Percona PAM with AD authentication using SSSD
All i had to do is add the dba group using the following realm command:

realm permit -g dba


Doing so will automatically change the /etc/sssd/sssd.conf file and add the following line(s):

access_provider = simple
simple_allow_groups = dba


Before running real, access_provider was setup as "ad", and was automatically changed to "simple" as shoen above.