics as an add-on for their hospital sales force but, as far as I know, has not yet committed to re-establishing their antibiotic discovery research effort (an email to Pfizer went unanswered).