Abstract
Objectives: This study assessed MDR invasive isolates of Streptococcus pneumoniae, in relation to serotype evolution in Canada between 2011 and 2015 as part of the annual SAVE study.
Methods: As part of a collaboration between the Canadian Antimicrobial Resistance Alliance and Public Health Agency of Canada-National Microbiology Laboratory, 6207 invasive isolates of S. pneumoniae were evaluated. All isolates were serotyped and had antimicrobial susceptibility testing performed, in accordance with CLSI guidelines (M07-A10, 2015). Complete susceptibility profiles were available for 6001 isolates. MDR was defined as resistance to three or more classes of antimicrobial agents (with penicillin MIC ≥2 mg/L defined as resistant).
Results: The overall rate of MDR S. pneumoniae was 6.2% (372/6001) in SAVE, decreasing significantly from 8.5% in 2011 to 5.6% in 2015 (P = 0.0041). MDR was observed in 32 serotypes, with serotypes 15A and 19A predominating (26.6% and 41.7% of the MDR isolates, respectively). The overall proportion of serotypes 19A, 7F and 33A decreased significantly (P < 0.0001) throughout the study. The annual proportion of serotypes 7C, 8, 9N, 10A, 20, 24F, 29, 31, 33F, 35B and 38 increased throughout the study; however, among these increasing serotypes, MDR was only notable (>5%) for 24F and 33F.
Conclusions: In 2015, 56.3% of invasive MDR S. pneumoniae were serotypes included in the PCV-13 vaccine. PCV-13 includes the most commonly identified serotype, 19A; however, other increasingly important MDR serotypes, such as 15A, 24F and 33F, are notably not in the currently used vaccines.
Original language | English |
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Pages (from-to) | vii12-vii19 |
Journal | Journal of Antimicrobial Chemotherapy |
Volume | 73 |
Issue number | suppl_7 |
DOIs | |
Publication status | Published - 2 Jul 2018 |
Keywords
- Adolescent
- Adult
- Aged
- Anti-Bacterial Agents/pharmacology
- Canada
- Child
- Child, Preschool
- Clarithromycin/pharmacology
- Drug Resistance, Multiple, Bacterial
- Humans
- Infant
- Infant, Newborn
- Microbial Sensitivity Tests
- Middle Aged
- Penicillins/pharmacology
- Pneumococcal Infections/blood
- Pneumococcal Vaccines/administration & dosage
- Serogroup
- Serotyping
- Streptococcus pneumoniae/classification
- Vancomycin/pharmacology
- Young Adult