Under which circumstances is Pseudomonas turning to be mucoid?

Question

Hello,
my daughter, CF, 8 years old, has had in February 2015 for the first time Pseudomonas aeruginosa. Two cycles of tobramycin per inhalation followed, in the third cycle in combination with ciprofloxacin, after 3-6months PA could be again and again found. Then three i.v. therapies followed (1. tobramycin and ceftazidim, 2. tobramycin and meropenem, 3. tobramycin and piperacillin) and permanent inhalation of colistin, for 9 months every 4 weeks in change with tobramycin.
For one year, the antibodies had always been positive. They have fortunately turned to be negative again. As the PA have anew been found and another i.v.therapy is planned, I ask myself, which circumstances make the germ turn to be mucoid. Fortunately it deals until now with a non-mucoid PA.
Is there any data about this when it is turning to become mucoid?
Many thanks for your advice.
V.M.

Answer

Dear questioner,
a mucoid Pseudomonas aeruginosa is always a hint for a long-term infection with the germ. Mucoid means that a different way of growing of the germ started. The germs produce due to a mutation of a certain gene (muc-gene) a permanent over-production of a mucus substance. This substance, also called alginate, protects the germ of antibiotics and the defence cells of the host. By this change it is even more difficult to eliminate the germ. And often the mucoid PA can be cultured over many years. Mostly the initiators of the mucoid growth are regarded to be antibiotic therapies as well as the infection defense (thus the leukocytes and many other substances, that are produced during an infection). Therefore it is best, to treat the germ as intensive as possible, like it has been done in your daughter, in order to prevent a chronic infection.
I hope to have helped you with my anser,
Best regards,

BarbaraKahl

05.12.2016