Sequencing and culture-based characterization of the vaginal and uterine microbiota in beef cattle that became pregnant or remained open following artificial insemination.

IMPORTANCE: Emerging evidence suggests that microbiome-targeted approaches may provide a novel opportunity to reduce the incidence of reproductive failures in cattle. To develop such microbiome-based strategies, one of the first logical steps is to identify reproductive microbiome features related to fertility and to isolate the fertility-associated microbial species for developing a future bacterial consortium that could be administered before breeding to enhance pregnancy outcomes. Here, we characterized the vaginal and uterine microbiota in beef cattle that became pregnant or remained open via artificial insemination and identified microbiota features associated with fertility. We compared similarities between vaginal and uterine microbiota and between heifers and cows. Using culturing, we provided new insights into the culturable fraction of the vaginal and uterine microbiota and their antimicrobial resistance. Overall, our findings will serve as an important basis for future research aimed at harnessing the vaginal and uterine microbiome for improved cattle fertility.

Data Driven Computational Design and Experimental Validation of Drugs for Accelerated Mitigation of Pandemic-like Scenarios.

Emerging pathogens are a historic threat to public health and economic stability. Current trial-and-error approaches to identify new therapeutics are often ineffective due to their inefficient exploration of the enormous small molecule design space. Here, we present a data-driven computational framework composed of hybrid evolutionary algorithms for evolving functional groups on existing drugs to improve their binding affinity toward the main protease (Mpro) of SARS-CoV-2. We show that combinations of functional groups and sites are critical to design drugs with improved binding affinity, which can be easily achieved using our framework by exploring a fraction of the available search space. Atomistic simulations and experimental validation elucidate that enhanced and prolonged interactions between functionalized drugs and Mpro residues result in their improved therapeutic value over that of the parental compound. Overall, this novel framework is extremely flexible and has the potential to rapidly design inhibitors for any protein with available crystal structures.

Expression of anti-chikungunya single-domain antibodies in transgenic Aedes aegypti reduces vector competence for chikungunya virus and Mayaro virus.

Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are closely related alphaviruses that cause acute febrile illness accompanied by an incapacitating polyarthralgia that can persist for years following initial infection. In conjunction with sporadic outbreaks throughout the sub-tropical regions of the Americas, increased global travel to CHIKV- and MAYV-endemic areas has resulted in imported cases of MAYV, as well as imported cases and autochthonous transmission of CHIKV, within the United States and Europe. With increasing prevalence of CHIKV worldwide and MAYV throughout the Americas within the last decade, a heavy focus has been placed on control and prevention programs. To date, the most effective means of controlling the spread of these viruses is through mosquito control programs. However, current programs have limitations in their effectiveness; therefore, novel approaches are necessary to control the spread of these crippling pathogens and lessen their disease burden. We have previously identified and characterized an anti-CHIKV single-domain antibody (sdAb) that potently neutralizes several alphaviruses including Ross River virus and Mayaro virus. Given the close antigenic relationship between MAYV and CHIKV, we formulated a single defense strategy to combat both emerging arboviruses: we generated transgenic Aedes aegypti mosquitoes that express two camelid-derived anti-CHIKV sdAbs. Following an infectious bloodmeal, we observed significant reduction in CHIKV and MAYV replication and transmission potential in sdAb-expressing transgenic compared to wild-type mosquitoes; thus, this strategy provides a novel approach to controlling and preventing outbreaks of these pathogens that reduce quality of life throughout the tropical regions of the world.

Insulin reduces the transmission potential of chikungunya virus and activates the toll pathway in Aedes aegypti mosquitoes.

