Ciprofloxacin is a broad spectrum antibiotic which is bactericidal to dangerous gram negative bacteria like pseudomonas and also effective against gram positive bacteria like staphylococcus aureus if they are methicillin sensitive strains. Ciprofloxacin is not effective against MRSA (methicillin resistant) strains.
If the S.aureus strain you are having is confirmed to be MRSA, then another antibiotic Vancomycin may have to be added. MRSA is very difficult to treat and develop resistance to most of the antibiotics. So treatment must be planned carefully. Pseudomonas is dangerous especially in old age and more so, if you have diabetes. Vancomycin though effective against MRSA, does not work against gram negative bacteria like pseudomonas. So either ciprofloxacin has to be continued along with vancomycin or another antibiotic with good activity against pseudomonas must be added. Extended spectrum pencillins like piperacillin and ticarcillin are very effective against pseudomonas but are again ineffective against MRSA. Treatment must be concentrated on getting rid of both the pathogens. Check with your doctor first regarding the sensitivity and strain of S.aureus and if found out to be resistant strain, a combination of antibiotics might be necessary for effective treatment.
Hope this helps. Thank you.