Epidemiology of drug-resistant Streptococcus pneumoniae in the era of conjugate vaccines

ITQB PhD Seminars

Title : Insights into the epidemiology of drug-resistant Streptococcus pneumoniae and closely related streptococci in the era of conjugate vaccines

Speaker: Alexandra Simões

Laboratory: Molecular Genetics

Abstract
Streptococcus pneumoniae is an important human pathogen that can cause a wide range of diseases from otitis media to pneumoniae and meningitis. The correct identification of these isolates is not always easy since they have a lot of phenotypic and genotypic characteristics similar to closely related species from streptococcus of mitis group.
We will describe the phenotypic and genotypic properties of a collection of streptococcal isolates obtained in a single cross-sectional study conducted in 2006 aimed to describe the impact of the seven-valent pneumococcal conjugate vaccine (PCV7) in colonization. Strikingly, 5% of the presumptively identified pneumococcal isolates were found to have very high penicillin MICs which were absent in previous studies and could have serious clinical implications. Thus, we initiated a detailed characterization of these isolates consisting not only on classical strategies for pneumococcal identification, but also molecular strategies such as multilocus sequence analyses (MLSA), and comparative genomic hybridization (CGH).
We found that these isolates are not true pneumococci but have phenotypic properties and genomic determinants that are frequently associated with S. pneumoniae, challenging their correct identification by several of the currently accepted assays.

Short CV
• October 1998 - January 2003 - Degree (“licenciatura”) in Biotechnology of Natural Products by Universidade Independente.
• October 2003 - February 2006 – Master degree in Medical Microbiology by Universidade Nova de Lisboa.
• September 2004 - October 2005 - Master student at Laboratory of Molecular Genetics, ITQB/UNL under the supervision of Prof. Hermínia de Lencastre and Dr. Raquel Sá Leão.
• November 2005 - September 2006 - Research student at Laboratory of Molecular Genetics, ITQB/UNL under the supervision of Prof. Hermínia de Lencastre and Dr. Raquel Sá Leão.
• October 2006 - present - PhD student at Laboratory of Molecular Genetics, ITQB/UNL under the supervision of Prof. Hermínia de Lencastre and Dr. Raquel Sá Leão.