Development of an \u3ci\u3ein vitro\u3c/i\u3e assay for detecting botulinum neurotoxin type E with application to avian botulism in the Great Lakes

Purpose of study: Botulinum neurotoxin serotype E (BoNT/E) outbreaks in the Great Lakes region cause large annual avian mortality events with an estimated 17,000 bird deaths reported in 2007 alone. It is proposed that environmental conditions following blooms of the native algae Cladophora may promote growth of C. botulinum within Great Lakes sediments and subsequent BoNT/E production. BoNT/E may then be mobilized from the lake bed through food chains consisting of exotic species. We set out to develop a sensitive in vitro assay for diagnosis of avian BoNT intoxication and analysis of drivers that contribute to these outbreaks. Methods used: The BoTest™ Matrix E BoNT/E detection assay combines immuno-precipitation with high-affinity endopeptidase activity detection by Förster Resonance Energy Transfer to rapidly quantify BoNT/E activity in avian blood and other samples with detection limits comparable to the mouse bioassay. Summary of results: Based upon the analysis of archived blood samples (n=87) collected from bird carcasses during avian mortality investigations, BoTest Matrix E detected picomolar quantities of BoNT/E following a two–hour incubation and femtomolar quantities of BoNT/ E following extended incubation (24 hours), with 100% diagnostic specificity and 91% diagnostic sensitivity. Further, BoNT activity, as determined by the BoTest Matrix E assay, correlated linearly with total BoNT/E protein concentration contained within avian blood samples, as measured by sandwich ELISA (slope = 1.2). The BoTest Matrix E assay also detected BoNT/E in spiked mussels, fish and seaweed, suggesting its utility for analysis of food web components. Conclusions: Sensitive in vitro assays for the diagnosis of botulinum intoxication in birds and for the identification of BoNT/E in food web components will facilitate understanding of environmental toxin mobilization pathways and will provide useful tools for the conservation of bird species in the Great Lakes region

Geomyces destructans sp. nov. associated with bat white-nose syndrome

We describe and illustrate the new species Geomyces destructans. Bats infected with this fungus present with powdery conidia and hyphae on their muzzles, wing membranes, and/or pinnae, leading to description of the accompanying disease as white-nose syndrome, a cause of widespread mortality among hibernating bats in the northeastern US. Based on rRNA gene sequence (ITS and SSU) characters the fungus is placed in the genus Geomyces, yet its distinctive asymmetrically curved conidia are unlike those of any described Geomyces species

Malassezia vespertilionis sp. nov.: a new cold-tolerant species of yeast isolated from bats

Malassezia is a genus of medically-important, lipid-dependent yeasts that live on the skin of warmblooded animals. The 17 described species have been documented primarily on humans and domestic animals, but few studies have examined Malassezia species associated with more diverse host groups such as wildlife. While investigating the skin mycobiota of healthy bats, we isolated a Malassezia sp. that exhibited only up to 92 % identity with other known species in the genus for the portion of the DNA sequence of the internal transcribed spacer region that could be confidently aligned. The Malassezia sp. was cultured from the skin of nine species of bats in the subfamily Myotinae; isolates originated from bats sampled in both the eastern and western United States. Physiological features and molecular characterisation at seven additional loci (D1/D2 region of 26S rDNA, 18S rDNA, chitin synthase, second largest subunit of RNA polymerase II, β-tubulin, translation elongation factor EF-1α, and minichromosome maintenance complex component 7) indicated that all of the bat Malassezia isolates likely represented a single species distinct from other named taxa. Of particular note was the ability of the Malassezia sp. to grow over a broad range of temperatures (7–40 °C), with optimal growth occurring at 24 °C. These thermal growth ranges, unique among the described Malassezia, may be an adaptation by the fungus to survive on bats during both the host’s hibernation and active seasons. The combination of genetic and physiological differences provided compelling evidence that this lipid-dependent yeast represents a novel species described herein as Malassezia vespertilionis sp. nov. Whole genome sequencing placed the new species as a basal member of the clade containing the species M. furfur, M. japonica, M. obtusa, and M. yamatoensis. The genetic and physiological uniqueness of Malassezia vespertilionis among its closest relatives may make it important in future research to better understand the evolution, life history, and pathogenicity of the Malassezia yeasts

Possibility for reverse zoonotic transmission of sars-cov-2 to free-ranging wildlife: A case study of bats

10.1371/journal.ppat.1008758PLoS Pathogens169e100875