Prevalence and Characterization of Salmonellae in Commercial Ground Beef in the United States

Abstract

Commercially produced ground beef samples (n ‫؍‬ 4,136) were collected from seven regions of the United States over a 24-month period (July 2005 to June 2007) and analyzed for the presence of Salmonella enterica by using methods that concurrently provided total prevalence and enumerable levels. The overall prevalence of Salmonella strains was 4.2%. Enumeration showed that 94.2% were present at levels below 2 CFU/g. Regional monthly prevalences of Salmonella strains varied from 1.8% to 6.5% but were not statistically different (P > 0.05). All Salmonella isolates were serotyped and their antibiotic susceptibilities determined and analyzed by pulsed-field gel electrophoresis (PFGE). The most common serotypes identified were Salmonella enterica serotypes Montevideo, Anatum, Muenster, and Mbandaka, with these accounting for one-half of the isolates obtained. The prevalence of multidrug-resistant (MDR) Salmonella was determined to be 0.6%. The most common MDR serotypes were Salmonella enterica serotypes Dublin, Reading, and Typhimurium. MDR strains had resistance to between 2 and 10 antibiotics. There were no regional differences in prevalence of MDR Salmonella. PFGE analysis revealed that indistinguishable XbaI and AvrII restriction digest patterns (RDPs) could be observed in isolates of the same serotype found in different regions and months of sampling. The RDPs of 19 Salmonella strains were compared to RDPs in the PulseNet USA database. Thirteen were indistinguishable from existing patterns, and the number of records for each ranged from 1 to 478. These data show that Salmonella prevalence in commercial ground beef is low and suggest that attempts to identify sources contributing to Salmonella in ground beef by serotype, antibiogram, and PFGE cannot be made without additional documented evidence.

Risk Factors and Control Measures for Bacterial Contamination in the Bovine Meat Chain: A Review on Salmonella and Pathogenic E.coli

“…The variations in Salmonella and pathogenic E. coli prevalence amongst different countries could be attributed to a number of factors (including the farming systems and practices, slaughtering practices and post slaughter handling of meat as well as the general hygiene at different stages of the meat chain); which differ from one country to another. Higher prevalences are principally observed in developing countries, where poor hygienic conditions during slaughtering and meat handling are generally reported (Gashe & Mpuchane, 2000;Hassanein et al, 2011;Magwira, Gashe, & Collison, 2005;Stevens et al, 2006), whereas lower prevalence are mostly observed in developed countries where good hygienic practices are reported to be strictly followed and monitored along the meat chain (EFSA and ECDC, 2013;Vipham et al, 2012;Bosilevac et al, 2009). …”

“…In some studies the number of analyzed samples amounted to thousands (Bosilevac et al, 2009;EFSA and ECDC, 2013b) , whereas in others only a very limited number of samples was analysed (Gashe & Mpuchane, 2000;Temellİ, Eyİgör, & Anar, 2012). Differences were also observed in sampling methodology, where the surface swabbed on bovine carcasses to detect pathogens or the weight of the meat samples analysed varied between different studies.…”

Interactions of Organic Acids with Salmonella Strains from Feedlot Water-Sprinkled Cattle

“…Cerro, Meleagridis, Typhimurium, Dublin and Kentucky [7]. These ten Salmonella serovars also have been associated with outbreaks of foodborne illness: Montevideo [8,9], Anatum [10], Muenster [11], Mbandaka [8], Agona [12], Cerro [13,14], Meleagridis [15], Typhimurium [16][17][18], Dublin [19,20] and Kentucky [21,22], to list a few instances.…”

“…Recently, the Salmonella serovars Anatum, Montevideo and Kentucky were identified in cattle feces during a study to determine the prevalence of Salmonella enterica in South Texas beef cattle feedlots [29]. These Salmonella serovars are among the top 10 Salmonella serovars isolated from commercial ground meat [7], and can be important players in outbreaks of foodborne illness [8-10, 21, 22].…”

Inducers and autoinducers on Salmonella enterica serovar Typhimurium motility, growth and gene expression

“…bacteria are among the major pathogenic microorganisms transmitted by food in the world (CDC, 2011), and animal-derived products are the main carriers of this bacterium (BOSILEVAC et al, 2009;MURMANN et al, 2009). Salmonella Enteritidis and Salmonella Typhimurium are the main serovars isolated from human sources (CDC, 2011).…”