title: Prevalence, characterization and sources of Listeria monocytogenes in blue crab (Callinectus sapidus) meat and blue crab processing plants.
abstract: Seven blue crab processing plants were sampled to determine the prevalence and sources of Listeria spp. and Listeria monocytogenes for two years (2006-2007). A total of 488 raw crabs, 624 cooked crab meat (crab meat) and 624 environmental samples were tested by standard methods. Presumptive Listeria spp. were isolated from 19.5% of raw crabs, 10.8% of crab meat, and 69.5% of environmental samples. L. monocytogenes was isolated from 4.5% of raw crabs, 0.2% of crab meat, and 2.1% of environmental samples. Ninety-seven percent of the isolates were resistant to at least one of the ten antibiotics tested. Eight different serotypes were found among 76 L. monocytogenes isolates tested with the most common being 4b, 1/2b and 1/2a. Automated EcoRI ribotyping differentiated 11 ribotypes among the 106 L. monocytogenes isolates. Based on ribotyping analysis, the distribution of the ribotypes in each processing plant had a unique contamination pattern. A total of 92 ApaI and 88 AscI pulsotypes among the 106 L. monocytogenes isolates were found and distinct pulsotypes were observed in raw crab, crab meat and environmental samples. Ribotypes and serotypes recovered from crab processing plants included subtypes that have been associated with listeriosis cases in other food outbreaks. Our findings suggest that molecular methods may provide critical information about sources of L. monocytogenes in crab processing plants and will augment efforts to improve food safety control strategies such as targeting specific sources of contamination and use of aggressive detergents prior to sanitizing.
authors.affiliation: Food Science and Technology Ph.D. Program, Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, 2116 Center for Food Science and Technology, Princess Anne, MD 21853, USA.
authors.forename: Sivaranjani
authors.initials: S
authors.lastname: Pagadala
authors.forename: Salina
authors.initials: S
authors.lastname: Parveen
authors.forename: Thomas
authors.initials: T
authors.lastname: Rippen
authors.forename: John B
authors.initials: JB
authors.lastname: Luchansky
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Call
authors.forename: Mark L
authors.initials: ML
authors.lastname: Tamplin
authors.forename: Anna C S
authors.initials: AC
authors.lastname: Porto-Fett
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D003386:Brachyura / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis / Q000706:statistics & numerical data; D005511:Food Handling / Q000706:statistics & numerical data*; D008089:Listeria monocytogenes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology*; D017747:Seafood / Q000382:microbiology*