Cat fleas (Ctenocephalides felis) are insect vectors for human bacterial diseases such as murine typhus, cat scratch disease, and bubonic plague. After a flea ingests an infected blood meal, flea-borne pathogens have been shown to transverse the flea gut epithelial barrier and invade the salivary glands, which may result in pathogen transmission via flea bite. However, the mechanism(s) by which pathogens escape from the flea gut barrier remains unclear. This project aimed to determine whether mechanical damage during blood feeding compromises the integrity of the flea gut epithelia. Because the insect gut primarily comprises collagen, we measured denatured collagen using a fluorescent collagen hybridizing peptide (CHP) from pooled flea guts at different time points post-emergence (0, 2, 7, 14, and 21 days). Our results show that collagen damage increases with age in the gut of blood-feeding fleas. In particular, collagen damage is highest at 7 days post-emergence.
