Pathogenic Bacteroides fragilis strains can emerge from gut-resident commensals.

Bacteroides fragilis is a prominent member of the human gut microbiota, playing crucial roles in maintaining gut homeostasis and host health. Although it primarily functions as a beneficial commensal, B. fragilis can become pathogenic. To determine the genetic basis of its duality, we conducted a comparative genomic analysis of 813 B. fragilis strains, representing both commensal and pathogenic origins. Our findings reveal that pathogenic strains emerge across diverse phylogenetic lineages, due in part to rapid gene exchange and the adaptability of the accessory genome. We identified 16 phylogenetic groups, differentiated by genes associated with capsule composition, interspecies competition, and host interactions. A microbial genome-wide association study identified 44 genes linked to extra-intestinal survival and pathogenicity. These findings reveal how genomic diversity within commensal species can lead to the emergence of pathogenic traits, broadening our understanding of microbial evolution in the gut.

Pangenome comparison of Bacteroides fragilis genomospecies unveils genetic diversity and ecological insights.

Bacteroides fragilis is a Gram-negative commensal bacterium commonly found in the human colon, which differentiates into two genomospecies termed divisions I and II. Through a comprehensive collection of 694 B. fragilis whole genome sequences, we identify novel features distinguishing these divisions. Our study reveals a distinct geographic distribution with division I strains predominantly found in North America and division II strains in Asia. Additionally, division II strains are more frequently associated with bloodstream infections, suggesting a distinct pathogenic potential. We report differences between the two divisions in gene abundance related to metabolism, virulence, stress response, and colonization strategies. Notably, division II strains harbor more antimicrobial resistance (AMR) genes than division I strains. These findings offer new insights into the functional roles of division I and II strains, indicating specialized niches within the intestine and potential pathogenic roles in extraintestinal sites. IMPORTANCE: Understanding the distinct functions of microbial species in the gut microbiome is crucial for deciphering their impact on human health. Classifying division II strains as Bacteroides fragilis can lead to erroneous associations, as researchers may mistakenly attribute characteristics observed in division II strains to the more extensively studied division I B. fragilis. Our findings underscore the necessity of recognizing these divisions as separate species with distinct functions. We unveil new findings of differential gene prevalence between division I and II strains in genes associated with intestinal colonization and survival strategies, potentially influencing their role as gut commensals and their pathogenicity in extraintestinal sites. Despite the significant niche overlap and colonization patterns between these groups, our study highlights the complex dynamics that govern strain distribution and behavior, emphasizing the need for a nuanced understanding of these microorganisms.

A Novel REBOA Training Curriculum for Emergency Medicine Residents: A Pilot Study.

BACKGROUND: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a potentially life-saving intervention to treat noncompressible torso hemorrhage. Traditionally, REBOA use has been limited to surgeons. However, emergency physicians are often the first point-of-contact and are well-versed in obtaining rapid vascular access and damage control resuscitation, making them ideal candidates for REBOA training. STUDY OBJECTIVES: To fill this gap, we designed and evaluated a REBOA training curriculum for emergency medicine (EM) residents. METHODS: Participants enrolled in an accredited 4-year EM residency program (N = 11) completed a 12-hour REBOA training course. Day 1 included lectures, case studies, and hands-on training using REBOA task trainers and perfused cadavers. Day 2 included additional practice and competency evaluations. Assessments included a 25-item written knowledge exam, decision-making on case studies, REBOA placement success, and time-to-placement. Participants returned at 4 months to assess long-term retention. Data were analyzed using t-tests and nonparametric statistics at p < 0.05. RESULTS: Scores on a 25-item multiple choice test significantly increased from pre-training (65% ± 5%) to post-training (92% ± 1%), p < 0.001. On Day 2, participants scored 100% on correct recognition of REBOA indications and scored 100% on correct physical placement of REBOA. Exit surveys indicated increased preparedness, confidence, and support for incorporating this course into EM training. Most importantly, REBOA knowledge, correct recognition of REBOA indications, and correct REBOA placement skills were retained by the majority of participants at 4 months. CONCLUSION: This course effectively teaches EM residents the requisite skills for REBOA competence and proper placement. This study could be replicated at other facilities with larger, more diverse samples, aiming to expand the use of REBOA in emergency physicians and reducing preventable deaths in trauma.

