[Streptococcus pneumoniae and beta-lactam antibiotic agents].

Pneumococcus has been known for over 100 years. Despite an intensive research, the problem of pneumococcal diseases has not yet been solved. During the last few decades, the incidence of pneumococcal pneumonia has declined, but the S. pneumoniae is today the main, or one of the most frequent, causative agents of meningitis, sinusitis, otitis media and conjunctivitis. Besides, cases of pneumococcal appendicitis, tubo-ovarian abscess, haemolytico-uremic syndrome, cellulitis and urinary infections have been described. Therefore, it is very important from medical point of view to follow-up its sensitivity to antibacterial drugs. Unfortunately, during the latest decades, an increase in percentage of resistant clinical isolates has been registered. It is obvious that the investigation of the sensitivity of pneumococci, that is, of their resistance to beta-lactam antibiotics is essential. The examination of the interaction between pneumococci and penicillin has resulted in significant discoveries concerning the mechanism of the effect of penicillin as well as the impact of penicillin-binding proteins, lipoteichoic acid and choline-residues in the cell wall. A particular contribution as regards the effect of penicillin has been achieved by linking murein hydrolases (autolythic enzymes) with the expression of bactericidal effect of penicillin. Besides, the model of pneumococcal resistance to penicillin together with the model of meticillin resistance of staphylococci enabled the perception of the new mechanism of bacteria resistance to beta-lactam antibiotics. Given the pathogenic potential of pneumococci and the increase of clinical isolates resistant to antibiotics, it can be concluded that immunoprophylaxis is of great importance. Although several polyvalent vaccines are being used, there are still unsolved problems whose solution will improve the safety of their application, contribute to a better efficiency and enable a widespread application of antipneumococcal vaccines.