NEW YORK — A New York man and his girlfriend were sentenced on Thursday to 580 years and 300 years in federal prison, respectively, for drugging and sexually exploiting half a dozen young girls, including two Amish sisters they abducted from a roadside farm stand, according to court records.

Stephen Howells and Nicole Vaisey had pleaded guilty in May to numerous child pornography counts in federal court in Syracuse, admitting they abused six girls ranging in age from 5 to 11.

US District Judge Glenn Suddaby imposed the sentences after prosecutors urged him to deliver stiff penalties for the two defendants.

“Stephen Howells is the basest among us,” Assistant US Attorney Lisa Fletcher wrote in court papers prior to the sentencing. “He poses a real and substantial threat to children, and to young girls in particular.”

Howells, a father of three, used his job as a registered nurse to obtain sedatives the couple then gave to the girls, according to authorities.

From December 2012 to August 2014, prosecutors said, Howells sexually abused the children while Vaisey made video recordings. Vaisey also participated in the abuse on two occasions, according to the government.

On Aug. 13, 2014, after scouting possible locations, Howells and Vaisey visited an Amish farm stand posing as customers, prosecutors said. The couple kidnapped two girls, ages 7 and 12, using a dog to lure the children into their car, prosecutors said.

The federal charges are specifically tied to the production of the child pornography.

Howells and Vaisey earlier also pleaded guilty to New York state charges related to the kidnapping as part of a plea deal calling for 25 years in state prison for each.

In court papers, Howells’ defense lawyer asked Suddaby to impose a prison term of 30 years, citing as mitigating factors the fact that the couple never disseminated the images and Howells’ difficult upbringing.

“The essence of Stephen’s childhood can be summarized in two words: abuse and neglect,” his court-appointed lawyer, Randi Bianco, wrote.

A lawyer for Vaisey argued in court papers that she was the victim of child abuse and that Howells sexually abused her as a method of control.

“Howells owned her body, her soul and her will,” Bradford Riendeau wrote in asking for a more lenient sentence.