Issue with onBackPressed() is not refresh fragment

In my Android Application, I have two Fragment activity A and B.

In “A” Fragment I have developed one form and in that form some data are coming from database. I have used fragment transaction and using that replace fragment “A” to fragment “B”.

Here is my code for Fragment A where I replace fragment.

final FragmentManager fragmentManager = getFragmentManager();   
final FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();  
FragmentB reload = new FragmentB();  
fragmentTransaction.replace(android.R.id.content,reload);
fragmentTransaction.addToBackStack(null);  
fragmentTransaction.commit();

In “B” Fragment, I am fetching data from server and store it in sqlite database so we can use latest data in application.When I click on back button its return back to Fragment “A” but all the data in Fragment “A” will not refresh based on new reloaded data.

Here is my code for main activity where I override onBackPressed() method.

@Override    
public void onBackPressed() {

     // TODO Auto-generated method stub
         getFragmentManager().popBackStack();
  }

I want to refresh the fragment A's data with latest value from Database when i do back-press from main activity. As much i know we can not do back-press event in fragment B. Please correct me if i am wrong and suggest me how can i solve issue.

Does anybody know how i can achieve it?