Many organisms have intimate associations with beneficial microbes acquired from the environment. These host-symbiont associations can be specific and stable, but they are prone to lower partner specificity and more partner-switching than vertically transmitted mutualisms. To investigate partner specificity in an environmentally acquired insect symbiosis, we used 16S rRNA gene and multilocus sequencing to survey the bacterial population in the bacteria-harbouring organ (crypts) of 49 individuals across four sympatric broad-headed bug species (Alydus calcaratus, A. conspersus, A. tomentosus and Megalotomus quinquespinosus). Similar to other insect-bacteria associations, Burkholderia spp. were the most common residents of the crypts in all four insect species (77.2% of recovered sequences). Burkholderia presence was associated with prolonged survival to adulthood in A. tomentosus, suggesting a beneficial role of these specialized associations. Burkholderia were also found in environmental reservoirs in the insects' habitat, which may facilitate acquisition by insects by increasing Burkholderia-insect encounters. Symbiont establishment could also be facilitated by resistance to insect defences; zone of inhibition assays demonstrated that Burkholderia and other bacteria isolated from crypts are resistant to insect defences that limit growth of Escherichia coli. Alternatively, the insects' defences may not efficiently kill a broad range of bacteria. Although the symbiosis is targeted to Burkholderia, the insects' crypts housed other bacteria, including non-Burkholderiaceae species. There is no significant effect of host insect species on Burkholderia distribution, suggesting a lack of strong partner specificity at finer scales. The presence of frequent partner-switching between sympatric insects and their symbionts likely prevents tight co-evolutionary dynamics.

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Background Despite the importance of pain management across specialties and the effect of poor management on patients, many physicians are uncomfortable managing pain. This may be related, in part, to deficits in graduate medical education (GME). Objective We sought to evaluate the methodological rigor of and summarize findings from literature on GME interventions targeting acute and chronic non-cancer pain management. Methods We conducted a systematic review by searching PubMed, MedEdPORTAL, and ERIC (Education Resources Information Center) to identify studies published before March 2019 that had a focus on non-cancer pain management, majority of GME learners, defined educational intervention, and reported outcome. Quality of design was assessed with the Medical Education Research Study Quality Instrument (MERSQI) and Newcastle-Ottawa Scale–Education (NOS-E). One author summarized educational foci and methods. Results The original search yielded 6149 studies; 26 met inclusion criteria. Mean MERSQI score was 11.6 (SD 2.29) of a maximum 18; mean NOS-E score was 2.60 (SD 1.22) out of 6. Most studies employed a single group, pretest-posttest design (n=16, 64%). Outcomes varied: 6 (24%) evaluated reactions (Kirkpatrick level 1), 12 (48%) evaluated learner knowledge (level 2), 5 (20%) evaluated behavior (level 3), and 2 (8%) evaluated patient outcomes (level 4). Interventions commonly focused on chronic pain (n=18, 69%) and employed traditional lectures (n=16, 62%) and case-based learning (n=14, 54%). Conclusions Pain management education research in GME largely evaluated chronic pain management interventions by assessing learner reactions or knowledge at single sites.

Background: Acute chest syndrome (ACS) is a common complication in patients with sickle cell disease (SCD) and is a leading cause of morbidity and mortality.Chest X-ray (CXR) is recommended for evaluating ACS in patients with SCD because clinical findings alone have a low sensitivity. Children with SCD are repeatedly exposed to diagnostic radiation for the evaluation of ACS. Lung ultrasound (LUS) has been compared to CXR as an alternative imaging modality for evaluating ACS, and a lung consolidation > 1 cm is sensitive and specific for diagnosing patients with ACS. Consolidations < 1 cm, or subpleural consolidations, can detect pneumonia earlier than CXR; however, the significance of these findings for evaluating ACS is unknown. We evaluated LUS with consolidations <1 cm to determine if they could identify patients with ACS. Methods: This is a prospective observational study that took place from November 2014-July 2016 in 2 urban pediatric emergency departments (EDs). The study population consisted of a convenience sample of patients with SCD from birth to 18 years of age at risk for ACS and who received a clinically-indicated CXR for suspected ACS. ACS was defined as a new pulmonary infiltrate on CXR together with the presence of fever, cough, chest pain, or respiratory symptoms. LUS were performed to evaluate for lung consolidation and determine the sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) of LUS to identify ACS. In a subanalysis, the charts of patients who had a negative CXR interpreted by a pediatric radiologist or consolidation < 1 cm on LUS at the time of enrollment were reviewed for development of ACS within 7 days of the visit. The development of ACS in patients with subpleural findings on LUS was compared to patients with negative ultrasound findings. Fischer's-Exact Test was used to determine significance between the 2 groups with α = 0.05. Results: One hundred sixty-eight patients were enrolled. ACS was diagnosed in 14% of patients, while a CXR was negative in 150 cases. The sensitivity of LUS to predict ACS was 91%, specificity was 91%, LR+ 10.5, LR- 0.1. Thirty-six cases had subpleural consolidation on LUS and 3 patients (8%) developed ACS. Of the 114 patients with negative LUS, 7 (6%) developed ACS. There was no statistical difference between these groups with p-value of 0.7. Conclusions: Patients with subpleural consolidations on LUS were no more likely to develop ACS than those patients with a negative LUS. The small number of patients who developed ACS may have failed to show a statistical difference between these groups. Further studies with serial ultrasound examinations are needed to better define the significance of this finding. Disclosures Morris: MAST: Research Funding; Pfizer: Consultancy; Calithera: Consultancy; Nourish Life: Patents & Royalties: I am the inventor of IP owned by UCSF-Benioff Children's Hospital that is licensed to NL; Endeavor: Consultancy; Nestle: Honoraria.

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