USGS ScienceSearch

Geology topics

Ara S. Winter

Publications and source records attributed to Ara S. Winter.

3 recordsLinked to original sources

Great diversity of KSα sequences from bat-associated microbiota suggests novel sources of uncharacterized natural products

Polyketide synthases (PKSs) are multidomain enzymes in microorganisms that synthesize complex, bioactive molecules. PKS II systems are iterative, containing only a single representative of each domain: ketosynthase alpha (KS &#x03B1; "> α � ⁠ ), ketosynthase beta and the acyl carrier protein. Any gene encoding for one of these domains is representative of an entire PKS II biosynthetic gene cluster (BGC). Bat skin surfaces represent an extreme environment prolific in Actinobacteria that may constitute a source for bioactive molecule discovery. KS &#x03B1; "> α � sequences were obtained from culturable bacteria from bats in the southwestern United States. From 467 bat bacterial isolates, we detected 215 (46%) had KS &#x03B1; "> α � sequences. Sequencing yielded 210 operational taxonomic units, and phylogenetic placement found 45 (21%) shared <85% homology to characterized metabolites. Additionally, 16 Actinobacteria genomes from the bat microbiome were analyzed for biosynthetic capacity. A range of 69–93% of the BGCs were novel suggesting the bat microbiome may contain valuable uncharacterized natural products. Documenting and characterizing these are important in understanding the susceptibility of bats to emerging infectious diseases, such as white-nose syndrome. Also noteworthy was the relationship between KS &#x03B1; "> α � homology and total BGC novelty within each fully sequenced strain. We propose amplification and detection of KS &#x03B1; "> α � could predict a strain's global biosynthetic capacity.

FEMS Microbiology Ecology

Southwestern bats and their external bacteria

Bat species diversity within the United States is greatest in the Southwest, with approximately 30 species present. At least 16 of these bat species hibernate and are susceptible to white-nose syndrome (WNS), which is caused by the fungus Pseudogymnoascus destructans . Since 2006, millions of bats from 35 U.S. states and 7 Canadian provinces have died from WNS. In previous studies of external surfaces of bats sampled from southwestern states, Actinobacteria were detected that were shown to have antifungal properties against P. destructans in laboratory testing. These studies motivated us to expand our research to sites that represent possible gateways for P. destructans to enter the Southwest so that we could establish a baseline of bat microbiota before the arrival of WNS. We surveyed for the presence of bats and their external microbiota at 3 national parks and monuments located in southeastern Colorado and northeastern New Mexico. Our results document new occurrence records of bat species and their external bacteria at each sampling location. Additionally, we provide insight on the composition of bat external microbiota in the absence of P. destructans , while revealing information about the Streptomyces and other possible native defenses of bats against P. destructans at a gateway into the Southwest.

Western North American Naturalist

Skin and fur bacterial diversity and community structure on American southwestern bats: effects of habitat, geography and bat traits

Microorganisms that reside on and in mammals, such as bats, have the potential to influence their host’s health and to provide defenses against invading pathogens. However, we have little understanding of the skin and fur bacterial microbiota on bats, or factors that influence the structure of these communities. The southwestern United States offers excellent sites for the study of external bat bacterial microbiota due to the diversity of bat species, the variety of abiotic and biotic factors that may govern bat bacterial microbiota communities, and the lack of the newly emergent fungal disease in bats, white-nose syndrome (WNS), in the southwest. To test these variables, we used 16S rRNA gene 454 pyrosequencing from swabs of external skin and fur surfaces from 163 bats from 13 species sampled from southeastern New Mexico to northwestern Arizona. Community similarity patterns, random forest models, and generalized linear mixed-effects models show that factors such as location (e.g., cave-caught versus surface-netted) and ecoregion are major contributors to the structure of bacterial communities on bats. Bats caught in caves had a distinct microbial community compared to those that were netted on the surface. Our results provide a first insight into the distribution of skin and fur bat bacteria in the WNS-free environment of New Mexico and Arizona. More importantly, it provides a baseline of bat external microbiota that can be explored for potential natural defenses against pathogens.

PeerJ