Cloned DNA of the geminivirus wheat dwarf virus (WDV) was successfully used to infect seedling wheat plants. The clone was derived from circular double-stranded viral DNA isolated from naturally infected tissue. The initiation of infection was mediated by Agrobacterium tumefaciens using cloned dimeric WDV genomes in a binary Agrobacterium vector. The WDV DNA which comprised the infectious clone was sequenced and is compared with the published sequence of a Swedish isolate of the same virus. The results confirm that the single WDV genome component of 2.75 kb carries all the information necessary for production of viral symptoms, virus particles and viral double- and single-stranded DNA forms.

The introduction of a new group of dendrobatid frogs to an established captive amphibian collection was followed by several acute mortalities in both resident and introduced frog populations. Chytridiomycosis, caused by Batrachochytrium dendrobatidis, was diagnosed by histology in two of the dead frogs. Following the diagnosis, all amphibians were moved to a specially made quarantine room with strict handling protocols and treated with itraconazole. Frogs, being terrestrial amphibians, were treated with itraconazole (Sporanox, 10 mg/ml) at 0.01% in 0.6% saline in a 5-min bath for 11 consecutive days. Axolotls (Ambystoma mexicanum) and Kaup's caecilians (Potymotyphlus kaupii), being aquatic amphibians, were treated with itraconazole administered directly in their primary tank water to achieve a concentration of 0.01% for 30 min every 5 days for four treatments. Itraconazole was removed from the tank water after 30 min by high-rate-of-flow activated charcoal filters. The treatment and quarantine procedures were successful in eradicating the disease. The few amphibian mortalities that occurred in the 18 mo after the start of the treatment have been histologically negative for the presence of chytrid fungi. The collection is now considered free of chytridiomycosis.

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