| phage types, virulence genes and pfge profiles of shiga toxin-producing escherichia coli o157:h7 isolated from raw beef, soft cheese and vegetables in lima (peru). | the present study was conducted in lima metropolitana to evaluate the prevalence of shiga toxin-producing escherichia coli (stec) o157:h7 in raw beef, raw ground beef, soft cheese and fresh vegetables, sampled at different markets in the city. between october 2000 and february 2001, 407 food samples were collected from different markets in the 42 districts of lima metropolitana. samples were assayed for e. coli o157 by selective enrichment in modified tryptic soy broth containing novobiocin, fol ... | 2007 | 17187886 |