Porn Star Syphilis Case: Jesse Spencer, aka 'Mr. Marcus,' sentenced to jail for knowingly exposing co-stars to disease

(CBS/AP) LOS ANGELES - Prosecutors say a veteran porn actor known as "Mr. Marcus" has been sentenced in Los Angeles to 30 days in jail for knowingly exposing at least two co-stars to syphilis, CBS Los Angeles reports.

PICTURES: Porn star jailed in syphilis case

The 42-year-old actor, whose real name is Jesse Spencer, was sentenced Tuesday after pleading no contest to one count of exposing another to a communicable disease.

Prosecutors said he must also serve 15 days of community service and three years of probation. Spencer has been in police custody since May 22 following a separate DUI arrest, the District Attorney's Office said, reports CBS Los Angeles.

On July 13, 2012, Spencer received a penicillin shot after testing positive for syphilis during a routine industry screening before he was to make a film. Following a second screening July 21, prosecutors said Spencer continued to test positive for syphilis and altered the original form by obscuring the result on a photocopy, reports the station. They say he then returned to work, participating in two adult movie shoots.

Two actresses who worked with Spencer filed police reports after a producer discovered the altered form, CBS Los Angeles reports.

"The potential spread of syphilis and other communicable diseases is a serious threat to our entire community," said City Attorney Carmen Trutanich, reports the station. "My office will continue to hold accountable those who place the health and welfare of others in danger in such a reckless and thoughtless manner."

None of the actresses contracted the disease after being exposed, the District Attorney's Office said, reports the station.