[Microbiology and cystic fibrosis]

The respiratory infections are the rule in sick persons of cystic fibrosis. After the colonization in one's early childhood by Staphylococcus aureus and Haemophilus influenzae, it is established the colonization produced by the mucous strains of Pseudomonas aeruginosa, the principal etiogenic of this illness, that can become to isolate in more than 95% of sick persons at three years old. That's why the etiogenic factors of this bacterium are studied, as they are toxins, pigments, enzymes, and principally the alginate, hydrocarbonated polymer responsible of the mucous substance that covers these characteristic strains of cystic fibrosis sick persons. All these components are regulated by a complex genome, the biggest until noe sequenced in bacterium, and that explains the importance of the microorganism and its natural resistance or acquired to environmental alterations and to antibiotics and disinfectants. In the evolution of the clinic chart, it can appear others gramnegative bacteriums (among it emphasizes Burkholderia cepacia and Stenotrophomonas maltophilia), mycobacterium and even fungus; all that would explain the chronification of lung charts and the difficulty of these sick persons treatment.