[Microbial spectrum of respiratory tract in patients with different pulmonary diseases]

To study microbial spectrum of respiratory tract in patients with pulmonary diseases.

Culture of sputum/bronchial lavage fluid (S/BLF) and bronchoalveolar lavage fluid obtained from 36 HIV-negative patients with infiltrative pulmonary tuberculosis (IT), 18 patients with community-acquired pneumonia (CAP), 18 patients with lung cancer (LC) was performed on 5% blood agar using method of serial dilutions. Following concentrations of microorganisms were considered as diagnostic: 10(6) CFU/ml--in sputum, 10(4) CFU/ml--in bronchial lavage fluid, 10(3) CFU/ ml--in bronchoalveolar lavage fluid.

Nonspecific microflora in S/BLF was isolated 94.4% of patients (34--IT, 17--CAP, and 17-LC), and in bronchoalveolar lavage fluid - in 69.4%, 61.1%, and 77.8% of patients respectively. Nonspecific microflora was presented as both monoculture and microbial associations. In group of patients with IT, the most frequent were associations of bacteria from Nesseriaceae family and streptococci, streptococci and staphylococci, streptococci and fungi from Candida genus. In group of patients with CAP, monocultures of microorganisms were detected rarely, whereas, in contrast, microbial associations were detected more frequently. In patients with LC, monocultures of microorganisms were isolated from S/ BLF in 2 cases and from broncoalveolar lavage fluid--in 9 cases; associations were detected in overwhelming majority of patients, more frequently--combination of streptococci and Neisseria, streptococci and yeast-like fungi. In patients with IT and CAP, Streptococcus pneumoniae was the most frequently detected microorganism, whereas non-fermenting bacteria predominated in lavage fluid. Diagnostic titers from bronchoalveolar lavage fluid in patients with CAP were detected only for Acinetobacter calcoaceticus, Citrobacterfreundii, and Escherichia coli. S.pneumoniae and Staphylococcus spp. were most frequently isolated from S/BLF in patients with LC, whereas in broncoalveolar lavage fluid of such patients S. pneumoniae, Pseudomonas aeruginosa, and non-fermenting bacteria were detected in titers exceeding diagnostic threshold.

Species composition of nonspecific microflora during IT, CAP, and LC was virtually the same; microorganisms were detected in equal proportions.