Shiga toxin 2e-producing Escherichia coli isolates from humans and pigs differ in their virulence profiles and interactions with intestinal epithelial cells.
Thirteen Escherichia coli strains harboring stx2e were isolated from 11,056 human stools. This frequency corresponded to the presence of the stx2e allele in 1.7% of all Shiga toxin-producing E. coli (STEC) strains. The strains harboring stx2e were associated with mild diarrhea (n = 9) or asymptomatic infections (n = 4). Because STEC isolates possessing stx2e are porcine pathogens, we compared the human STEC isolates with stx2e-harboring E. coli isolated from piglets with edema disease and postweaning diarrhea. All pig isolates possessed the gene encoding the F18 adhesin, and the majority possessed adhesin involved in diffuse adherence; these adhesins were absent from all the human STEC isolates. In contrast, the high-pathogenicity island encoding an iron uptake system was found only in human isolates. Host-specific patterns of interaction with intestinal epithelial cells were observed. All human isolates adhered to human intestinal epithelial cell lines T84 and HCT-8 but not to pig intestinal epithelial cell line IPEC-J2. In contrast, the pig isolates completely lysed human epithelial cells but not IPEC-J2 cells, to which most of them adhered. Our data demonstrate that E. coli isolates producing Shiga toxin 2e have imported specific virulence and fitness determinants which allow them to adapt to the specific hosts in which they cause various forms of disease.
Sonntag
Anne-Katharina
AK
Institute of Hygiene and the National Consulting Laboratory on Hemolytic Uremic Syndrome, University Hospital Münster, Robert Koch Str. 41, Münster, Germany.
Bielaszewska
Martina
M
Mellmann
Alexander
A
Dierksen
Nadine
N
Schierack
Peter
P
Wieler
Lothar H
LH
Schmidt
M Alexander
MA
Karch
Helge
H
D000818:Animals; D002460:Cell Line; D017931:DNA Primers; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary; D004487:Edema / Q000382:microbiology / Q000662:veterinary; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D005243:Feces / Q000382:microbiology; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D022641:Shiga Toxin 2 / Q000235:genetics*; D013045:Species Specificity; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology; D014774:Virulence / Q000235:genetics
D017931:DNA Primers; D022641:Shiga Toxin 2