La. R.S. 45:1135

The bonds shall be signed by the presiding officer and the secretary or clerk of the governing body under the official seal of the governing body, in such manner as may be provided in the resolution authorizing their issuance. Interest coupons to be attached thereto may be executed with the facsimile signatures of those officers, and in the event that any officer whose signature appears on the bonds or coupons shall cease to be such before the delivery of the bonds to the purchaser, those signatures shall nevertheless be valid and sufficient for all purposes.