After buying Merck & Co. Inc.'s central Pennsylvania manufacturing plant, PRWT Services Inc. today is expected to introduce the management team that will lead it. PRWT chairman and CEO Willie F. Johnson has grown his Philadelphia company into one of the nation's largest African-American-owned businesses over the last 20 years. With a supply contract in hand from Merck, the new venture has the potential to triple PRWT's annual revenue, which was $76 million in 2007.
