The Journal of Medical Microbiology, Vol 38, Issue 6 442-448, Copyright © 1993 by Society for General Microbiology
Alteration of transfer ribonucleic acid of Neisseria meningitidis during growth in the presence of human transferrin
D. A. Ala'Aldeen, S. P. Borriello and E. Griffiths
Microbial Pathogenicity Research Group, Clinical Research Centre, Harrow, Middlesex.
Iron-related tRNA alterations have been shown to occur in several pathogens
but nothing has been reported about the effect of iron on meningococcal
tRNA. The chromatographic elution profile of 3H-tryptophan-tRNA(trp) from a
Neisseria meningitidis strain grown under different conditions was
examined. The profile showed an early (P1) and a late (P2) eluting species
of tRNA(trp), but the proportion of the two species varied under different
growth conditions. The elution profile of trp-tRNA(trp) from bacteria grown
in iron-sufficient Mueller Hinton broth yielded a minor P1 species and a
major P2 species, whereas under iron-restricted growth induced by
desferrioxamine, the pattern was one of a major P1 species and minor P2
species. Iron-restriction induced by human transferrin (HTF) resulted in
almost equal amounts of the two tRNA(trp) species (P1 congruent to P2).
Differences in the proportions of the tRNA species were also found between
cells grown in liquid medium (P1 << P2) and on the same medium
solidified with agar (P1 >> P2). The growth phase of the bacteria did
not have any effect on the tRNA(trp) elution profile. Changes in tRNA(trp)
induced by HTF were readily and completely reversible when the cells were
transferred to an iron-rich medium, but those induced by desferrioxamine
remained irreversible for a long period (16 h) after such transfer.
