Li, Guyu

Background: Acute bacterial rhinosinusitis (ABRS) is a common, often self-limited condition that frequently leads to inappropriate antimicrobial prescribing in children. Continued reliance on the 2013 American Academy of Pediatrics (AAP) sinusitis guidelines and limited awareness of newer recommendations—particularly those supporting shorter treatment durations—have contributed to antibiotic overuse. As part of an enterprise-wide antimicrobial stewardship initiative, an intervention was implemented to support outpatient pediatric clinicians in identifying children most likely to benefit from antibiotics and in prescribing a 5-day course of guideline-concordant therapy consistent with the 2024-2027 AAP Red Book. We evaluated the impact of this intervention on prescribing practices and clinical outcomes. Methods A retrospective study was conducted among pediatric outpatients diagnosed with uncomplicated ABRS between January 1 and December 1, 2025 at an urban primary care pediatrics clinic within a large health system. The intervention consisted of a brief, targeted educational lecture delivered at a division meeting by pediatric antimicrobial stewardship leadership (pharmacist and physician), emphasizing updated guidance and promoting use of a sinusitis Epic order set. A one-page summary infographic was also distributed for reference. Data were extracted using Epic SlicerDicer and included patient demographics, clinical presentation, antibiotic selection and duration, use of the sinusitis order panel, and clinical outcomes. Outcomes before and after the intervention (May 14, 2025) were compared. Results A total of 99 pediatric patients with uncomplicated ABRS were included, with 55 treated before and 44 after the intervention. Use of the sinusitis order panel increased from 16% to 39% of encounters. The proportion of patients meeting diagnostic criteria for ABRS decreased slightly from 95% to 91%. Prescribing of 5-day antibiotic courses increased from 11% to 34%. There were no significant differences in prescribing provider type, antibiotic selection, or clinical outcomes—including Clostridioides difficile infection, return outpatient visits, or hospital admissions related to ABRS within 30 days—between patients receiving 5 versus <5 days of antibiotics (p<0.05). Conclusions A single, brief educational intervention paired with promotion of an Epic order set and summary infographic increased prescribing of shorter (5-day) antibiotic courses for pediatric ABRS without adversely affecting short-term clinical outcomes. Further studies are needed to assess the durability and long-term impact of this intervention on prescribing behavior.

Abstract Background Identification of the microorganisms causing infection in children with central nervous system infection is important. Conventional cerebrospinal fluid (CSF) tests may provide limited pathogen detection. CSF metagenomic next-generation sequencing (mNGS) may provide broader pathogen detection in a single assay. Methods Results of CSF mNGS testing performed at Mayo Clinic on patients and nonpatients between January 2024 and June 2025 were retrospectively analyzed. The subcohort of children treated at Mayo Clinic was analyzed to assess test performance as compared with conventional CSF diagnostics and potential clinical impact. Results In total 134 patients (138 CSF mNGS tests) from 22 US states and 2 international sites were included. Overall positivity was 16% with viruses representing most (59%) detections. In the Mayo Clinic subcohort (n = 15), test positivity was 27%: organisms included single detections of Streptococcus mitis group and HIV type 1, as well as 2 detections of Epstein-Barr virus, all confirmed by conventional tests. Positive results were associated with CSF pleocytosis (P = .026). Higher yield was observed in participants whose care was overseen by pediatric infectious diseases (PID) specialists (P = .026) and when a specimen hold strategy was applied (P = .033). Most results (87%) did not alter antimicrobial therapy, with 2 negative results contributing to antimicrobial de-escalation. Conclusions CSF mNGS demonstrated higher diagnostic yield in patients whose specimens showed CSF pleocytosis and in those who had PID consultation. Diagnostic stewardship strategies were applied, including specimen hold approaches and PID consultation.

