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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Publications at this Location » Publication #204657
Title: Microbiological characterization of lamb carcasses at commercial processing plants in the United States

Author
item Kalchayanand, Norasak - Nor
item Arthur, Terrance
item Bosilevac, Joseph - Mick
item Harhay, Dayna
item Guerini, Michael
item Shackelford, Steven
item Wheeler, Tommy
item Koohmaraie, Mohammad

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2007
Publication Date: 8/1/2007
Citation: Kalchayanand, N., Arthur, T.M., Bosilevac, J.M., Harhay, D.M., Guerini, M.N., Shackelford, S.D., Wheeler, T.L., Koohmaraie, M. 2007. Microbiological characterization of lamb carcasses at commercial processing plants in the United States. Journal of Food Protection 70(8):1811-1819.

Interpretive Summary: The United States produces 203 million pounds of domestic lamb and mutton each year. However, thorough studies of the microbiological evaluation during lamb processing are very limited. To address this missing information, samples from three different commercial lamb plants were collected from three stages of processing between spring and summer of 2005. The prevalence of E. coli O157:H7 from pelt, preevisceration, and postintervention carcasses averaged 12.8, 1.6, and 2.9%, respectively. The average Salmonella prevalence was 14.4, 4.3, and 1.8% from pelt, preevisceration, and postintervention carcasses, respectively. The data suggests that the lamb processing industry could benefit from more effective antimicrobial interventions, such as hot water.

Technical Abstract: Although the United States (U.S.) produces 203 million pounds of domestic lamb and mutton each year, thorough studies of the microbiological safety during the production of this meat are lacking. To address this missing information, a total of 2592 sponge samples from pelt, preevisceration, and postintervention carcasses were collected from multiple large commercial lamb processing plants to determine aerobic plate counts, the prevalence of Escherichia coli O157:H7, non-O157 Shiga toxin producing E. coli (STEC), and Salmonella. The average of aerobic plate counts from pelt, preevisceration, and postintervention carcasses was 6.3, 4.4, and 2.4 log CFU/100 cm2, respectively. The prevalence of E. coli O157:H7 from pelt, preevisceration, and postintervention carcasses averaged 12.8, 1.6, and 2.9%, respectively. The average Salmonella prevalence was 14.4, 4.3, and 1.8% from pelt, preevisceration, and postintervention carcasses, respectively. The prevalence of non-O157 STEC from pelt, preevisceration, and postintervention carcasses averaged 86.2, 78.6, and 81.6%, respectively. A total of 488 non-O157 STEC strains were isolated from postintervention carcasses. Sixty-nine different serotypes of non-O157 STEC were identified. The most frequently detected serotypes were O91:H14 (40.8%) followed by O5:H19 (18.4%). A small number of STEC serotypes associated with severe human illness were isolated from postintervention carcasses. Of 488 isolates, these were serotypes O76:H19, O128:H2 (0.8%), O146:H8 (2.1%), O146:H21, O163:H19, and O174:H8 (1.3%). The results of this study establish a baseline for microbiological quality and prevalence of Salmonella, E. coli O157:H7, and STEC in U.S. lamb processing plants.