Establishment and Clinical Application of a RPA-LFS Assay for Detection of Capsulated and Non-Capsulated Haemophilus influenzae

A recombinase polymerase amplification-lateral flow strip assay was established for detection of the outer membrane protein P6 ( ) and the capsule encoding gene of and the detection limit, sensitivity, and specificity were determined. Specific primers and probes were designed based on the published nucleotide sequences of and . The minimum detection limit was determined with standard strains and the practical applicability of the RPA-LFS assay was assessed by detection of 209 clinical samples. The results confirmed that the RPA-LFS assay was both specific and sensitive for the detection of capsulated and non-capsulated with a detection limit of 1 CFU/µL. The detection rate of the 209 clinical samples was 97.1%, while the detection rate of capsulated was 63.2%. The detection results were consistent with the traditional culture method and dual polymerase chain reaction (PCR), confirming the applicability of the RPA-LFS assay.