Many centers routinely culture bronchoscopy samples for bacteria and mycobacteria even when infections including tuberculosis (TB) are not strongly suspected. However, the value of this practice has been poorly defined.

Many centers routinely culture bronchoscopy samples for bacteria and mycobacteria even when infections including tuberculosis (TB) are not strongly suspected. However, the value of this practice has been poorly defined. Unnecessary bronchial cultures of bacteria may lead to over treatment in patients without clinical evidence of infections and may increase the drug resistant strains.

In areas with a high prevalence of TB, routine bronchial cultures may detect clinically unsuspected TB in an appreciable proportion of cases. However, in population with a low prevalence of TB, routine culture of bronchial aspirates may incur an unnecessary expanse and may lead to over diagnosis and over treatment of patients with non pathogenic atypical mycobacteria detected by acid-fast bacillus strains.

Inclusion Criteria:

1. patients who will undergo a bronchoscopy examination at pulmonary department in Meir Medical Center
2. patients who will sign on informed consent. -

Exclusion Criteria:

• 1)age under 18 years

All patients who will undergo a bronchoscopy examination at pulmonary department in Meir Medical Center and will sign on informed consent.