The phrase "discredit of" is grammatically correct and can be used in written English.
Example: The scandal caused a discredit of the company's reputation.
To the discredit of unspecified powers, this reform has been indefinitely delayed.
Errors to the discredit of the hospital are unlikely to ever go undiscovered or unaddressed.
It is greatly to the discredit of the industry that this should be so.
Mr Correa's strongest card is the discredit of his opponents in the traditional parties and their businessmen friends.
That last bit is a quote from Rudyard Kipling, whom Brooks mimics, to the discredit of both.
Its victory is less due to its own qualities than to the failure and discredit of the ruling elite.
But the covert fact-collectors have been discredited of late.
A side effect was the discrediting of candor about unpleasant truths and the enshrinement of "optimism".
But the totally bogus "discrediting" of climate science has had serious implications.
Their collapse was portrayed as the final discrediting of socialism, and the ultimate vindication of capitalism.
For many people, this discrediting of their experience is hard to accept.
