Legionella pneumophlla (L.. Pneumophila) organisms although constitute a small
proportion of bacterial count, they can cause severe pneumonia or acute respiratory
insufficiency. It is now considered as one of the important nosocomial agents. We aimed to
study Legionella as a causative agent of nosocomial pneumonia. This was achieved by complete
bacteriological examination and genetic study of clinical and environmental samples. Out of
150 environmental samples, only 8 (5.3 %) were positive for L pneumophila, and out of 100
clinical samples, only 2 (2%) were positive for L. pneumophila. As regards the 8 environmental
samples, 5 (62.5%) were from faucets, and the swab method gave the greatest yield 4 (50%) out
of 8 positive samples. Regarding the clinical samples, the isolated strains were; one from
. sputum and the other from pleural effusion. They were isolated from patients with malignant
diseases. Restriction endonucleasc analysis (REA) showed that the isolates from patients and
water faucets were genetically similar indicating that water faucets were the most probable
source of infection. All the isolated 10 strains (environmental and clinical) belonged to
serogroup 1 (6) and to serogroup 2 (4). These results revealed the importance of considering
legionella in any nosocomial infection especially in those high risk patients. |
