The jailer or keeper of the jail, unless the sheriff elects to act as jailer in person or unless a county board of corrections exists and has assumed responsibility over the jail pursuant to sections 23-2801 to 23-2806, shall be a deputy appointed by the sheriff, and such jailer shall take the necessary oath before entering upon the duties of his or her office; Provided, the sheriff shall in all cases be liable for the negligence and misconduct of the jailer, as of other deputies.