Dysphagia.

Dysphagia is an important clinical symptom that increases in prevalence with age. Both oropharyngeal and esophageal processes can contribute to dysphagia, and these can be differentiated with a careful history. Neuromuscular processes are more prevalent than structural causes in oropharyngeal dysphagia, therefore, investigation should start with a modified barium swallow. In contrast, structural processes dominate in esophageal dysphagia, and endoscopy can offer biopsy and therapy by way of dilation. Manometry is performed for esophageal dysphagia when no structural etiology is found. Specific management of dysphagia is dependent on the etiology and mechanism of dysphagia.

Harnessing Electronic Medical Record Tools to Provide Proceduralist Feedback on Pediatric Endoscopy Quality Metrics.

In 2022, the Pediatric Endoscopy Quality Improvement Network published quality metrics related to pediatric endoscopy. We utilized electronic medical record (EMR) tools to collect pediatric endoscopy quality metrics (PEQM) and to standardize proceduralist feedback. EMR tools were created to capture and display PEQM: (1) an endoscopy documentation template, (2) nursing documentation of events during endoscopy for timed calculations, and (3) a data dashboard. Dashboard metrics provided individualized PEQM feedback relative to group performance and ideals where available. Utilization of the endoscopy documentation tools and data dashboard was measured. Utility was assessed using a survey based on the Technology Adoption Model. Adoption of documentation tools has been nearly universal with positive survey outcomes. Robust dashboard visualization has been demonstrated. Use of EMR documentation tools standardized PEQM collection. Future capture and sharing of common PEQM data across institutions could help determine PEQM benchmarks.

Pangenome comparison of Bacteroides fragilis genomospecies unveil genetic diversity and ecological insights.

Bacteroides fragilis is a Gram-negative commensal bacterium commonly found in the human colon that differentiates into two genomospecies termed division I and II. We leverage a comprehensive collection of 694 B. fragilis whole genome sequences and report differential gene abundance to further support the recent proposal that divisions I and II represent separate species. In division I strains, we identify an increased abundance of genes related to complex carbohydrate degradation, colonization, and host niche occupancy, confirming the role of division I strains as gut commensals. In contrast, division II strains display an increased prevalence of plant cell wall degradation genes and exhibit a distinct geographic distribution, primarily originating from Asian countries, suggesting dietary influences. Notably, division II strains have an increased abundance of genes linked to virulence, survival in toxic conditions, and antimicrobial resistance, consistent with a higher incidence of these strains in bloodstream infections. This study provides new evidence supporting a recent proposal for classifying divisions I and II B. fragilis strains as distinct species, and our comparative genomic analysis reveals their niche-specific roles.

Anti-Inflammatory Properties of Plasma from Children with Short Bowel Syndrome.

Sepsis, resulting from a dysregulated host immune response to invading pathogens, is the leading cause of mortality in critically ill patients worldwide. Immunomodulatory treatment for sepsis is currently lacking. Children with short bowel syndrome (SBS) may present with less severe symptoms during gram-negative bacteremia. We, therefore, tested the hypothesis that plasma from children with SBS could confer protection against Escherichia coli sepsis. We showed that SBS plasma at 5% and 10% concentrations significantly (p < 0.05) inhibited the production of both TNF-α and IL-6 induced by either E. coli- or LPS-stimulated host cells when compared to plasma from healthy controls. Furthermore, mice treated intravenously with select plasma samples from SBS or healthy subjects had reduced proinflammatory cytokine levels in plasma and a significant survival advantage after E. coli infection. However, SBS plasma was not more protective than the plasma of healthy subjects, suggesting that children with SBS have other immunomodulatory mechanisms, in addition to neutralizing antibodies, to alleviate their symptoms during gram-negative sepsis.

