Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/3/2009
Publication Date: 5/17/2009
Citation: Pagadala, S., Parveen, S., Luchansky, J.B., Porto Fett, A.C., Rippen, T., Wiedmann, M. 2009. Characterization of Listeria monocytogenes isolated from Blue Crab Meat and Blue Crab Processing Plants. Meeting Abstract. (P-041-P420). Interpretive Summary:
Technical Abstract: Listeria monocytogenes is an important food-borne pathogen associated with severe invasive disease in both humans and animals. It can inhabit different niches within food processing plants, including food contact equipment, leading to cross-contamination of finished products. However, there is only limited information on characterization of L. monocytogenes recovered from blue crab meat or crab processing plants. The purpose of this study was to address this data gap. In this study, 106 isolates of L. monocytogenes recovered from live crabs, finished products, and different environmental samples, most commonly from raw crab coolers and receiving docks, from among 7 processing plants over a 2-year period were characterized by serotyping, ribotyping, and pulsed-field gel electrophoresis (PFGE). In addition, one isolate from each pulsotype was serotyped using commercial antiserum. Automated EcoRI ribotyping identified eleven ribotypes among the 106 isolates. Ribotypes DUP 1042B, DUP 1044B, and DUP 1038B were isolated at the highest overall frequency. Ribotypes DUP 1044B and DUP 1042C persisted in most of the processing plants. In one plant, strains displaying a specific ribotype persisted on both raw crab and within the environment and, as such, may have also been responsible for contamination of the finished product. A total of 92 ApaI and 88 AscI pulsotypes were observed among the 106 isolates. Indistinguishable pulsotypes were observed both on raw crabs and from among several environmental sites. Eight different serotypes were found among 76 of the 106 isolates, with serotypes 4b, 1/2b, and 1/2a predominating. Most of the serotypes were distributed randomly among all the processing plants. Collectively, these data suggest that L. monocytogenes recovered from these 7 processing plants are genetically diverse. These results also indicate that live crabs and associated processing plant surfaces can serve as niches/sources of L. monocytogenes contamination for processed blue crab meat.