An epizootic of cutaneous zygomycosis in cultured dwarf African clawed frogs (Hymenochirus curtipes) due to Basidiobolus ranarum.
Morbidity and mortality approaching 100% occurred in dwarf African clawed frogs (Hymenochirus curtipes) from a culture facility in central California. Moribund frogs exhibited preference for a terrestrial environment rather than their normal aquatic environment. Affected animals had a slight pallor of the integument but were otherwise grossly unremarkable. Microscopic examination revealed a fungal infection of the integument primarily characterized by the presence of surface and intra-epidermal conidia. Skin cultures of the infected animals yielded an organism identified as Basidiobolus ranarum, based on the formation of conidia in culture with internal cleavage to form sporangiospores. The organism was transmitted to healthy frogs by co-habitation with infected frogs but not by short-term immersion exposure of healthy frogs to homogenized broth cultures of the fungus. Benzalkonium chloride at 2.0 mg l-1 was efficacious in controlling the infection. Although Basidiobolus species are normally found in the intestinal tract of amphibians, the severity of this epizootic indicates that B. ranarum may be an important pathogen of amphibians reared in culture facilities.
Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.
J M
JM
Groff
A
A
Mughannam
T S
TS
McDowell
A
A
Wong
M J
MJ
Dykstra
F L
FL
Frye
R P
RP
Hedrick
D000818:Animals; D001548:Benzalkonium Compounds / Q000627:therapeutic use; D003881:Dermatomycoses / Q000188:drug therapy / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D004196:Disease Outbreaks / Q000662:veterinary*; D005658:Fungi / Q000302:isolation & purification* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009091:Mucormycosis / Q000188:drug therapy / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D011898:Ranidae; D012867:Skin / Q000382:microbiology / Q000648:ultrastructure
D001548:Benzalkonium Compounds