Chikungunya virus (CHIKV) is an alphavirus that has re-emerged globally over the last two decades and has the potential to become endemic in the United States due to the presence of competent mosquito vectors, Aedes aegypti and Aedes albopictus. CHIK disease is characterised by fever, rash, and joint pain, and causes chronic debilitating joint pain and swelling in >50% of infected individuals. Given the disease severity caused by CHIKV and the global presence of vectors to facilitate its spread, strategies to reduce viral transmission are desperately needed; however, the human biological factors driving CHIKV transmission are poorly understood. Towards that end, we have previously shown that mosquitoes fed on alphavirus-infected obese mice have reduced infection and transmission rates compared to those fed on infected lean mice despite similar viremia in lean and obese mice. One of the many host factors that increase in obese hosts is insulin, which was previously shown to impact the infection of mosquitoes by several flaviviruses. However, insulin's impact on alphavirus infection of live mosquitoes is unknown and whether insulin influences mosquito-borne virus transmission has not been tested. To test this, we exposed A. aegypti mosquitoes to bloodmeals with CHIKV in the presence or absence of physiologically relevant levels of insulin and found that insulin significantly lowered both infection and transmission rates. RNA sequencing analysis on mosquito midguts isolated at 1-day-post-infectious-bloodmeal (dpbm) showed enrichment in genes in the Toll immune pathway in the presence of insulin, which was validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We then sought to determine if the Toll pathway plays a role in CHIKV infection of Ae. aegypti mosquitoes; therefore, we knocked down Myd88, a critical immune adaptor molecule for the Toll pathway, in live mosquitoes, and found increased CHIKV infection compared to the mock knockdown control group. Overall, these data demonstrate that insulin reduces CHIKV transmission by Ae. aegypti and activates the Toll pathway in mosquitoes, suggesting that conditions resulting in higher serum insulin concentrations may reduce alphavirus transmission. Finally, these studies suggest that strategies to activate insulin or Toll signalling in mosquitoes may be an effective control strategy against medically relevant alphaviruses.

A Longitudinal Characterization of the Seminal Microbiota and Antibiotic Resistance in Yearling Beef Bulls Subjected to Different Rates of Gain.

In this study, we evaluated the seminal and fecal microbiota in yearling beef bulls fed a common diet to achieve moderate (1.13 kg/day) or high (1.80 kg/day) rates of weight gain. Semen samples were collected on days 0 and 112 of dietary intervention (n = 19/group) as well as postbreeding (n = 6/group) using electroejaculation, and the microbiota was assessed using 16S rRNA gene sequencing, quantitative PCR (qPCR), and culturing. The fecal microbiota was also evaluated, and its similarity with seminal microbiota was assessed. A subset of seminal bacterial isolates (n = 33) was screened for resistance against 28 antibiotics. A complex and dynamic microbiota was detected in bovine semen, and the community structure was affected by sampling time (R2 = 0.16, P < 0.001). Microbial richness increased significantly from day 0 to day 112, and diversity increased after breeding (P > 0.05). Seminal microbiota remained unaffected by the differential rates of gain, and its overall composition was distinct from fecal microbiota, with only 6% of the taxa shared between them. A total of 364 isolates from 49 different genera were recovered under aerobic and anaerobic culturing. Among these seminal isolates were pathogenic species and those resistant to several antibiotics. Overall, our results suggest that bovine semen harbors a rich and complex microbiota which changes over time and during the breeding season but appears to be resilient to differential gains achieved via a common diet. Seminal microbiota is distinct from the fecal microbiota and harbors potentially pathogenic and antibiotic-resistant bacterial species. IMPORTANCE Increasing evidence from human and other animal species supports the existence of a commensal microbiota in semen and that this seminal microbiota may influence not only sperm quality and fertility but also female reproduction. Seminal microbiota in bulls and its evolution and factors shaping this community, however, remain largely underexplored. In this study, we characterized the seminal microbiota of yearling beef bulls and its response to the bull age, different weight gains, and mating activity. We compared bacterial composition between seminal and fecal microbiota and evaluated the diversity of culturable seminal bacteria and their antimicrobial resistance. Our results obtained from sequencing, culturing, and antibiotic susceptibility testing provide novel information on the taxonomic composition, evolution, and factors shaping the seminal microbiota of yearling beef bulls. This information will serve as an important basis for further understanding of the seminal microbiome and its involvement in reproductive health and fertility in cattle.

