giardia intestinalis protozoan

abdominal background biology black cell cyst dangerous diarrhea digestive disease duodenalis duodenum flagella giardia giardiasis human illustration infection infectious intestinal intestinalis intestine invasion isolated jejunum lamblia lambliasis medical medicine microbe microbiology microorganism microscope microscopic microscopy parasite parasites parasitic parasitology poster protozoa protozoan science scientific small stomach system trophozoite