Identification of Listeria monocytogenes from unpasteurized apple juice using rapid test kits

Patricia N. Sado, Karen C. Jinneman, Gary J. Husby, Susan M. Sorg, Curtis J. Omiecinski

Research output: Contribution to journalArticlepeer-review

68 Scopus citations


A microbiological survey of 50 retail juices was conducted in the fall of 1996. These juices were analyzed for Listeria monocytogenes, Escherichia coli O157:H7, Salmonella, coliforms, fecal coliforms, and pH. Two unpasteurized juices were positive for L. monocytogenes: an apple juice and an apple raspberry blend with a pH of 3.78 and 3.75, respectively. Three L. monocytogenes isolates were characterized. The colonies were typical for Listeria sp. on Oxford and lithium chloridephenylethanol-moxalactam agars and were β-hemolytic on sheep blood agar. The isolates required 5 days of incubation at 35°C to produce a positive rhamnose reaction in a phenol red carbohydrate broth. This slow rhamnose utilization resulted in these isolates not being identified using the Micro-ID test strip (Organon Technika). However, the isolates were positive for L. monocytogenes using the API Listeria strip (BioMerieux) and a multiplex polymerase chain reaction for detection of the hemolysis (hyla) and invasion-associated protein (iap) genes.

Original languageEnglish (US)
Pages (from-to)1199-1202
Number of pages4
JournalJournal of food protection
Issue number9
StatePublished - Sep 1998

All Science Journal Classification (ASJC) codes

  • Food Science
  • Microbiology


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