Mo. Rev. Stat. § 55.020

Before taking over his duties, the county auditor of a county of the first class having a charter form of government shall give bond to the county in such amount and with such surety as shall be required by the county commission. The bond shall be conditioned upon the faithful performance by such county auditor of all those duties which are imposed upon him by section 55.030, and by chapter 50, and which are or may hereafter be imposed upon him by any other statutory provision relating to county auditors. The cost of the bond shall be paid from the general revenue fund of the county.