Seminal and vagino-uterine microbiome and their individual and interactive effects on cattle fertility.

Reproductive failure is a major economical drain on cow-calf operations across the globe. It can occur in both males and females and stem from prenatal and postnatal influences. Therefore, the cattle industry has been making efforts to improve fertility and the pregnancy rate in cattle herds as an attempt to maintain sustainability and profitability of cattle production. Despite the advancements made in genetic selection, nutrition, and the implementation of various reproductive technologies, fertility rates have not significantly improved in the past 50 years. This signifies a missing factor or factors in current reproductive management practices that influence successful fertilization and pregnancy. Emerging lines of evidence derived from human and other animals including cattle suggest that the microbial continuum along the male and female reproductive tracts are associated with male and female fertility-that is, fertilization, implantation, and pregnancy success-highlighting the potential for harnessing the male and female reproductive microbiome to improve fertility in cattle. The objective of this narrative review is to provide an overview of the recent studies on the bovine seminal and vagino-uterine microbiome and discuss individual and interactive roles of these microbial communities in defining cattle fertility.

Bivalent single domain antibody constructs for effective neutralization of Venezuelan equine encephalitis.

Venezuelan equine encephalitis virus (VEEV) is a mosquito borne alphavirus which leads to high viremia in equines followed by lethal encephalitis and lateral spread to humans. In addition to naturally occurring outbreaks, VEEV is a potential biothreat agent with no approved human vaccine or therapeutic currently available. Single domain antibodies (sdAb), also known as nanobodies, have the potential to be effective therapeutic agents. Using an immune phage display library derived from a llama immunized with an equine vaccine that included inactivated VEEV, five sdAb sequence families were identified that showed varying ability to neutralize VEEV. One of the sequence families had been identified previously in selections against chikungunya virus, a related alphavirus of public health concern. A key advantage of sdAb is the ability to optimize properties such as neutralization capacity through protein engineering. Neutralization of VEEV was improved by two orders of magnitude by genetically linking sdAb. One of the bivalent constructs showed effective neutralization of both VEEV and chikungunya virus. Several of the bivalent constructs neutralized VEEV in cell-based assays with reductions in the number of plaques by 50% at protein concentrations of 1 ng/mL or lower, making future evaluation of their therapeutic potential compelling.

Noble Metal Organometallic Complexes Display Antiviral Activity against SARS-CoV-2.

SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl2 (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.

Stabilization of a Broadly Neutralizing Anti-Chikungunya Virus Single Domain Antibody.

A single domain antibody (clone CC3) previously found to neutralize a vaccine strain of the chikungunya virus (PRNT50 = 2. 5 ng/mL) was found to be broadly neutralizing. Clone CC3 is not only able to neutralize a wild-type (WT) strain of chikungunya virus (CHIKV), but also neutralizes WT strains of Mayaro virus (MAYV) and Ross River virus (RRV); both arthralgic, Old World alphaviruses. Interestingly, CC3 also demonstrated a degree of neutralizing activity against the New World alphavirus, Venezuelan equine encephalitis virus (VEEV); albeit both the vaccine strain, TC-83, and the parental, WT Trinidad donkey strain had PRNT50 values ~1,000-fold higher than that of CHIKV. However, no neutralization activity was observed with Western equine encephalitis virus (WEEV). Ten CC3 variants designed to possess a range of isoelectric points, both higher and lower, were constructed. This approach successfully identified several lower pI mutants which possessed improved thermal stabilities by as much as 10°C over the original CC3 (Tm = 62°C), and excellent refolding abilities while maintaining their capacity to bind and neutralize CHIKV.

Are Women Disproportionately Represented in Education Compared to Other Roles in Academic Radiology?

