Growth in vitro of mycoplasma-infected human amnion cells, fl amnion cells, and mycoplasma-modified FL cells.

Abstract

SummaryThe population doubling time for lines of FL human amnion cells infected with mycoplasma fermentans (strain HT) was increased (30 hr) compared to uninfected FL cells (17.5 hr). Infected FL cell lines from which mycoplasma was eliminated, had a doubling time of 21 hr and showed an increased resistance to reinfection, even several years after the mycoplasma elimination. Although the amounts of cell-associated mycoplasma were similar to those of infected FL cells, cytopathic effects and cell destruction were much less pronounced after reinfection of such lines. The amounts of cell-associated, as well as free mycoplasma, were reduced in cultures of primary amnion cells as compared to the transformed cells. Primary amnion cells were highly resistant to mycoplasma infection as judged by the number of glass-attached cells and lack of cell destruction. The theoretical and practical implications of these observations are discussed.