Jb. Baseman et Jg. Tully, MYCOPLASMAS - SOPHISTICATED, REEMERGING, AND BURDENED BY THEIR NOTORIETY, EMERGING INFECTIOUS DISEASES, 3(1), 1997, pp. 21-32
Mycoplasmas are most unusual self-replicating bacteria, possessing ver
y small genomes, lacking cell wall components, requiring cholesterol f
or membrane function and growth, using UGA codon for tryptophan, passi
ng through ''bacterial-retaining'' filters, and displaying genetic eco
nomy that requires a strict dependence on the host for nutrients and r
efuge. In addition, many of the mycoplasmas pathogenic for humans and
animals possess extraordinary specialized tip organelles that mediate
their intimate interaction with eucaryotic cells. This host-adapted su
rvival is achieved through surface parasitism of target cells, acquisi
tion of essential biosynthetic precursors, and in some cases, subseque
nt entry and survival intracellularly. Misconceptions concerning the r
ole of mycoplasmas in disease pathogenesis can be directly attributed
to their biological subtleties and to fundamental deficits in understa
nding their virulence capabilities. In this review, we highlight the b
iology and pathogenesis of these procaryotes and provide new evidence
that may lead to increased appreciation of their role as human pathoge
ns.