Ciprofloxacin against Staphylococcus aureus

Question

Hello,
my daughter is 7-years-old and had in February the first finding of Pseudomonas. Therefore she inhaled 2 cycles of Tobramycin, after that, it still remained there, so that an i.v. therapy with ceftazidim and tobramycin has been done. Now she has to inhale for one year with colistin. Now the Pseudomonas can not be detected anymore, but a Staphylococcus aureus. It had been treated for four weeks with cefuroxim, now she is told to take every three months ciprofloxacin in addition to colistin with the message, that this would also fight the Staph aureus. In the antibiogram it is not listed and this is not the classical substance, or not?? Does ciprofloxacin has an effect on Staph aureus?
Many thanks for your advice. She is taking ciprofloxacin for 5 days now.
I am worrying that the Staph becomes an MRSA if it is not fought sufficiently or with a wrong substance.
V.m.

Answer

Hello,

you report, that your 7-year-old daughter has had the first finding of Pseudomonas in February. Then, an inhalation therapy with Tobramycin had been done for 8 weeks. Because the germ could then still be found, an i.v. therapy with ceftazidim and tobramycin had been performed and afterwards an inhalative therapy with colistin had been started. Pseudomonas can at the moment not be found, but Staphylococcus aureus, that had been treated for four weeks with cefuroxim: now you have been advised that your daughter should take every 3 months ciprofloxacin, as this drug would also treat the Staph aureus. You worry because ciprofloxacin would be known to be a classical drug against Staphylococcus and you are afraid, that the Staph could probably turn to be an MRSA.
In general it can be said about the plan of your CF physicians, that they used one of the actual common treatment regimes of the first therapy of Pseudomonas. As after the first inhalation of tobramycin the Pseudomonas could not be eliminated, it has been changed to a treatment regimen, that has been developed by the collegues of a large CF center in Kopenhagen and that is accepted worldwide. The combination of an inhalation with colistin with an oral interval therapy with ciprofloxacin is therefore primarily targeted to the Pseudomonas. It is only partly true, that ciprofloxacin also treats the Staph aureus. Ciprofloxacin has olny moderate activity aginst Staph and is therefore not tested in the antibiogram. Therefore one cannot count on a considerable effect of ciprofloxacin on Staph aureus. On the other hand, it is improbable that the Staph is going to get an MRSA because of this treatment. At the moment, the main target shoule be the treamtent and elimination of Pseudmonas. One should observe the Staph with calmness, as long as the health status of your daughter is stable. If it should come to a clinical worsening under the current therapeutic regimen and the sole finding of Staphy aureus, a targeted therapy with cefuroxim sholuld be initiated.

Best regards,
Dr. H.-G. Posselt

03.12.2015