  Casimir-Polder potential is investigated for a polarizable microparticle in
the geometry of a straight cosmic string with a metallic cylindrical shell. The
electromagnetic field Green tensor is evaluated on the imaginary frequency
axis. The expressions for the Casimir-Polder potential is derived in the
general case of anisotropic polarizability for the both interior and exterior
regions of the shell. The potential is decomposed into pure string and
shell-induced parts. The latter dominates for points near the shell, whereas
the pure string part is dominant near the string and at large distances from
the shell. For the isotropic case and in the region inside the shell the both
pure string and shell-induced parts in the Casimir-Polder force are repulsive
with respect to the string. In the exterior region the shell-induced part of
the force is directed toward the cylinder whereas the pure string part remains
repulsive with respect to the string. At large distances from the shell the
total force is repulsive.
