Definition:

Streptococcus pneumoniae is a common causative pathogen in community-acquired respiratory tract infections (RTIs), including acute otitis media, acute bacterial exacerbations of chronic bronchitis, acute bacterial sinusitis, and community-acquired pneumonia. It is also a major cause of bacteremia. Pneumococcal antibiotic resistance towards different families of antibiotics, in particular, penicillin and the macrocodes, continues to be a much-debated issue. The main mechanism of resistance in clinical isolates of S. pneumoniae involves the alteration of penicillin target proteins, the so-called penicillin binding protein (PBPs), which cause reduced affinities and/or binding capacities for the antibiotic molecule.