SURVIVAL OF ESCHERICHIA-COLI O157-H7 IN-GROUND BEEF JERKY ASSESSED ON2 PLATING MEDIA

Recent outbreaks of food-borne illness due to Salmonella spp. in beef jerky and Escherichia coli O157:H7 in venison jerky, coupled with the fact that a variety of preparation methods and drying procedures aboun d, raise concern over the safety of processed meat products made in th e home. The potential of injured bacterial cells to regain the ability to cause illness is a particular threat with pathogens such as E. col i O157:H7, which is believed to have a low infectious dose. This study examined the efficacy of various methods of jerky preparation in redu cing populations of E. coli O157:H7 in ground beef jerky and compared the recovery rate of E. coli O157:H7 on two selective plating media, m odified sorbitol MacConkey agar (MSMA) and modified eosin methylene bl ue agar (MEMB). Populations of E. coli O157:H7 in both heated and unhe ated samples exhibited a greater decline during drying when a nitrite and salt cure mix was added during jerky preparation. When recovery of E. coli O157:H7 on MSMA and MEMB was compared, a trend toward slightl y higher recovery rates with MEMB was observed. On the basis of these results, MEMB is a suitable alternative to MSMA for the recovery of E. coli O157:H7 from heated and dried meat samples similar to beef jerky .