In vitro Cultivation Procedures for Parasitic Helminths

Abstract

This chapter focuses on the in vitro cultivation procedures for parasitic helminths. In most in vitro cultures of parasitic helminths, cultivation is carried out under a protective umbrella of antibiotics, which maintains a bacteriostatic environment for the helminths under investigation. Because of the variable source of helminth material, there is considerable variation among individual cultures in the types of associated micro-organisms. The only meaningful environmental condition is the true axenic one, which, for successful rearing of some helminthes is an absolute prerequisite. A wide variety of criteria have been used for assessing success in in vitro cultivation procedures. These depend on the parasite and the stage with which one begins and include motility and reaction to stimulus and physiological criteria, such as the utilization of substrates, cytological evidence of an increase in mitotic division, organogeny, gametogenesis, and oviposition. In vitro cultivation procedures provide an insight into many of the essential physiological requirements of the parasite and when used intelligently in conjunction with carefully planned in vivo experiments, they help to elucidate some of the many aspects of the host–parasite relationship. Work on the metabolism and physico-chemical requirements of parasites, investigations of certain features of behavior in parasites, and studies of antigens and other materials secreted and excreted during growth and metamorphosis, can be implemented effectively by means of in vitro culture techniques.