RATIONALE AND OBJECTIVES: Women in academic medicine, and radiology specifically, are underrepresented in departmental leadership roles and achieve fewer professional metrics of success. We have observed, however, that women are more broadly represented in medical education leadership. The purpose of this study was to determine if women in academic radiology are overrepresented in educational scholarship and educational leadership compared to general research scholarship and leadership positions, and to determine if there is any difference in the distribution of women in these roles compared to internal medicine. MATERIALS AND METHODS: We performed a PubMed search of education articles in radiology and internal medicine over the last 5 years, and the gender of the authors was determined. Data on gender for authorship of general research topics, departmental leaders, and society leadership was obtained via literature and internet searches and the data was aggregated. Representation ratios (RR of 1.0 = parity) were obtained via risk ratio calculation to compare education versus general scholarship, and the distribution of leadership roles within and between these fields. RESULTS: Women make up 28.5% of academic radiologists and 40.1% of academic internists. A higher proportion of education articles were first authored by women than would be expected in both fields with an RR of 1.46 (p < 0.001) in radiology and 1.23 (p < 0.001) in internal medicine. This overrepresentation was significant compared to general research scholarship in both fields (p < 0.001). In both fields, women were overrepresented in the position of Medical Student Director (RR of 1.47 and 1.22, respectively). For Program Directors, women were overrepresented in radiology (RR of 1.12) and underrepresented in internal medicine (RR of 0.69-0.75). Women in radiology were overrepresented in education society leadership (RR = 1.63) compared to general society leadership (0.98, p = 0.001). CONCLUSION: We found that women in radiology are overrepresented in authorship of education articles, and in departmental and society education leadership roles. This trend was also seen in internal medicine, suggesting that women are more broadly represented in medical education.

Effects of Chikungunya virus immunity on Mayaro virus disease and epidemic potential.

Mayaro virus (MAYV) causes an acute febrile illness similar to that produced by chikungunya virus (CHIKV), an evolutionary relative in the Semliki Forest virus complex of alphaviruses. MAYV emergence is typically sporadic, but recent isolations and outbreaks indicate that the virus remains a public health concern. Given the close phylogenetic and antigenic relationship between CHIKV and MAYV, and widespread distribution of CHIKV, we hypothesized that prior CHIKV immunity may affect MAYV pathogenesis and/or influence its emergence potential. We pre-exposed immunocompetent C57BL/6 and immunocompromised A129 or IFNAR mice to wild-type CHIKV, two CHIKV vaccines, or a live-attenuated MAYV vaccine, and challenged with MAYV. We observed strong cross-protection against MAYV for mice pre-exposed to wild-type CHIKV, and moderately but significantly reduced cross-protection from CHIKV-vaccinated animals. Immunity to other alphavirus or flavivirus controls provided no protection against MAYV disease or viremia. Mechanistic studies suggested that neutralizing antibodies alone can mediate this protection, with T-cells having no significant effect on diminishing disease. Finally, human sera obtained from naturally acquired CHIKV infection cross-neutralized MAYV at high titers in vitro. Altogether, our data suggest that CHIKV infection can confer cross-protective effects against MAYV, and the resultant reduction in viremia may limit the emergence potential of MAYV.

The Stability of Factors Influencing the Choice of Medical Specialty Among Medical Students and Postgraduate Radiology Trainees.

OBJECTIVE: To investigate whether general psychological motivating factors that guide career selection of a medical specialty differ over the course of medical school and to compare differences in motivating factors among students choosing "controllable" lifestyle specialties, students choosing "uncontrollable" lifestyle specialties, and a cohort of radiology residents. MATERIALS AND METHODS: An anonymous survey was distributed to first- through fourth-year medical students and radiology residents at a single institution. Participants were asked to select their top three of seven factors that most influenced their choice of medical specialty. Fourth-year students were asked to designate the specialty to which they had applied. RESULTS: The survey was distributed to 259 students and 47 radiology residents with a response rate of 93.8% (243 of 259) and 95.7% (45 of 47), respectively. The top three factors indicated by medical students were finding the daily work fulfilling, work-life balance, and interest in the subject. These top three factors were common to all medical student classes and did not differ between students choosing "controllable" versus "uncontrollable" fields. The factors uncommonly selected were similar personality to others in the field, attending income, competitiveness or prestige, and job market conditions. For radiology residents, the top three motivating factors were the same as for medical students. CONCLUSION: Three out of seven motivating factors were universally important to trainees, regardless of their stage of medical training or their selection of a controllable versus uncontrollable lifestyle specialty. These data suggest the variety of career choices made by students may not derive from differing underlying values.

