Characterization of pneumococcal polysaccharides and serotyping of clinical isolates from Streptococcus pneumoniae by Fourier-transform infrared spectroscopy

TAMARA MENENDEZ; ALEJANDRA BOSCH; MARIA EUGENIA RODRIGUEZ; YOELIS CRUZ LEAL; DIEGO SERRA; CLAUDIA PRIETO; L CANAAN; J CHANG; GERARDO GUILLEN; OSVALDO YANTORNO

Alice Springs, Central Australia

Simposio; 5th International Symposium on Pneumococci and Pneumococcal Diseases; 2006

Infection control and epidemiological studies primarily require rapid and simple means of identifying and typing clinical isolates. Rapid and accurate identification of Streptococcus pneumoniae serotypes is an essential task in clinical microbiology since this organism is one of the leading causes of acute respiratory infections worldwide. Fourier transform (FT)- infrared (IR) spectroscopy could provide potential alternatives to conventional typing methods, because is fast, easy to perform, and economical. This vibrational spectroscopic technique could also be useful in the characterization of capsular polysaccharides purified from cells of S. pneumoniae, intended to be used in the formulation of plain or conjugated polysaccharide-based anti-pneumococcal vaccine. In the present work we present an analysis of capsular polysaccharides purified from strains of S. pneumoniae belonging to several serotypes. Contents of protein, lipopolysaccharide, DNA and cell-wall polysaccharide were assessed using FT-IR. Capsular polysaccharides belonging to several serotypes were well discriminated showing the potential usefulness of this techniques in the differentiation of pneumococci. Furthermore clinical isolates, belonging to several serotypes, were also discriminated by FT-IR. These results demonstrated the potential of FT-IR technique as routine methods for Streptococcus pneumoniae microbiological studies.