title: Infection of hamsters with historical and epidemic BI types of Clostridium difficile.
abstract: BACKGROUND
  North American and European hospitals have reported outbreaks of Clostridium difficile-associated disease with unexpectedly high mortality caused by a newly recognized group of C. difficile strains, group BI. Our objective was to compare, in hamsters, the virulence of a historical nonepidemic BI type, BI1, with that of 2 recent epidemic BI types, BI6 and BI17, and with that of 2 standard toxigenic strains, K14 and 630.
  
  
  METHODS
  For each strain, 10 hamsters were given 1 dose of clindamycin, followed 5 days later with 100 C. difficile spores administered by gastric inoculation. Outcomes were recorded.
  
  
  RESULTS
  The hamster model demonstrated variations in mean times from inoculation to death (for BI6, 40 h; for BI1, 48 h; for K14, 49 h; for BI17, 69 h; for 630, 102 h; for BI6, BI1, and K14 vs. 630, P< .01; for BI17 vs. 630, P< .05) and from colonization to death (for BI1, 7 h; for BI17, 13 h; for BI6, 16 h; for K14, 17 h; for 630, 52 h; for BI1, BI17, BI6, and K14 vs. 630, P< .01).
  
  
  CONCLUSIONS
  Group BI strains were not more rapidly fatal than the standard toxinotype 0 strain K14 but were more rapidly fatal than the standard toxinotype 0 strain 630. BI6, the most common BI type in our collection, was particularly virulent in hamsters, consistently causing death within 48 h of inoculation.
authors.affiliation: Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Razaq
authors.forename: Susan
authors.initials: S
authors.lastname: Sambol
authors.forename: Kristin
authors.initials: K
authors.lastname: Nagaro
authors.forename: Walter
authors.initials: W
authors.lastname: Zukowski
authors.forename: Adam
authors.initials: A
authors.lastname: Cheknis
authors.forename: Stuart
authors.initials: S
authors.lastname: Johnson
authors.forename: Dale N
authors.initials: DN
authors.lastname: Gerding
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis; D002981:Clindamycin / Q000494:pharmacology; D016360:Clostridioides difficile / Q000187:drug effects / Q000378:metabolism / Q000472:pathogenicity*; D003015:Clostridium Infections / Q000188:drug therapy / Q000382:microbiology*; D006224:Cricetinae; D004195:Disease Models, Animal; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D008297:Male; D008647:Mesocricetus
chemical_list: D001427:Bacterial Toxins; D002981:Clindamycin