Environment and weight class linked to skin microbiome structure of juvenile Eastern hellbenders (<i>Cryptobranchus alleganiensis alleganiensis</i>) in human care

by Andrea C. Aplasca, Peter B. Johantgen, Christopher Madden, Kilmer Soares, Randall E. Junge, Vanessa L. Hale, Mark Flint

Amphibian skin is integral to promoting normal physiological processes in the body and promotes both innate and adaptive immunity against pathogens. The amphibian skin microbiota is comprised of a complex assemblage of microbes and is shaped by internal host characteristics and external influences. Skin disease is a significant source of morbidity and mortality in amphibians, and increasing research has shown that the amphibian skin microbiota is an important component in host health. The Eastern hellbender (Cryptobranchus alleganiensis alleganiensis) is a giant salamander declining in many parts of its range, and captive-rearing programs are important to hellbender recovery efforts. Survival rates of juvenile hellbenders in captive-rearing programs are highly variable, and mortality rates are overall poorly understood. Deceased juvenile hellbenders often present with low body condition and skin abnormalities. To investigate potential links between the skin microbiota and body condition, we collected skin swab samples from 116 juvenile hellbenders and water samples from two holding tanks in a captive-rearing program. We used 16s rRNA gene sequencing to characterize the skin and water microbiota and observed significant differences in the skin microbiota by weight class and tank. The skin microbiota of hellbenders that were housed in tanks in close proximity were generally more similar than those housed physically distant. A single taxa, Parcubacteria, was differentially abundant by weight class only and observed in higher abundance in low weight hellbenders. These results suggest a specific association between this taxa and Low weight hellbenders. Additional research is needed to investigate how husbandry factors and potential pathogenic organisms, such as Parcubacteria, impact the skin microbiota of hellbenders and ultimately morbidity and mortality in the species.

Testing learning as alternative to the blank slate hypothesis in the honey bee, <i>Apis mellifera</i>

by Olav Rueppell, Kayla De Jong, Jacob J. Herman, Cleo Randall

Reliable recognition of nestmates and discrimination against non-nestmates is key to the integrity of social insect colonies. Cuticular hydrocarbon profiles play a key role in this recognition process in many species, including honey bees. Newly emerged worker bees are largely devoid of cuticular hydrocarbons and therefore believed to represent a “blank slate” that is not discriminated against and instead accepted into other colonies regardless of colony origin. However, instead of being unrecognizable, the absence of cuticular hydrocarbons may also represent a recognizable “Gestalt”. Thus, an alternative hypothesis for the universal acceptance of newly emerged workers may be that older workers in every colony learn the absence of cuticular hydrocarbons as a familiar stimulus that belongs to their colony because other such workers are constantly emerging under normal circumstances. Here, we tested this hypothesis by comparing the response to newly emerged workers between bees that matured in colonies with and without newly emerging bees. Contrary to our prediction, we found no significant difference between these two experimental groups in an aggression bioassay towards newly emerged workers. We thus failed to provide empirical evidence against the blank slate hypothesis. However, the groups displayed significant differences in aggression towards foragers from their own respective colonies, indicating that the emergence of new workers in a colony can affect group discriminatory behavior in honey bees. Furthermore, we identified a negative effect of temperature on aggressive behavior toward newly emerged workers.

Patient-Selection of a Clinical Trial Primary Outcome: The ENHANCE-AF Outcomes Survey

by Randall S. Stafford, Eli N. Rice, Rushil Shah, Mellanie T. Hills, Julio C. Nunes, Katie DeSutter, Amy Lin, Karma Lhamo, Bryant Lin, Ying Lu, Paul J. Wang

Introduction

Before the initiation of the ENHANCE-AF clinical trial, which tested a novel digital shared decision-making tool to guide the use of anticoagulants in stroke prevention for patients with atrial fibrillation, this study aimed to identify the most appropriate, patient-selected primary outcome and to examine whether outcome selection varied by demographic and clinical characteristics.

Methods

Our cross-sectional survey asked 100 participants with atrial fibrillation to rank two alternative scales based on the scales’ ability to reflect their experiences with decision-making for anticoagulation. The Decisional Conflict Scale (DCS), a 16-item scale, measures perceptions of uncertainty in choosing options. The 5-item Decision Regret Scale (DRS) focuses on remorse after a healthcare decision. We included adults with non-valvular AFib and CHA₂DS₂VASc scores of at least 2 for men and 3 for women. Multivariable logistic regression with backward selection identified characteristics independently associated with scale choice.

Results

The DCS was chosen over the DRS by 77% [95% confidence interval (CI) 68 to 85%] of participants. All subgroups designated a preference for the DCS. Those with higher CHA₂DS₂VASc scores (≥5, n = 26) selected the DCS 54% of the time compared with 86% of those with lower scores (p =  0.002). Multiple logistic regression confirmed a weaker preference for the DCS among those with higher CHA₂DS₂VASc scores.

Conclusions

Individuals with atrial fibrillation preferred the DCS over the DRS for measuring their decision-making experiences. As a result of this survey, the DCS was designated as the ENHANCE-AF clinical trial’s primary endpoint.