73 yr. old male with respiratory problems had aeromonas infection treated with invanz administered into vena cava intravenously for 2 weeks. This was followed by a stenotrophomonas infection 2 weeks after prior treatment ended. Hospitalized for 4 days and now being treated with Bactrim and prenidsone. Any other treatment suggestions? How to prevent reoccurence of gram negative bacteria? Uses a nebulized and aerosol inhalers. Can they be a source of infection?