Revista argentina de microbiología
versión On-line ISSN 1851-7617
WELTMAN, G. et al. PCR-based capsular typing of Haemophilus influenzae isolates non-typeable by agglutination. Rev. argent. microbiol. [online]. 2005, vol.37, n.4, pp. 199-202. ISSN 1851-7617.
Haemophilus influenzae is recognized as a pathogenic agent responsible of localized and systemic infections. Six antigenically different capsular polysaccharide types have been described (a, b, c, d, e, and f ) which can be identified by slide agglutination with specific antisera. Besides there are non capsulated strains that cannot be typed by slide agglutination. The introduction of the conjugated vaccine produced an important reduction of invasive diseases caused by H. influenzae type b. Capsular typing by PCR is the most appropriated method for distinguishing non capsulated strains from capsule deficient type b mutants (b-) and for detecting strains of other serotypes that cannot be detected by slide agglutination. Capsular genotype was studied in 38 isolates of non-typeable Haemophilus influenzae received at INEIANLIS "Dr. Carlos G. Malbrán" between 2002-2004. Of the isolates included in this study 78.9% of them were recovered from blood cultures and most of them were associated with a respiratory focus. By PCR technique 100% of the isolates were identified as non-capsulate H. influenzae and genotype b-was not detected.
Palabras clave : Haemophilus influenzae; non-capsulate isolates; PCR capsular typing.