Toxin detection

Toxin detection in Vibrio cholerae

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

Isolate provided on appropriate culture medium for Vibrio species.

Send as growth on appropriate culture medium or in appropriate transport medium.  Culture vessel should be leak-proof or sealed appropriately.

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

Completed Division of Enteric Diseases requisition form.

N/A

Testing is performed, in whole or in part, using a lab-developed test which has not been fully validated/verified due to a lack of well-characterized panel.

PCR-based identification of genes encoding toxins and virulence factors:

• ctx (Cholera toxin): causes severe diarrhea; indicative of toxigenic Vibrio spp.(1)
• vhlyA (Hemolysin A): a pore-forming exotoxin; widely thought to enhance virulence of V. cholerae (accessory toxin)(2)
• rtx (repeat/accessory toxin): associated with toxin transportation(2)

1. Fields, P.I. et al. 1992. Use of Polymerase Chain Reaction for the Detection of Toxigenic Vibrio cholerae O1 strains from Latin American Cholera Epidemic. J. Clin. Microbiol. Aug: 2118-2121.
2. In-house developed assays for the vhlyA and rtx genes.

 7 calendar days. Note: Turnaround times for routine isolates may be extended during major foodborne outbreak activities or due to limited availability of resources.