Toxin Testing – Cell culture

Cell culture based testing of: E. coli for verotoxin 1* and verotoxin 2*, cytolethal distending toxin, Cytotoxic Necrotizing Factor toxin, Heat-labile toxin, Heat-stable toxin.

Isolate from urine, stool, blood, environmental, food, other.

Isolate provided on culture medium.

Send as growth on culture medium or in transport medium.

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

Gastroenteritis, septicemia, infection, other. Upon request, other enteric species may be tested for cytotoxic activity. If no specific organism can be isolated, stool samples can be tested for verotoxin or cytotoxic activity.

Completed Enteric Diseases Program requisition form.

Upon request, other enteric species may be tested for cytotoxic activity. If no specific organism can be isolated, stool samples can be tested for verotoxin or cytotoxic activity.

* This test is accredited.

stx1, stx2 - shigatoxins, also known as verotoxins (toxins secreted into extracellular milieu); cause mild-bloody diarrhea, can lead to HUS; stx-2 typically associated with more severe disease.

CDT - Cytolethal Distending Toxin; isolated from patients with GI or UTIs, and sepsis. suggested link to diarrhea and bloody diarrhea

CNF - Cytotoxic Necrotizing Factor; associated mainly with extraintestinal pathogenic strains causing UTIs and meningitis; associated with septicemia and/or diarrhea

LT - heat-labile enterotoxin; generally LT-1 is more important in human illness, but LT-II has been isolated from human cases of ETEC diarrhea

ST - heat-stable enterotoxin; found solely or with LT; more frequently found in severe human disease than LT-only isolates; causes watery diarrhea

Cell-culture based testing of E. coli.

14 calendar days (unless prior notification that the sample is urgent)

1. Karmali, M.A., M. Petric, C. Lim, P.E. Fleming, G.S. Arbus, and H. Lior. 1985. The association between idiopathic hemolytic uremic syndrome and infection by verotoxin-producing Escherichia coli. J. Infect. Dis. 151:775-782.
2. Donta, S.T., H.W. Moon, and S. C. Whipp. 1974. Detection of heat-labile Escherichia coli enterotoxin with the use of adrenal cells in tissue culture. Science 183:334-336.
3. Johnson WM and H Lior. A new heat-labile cytolethal distending toxin (CLDT) produced by Escherichia coli isolates from clinical material. Micro Path 1988; 4: 103-113.