  In this paper, we find the necessary and sufficient conditions, inclusion
relations for Poisson distribution series $\mathcal{K}(m,z)=z+\sum_{n=2}^\infty
\frac{m^{n-1}}{(n-1)!}e^{-m}z^{n}$ belonging to the subclasses
$\mathcal{S}(k,\lambda )$ and $\mathcal{C}(k,\lambda )$ of analytic functions
with negative coefficients. Further, we consider the integral operator
$\mathcal{G}(m,z) = \int_0^z \frac{\mathcal{F}(m,\zeta)}{\zeta} d\zeta$
belonging to the above classes.