Aberrant Epithelial Differentiation Contributes to Pathogenesis in a Murine Model of Congenital Tufting Enteropathy.

BACKGROUND & AIMS: Congenital tufting enteropathy (CTE) is an intractable diarrheal disease of infancy caused by mutations of epithelial cell adhesion molecule (EpCAM). The cellular and molecular basis of CTE pathology has been elusive. We hypothesized that the loss of EpCAM in CTE results in altered lineage differentiation and defects in absorptive enterocytes thereby contributing to CTE pathogenesis. METHODS: Intestine and colon from mice expressing a CTE-associated mutant form of EpCAM (mutant mice) were evaluated for specific markers by quantitative real-time polymerase chain reaction, Western blotting, and immunostaining. Body weight, blood glucose, and intestinal enzyme activity were also investigated. Enteroids derived from mutant mice were used to assess whether the decreased census of major secretory cells could be rescued. RESULTS: Mutant mice exhibited alterations in brush-border ultrastructure, function, disaccharidase activity, and glucose absorption, potentially contributing to nutrient malabsorption and impaired weight gain. Altered cell differentiation in mutant mice led to decreased enteroendocrine cells and increased numbers of nonsecretory cells, though the hypertrophied absorptive enterocytes lacked key features, causing brush border malfunction. Further, treatment with the Notch signaling inhibitor, DAPT, increased the numbers of major secretory cell types in mutant enteroids (graphical abstract 1). CONCLUSIONS: Alterations in intestinal epithelial cell differentiation in mutant mice favor an increase in absorptive cells at the expense of major secretory cells. Although the proportion of absorptive enterocytes is increased, they lack key functional properties. We conclude that these effects underlie pathogenic features of CTE such as malabsorption and diarrhea, and ultimately the failure to thrive seen in patients.

Renal angiomyolipoma rupture in a young female with COVID-19.

While primarily a respiratory illness, infection with the novel coronavirus (COVID-19) is associated with pathologic changes in coagulation, characterized by both thromboembolic and bleeding events. We present the case of a 22-year-old female diagnosed with renal angiomyolipoma (AML) rupture 2 weeks after COVID-19 infection, ultimately requiring admission for hemorrhage control via endovascular embolization. Emergency medicine physicians should maintain a high index of suspicion for renal AML rupture and other spontaneous bleeding events in patients with recent COVID-19 infection due to a possible correlation between the two.

Does Changing Residency Obstetric Call to a Group Model Significantly Impact Patient Continuity?

BACKGROUND AND OBJECTIVES: Group sharing of prenatal care and inpatient obstetric (OB) call is increasingly replacing single-provider longitudinal models including in family medicine (FM) residencies. Such change in care models could impact continuity of prenatal and delivery care.The University of Rochester's family medicine residency program changed the resident maternal care coverage to an obstetric group model from a single-provider model in 2016 to improve work-life balance, which provided an opportunity to examine how these two practice styles impacted provider continuity. METHODS: We performed a retrospective chart review of family medicine resident-assigned obstetric patients receiving care at the University of Rochester's residency clinic. The study evaluated provider continuity differences in two models of prenatal care and obstetric call: (1) single provider model (SPM) with one primary provider and one backup support resident vs (2) OB group-provider model (GPM) with three to four resident providers and one primary provider. RESULTS: The average number of different providers seen significantly increased in the GPM vs SPM (3.47 vs 2.87, P=.02), however the average percentage of prenatal visits with either a primary or designated backup provider was not statistically different (83.1% vs 90.1%, P=.07). Among delivery continuity measures, there was no significant difference between models in the percentage of deliveries attended by the primary or designated backup residents compared with nongroup providers. (76.9% vs 82.3%, P=.51). CONCLUSIONS: This study provides quantitative evidence on how differing models of residency maternal care coverage impact continuity of care. Study findings did not show an inferiority of an OB group-provider model compared to a single-provider model when considering how often patients were seen prenatally and delivered by providers from their continuity group.

