。
The mail carrier got bitten by that dog.
Literal
Postal-delivery-of person [subject-が] that dog [by-に] bite-[passive-past-れた].
A neat example of the direct passive — the subject (mail carrier) is the affected party and the agent (the dog) is marked with に. かみつく ('to bite, snap at') is an intransitive verb for biting behavior; its passive form かみつかれる is 'to be bitten by.' Distinct from the suffering passive (迷惑の受身), which adds an adverse-effect nuance even with intransitive verbs.