Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 41 2 2019 06 10 A comparative survey on effect of nanoparticles and microparticles of Chitosan on Cryptosporidium parvum experimental infection in mice. 72 80 10.34172/mj.2019.022 EN Parisa Shahbazi https://orcid.org/0000-0003-3451-044X Ahmad Nematollahi https://orcid.org/0000-0001-5219-3420 Ali Haghi https://orcid.org/0000-0001-5178-5408 Amir Ali Shahbazfar https://orcid.org/0000-0003-4651-9417 Katayoon Nofuzi https://orcid.org/0000-0001-8270-595X Journal Article 10.34172/mj.2019.022 2017 08 08 Background: The inhibitory effect of Nanoparticles and microparticles of Chitosan on infection due to Cryptosporidium was studied. Methods: For this purpose 30 NMRI mice with 4-6 weeks old were randomly divided into five groups including, uninfected /untreated control group, infected/untreated control group, infected/ treated with chitosan (0.5 mg in per approve), infected/ treated with nano chitosan (0.5 mg in per approve) and infected/ treated with nano chitosan (1 mg in per approve). Except first group, mice were experimentally infected by oral administration of 104 C. parvum oocysts for per animal. Treatment groups were administered with nano chitosan and micro particles of chitosan. The presence of oocyst shedding, weight gain/loss, the histopathology of intestine sections and serology were examined in all groups. Results: There was no significant difference between the mean of weight gain/loss in control and treatment groups. Oocyst shedding was significantly (p<0.05) reduced in treatment groups; in spite of more reduction in oocyst shedding in use of nano chitosan but no significant difference (p≤0.05) between the treatment with chitosan and nano chitosan was seen. In the HI test was also significant difference (p≤0.05) between the treatment and control groups. Histopathological analysis of intestine sections further not supported the clinical and parasitological findings . Conclusion: The nano chitosan and chitosan were effective against experimentally infection with Cryptosporidium parvum in mice; therefore can be used as a treatment for cryptosporidiosis.