HAEMOPHILUS INFLUENZAE CAPSULAR SEROTYPES AS DETERMINED BY FTIR AND MULTIVARIATE ANALYSIS

M. SANTOS, L. MARTORELLI, A. EFRON, M. REGUEIRA, A. GOMEZ ZAVAGLIA

Glasgow

Congreso; 10th SPEC conferences; 2018

Haemophilus influenzae is a human pathogen responsible for a wide range of localized and invasive infections, including meningitis, pneumonia, bacteremia, cellulitis, osteoarthritis and sepsis. It is also responsible for other localized diseases such as otitis, sinusitis and conjunctivitis1. Encapsulated H. influenzae isolates express one out of six antigenically different capsular polysaccharides (a, b, c, d, e, f), that can be identified using specific antisera. There also exist unencapsulated strains, which cannot be phenotypically typified. PCR is the method of choice to identify encapsulated H. influenzae. However, this technique is highly sensitive to contamination, thus requiring rigorous schemes of work2.The goal of this work was to define a multivariate model based on Fourier transform infrared spectroscopy (FTIR) and partial least squares discriminant analysis (PLS-DA) to determine the capsular type of H. influenza isolates, using PCR as a reference method.The model was constructed using 50 isolates from pediatric and adult patients with invasive H. influenza disease, attended at Malbrán Institute. The model was calibrated and then, validated using independent sets of data (100 spectra for calibration and 100 for validation).The model developed resulted an accurate one, and its implementation at a clinical level would contribute to replace more complex and time consuming techniques that require a harder work. This certainly contributes to improve the epidemiological vigilance of invasive disease caused by H. influenzae. Taking into account that it is a vaccine-preventable disease that primarily affects the pediatric population, this work provide a valuable tool to obtain relevant information that is critical to take decisions in Public Health.