title: Isolation and characterization of Clostridium difficile associated with beef cattle and commercially produced ground beef.
abstract: The incidence of Clostridium difficile infection has recently increased in North American and European countries. This pathogen has been isolated from retail pork, turkey, and beef products and reported associated with human illness. This increase in infections has been attributed  to the emergence of a toxigenic strain designated North America pulsed-field gel electrophoresis type 1 (NAP1). The NAP1 strain has been isolated from calves as well as ground meat products, leading to speculation of illness from consumption of contaminated meat products. However, information  on C. difficile associated with beef cattle during processing and commercially produced ground beef is limited. To address this data gap, samples from various steps during beef production were collected. Samples from hides (n = 525), preevisceration carcasses (n = 475),  postintervention carcasses (n = 471), and 956 commercial ground beef samples were collected from across the United States. The prevalence of C. difficile spores on hides was 3.2%. C. difficile spores were not detected on preevisceration and postintervention carcasses or  in commercially produced ground beef. Phenotypic and genetic characterizations were carried out for all 18 isolates collected from hide samples. Twenty-two percent of the isolates were nontoxigenic strains, while 78% of the isolates were toxigenic. Toxinotyping and PCR ribotyping patterns  revealed that 6 and 33% of the isolates were identified as NAP1 and NAP7 strains, respectively. This article evidences that the prevalence of C. difficile, specifically pathogenic strains, in the U.S. beef production chain is low.
authors: U.S. Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, NE 68933-0166, USA. norasak.kalchayanand@ars.usda.gov
authors: Norasak
authors: N
authors: Kalchayanand
authors: Terrance M
authors: TM
authors: Arthur
authors: Joseph M
authors: JM
authors: Bosilevac
authors: Dayna M
authors: DM
authors: Brichta-Harhay
authors: Steven D
authors: SD
authors: Shackelford
authors: James E
authors: JE
authors: Wells
authors: Tommy L
authors: TL
authors: Wheeler
authors: Mohammad
authors: M
authors: Koohmaraie
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D016360:Clostridioides difficile / Q000145:classification / Q000302:isolation & purification*; D016521:Electrophoresis, Gel, Pulsed-Field; D005060:Europe; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D005525:Food-Processing Industry / Q000379:methods / Q000592:standards; D006801:Humans; D008461:Meat Products / Q000382:microbiology*; D009656:North America; D016133:Polymerase Chain Reaction; D015995:Prevalence; D021521:Ribotyping; D014481:United States / Q000453:epidemiology