[Bacteriological and mycological analysis of material taken from lower respiratory tract in patients with malignancy]

The immunosuppression and incorrect function of the natural protection mechanisms are conducive to lower respiratory tract infections. The patients with malignancy, especially with lung cancer, belong to the group at higher risk to develop an infection due to accumulation of numerous risk factors.

The aim of this study was to assess the occurrence of bacteria and fungi in materials taken from lower respiratory tract from the patients treated in Thoracic Surgery and Clinical Department of Thoracic Surgery and Tumours from 2000 to 2004. The frequency of occurrence of alert-pathogens was also analyzed.

The retrospective analysis was carried out among 102 positive samples (sputum--68, bronchial secretion--32 and bronchoalveolar lavage--2). The material was obtained from patients treated due to lung cancer (n=84), pulmonary metastases (n=6), primary neoplasms of the chest wall (n=2), lymphoma of the mediastinum (n=3), mesothelioma (n=1) and other malignancies (n=6). The examinations were conducted in compliance with the current procedures, generally accepted in microbiological laboratories.

Seventy examined patients (68.63%) had bronchial colonization with bacteria being the potential etiologic agents of lower respiratory tract infections. The presence of yeast-like fungi was confirmed in 62 patients (60.78%). The most frequent strains isolated were: Enterobacteriaceae (40.86%), followed by Staphylococcus aureus (21.51%), Haemophilus influenzae (16.13%) and Streptococcus pneumoniae (7.53%). The nonfermenting gram-negative rods Pseudomonas spp. and Acinetobacter spp. occurred as follows: 6.45% and 3.23%. Among yeast-like fungi the most common species isolated was Candida albicans (63.77%) which occurred more frequently in sputum than in bronchial secretion (p < 0.0004). The strains of Enterobacteriaceae and nonfermenting gram-negative bacillus producing extended-spectrum beta lactamase (ESBL) were not discovered like MBL (metallo- beta lactamase) positive strains. All of the Staphylococcus aureus strains were sensitive to the methicillin. Haemophilus influenzae did not show ampicillin resistance. We observed two strains Streptococcus pneumoniae which were penicillin intermediate but susceptible to the third-generation cephalosporins.

Identification of the potential etiological agents of lower respiratory tract infections can be useful in the rational management of the antibiotics policy in the patients with maliganacy.