Original Article Antimicrobial Resistance of Major Foodborne Pathogens from Major Meat Products Panagiota Gousia, Vagelis Economou, Hercules Sakkas, Stamatina Leveidiotou, and Chrissanthy Papadopoulou Abstract The bacterial contamination of raw and processed meat products with resistant pathogens was studied. The raw samples included sheep (40), goat (40), pork (120), beef (80), and chicken (19) meat, and the processed samples included turkey filets (33), salami (8), readymade mincemeat (16), stuffing (22), and roast-beef (50). The samples were collected from retail shops in Northwestern Greece over a period of 3 years. The isolated pathogens were evaluated for susceptibilities to 19 antimicrobial agents used in humans. Out of 428 samples, 157 strains of Escherichia coli, 25 of Yersinia enterocolitica, 57 of Staphylococcus aureus, 57 of Enterococcus spp., 4 of Salmonella spp., and 3 of Campylobacter jejuni were isolated. Among the isolates 14.6% of the E. coli, 10.5% of S. aureus, 4% of Y. enterocolitica, 25% of Salmonella spp., and 42.1% of Enterococcus spp. were susceptible to antibiotics. E. coli from chicken exhibited high rates of resistance to ciprofloxacin (62.5%) followed by lamb=goat (10.9%), pork (15.7%), and beef (27.9%) meat. Resistance to nitrofurantoin dominated in the lamb=goat isolates (60%). Resistance to tetracycline predominated in pork (68.2%) and chicken (62.5%), and resistance to aminoglycosides dominated in lamb=goat meat isolates. S. aureus resistance to clindamycin predominated in lamb=goat isolates (50%), whereas resistance to ciprofloxacin predominated in the pork strains, but no resistance to methicillin was observed. Of the enterococci isolates 21.1% were resistant to vancomycin. High resistance to ampicillin (96%) was observed in Y. enterocolitica and all of the C. jejuni isolates were resistant to ampicillin, cephalothin, and cefuroxime. These results indicate that meat can be a source of resistant bacteria, which could potentially be spread to the com- munity through the food chain. Introduction S almonella, Campylobacter, Escherichia coli, Yersi- nia, and Staphylococcus aureus are the major bacterial agents causing foodborne infections. Although many food- borne infections are self-limiting and do not require treatment, they can cause severe complications and increased risk of death in a subset of patients (the very young, the very old, and the immunocompromised) (Helms et al., 2002a, 2002b). There are studies reporting that current assessments of the burden of foodborne diseases underestimate the number of deaths from bacterial gastrointestinal infections (Helms et al., 2002a, 2002b). Also, the Salmonella, Campylobacter, and Yersinia infections are associated with increased long-term mortality (Helms et al., 2002b; Martin et al., 2004). Thus, antimicrobial treatment is a necessity for the severe cases. Resistant foodborne pathogens are acquired primarily through the consumption of contami- nated food and constitute a significant food safety problem due to their potential to cause increased morbidity after the failure of treatment (Mølbak et al., 1999; Smith et al., 1999; Marano et al., 2000; Helms et al., 2002a; Travers and Barza 2002; Martin et al., 2004; Mølbak, 2005). Although there is an ongoing controversy about the causes of the development of resistance, there is growing evidence based on research data suggesting the potential link between the antimicrobial resistance and the veterinary practices (Engberg et al., 2001; Delsol et al., 2004; Mathew et al., 2005; Funk et al., 2006; Rosengren et al., 2009). In addition, there are reports by international public health authorities (EMEA, 2009a,b; WHO, 2009; EFSA, 2010) dealing with the potential link and risk between the overuse of antibiotics in veterinary practice and the emergence of resistant human pathogens. It is generally agreed that the administration of antimicrobials to food animals for growth promotion, prophylaxis, and treat- ment can lead either to the selection of resistant bacteria, which can be transmitted through the food chain (Witte, 2000; Mayrhofer et al., 2004), or to the horizontal transfer of resis- tance genes to human pathogenic or commensal microflora Food, Water, and Environmental Microbiology Unit, Department of Microbiology, Medical School, University of Ioannina, Ioannina, Greece. FOODBORNE PATHOGENS AND DISEASE Volume 8, Number 1, 2011 ª Mary Ann Liebert, Inc. DOI: 10.1089=fpd.2010.0577 1