115 Mark Wilks (ed.), PCR Detection of Microbial Pathogens: Second Edition, Methods in Molecular Biology, vol. 943, DOI 10.1007/978-1-60327-353-4_7, © Springer Science+Business Media, LLC 2013 Chapter 7 PCR Detection of Haemophilus influenzae from Respiratory Specimens Guma M.K. Abdeldaim and Björn Herrmann Abstract The detection of Haemophilus influenzae by conventional methods like culture is time-consuming and may give false-negative results, especially during ongoing antibiotic treatment. Therefore, non-culture based methods that are sensitive, specific, and rapid are valuable for early diagnosis and effective therapy. Here we describe a quantitative real-time PCR assay based on the outer membrane P6 gene omp6, to detect H. influenzae and its application on respiratory tract specimens. Key words: Haemophilus influenzae, Outer membrane P6, Quantitative PCR, Real-time PCR, Pneumonia Haemophilus influenzae is a common pathogen causing a variety of infections, including respiratory tract infections and meningitis. Detection of H. influenzae by conventional methods like culture is cheap and facilitates antibiotic resistance detection; however, it is time-consuming and may give false-negative results especially dur- ing ongoing antibiotic treatment. Therefore, there is a need for non-culture methods that are sensitive, specific and rapid for early diagnosis and effective therapy. In the last decade an abundance of nucleic acid-based assays have been developed for the detection of H. influenzae. The genus Haemophilus is characterized by a promiscuous abil- ity to exchange genetic material by transformation and recombina- tion, both between strains within species (1–3) and between species (4). This genetic exchange can lead to high strain to strain variation 1. Introduction