Experimental study on concurrent infection with giardia lamblia and hymenolepis nana in mice

ABSTRACT

Many individuals are infected with more than one intestinal parasite. The presence of dual infection is a common incidence especially by parasites causing autoinfection or direct infection. Therefore, this work was planned to study the effect of concurrent infection with Giardia lamblia and Hymenolepis nana on the course of infection and local inflammatory reaction and immunity. Materials and methods: 170 Swiss albino mice, 18-20 gm each were used and divided into five groups; G [1] infected with G. lamblia [100, 000 cysts orally] only, G [2] infected with H. nana [500 shell free eggs orally] only, G [3] infected with G. lamblia then H. nana, G [4] infected with H. nana then G. lamblia and G [5] control non infected. Animals were sacrificed weekly after the last infection for 4 weeks. The intestines were processed for histopathological examination, stained with Alcian blue to examine the goblet cells and toluidine blue for identification of mast cells and IL-6 mRNA estimation by PCR technique in the small intestinal tissue homogenates. Two-hour cyst and trophozoite counts were performed weekly in Giardia groups and cysticercoids and adult H. nana were counted in Hymenolepis groups. There was a significant decrease in H. nana cystcercoid and adult worm counts in G [3]; and in G. lamblia cyst and trophozoite counts in G [4]. There was increased intensity of histopathological changes, lymphocytic infiltration in the lamina propria and hyperplasia of mast cells and goblet cells in Gs [3 and 4]. IL-6 mRNA was higher in the mixed infection than in the single infection groups. The presence of a preceding infection may produce a state of partial immunity against a second heterologus parasite and decrease the severity of infection by this parasite