Understanding the mechanisms of pathogenesis in the pathogenic alga Prototheca

Prototheca are a genus of heterotrophic algae containing several species of known opportunistic pathogens; notably Prototheca zopfii and Prototheca wickerhamii.
They are a known, though rare, pathogen of humans, and are a potentially significant causative agent of bovine mastitis. Almost nothing is known about the pathogenicity of these organisms, and even knowledge about their prevalence is somewhat scarce.
The only available nationwide study (conducted in Poland) estimates that Prototheca species may be the third most common cause of bovine mastitis. Treatment of bovine Prototheca infections is not economical, meaning the primary response is culling of any infected animals. These infections therefore represent a potentially huge economic loss and have a significant impact on animal welfare.
On a more fundamental level, investigation of Prototheca, and related organisms, provides an opportunity to produce novel insights into the evolution of virulence more generally. Furthermore, as Prototheca is a rare class of pathogen (an alga), investigations of the host's immune response against it may reveal new mechanisms for mammalian immunity, and highlight previously unappreciated flexibility/limitations of the mammalian immune system.