[Isolation of mycobacteria in patients with cystic fibrosis: a prospective study].

OBJECTIVE

A prospective study to assess the incidence of mycobacterial infection in patients with cystic fibrosis in our geographical area was performed.

PATIENTS AND METHODS

A monitored follow-up was carried out in 91 patients over a period of 20 months, during which time 522 respiratory samples were obtained. These were processed by standard techniques of decontamination with sodiumlaurylsulphate, cultured on Löwenstein-Jensen medium and identified by biochemical and cultural characteristics and hybridization by specific probes. At the same time, the clinical reports of the patients with positive culture were reviewed.

RESULTS

Positive cultures of mycobacteria were obtained from 4 patients. Environmental mycobacteria were isolated in three of them (M. xenopi, M. fortuitum and M. avium) and M. chelonei and later M. tuberculosis in the forth. None of the isolations of environmental mycobacteria were associated with deterioration of pulmonary function, while the isolation of M. tuberculosis in one of the patients coincided with an episode of decompensation in respiratory function. None of the patients presented sensitivity of the tuberculin skin test.

CONCLUSIONS

It is advisable to investigate the mycobacteria in the presence of exacerbation of the respiratory process, above all taking into account the high incidence of tuberculosis in our geographical area. The isolation of environmental mycobacteria was not associated with pulmonary deterioration, but they represent a potential danger as opportunist pathogens, affecting patients of which many are candidates for lung transplants.