Therapeutic Effect of Chitosan Nanoparticles and Metronidazole in Treatment of Experimentally Giardiasis Infected Hamsters

Background: the present study aimed to assess the therapeutic effect of chi-tosan nanoparticles and metronidazole against giardia lamblia as well as evaluate the efficacy of loading metronidazole on chitosan nanoparticles. methods: this study was carried out at medical parasitology department, fac-ulty of medicine, zagazig university and theodor bilharz research institute (tbri) from february 2019 to february 2020 on 45 hamsters. they were divid-ed into 5 groups 9 hamsters each: group a non-infected hamsters, group b infected control group, group c, d and e infected with g. lamblia and treated with chitosan nanoparticles (csnps), metronidazole (mtz) and metronidazole-loaded chitosan nanoparticles (mtz-csnps) respectively. results: the highest percentage of reduction in the giardia cyst and trophozo-ite counts were in group that received mtz-csnps (94.69%, 94.29%). lower percentages of reduction were recorded for mtz treated group (90.15%, 89.52%) and csnps treated group (63.64%, 75.24%). histopathological exami-nation showed marked healing of intestinal mucosa after treatment with mtz-csnps. conclusion: csnps showed a therapeutic effect against giardia infection in hamsters. loading of metronidazole on chitosan nanoparticles enhanced thera-peutic effect of both csnps as well as metronidazole.