Clinician and Staff Perceptions of Barriers to Providing Contraception in Primary Care.

INTRODUCTION: Short interpregnancy periods increase the likelihood of preterm delivery and low birth weight,1 both of which are significant causes of infant morbidity and mortality.2 Since nearly half of pregnancies in the United States are unplanned,3 opportunities exist to better understand barriers to contraceptive services. Studying these barriers as perceived by clinical staff can better guide programs to improve interpregnancy spacing. METHODS: Between September and November 2017, 76 staff and 95 primary care clinicians from two family medicine residency practices (Highland Family Medicine (HFM) in Rochester, New York and St Margaret Family Medicine (SM) in Pittsburgh, Pennsylvania) completed surveys. Questions assessed perceived barriers to providing contraceptive services, contraception knowledge, and opportunities for improvement. Survey-based analysis focused on comparative descriptive statistics between staff and provider responses. RESULTS: Clinicians ranked side effects and patient lack of awareness and misconceptions about contraceptive methods more highly than staff (P=0.0073 and P=0.0001, respectively). Staff identified childcare and work absence as more significant barriers (P=0.0114 and P=0.0380, respectively). Providers felt appointment timing was the largest constraint to contraceptive care. Staff perceived financial limitations and scheduling to be the top barriers. Nonclinician staff exhibited significant knowledge gaps regarding contraception. CONCLUSIONS: Numerous modifiable barriers contribute to difficulty providing contraceptive services. Providers and staff largely agree on the perceived barriers, but there is a significant gap in nonclinician staff knowledge of contraception. Education can address one of the leading concerns, but improvement efforts should also address areas such as availability of devices, scheduling issues, and resident supervision.

Parkinson's disease: A treatment guide.

By following this stepwise approach, you can confidently incorporate newer agents into your armamentarium with little or no consultation with subspecialists.

Bibliometric Analysis of Gender Authorship Trends and Collaboration Dynamics Over 30 Years of Spine 1985 to 2015.

STUDY DESIGN: A bibliometric analysis. OBJECTIVE: The aim of this article was to study bibliometric changes over the last 30 years of Spine. These trends are important regarding academic publication productivity. SUMMARY OF BACKGROUND DATA: Inflation in authorship number and other bibliometric variables has been described in the scientific literature. The issue of author gender is taking on increasing importance, as efforts are being made to close the gender gap. METHODS: From 1985 to 2015, 10-year incremental data for several bibliometric variables were collected, including author gender. Standard bivariate statistical analyses were performed. Trends over time were assessed by the Cochran linear trend. A P < 0.05 was considered statistically significant. RESULTS: Inclusion criteria were met for 1566 manuscripts. The majority of the manuscripts were from North America (51.2%), Europe (25.2%), and Asia (20.8%). The number of manuscripts, authors, countries, pages, and references all increased from 1985 to 2015. There was a slight increase in female first authors over time (17.5% to 18.4%, P = 0.048). There was no gender change over time for corresponding authors (14.3% to 14.0%, P = 0.29). There was an 88% increase in the percentage of female first authors having male corresponding authors (P = 0.00004), and a 123% increase in male first authors having female corresponding authors (P = 0.0002). The 14% to 18% of female authors in Spine is higher than the ∼5% female membership of the Scoliosis Research Society and North American Spine Society. CONCLUSION: Manuscripts in Spine over the past 30 years have shown a significant increase in the number of authors, collaborating institutions and countries, printed pages, references, and number of times each manuscript was cited. There has been a mild increase in female first authorship, but none in corresponding authorship. Increases in female authorship will likely require recruitment of more females into the discipline rather than providing females in the discipline with authorship opportunities. LEVEL OF EVIDENCE: N/A.

Injuries associated with bunk beds that occur in jail.

