SPARTANBURG, South Carolina, Sept. 6 -- The office of the U.S. Attorney for the District of South Carolina issued the following news release: Six individuals in the Upstate have pleaded guilty to conspiring to distribute methamphetamine. The following defendants entered guilty pleas in federal court: Jonathan Sarratt, 38, of Gaffney Christopher Biggerstaff, 41, of Chester. Biggerstaff also pleaded guilty to possessing a firearm in furtherance of a drug trafficking crime. Mikenzi Walker, 25,  more