--Bruce Stallsmith
along the sunny Tennessee
Huntsville, AL, US of A
*******************
LAB ANI
Chytrid Found in Newts Purchased From Commercial Suppliers
During this year (2006) Chytrid fungus (Batrachochytrium dendrobatidis) was
found in red-spotted newts (Notophthalmus viridescens) from two well-known
commercial vendors of amphibians. In two shipments received from a vendor
in the southern portion of the United States mortality from the disease
exceeded 60% of over 400 animals. In another shipment from the East Coast,
newts tested positive for the disease but no mortality was experienced ion
over a month of quarantine. Although chytrid is very wide spread, this may
be the first report of infection in a commercial source. The purpose of
this note is to alert scientific users to the possibility of the fungus in
shipments from these and other suppliers of amphibians. Many species of
amphibians in addition to red-spotted newts are susceptible to the disease
so the concern extends beyond a single species. Chytrid infects epidermis
where it is saprophytic on keratin and may interfere with respiration, gas
exchange and uptake of chemicals. Infections are frequently lethal.
Studies indicate that Chytrid may be more deleterious to adult and juvenile
amphibians than to larvae but larvae may carry the disease only to have it
expressed after metamorphosis. Amphibians collected and shipped as eggs or
embryos may have lower or no incidence of the disease because keratin has
not yet formed in these life stages.
To reduce the potential for problems associated with Chytrid, we recommend
that all shipments of wild-caught larvae, juvenile and adult amphibians be
inspected for the fungus. This can be done by having someone experienced
with the disease examine epidermal scrapings microscopically or
histologically. A more definitive method of determining the presence of
Chytrid is to collect epidermal swabs and have them genetically tested via
polymerase chain reaction (PCR). Quarantining animals for two or more weeks
prior to placement on study may aid in diagnosis but will not guarantee
absence of the disease. Unusually high sloughing of skin seems to be a sign
of infection in newts.
Chytrid may be treated with anti-fungal medication such as
trimethoprimsulfadiazine (TMS), miconazole, or itraconazole (Nichols, D.K.
and E.W. Lamirande Froglog, the Newsletter of the Declining Amphibian
Populations Task Force, August 2001, No.46). However, investigators should
consider if the medication will interfere with the results of the research.
For additional information you may contact Dr. Donald Sparling, Cooperative
Wildlife Research Laboratory (dsparl-in-siu.edu) or Gretchen Flohr, Department
of Zoology (GPadgettFlohr-in-aol.com), Southern Illinois University,
Carbondale, IL. 62901.
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