Characterizations of Prototheca wickerhamii clinical isolates and their interactions with macrophages

As global climate change exacerbates, the emergence of rare pathogens causing outbreaks is on the rise, with Prototheca species becoming notable threats. Within the protothecosis science popularization and monitoring consortium (PSPMC), we have isolated nearly a hundred strains of Prototheca species in China in recent years. Notably, Prototheca wickerhamii is the predominant pathogen, causing skin and soft tissue infections and occasionally bloodstream infections. This study, conducted from the clinical microbiology laboratory perspective, delineates the characteristics of P. wickerhamii to facilitate its swift identification by clinical microbiologists. We discovered that tigecycline shows exceptional in vitro activity against P. wickerhamii. Additionally, our findings suggest that P. wickerhamii may exhibit low virulence towards macrophages, while macrophages also demonstrate a low killing ability against P. wickerhamii.