BACKGROUND: There are many studies of bunk bed injuries, but none specifically addressing those occurring in jails. It was the purpose of this study to investigate the magnitude and patterns of bunk bed injuries occurring in correctional institutions. METHODS: The National Electronic Injury Surveillance System (NEISS) data for the 10 year period 2006 through 2015 due to bunk beds was accessed. Injuries involving bunk beds were identified and the mechanism of injury determined. Statistical analyses were performed with SUDAAN 10™ software. A p < 0.05 was considered statistically significant. RESULTS: There were an estimated 639,505 ED visits for bunk bed associated injuries; 51,204 occurred in jail. All jail cases occurred in the age groups ≥10 years (177,165); 29% of these 177,165 sustained the injury in jail. Those who sustained a bunk bed injury in jail compared to those who did not were older, more commonly male, seen in smaller hospitals, more likely admitted, and more frequently associated with a seizure. For those injuries occurring in jail, the most common injury in the trunk and lower extremity was a strain/sprain; the upper extremity a contusion/abrasion; and the head/neck a laceration or traumatic brain injury. A fall off the bunk bed accounted for 71.8% of the injuries, had the highest hospital admission rate (7.4%), accounted for all of the spine injuries, 96% of the head injuries, and had the highest proportion of fractures (14.4%). Inmates having a seizure before the injury sustained fewer fractures, more lacerations, and more head/neck injuries. CONCLUSIONS: Injuries in jail account for 29% of all bunk bed injuries resulting in an ED visit in the USA in those age groups ≥10 years. A fall from the bed occurred in 72% and a seizure disorder was 4.5 times more common in jail inmates compared to non inmates. Possible prevention strategies include railings/ladders to reduce the incidence of falls, changes in flooring surfaces, and seizure education and placing inmates with seizure and/or alcohol related disorders on the bottom bunk. This will require a multidisciplinary approach involving the disciplines of medicine, material engineering, and criminal justice.

Sarcomatoid Renal Cell Carcinoma and Collecting Duct Carcinoma: Discrimination From Common Renal Cell Carcinoma Subtypes and Benign RCC Mimics on Multiphasic MDCT.

RATIONALE AND OBJECTIVES: To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can help discriminate sarcomatoid renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) from other solid renal masses. MATERIALS AND METHODS: With institutional review board approval for this HIPAA-compliant study, we derived a cohort of 7 sarcomatoid RCCs, 4 CDCs, 165 clear cell RCCs, 56 papillary RCCs, 22 chromophobe RCCs, 49 oncocytomas, and 16 lipid-poor angiomyolipomas with preoperative multiphasic MDCT with up to four phases (unenhanced, corticomedullary, nephrographic, and excretory). Each lesion was reviewed for contour, spread pattern, pattern of enhancement, neovascularity, and calcification. RESULTS: Sarcomatoid RCCs and CDCs were more likely than other solid renal masses to have an irregular contour (64% vs 2%, P < 0.001) and an infiltrative spread pattern, defined as infiltration into adjacent renal parenchyma, collecting system, or neighboring structures (82% vs 7%, P < 0.001). When used to discriminate sarcomatoid RCC and CDC from other solid renal masses, an infiltrative spread pattern had a specificity of 93% (287/308) and sensitivity of 82% (9/11), and an irregular contour had a specificity of 98% (303/308) and sensitivity of 64% (7/11). CONCLUSIONS: Solid renal lesions with an irregular contour or an infiltrative spread pattern are suspicious for sarcomatoid RCC or CDC.

Clear cell renal cell carcinoma: identifying the gain of chromosome 20 on multiphasic MDCT.

