Identification of bacteria in human hydatid cyst specimens using molecular and aerobic / anaerobic culture methods

Cystic echinococcosis (CE), caused by the larval stage (metacestode)of the small tapeworms of dogs Echinococcus granulosus sensu lato, is oneof the most important zoonotic helminths in many parts of the world andimposes a significant medical and economic burden on endemiccommunities. Humans can accidentally become infected by the larval stageof the parasite, result in the formation of hydatid cysts in the liver and lungs,and less commonly in other organs of the body. Hydatid cysts (HCs) arefilled with hydatid fluid that is usually bacteriologically sterile. Howeverstudies indicate that several species of bacteria can be found in animalhydatid cysts. Recently in other helminth infections it has been shown thatsymbiotic bacteria play an important role in the biology and pathogenesis ofcertain helminth parasites. Our knowledge on the presence of bacteria inhuman CE is very limited and no molecular evidence is available on thebacterial communities in hydatid cysts. The purpose of the present studywas to determine the presence of different species of bacteria in human CEpatients using both bacteriological and molecular tools.