LOS ANGELES (AP) — The veteran porn actor known as Mr. Marcus was sentenced Tuesday to 30 days in jail after pleading no contest to knowingly exposing his co-stars to syphilis.

The 42-year-old actor, whose real name is Jesse Spencer, was also ordered to perform 15 days of community service and serve three years on probation.

His infection was discovered in July 2012 during a routine industry screening before he was to begin making a film. He immediately received a penicillin shot, but when he was rescreened 11 days later he still showed signs of syphilis. Authorities say he altered the results of that second test and returned to work the following day.

Spencer is jailed on $200,000 bail in an unrelated drunken driving case. An e-mail was sent to his management company seeking comment.

Spencer has said previously he thought he was no longer infectious when he returned to work.

Prosecutors said he took part in two adult movie shoots within a week of failing the second test.

Two actresses who worked with him contacted police after a producer discovered the altered test result. Neither woman contracted syphilis, the city attorney’s office said.

According to the Centers for Disease Control and Prevention, syphilis is caused by a bacterium and is transmitted through direct contact with syphilis sores, which mainly occur on the external genitals, vagina, anus or in the rectum. A single shot of penicillin can cure a person who has had syphilis for less than a year, according to the CDC. Additional doses are necessary for people who have had the STD for a longer period.

Spencer was one of nearly a dozen porn actors who tested positive during a syphilis outbreak last summer that led industry officials to briefly call for a moratorium on filming.

In November, Los Angeles County voters approved a ballot initiative requiring porn actors use condoms for most film shoots. The industry has sued to overturn the law, arguing that its own testing guidelines for sexually transmitted diseases are sufficient.