Serotyping and antibiotic susceptibility of Streptococcus pneumoniae strains isolated in Algeria from 2001 to 2010

Introduction. - Pneumococcal infections are a major public health problem because of the virulence of this bacterium and its ability to develop resistance. Material and method. - Two hundred and ninety-four strains of Streptococcus pneumoniae were isolated from sterile (56.8%) and non-sterile samples (43.2%), from January 2001 to July 2010. Results. - The interpretation of antibiotic susceptibility testing, according to CLSI criteria (M100-S21 2011), yielded a 25.2% overall resistance to penicillin, with 23.5% of strains isolated from CSF (meningitis), and only 1.7% in other samples. Resistance to cefotaxime was 8.1% (including 4.4% at a high level). The most common serotypes were: 14 (19.5%), 23F (9.7%), 6B (9.3%), 19F (5.4%), and serotype 1 (5%). The percentage of these serotypes isolated from normally sterile sites in children under 5 years of age was 31.25% for 14, 10.4% for 23F, 8.3% for 19F, 6.25% for 6B, and 4.2% for serotype I. The theoretical vaccinal coverage against invasive infections in children under 2 years of age was 61.5%, 69.2%, and 76.9% for the 7-valent, 10-valent, and 13-valent conjugate vaccines, respectively. Penicillin non-susceptible Streptococcus pneumoniae (PNSP) strains accounted for 67.1, 68.6, and 72.8% for each of these three vaccines. Conclusion. - There was a variation of serotype rates compared to previous studies. The increase in pneumococcal antibiotic resistance is concerning, particularly for the treatment of pneumococcal infections in children and infants. Pneumococcal vaccination is not compulsory yet in Algeria. (C) 2011 Elsevier Masson SAS. All rights reserved.