The city auditor, with the consent and approval of the governing body of the city, may appoint a deputy and file such appointment in the city auditor’s office. The deputy, if one is appointed, shall aid in the performance of the duties of the office under the auditor’s direction and in the absence or disability of the auditor, or if there is a vacancy in the office of the auditor, the deputy shall perform the duties of the auditor. The auditor and the surety on the auditor’s official bond shall be liable for the acts of the deputy.