Cryptosporidium spp. in Synanthropic Rodents: A Molecular Characterisation Study

Cryptosporidiosis is a zoonotic disease with a global distribution, caused by protozoa of the genus Cryptosporidium, and represents a significant public health concern worldwide. Synanthropic rodents are recognized as reservoirs of these pathogens, playing an important role in the dissemination and transmission. The aim of this study was to evaluate the occurrence and molecular diversity of Cryptosporidium spp. in synanthropic rodents and their potential role as reservoirs of zoonotic species.

A total of 85 intestinal samples from Rattus norvegicus (n = 25), Rattus rattus (n = 16), and Mus musculus (n = 44) captured in urban and peri-urban areas of La Plata and surrounding localities in Argentina were analysed. Molecular screening was performed using nested PCR targeting the 18 S rRNA gene and, in some selected cases, by analysing the gp60 gene.

Cryptosporidium DNA was detected in 11.8% (10/85; 95% CI: 5.8-20.5%) of the samples. The highest positivity rate was observed in R. norvegicus (16%, 4/25), followed by R. rattus (12.5%, 2/16) and M. musculus (9.1%, 4/44). Sequence analysis identified three isolates of C. muris, one C. ratti, one C. occultus, four C. tyzzeri, and one Cryptosporidium sp. rat genotype IV.

The detection of multiple Cryptosporidium species highlights the genetic diversity of this parasite in synanthropic rodents. Rodent-adapted Cryptosporidium spp. were detected in this study, some of which are potentially zoonotic, such as C. tyzzeri, C. muris and C. occultus. These findings emphasize the importance of integrated surveillance and control to understand transmission and reduce public health risks from Cryptosporidium spp.