First report of Cryptosporidium hominis in a freshwater sponge

Identification of Cryptosporidium oocyst is essential in ensuring water quality fit for human use, consumption, and recreation. This communication proposes the supplemental analysis of substrate-associated biofilms, in particular, freshwater sponges in improving case finding of waterborne-protozoan pathogens (WBPP) in environmental aquatic samples. In this study, a small portion of a mature freshwater sponge under the Genus Spongilla was subjected to microscopic and molecular analysis to identify the presence of Cryptosporidium. Microscopic screening with modified Kinyoun's staining (MK) and microscopic confirmation using direct antibody fluorescent testing (IFT) returned with Cryptosporidium spp. positive findings. Molecular investigation resulted in the confirmation of Cryptosporidium hominis upon sequencing of PCR products and phylogenetic analysis. This is the first report of a pathogenic protozoan, C. hominis isolated from a freshwater sponge. The results of this study provide evidence of the value of expanding water quality assessment strategies to the analysis of substrate-associated biofilms and sponges in improving case finding of WBPP in natural aquatic environments.