PURPOSE: To investigate whether multiphasic multidetector computed tomography (MDCT) enhancement can help identify the gain of chromosome 20 in clear cell renal cell carcinomas (RCCs), a rare prognostically significant cytogenetic abnormality. METHODS: With the Institutional Review Board approval, we queried our institution's pathology database to derive a cohort of 52 cases of clear cell RCC with preoperative four-phase renal mass protocol MDCT and karyotypes of the resected specimens during a 10-year period. Each lesion was evaluated for absolute and relative (compared to contralateral normal renal cortex) attenuations in each phase. Relative attenuation was calculated as [(lesion attenuation - cortex attenuation)/cortex attenuation] × 100. The absolute and relative attenuations were compared using t-tests. RESULTS: Clear cell RCCs with the gain of 20 had significantly less nephrographic and excretory phase enhancement than clear cell RCCs without the gain of 20 (86.4 HU vs. 111.4 HU, p = 0.007; 70.0 HU vs. 89.4 HU, p = 0.003; respectively). Additionally, the relative nephrographic and excretory phase attenuations of clear cell RCCs with the gain of 20 were significantly less than that of clear cell RCCs without the gain of 20 (-52.7 vs. -34.7, p = 0.002; -44.9 vs. -31.1, p = 0.005; respectively). CONCLUSION: Multiphasic MDCT enhancement may assist in identifying the gain of chromosome 20 in clear cell RCCs, if validated in a large prospective trial.

Diversity of fungi from the mound nests of Formica ulkei and adjacent non-nest soils.

Culture-based methods were employed to recover 3929 isolates of fungi from soils collected in May and July 2014 from mound nests of Formica ulkei and adjacent non-nest sites. The abundance, diversity, and richness of species from nest mounds exceeded those of non-mound soils, particularly in July. Communities of fungi from mounds were more similar to those from mounds than non-mounds; this was also the case for non-mound soils with the exception of one non-mound site in July. Species of Aspergillus, Paecilomyces, and Penicillium were dominant in nest soils and represented up to 81.8% of the taxa recovered. Members of the genus Aspergillus accounted for the majority of Trichocomaceae from nests and were represented almost exclusively by Aspergillus navahoensis and Aspergillus pseudodeflectus. Dominant fungi from non-mound sites included Cladosporium cladosporioides, Geomyces pannorum, and species of Acremonium, Fusarium, Penicillium, and Phoma. Although mound nests were warmer than adjacent soils, the dominance of xerotolerant Aspergillus in soils from mounds and the isolation of the majority of Trichocomaceae at 25 and 35 °C suggests that both temperature and water availability may be determinants of fungal community structure in nests of F. ulkei.

Clear cell renal cell carcinoma: multiphasic MDCT enhancement can predict the loss of chromosome 8p.

PURPOSE: To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can predict the loss of chromosome 8p in clear cell renal cell carcinomas (RCCs), a cytogenetic abnormality associated with a higher tumor grade and greater risk of recurrence. METHODS: With IRB approval for this HIPAA-compliant retrospective study, we queried our institution's pathology database to derive all histologically proven cases of clear cell RCC with preoperative multiphasic MDCT with as many as four phases (unenhanced, corticomedullary, nephrographic, and excretory) from January 2000 to July 2010. Of 170 clear cell RCCs with preoperative multiphasic MDCT, 105 clear cell RCCs, representing 98 unique patients, had karyotypes of the resected specimens. Lesions were evaluated for magnitude and pattern of enhancement, contour, neovascularity, calcifications, and size. RESULTS: The corticomedullary phase mean enhancement of clear cell RCCs with a loss of 8p was significantly greater than that of clear cell RCCs without a loss of 8p (169.5 vs. 127.2 HU, p = 0.004). A threshold of 165 HU predicted the loss of 8p in clear cell RCCs with an accuracy of 78% (69/88), a specificity of 81% (62/77), and a negative predictive value of 94% (62/66). There were no significant differences in the pattern of enhancement, contour, neovascularity, calcification, or size between clear cell RCCs with a loss of 8p and those without this abnormality. CONCLUSION: Enhancement on multiphasic MDCT can predict the loss of 8p in clear cell RCCs and can thus provide a non-invasive means of guiding further management, including surgery, ablation, watchful waiting, or medical management.