Listeria monocytogenes Contamination of Turkey Franks: Evaluation of a Production Facility

Abstract

A facility which produced turkey franks that had been microbiologically linked to a case of human listeriosis was evaluated to establish prevalence of contamination and identify potential points for intervention. Listeria monocytogenes was isolated from only two of 41 environmental samples obtained in the plant. Among production line product samples analyzed by the Centers for Disease Control, 0 to 8% of samples from the production stages before the peeler-conveyor belt apparatus were positive for the case strain of L. monocytogenes, whereas 12 of 14 (86%) samples collected from this apparatus were positive (p <0.001). The most probable number (MPN) of L. monocytogenes in finished product purchased from a retail outlet was less than 0.3 per gram; however, the opened package of franks from the case patient's refrigerator had an MPN of >1100 per gram. These data suggest that systematic culturing and analysis of products and production facilities may help identify appropriate interventions to reduce L. monocytogenes contamination in food processing plants and contribute to control of L. monocytogenes in ready-to-eat meat products.

The epidemiology of human listeriosis

“…The outbreak occurred following the delivery of an infant with early-onset disease born to a mother with amnionitis. (174).…”

Application of a Multiplex Polymerase Chain Reaction Assay for the Simultaneous Confirmation of Listeria monocytogenes and Other Listeria Species in Turkey Sample Surveillance

“…ERIC pro les of L. monocytogenes type 1 strains from turkey franks (n 5 15) linked to an earlier listeriosis fatality (38) and those of mechanically separated turkey meat samples (n 5 29) were compared to determine genetic similarity. By visual inspection, ERIC pro les of 13 of the 15 turkey frank isolates were found to be identical (Fig.…”

“…To estimate genetic similarity, we compared the ERIC pro les of serogroup 1 isolates recovered from mechanically separated turkey meat with those of strains associated with contaminated turkey franks linked to a listeriosis fatality (38). Our sole purpose was to determine if the pro le exhibited by the L. monocytogenes serotype 1/2 strains recovered in 1988 from turkey franks currently existed in turkey products.…”

“…ERIC pro les were obtained for all isolates from mechanically separated turkey meat that were con rmed to be of serotype 1 (n 5 29). ERIC pro les were compared with those generated by L. monocytogenes strains (NADC 2664 to NADC 2678, n 5 15) that had been recovered from turkey franks associated with a listeriosis fatality (38). A total of 44 L. monocytogenes strains were grown on TSA-YE plates, and DNA was extracted with the High Pure PCR Template Preparation Kit (Boehringer Mannhiem) according to the manufacturer's instructions.…”

“…Analysis of risk factors associated with infections in the United States has indicated that can-cer patients and immunocompromised individuals, in whom 69% of listeriosis cases occur, were more likely than control subjects to have eaten undercooked poultry (odds ratio 5 3.3) (34). In 1989, contaminated turkey franks were linked to a listeriosis fatality for a breast cancer patient in Oklahoma (38). After isolating L. monocytogenes 1/2a of the same isoenzyme type from the patient and from the turkey frankfurters, the U.S. Department of Agriculture Food Safety and Inspection Service requested a class 1 (voluntary) recall of 600,000 lb of the product (1).…”