Effect of gantry rotation speed and scan mode on peristalsis motion artifact frequency and severity at abdominal CT.

PURPOSE: The purpose of the study was to understand the effect of CT gantry speed and axial vs. helical scan mode on the frequency and severity of bowel peristalsis artifacts. METHOD: We retrospectively identified 150 oncologic abdominopelvic CT scans obtained on a 256 slice CT scanner: 50 scans obtained with Axial mode and 0.5-s gantry rotation time (Slow-Axial); 50 with Axial mode and 0.28-s gantry rotation time (Fast-Axial); and 50 scans with Helical mode and 0.28-s gantry rotation time (Fast-Helical). The patients included 74 women and 76 men with a mean age of 61 years (range 22-85 years). Two readers viewed all CT scans to record the presence and severity of bowel peristalsis artifact, location of artifact (stomach, duodenum/jejunum, ileum, and colon) and artifact location relative to bowel interface (gas-bowel, fluid-bowel, and gas-fluid). The severity of artifacts was recorded subjectively on a 3-point scale, and objectively based on maximum length of the artifact. RESULTS: Peristalsis artifact was more commonly seen with Slow-Axial scan acquisition (37 of 50 patient scans, or 74%) than Fast-Axial (15 in 50 patient scans, or 30%, p < 0.001) and Fast-Helical (22 of 50 patient scans, or 44%, p < 0.005). The bowel segment distribution and severity of peristalsis artifacts were not significantly different between scan techniques. CONCLUSION: Peristalsis artifacts are common at abdominopelvic CT scans. Fast gantry rotation speed significantly reduces the frequency of bowel peristalsis artifacts and should be a consideration when imaging of bowel and structures near bowel is critical.

Can Radiologists Learn From Airport Baggage Screening?: A Survey About Using Fictional Patients for Quality Assurance.

RATIONALE AND OBJECTIVES: For both airport baggage screeners and radiologists, low target prevalence is associated with low detection rate, a phenomenon known as "prevalence effect." In airport baggage screening, the target prevalence is artificially increased with fictional weapons that are digitally superimposed on real baggage. This strategy improves the detection rate of real weapons and also allows airport supervisors to monitor screener performance. A similar strategy using fictional patients could be applied in radiology. The purpose of this study was twofold: (1) to review the psychophysics literature regarding low target prevalence and (2) to survey radiologists' attitudes toward using fictional patients as a quality assurance tool. MATERIALS AND METHODS: We reviewed the psychophysics literature on low target prevalence and airport x-ray baggage screeners. An online survey was e-mailed to all members of the Association of University Radiologists to determine their attitudes toward using fictional patients in radiology. RESULTS: Of the 1503 Association of University Radiologists member recipients, there were 153 respondents (10% response rate). When asked whether the use of fictional patients was a good idea, the responses were as follows: disagree (44%), neutral (25%), and agree (31%). The most frequent concern was the time taken away from doing clinical work (89% of the respondents). CONCLUSIONS: The psychophysics literature supports the use of fictional targets to mitigate the prevalence effect. However, the use of fictional patients is not a popular idea among academic radiologists.

Interest in Interventional Radiology at Different Stages of Training: Possible Implications for the New Integrated Interventional Radiology Residency.

PURPOSE: Integrated interventional radiology (IR) residencies recently underwent their second year in the match, the first year of which involved only a limited number of programs. Now that students can choose to enter IR directly, student perceptions of IR vs diagnostic radiology (DR) are of paramount importance. METHODS: We surveyed first- through fourth-year medical students and radiology residents regarding interest in IR vs DR. RESULTS: Students considering a radiological career expressed more interest in IR than DR. Conversely, residents expressed more interest in DR. CONCLUSIONS: Medical student advisors and IR programs should continue to anticipate a high number of applications for integrated IR positions.