Characteristics of Isolates Streptococcus pneumoniae from Middle-Aged and Elderly Adults in Brazil: Capsular Serotypes and Antimicrobial Sensitivity to Invasive Infections.

Pneumococcal infection cause frequent, serious problems among middle aged and elderly populations worldwide. Efforts to prevent mortality caused by pneumococci are based mainly on rapid diagnosis of the infection and appropriate antimicrobial therapy. Vaccination is considered to be the best approach to prevent the disease in at risk populations and the current 23-valent pneumococcal polysaccharide vaccine is recommended for people &gte;65 years of age. To evaluate the present antibiotic sensitivity patterns and the potential for vaccine use to prevent this disease in Brazil, 94 isolates of pneumococci from normally sterile body sites from patients &gte;50 years of age were analyzed for capsular serotypes and antimicrobial resistance. Among the total isolates, 7.4% (n = 7) of the isolates showed intermediate level resistance to penicillin (IR). Among the IR isolates, 6 were also resistant to trimethoprim-sulfamethoxazole. All isolates were susceptible to cefotaxime, chloramphenicol, erythromycin, and vancomycin. Twenty-eight serotypes were identified and the serotypes included in the 23-valent vaccine accounted for 81.7%. By adding the cross-reacting serotypes, the percentage of vaccine preventable infections was 90.3%. Each of intermediate level resistant strains were among the 23 serotypes included in pneumococcal vaccine. This preliminary data on the distribution of serotype of S.pneumoniae among those &gte;50 years of age in Brazil, and the potential for increased antimicrobial resistance to penicillin and trimethoprim-sulfamethoxazole, support the use of pneumococcal vaccine in this population.