Simultaneous identification of Haemophilus influenzae and Haemophilus haemolyticus using real-time PCR.

Aim: To design a highly specific and sensitive multiplex real-time PCR assay for the differentiation of the pathogen Haemophilus influenzae from its nonpathogenic nearneighbor Haemophilus haemolyticus. Materials & methods: A comparison of 380 Haemophilus spp. genomes was used to identify loci specific for each species. Novel PCR assays targeting H. haemolyticus (hypD) and H. influenzae (siaT) were designed. Results & discussion: PCR screening across 143 isolates demonstrated 100% specificity for hypD and siaT. These two assays were multiplexed with the recently described fucP assay for further differentiation among H. influenzae. Conclusion: The triplex assay provides rapid, unambiguous, sensitive and highly specific genotyping results for the simultaneous detection of hypD and siaT, including fucose-positive H. influenzae (fucP), in a single PCR.