Invasive pneumococci before the introduction of pneumococcal conjugate vaccine in Turkey: antimicrobial susceptibility, serotype distribution, and molecular identification of macrolide resistance

Abstract

This study evaluates the antimicrobial susceptibilities and serotype distributions of invasive Streptococcus pneumoniae (SP) isolates identified in a Turkish hospital before the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). The susceptibilities of all isolates were determined by evaluating six antibiotics: penicillin (PEN), ceftriaxone (CRO), levofloxacin (LEV), erythromycin (ERY), clindamycin (CD), and vancomycin (VAN). Serotyping and amplification of macrolide resistance genes were performed. Sixteen (50%) and four (2%) isolates were resistant to PEN and LEV, respectively. No isolates demonstrated VAN resistance. Intermediate resistance to CRO was found in 4% of all invasive isolates. Twenty-three (12·6%) isolates were resistant to ERY. Four (2%) invasive SP isolates demonstrated multidrug resistance. Serogroups 3, 5, 6, 8, 9, and 23 were the most common in both age groups. The potential coverage rates of PCV7 and PCV13 were 44·1 and 66·1% in children and 39·8 and 71·5% in adults, respectively. Continuous surveillance of antimicrobial resistance is required.

Keywords:

• Antimicrobial resistance
• PCV7
• PCV13
• PCR
• Serotype
• Streptococcus pneumoniae

Acknowledgements

Part of this work was presented at the 21st European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) and the 27th International Congress of Chemotherapy (ICC), Milan, Italy, 7–10 May 2011. This study was supported by the Hacettepe University Scientific Research Unit (project no: 08D12101002).