In Swedish, the word for patricide (fadermord) is commonly used in a metaphorical sense for the act of the disciple, usually publicly, turning on their teacher or benefactor (which may be a person or an institution).
I have consulted several English dictionaries online, but none of them list an English equivalent of this metaphorical use of patricide, only the literal and judicial meaning of the word.
My question is therefore, if patricide is not generally used in this metaphorical sense in English, is there another word which conveys this specific nuance of treachery?
The Swedish usage usually implies a break with former convictions (passed down from one’s teacher or otherwise). It is not, therefore, a treachery for personal gain, but more often due to a change of convictions or beliefs.
In Swedish, it is also a fairly neutral term – fadermord in this sense is not morally despicable, though it may be tactless; it may even carry a note of enviable moral integrity.
Accepted answer: There are, of course, several ways in which this expression can be rendered in English. Among the answers below, "renegade" or "apostate" seem to be the closest single words, with "judas" a close third. By using an idiom, "the worm has turned to bite the hand that feeds it," though a bit quirky, can come quite close.
Since the word in Swedish has context dependent moral implications, which is not the case for the closest English equivalents, the appropriate word will have to be decided by the context.