Were any of the Apostolic Fathers Jews?

A simple question; I am reading the Apostolic Fathers and have noticed how they frequently refer to themselves as 'Gods Chosen' and speak of the Old Testament prophets as 'Our Forefathers'. This naturally leads us to ask whether or not any of them were ethnic Jews? Considering that Eusebius records the first fifteen Bishops of Jerusalem as 'being of the circumcision' it would be strange if none of the apostolic fathers were of that ethnicity.