2-C-methyl-D-erythritol-2,4-cyclopyrophosphate participates in bacterial oxidative stress reactions and their persistence in macrophages

Corynebacterium ammoniagenes cells when cultivated with aeration can accumulate the new compound 2-C-methyl-D-erythritol-2,4-cyclopyrophate (MEC) under heat shock conditions or in the presence of O-2(-)-generating agents or ozone. In this article we show that the ability to accumulate MEC is transferred from Corynebacterium ammoniagenes to E. coli XL-1 and is revealed during cultivation of the resulting recombinant clone 2-31 in the presence of glucose and glucose oxidase (H2O2-generating system) or benzyl viologen (O-2(-)-generator). This clone also possesses increased tolerance to the bactericidal. action of murine peritoneal macrophages, In model experiments imitating phagosome conditions (NO + H2O2 + O-2(-)) C. ammoniagenes does not accumulate MEC, but it synthesizes large quantities of polyphosphate. The latter can be interpreted as a result of selective oxidative stress damage to biosynthetic processes of the cell. The growth rate of Acanthamoeba cartellanii on solid medium covered with bacterial suspension depends on neither the species nor strain of the microorganism involved (C. ammoniagenes, E. coli XL-1, E. coli recombinant clone 2-31) nor on preliminary MEC accumulation. Recombinant clone 2-31 differs from recipient strain XL-1 in the ability to produce two nonpolar lipids (R(f) = 0.85 and 0.75, TLC in hexane on Silufol plates) and carotenoid pigments, whose production could be connected with some changes in the metabolic pathways of isopentenyl pyrophosphate, a possible precursor in MEC biosynthesis. Thus, MEC is involved in some aspects of bacterial stress response and its persistence in macrophages.