Original Article Listeria monocytogenes Circulating in Rabbit Meat Products and Slaughterhouses in Italy: Prevalence Data and Comparison Among Typing Results Alessandra De Cesare, 1 Antonio Parisi, 2 Renzo Mioni, 3 Damiano Comin, 3 Alex Lucchi, 1 and Gerardo Manfreda 1 Abstract Rabbit meat has outstanding dietetic and nutritional properties. However, few data on microbiological hazards associated with rabbit productions are available. In this study, the presence of Listeria monocytogenes was determined in 430 rabbit carcasses, 256 rabbit meat cuts and products, and 599 environmental sponges collected from four Italian rabbit slaughterhouses over a period of 1 year. Prevalence of L. monocytogenes among the 1285 rabbit meat and environmental samples was 11%, with statistically significant differences between slaughterhouses. The highest prevalence (33.6%) was observed in rabbit meat cuts and products; the majority of positive environmental samples were collected from conveyor belts. Overall, 27.9% and 14.3% of rabbit cuts and carcasses, respectively, had L. monocytogenes counts higher than 1 colony-forming unit (CFU)/10 g. A selection of 123 isolates from positive samples was genotyped and serotyped to determine genetic profiles and diversity among L. monocytogenes isolates contaminating different slaughterhouses and classes of products investigated. Discriminatory power and concordance among the results obtained using multilocus variable- number tandem-repeat analysis (MLVA), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), automated EcoRI ribotyping, and serotyping were assessed. The isolates selected for typing were classified into serotypes 1/2a (52.8%), 1/2c (32.5%), and 1/2b (14.6%). The majority of the isolates were classified as ST14 (34.1%), ST9 (35.5%), ST121 (17.9%), and ST224 (14.6%). The greatest discriminatory power was observed with the MLVA typing, followed by MLST, PFGE, and ribotyping. The best bidirectional concordance was achieved between PFGE and MLST. There was 100% correlation between both MLST and MLVA with serotype. Moreover, a high unidirectional correspondence was observed between MLVA and both MLST and PFGE, as well as between PFGE and both MLST and serotyping. The results of this study show for the first time in Italy prevalence and genetic profiles of L. monocytogenes isolated in rabbit products and slaughterhouses. Keywords: Listeria monocytogenes, meat, prevalence, risk assessment, typing Introduction R abbit meat has outstanding dietetic and nutritional properties (Dalle Zotte, 2002). In Italy, 40% of the rabbit production is concentrated in the Veneto region (source: UnaItalia, www.unaitalia.com), where rabbits are reared on intensive farms (Trocino and Xiccato, 2006). Data concern- ing Listeria monocytogenes contamination in rabbit carcasses and products are limited. L. monocytogenes is a Gram- positive, facultative intracellular bacterium that is responsi- ble for listeriosis. Listeriosis can cause meningitis, newborn septicemia, encephalomyelitis, or even death in humans. In humans, listeriosis has a 19% case-fatality rate in the United States (Scallan et al., 2011) and in the European Union in 2014, listeriosis had a notification rate of 0.52 cases per 100,000 population (EFSA, 2016). L. monocytogenes is widespread in nature. It can survive and grow over a wide range of environmental conditions, including refrigeration temperatures. Even if meat products are cooked before consumption, L. monocytogenes can 1 Department of Agricultural and Food Sciences, Alma Mater Studiorum—University of Bologna, Bologna, Italy. 2 Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Putignano, Italy. 3 Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy. FOODBORNE PATHOGENS AND DISEASE Volume 14, Number 3, 2017 ª Mary Ann Liebert, Inc. DOI: 10.1089/fpd.2016.2211 1