There shall be an estate administrator in the Department of Administrative Services, appointed by the Commissioner of Administrative Services under the provisions of chapter 67. In the case of a vacancy in such office and the filling of such vacancy by the commissioner, said commissioner shall file with the several probate courts a certificate attesting his appointment of a successor estate administrator and such successor shall be appointed by the Probate Court as the fiduciary in each case before it wherein the estate administrator was fiduciary without application, notice or hearing effective on the date of such vacancy. The Auditors of Public Accounts shall immediately make an audit of the accounts of the previous estate administrator and, if such accounts are found in order, they shall so certify to the Commissioner of Administrative Services. No final accounting of the previous estate administrator shall be required, provided the successor estate administrator shall include in his next accounting all the doings in each estate since the last previous accounting. Before entering upon the duties of his office the estate administrator shall take the oath provided by law for public officers.