Autor: |
Calicchia ML; Silliker Laboratories of California, 1139 E. Dominguez Street, Suite I, Carson, California 90746., Parker EL; Golden State Foods Corporation, 1525 Old Covington Road. Conyers, Georgia 30208., Gambrel-Lenarz S; 3M Microbiology Products, 275-5W-05 3M Center, St. Paul, Minnesota 55110, USA., Matner RR; 3M Microbiology Products, 275-5W-05 3M Center, St. Paul, Minnesota 55110, USA. |
Jazyk: |
angličtina |
Zdroj: |
Journal of food protection [J Food Prot] 1997 Jul; Vol. 60 (7), pp. 870-873. |
DOI: |
10.4315/0362-028X-60.7.870 |
Abstrakt: |
A total of 750 beef carcasses were assayed to detect E. coli O157:H7 by surface swabbing. Each swab represented a 200-cm 2 composite surface area. Escherichia coli O157:H7 was not detected in any of the carcass samples. Assays were conducted from carcass swab suspensions by direct plating on Petrifilm ™ E. coli Count plates followed by an E. coli O157:H7 assay using the Petrifilm ™ Test Kit-HEC direct blot enzyme immunoassay without sample pre-enrichment, and by enrichment using a modified U.S. Department of Agriculture (USDA) Petrifilm ™ E. coli O157:H7 procedure. Additionally, beef slabs were inoculated with E. coli O157 :H7 to verify that recovery by the direct swab technique was at least as efficient as enrichment of excised tissue samples, which is the usual USDA method. Escherichia coli O157:H7 inoculation of 4,32, and 180 CFU/25 cm 2 were designated low, medium, and high surface contamination levels, respectively. The percentage of recovery of E. coli O157:H7 using the direct swab technique without sample pre-enrichment was 60, 80, and 100% for low, medium, and high surface inoculation levels, respectively. In comparison, recovery from 25-g enrichments of ground excised samples from beef slabs containing 1.4,9.6, and 50 CFU of E. coli O157:H7 was 0, 20, and 73%, respectively. Similarly, the percent recovery of this organism from nonground excised samples containing 56 CFU/25 g enrichment was 68%, versus 100% by direct swab technique without sample pre-enrichment from beef containing 190 CFU/25 cm 2 Direct surface swab tests with the 3M Petrifilm ™ Test Kit-HEC without sample pre-enrichment proved to be a sensitive, nondestructive, alternate means of evaluating beef carcasses for the presence of E. coli O157:H7. |
Databáze: |
MEDLINE |
Externí odkaz: |
|