Real-time and multiplex real-time polymerase chain reactions for the detection of Bartonella henselae within cat flea, Ctenocephalides felis, samples

Bartonella henselae (Rhizobiales: Bartonellacae), the agent of cat-scratch disease, is an emerging bacterial pathogen which can be transmitted via infective faecal material of Ctenocephalides felis Bouche (Siphonaptera: Pulicidae). Worldwide, B. henselae has been identified in 1-53% of felines and 2.9-17.4% of fleas. Although culture is the routine method for detection, the procedure is time-consuming and is rarely used for isolation directly from flea vectors. The current study reports the development of a quantitative real-time polymerase chain reaction (qPCR) to detect and quantify B. henselae organisms from vector samples. The qPCR is specific and detects as few as 2.5 genome copies. To enable direct quantification of Bartonella organisms in different vector samples, we developed a qPCR to detect C. felis DNA that also acts as an extraction control. Combining both PCRs into a multiplex format validates B. henselae results when sampling flea populations, although there is a reduction in sensitivity. This reduction might be counteracted by a different combination of probe fluorophores.