  We report on the first measurement of charm-strange meson $D_s^{\pm}$
production at midrapidity in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 200
GeV from the STAR experiment. The yield ratio between strange ($D_{s}^{\pm}$)
and nonstrange ($D^{0}$) open-charm mesons is presented and compared to model
calculations. A significant enhancement, relative to a PYTHIA model calculation
of $p$+$p$ collisions, is observed in the $D_{s}^{\pm}/D^0$ yield ratio in
Au+Au collisions over a large range of collision centralities. Model
calculations incorporating strangeness enhancement and coalescence
hadronization in the quark-gluon plasma (QGP) medium qualitatively reproduce
the data. The transverse momentum integrated yield ratio of $D_{s}^{\pm}/D^0$
(0.42 $\pm$ 0.04 (stat.) $\pm$ 0.11 (sys.)) at midrapidity is consistent with a
prediction from a statistical hadronization model with the parameters
constrained by yields of light and strange hadrons in the same energy
collisions. These results suggest that coalescence of charm quarks with strange
quarks in the QGP plays an important role in charm-quark hadronization.
