What configuration of autothrottle is required when pilots are landing an Airbus?
Do Airbus pilots normally disengage the Auto Throttle on a manual landing ?


Depends on what you mean.

During the initial part of the approach, no, they do not deactivate the autothrust (not autothrottle, in this case):



But the autothrust is not designed for landing and just before touchdown there is an automatic callout in the cockpit: Retard. Retard. (it can be heard in this video 4 times). 

The callout is needed because of the A/THR inner working: while in SPEED mode it can apply any throttle between 0 and the current throttle lever position; i.e., if for example the throttle is at the 80% setting, the autothrust can apply any throttle between 0% and 80% (based on the required airspeed). At the Retard callout the pilots will move the levers to the IDLE position, effectively deactivating the autothrust: