Prevalence, distribution, and molecular characterization of Salmonella recovered from swine finishing herds and a slaughter facility in Santa Catarina, Brazil Jalusa D. Kich a, ⁎, Arlei Coldebella a , Nelson Morés a , Mariana Gomes Nogueira b , Marisa Cardoso b , Pina M. Fratamico c , Jeffrey E. Call c , Paula Fedorka-Cray d , John B. Luchansky c a Embrapa Suínos e Aves, Caixa Postal: 21, CEP: 89700-000, Concórdia-SC, Brazil b Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, UFRGS, Av. Bento Gonçalves, 9090, 90540-000, Porto Alegre, RS, Brazil c USDA, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA, USA d USDA, Agricultural Research Service, Richard B. Russell Agriculture Research Center, 950 Station Road, Athens, GA, USA abstract article info Article history: Received 10 June 2011 Received in revised form 14 September 2011 Accepted 24 September 2011 Available online 1 October 2011 Keywords: Salmonella Swine PFGE Resistance Epidemiology Swine can carry Salmonella strains that may be transmitted to humans by pork products. This investigation de- termined the distribution and types of Salmonella in 12 swine finishing herds and a slaughter facility in Santa Catarina, Brazil. A total of 1258 samples, consisting of environmental, feed, carcass, lymph node, and fecal ma- terial were collected and submitted to bacteriological isolation of Salmonella. From 487 positive samples, 1255 isolates were recovered and confirmed to be Salmonella. The distribution of positive samples was as follows: finishing pen floors 26% (16/61); feed 29% (42/143); feces 44% (52/119); pooled feces 59% (35/59); slaughter holding pens 90% (36/40); lymph nodes 46% (220/478); pre-chilled carcass surfaces 24% (24/98); and post- chilled carcass surfaces 24% (62/260). The most prevalent serovars were Typhimurium, Panama, Senftenberg, Derby, and Mbandaka. By pulsed-field gel electrophoresis, 1071 isolates were subtyped using XbaI, and dupli- cate isolates were removed. From the remaining 747 isolates, 163 macrorestriction profiles (pulsotypes) were identified. Six pulsotypes were considered very frequent, occurring in 33 isolates or more. The multiple corre- spondence analyses showed correlations between pulsotypes from shedding pigs (feces), herd environment (pen floors), and subiliac and prescapular lymph nodes and between lairage and carcass surface samples be- fore and after chilling. All sources of Salmonella investigated contributed to the carrier state; however, pre- slaughter contamination at lairage was the variable most strongly associated with carcass contamination. A total of 59 different antimicrobial resistance profiles were observed in 572 Salmonella isolates. From these iso- lates, 17% (97/572) were susceptible to all 15 antibiotics tested, 83% (475/572) were resistant to at least one, and 43% (246/572) were resistant to four or more antibiotics (multi-resistant). The AmpGenKanTet profile was the most prevalent in carcass isolates and was associated with farm origin. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Most Salmonella serotypes are considered potential human patho- gens (WHO, 2005), and Salmonella is recognized worldwide as a major human food-borne pathogen (CDC, 2008). Although eggs are considered an important vehicle of infection and associated with food-borne outbreaks, contaminated pork and pork products may be responsible for up to 25% of all Salmonella infections in humans (Borch et al., 1996). Swine was a primary source of human salmonel- losis in 15% of the cases in Denmark and The Netherlands and 25% of the cases in the U.S. (Bean and Griffin, 1990). The continuous entrance of animals carrying and shedding Salmonella in slaughterhouses is the main source of pork contamina- tion (Berends et al., 1997). Thus, efforts have been taken to minimize Salmonella shedding in swine in order to lower the hazard of contami- nation at slaughterhouses. Good Manufacturing Practices reduce cross- contamination during slaughter and processing; however, the first crit- ical control point involves the reduction of delivery of shedders to the slaughterhouse (Borch et al., 1996). In previous studies, the finishing stage was shown to be critical for Salmonella infection amplification in the swine production system (Funk et al., 2001; Silva et al., 2006). The spread of Salmonella from a number of sources and the variability in the serovars isolated from positive samples demonstrate the epide- miological complexity in the swine production chain. Thus, it is difficult to determine the epidemiological relationship between sources of Salmonella transmission throughout the production chain and pork contamination. There are several tools available for subtyping and dis- criminating Salmonella, and one commonly-used technique for this International Journal of Food Microbiology 151 (2011) 307–313 ⁎ Corresponding author. Tel.: + 55 49 34410400; fax: + 55 49 34410497. E-mail address: jalusa@cnpsa.embrapa.br (J.D. Kich). 0168-1605/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2011.09.024 Contents lists available at SciVerse ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro