Identification and Detection of Invasive Haemophilus Influenzae Type b Strains in Clinical Samples Using Polymerase Chain Reaction

Background and purpose: Haemophilus influenzae type b (Hib), is one of the major causes of bacterial meningitis in children younger than five years of age, especially in countries that immunization against Hib is not conducted. In this study we have determined the serotype, encapsulated Haemophilus influenzae strains isolated from clinical samples by polymerase chain reaction (PCR) method. Material and Methods: In this study, DNA of H. Influenzae spp was extracted through boiling method. The encapsulated strains were determined by bexA gene primers. The encapsulated strains serotype were then detected using type-specific primer sets "a to f". Results: From the total of 50 strains of the Haemophilus influenzae isolated from clinical specimen, four strains have shown the bex A gene which all of them were encapsulated and all of four isolates have been determined as type b strains. Conclusion: It is well shown that H influenzae spp were not detected by routinely culture method in many clinical laboratories. Despite the presence of pathogenic strains of Hib in different clinical specimens, molecular diagnostic such as PCR should be replaced and performed for miss detected bacteria.