[Identification of Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis by polymerase chain reaction]

Abstract

Introduction: Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis are the main human pathogens that cause meningitis.

Objective: Primers omp2, lytA and crgA were evaluated with H. influenzae, S. pnumoniae and N. meningitidis DNA in a multiplex PCR, determining the sensitivity and the specificity of the technique.

Materials and methods: Primers for H. influenzae outer membrane protein (omp2, 1000 pb), S. pneumoniae autolysin (lytA, 395 pb) and N. meningitidis, contact regulated gene (crgA, 230 pb) were evaluated in a multiplex PCR, determining the sensitivity and the specificity of the technique.

Results: Reproducible results were obtained with 50 nM of each of the three primers and annealing temperature of 57 degrees C in the multiplex PCR, obtaining a sensitivity of 12.5 fg for H. influenzae and S. pneumoniae and 3.12 fg for N. meningitidis. No cross reactions with other microorganisms agents of meningitis or related with the genera, appeared.

Conclusions: The results for sensitivity and specificity suggest that the evaluated primers can be used for the development of a PCR in a multiplex format to the identification of the three main pathogens that cause meningitis.