CAN CHILD SUPPORT ORDER GO AFTER WIFE IF CHILD WAS BORN OUT OF WEDLOCK.?

1 night stand resulted in a child born 2 and a half years ago. Father was married and mother informed him that the child could not be his. Father was easy to locate as he saw the mother on occion when she came to his employment to get some work done. Father got letter in mail requesting child support. He is not working now due to recession and wife is a teacher who is devastated by his betrayal but is trying to work through this. They have 2 sons of their own one 6 and the other 17 months. He is a great dad and husband but he cheated and the condom broke. He is just as devastated that he was not aware and was lied to. He told his wife of 8 years, they were together since he was 18 he is now 33. He wants to work something out with the mother but she is being difficult. He paid for the DNA he wanted to know ASAP. Can the courts go after his wifes income?