[Isolation and biological characterization of Legionella pneumophila mutants resistant to aminoglycoside antibotics and their protective action]. / Poluchenie, biologicheskaya kharakteristika mutantov Legionella pneumophila k nekotorym aminoglikozidnym antibiotikam i ikh protektivnye svolstva.

Preliminary estimation of virulence in some antibiotic resistant mutants of Legionella pneumophila, Philadelphia 1 in various models of infection revealed its decrease in the mutants resistant to azlocillin, cefotaxime, fluoroquinolone LIB-80, neamine and streptomycin. Detailed investigation of the neamine resistant mutants showed that in relation to streptomycin susceptibility such mutants could be divided into 3 classes: susceptible to streptomycin, resistant to high concentrations of streptomycin and resistant to moderate concentrations of streptomycin. Part of mutants Nea(r)Strr and Nea(r)Strr500 and all mutants Nea(r)Strr100 proved to be less virulent with respect to guinea pigs and chick embryos. The study of the spectinomycin resistant mutants of Legionella spp. did not reveal any changes in the virulence which made it possible to suggest that the influence of the mutations in the ribosomal protein genes determining resistance to streptomycin and neamine on virulence of L. pneumophila was based on the interdependence of the mutant effect on the suppression and the influence on the virulence detected by us in S. flexneri, Y. pseudotuberculosis, L. monocytogenes and F. tularensis. The Legionella mutants Nea(r)Strr100 were characterized by significant protective activity and protected immunized guinea pigs when tested in a model of their aerogenic infection.

[Community-acquired pneumonia: Etiological diagnosis]. / Vnebol'nichno priobretennaya pnevmoniya: 'etiologicheskil diagnoz

Microbiological and immunoserological approaches were used in etiological diagnosis of community-acquired pneumonia. It was concluded that Streptococcus pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Legionella pneumophila and Klebsiella pneumoniae predominated in the etiological structure of present severe community-acquired pneumonia. The most actual causative agents of nonsevere community-acquired pneumonia in persons under 60 were S. pneumoniae, Hemophilus influenzae, Mycoplasma pneumoniae and Chlamydia pneumoniae. Nonsevere community-acquired pneumonia in persons over 60 and/ or at the background of chronic obstructive pulmonary diseases, diabetes mellitus or other affections was most frequently due to S. pneumoniae, H. influenzae and aerobic gramnegative microbes.