Effects of Panmede and various horse serum concentrations on the axenic cultivation of Entamoeba histolytica strains in TPS-1 medium.

We analyzed the influence of Panmede and horse serum concentrations on the growth of five Entamoeba histolytica strains (HK9, HM1, HM2, HM3, and HM38) axenically cultivated in TPS-1 medium. Panmede was evaluated by comparing the growth of strain HM1 in medium prepared with each of 15 Panmede lots; the yields of E. histolytica trophozoites depended on the lot quality of Panmede, and their maximal values ranged from 8 x 10(3) to 8.9 x 10(4) amoebae/ml. The growth-promoting effect of eight lots of horse serum on strains HK9 and HM1 were studied using a single Panmede lot of good quality. Yields obtained with strain HK9 ranged from 8 x 10(4) to 1.8 x 10(5) amoebae/ml, whereas yields obtained with HM1 ranged from 3 x 10(4) to 1.2 x 10(5) amoebae/ml. Thus, the optimal serum concentration in TPS-1 medium that caused maximal growth of E. histolytica cultures depended on the quality of the serum lot and proved to be specific for each of the five E. histolytica strains investigated. It ranged from 18% (v/v) for strain HM2 to 28% (v/v) for strain HM1. Our results reveal that the growth of E. histolytica trophozoites in TPS-1 medium can be distinctly improved by selecting appropriate lots of Panmede and horse serum and using optimal serum concentrations.