A pumpless and tubeless microfluidic device enables extended in vitro development of Cryptosporidium parvum

The enteric parasite Cryptosporidium remains a treatment challenge for drinking water utilities globally due to its resistance to chlorine disinfection. However, the lack of an in vitro culture system for Cryptosporidium that is both cost-effective and reliable remains a key bottleneck in Cryptosporidium research. Here we report that the microfluidic culture of HCT-8 cells under fluid shear stress enables the extended development of Cryptosporidium parvum. Specifically, the growth of C. parvum in a user-friendly pumpless microfluidic device was assessed using immunofluorescence assays, scanning electron microscopy and quantitative PCR, which revealed that development peaked at six days post-infection but continued for ten days in total. Oocysts produced within the microfluidic device were infective to fresh HCT-8 monolayers, however these oocysts were only present at low levels. We anticipate that such microfluidic approaches will facilitate a wide range of in vitro studies on Cryptosporidium and may have the potential to be further developed as a routine infectivity assessment tool for the water industry.