Abstract Background Phage therapy has emerged as a generally safe approach, as demonstrated in preclinical and clinical studies. However, data on efficacy, including optimal dosing frequency, remain limited. MRSE is a leading cause of foreign body-associated osteomyelitis and a potential target for phage therapy. Here, the activity of phage K alone and in combination with vancomycin (VAN), administered once (QD) or three times (TID) daily, against biofilms formed by two orthopedic infection-associated MRSE isolates on orthopedic screws was evaluated.Fig 1.in vitro multi-dose assay of methicillin-resistant S. epidermidis biofilm-coated cortical bone screws.IDRL, Infectious Diseases Research Laboratory; DMEM, Dulbecco's Modified Eagle Medium; PBS, phosphate-buffered saline; CFU, colony-forming units. Created in https://BioRender.comFig 2.Quantities of biofilm on screws after 24 hours of treatment.*Log10 CFU/cm² of biofilm on screws before treatments. Biofilm burden of the MRSE isolates prior to treatment ranged from 5.7 to 6.3 log10 CFU/cm². A Kruskal-Wallis test was performed to evaluate the statistical significance of biofilm reduction between treatment groups. The minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm bactericidal concentration (MBBC) of vancomycin for both IDRL-9410 and IDRL-9403 were 2, 2, and &gt;128 µg/mL, respectively. Methods MRSE IDRL-9410 and IDRL-9403 biofilms were formed on titanium cortical bone screws (D 1.5 mm, L 4 mm, surface area 0.33 cm²) in 0.2 mL of tryptic soy broth containing 10⁶ CFU/mL (Fig 1); testing was performed in triplicate on two separate days. After 24 hours, screws were rinsed with PBS and randomly assigned to: Dulbecco’s Modified Eagle Medium (DMEM); vancomycin (VAN, 20 μg/mL) in DMEM; phage K (10⁹ PFU/mL) in DMEM; or VAN and phage K in DMEM. Every 8 hours, screws from the TID groups were transferred to new plates containing fresh treatment, with QD groups left in the original material. 24 hours post-treatment, screws were quantitatively cultured. Bactericidal activity was defined as ≥ 3 log₁₀ CFU/cm² reduction compared to the DMEM group, and synergy as ≥ 2 log₁₀ CFU/cm² reduction in the combination group compared to VAN or phage alone. Results After 24 hours, bactericidal activity was observed for QD and TID VAN-phage K groups against IDRL-9410 (p &lt; 0.05 and p &lt; 0.01, respectively) and IDRL-9403 (both p &lt; 0.01). Synergy was observed in the VAN-phage K QD group, with a 2.2 log₁₀ CFU/cm² reduction for IDRL-9410 compared to VAN alone (Fig 2). 3.0 and 5.3 log₁₀ CFU/cm² reductions were observed in the VAN TID groups for IDRL-9410 and IDRL-9403, respectively, compared to the DMEM group (both p &lt; 0.01). There was no statistically significant difference in biofilm reduction between the QD and TID groups for phage K alone or VAN-phage K for either strain. Conclusion Combination treatment with phage K and VAN, administered QD or TID, showed greater biofilm reduction compared to phage K alone. Increasing phage dosing frequency did not enhance biofilm reduction under the conditions studied. Disclosures Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication, a patent on PET imaging of bacterial infection: a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication, a patent on PET imaging of bacterial infection|MicuRx Pharmaceuticals and bioMérieux: Grant/Research Support|PhAST, Day Zero Diagnostics, DEEPULL DIAGNOSTICS, S.L., Nostics, HealthTrackRx, bioMérieux and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course: Honoraria

Abstract Background Streptococcus agalactiae (group B Streptococcus [GBS]) may cause pneumonia or may colonize the respiratory tract, making its clinical significance uncertain when detected in respiratory specimens. This study aimed to assess whether clinicians interpreted GBS detected by the BIOFIRE Pneumonia Panel (BF-PP) as a pathogen implicated in pneumonia. Methods This retrospective cohort study included adult patients hospitalized with suspected pneumonia at Mayo Clinic, Rochester, between September 2020 and February 2025. Cases were independently classified into pathogen and nonpathogen groups by 2 infectious diseases (ID) specialists, with a third reviewer resolving disagreements. Clinical characteristics and outcomes of both groups were recorded. A subgroup analysis of patients who had an ID consultation was performed. Results A total of 109 cases were included. GBS was considered a pneumonia pathogen in 47.7% of cases and a nonpathogen in 52.3%. ID consultation was performed in 33.0% of cases, with GBS considered a pathogen in 30.6% of those. Common comorbid conditions included pulmonary, gastrointestinal, neurologic, and cardiovascular disease and obesity. Rates of endotracheal intubation were similar in the pathogen and nonpathogen groups (51.9% vs 50.9%, respectively), with the in-hospital mortality rate being numerically but not significantly higher in the former versus the latter (21.2% vs 14.0%; P = .33); findings were similar in the ID-assessed subgroup. In 76.1% of GBS detections, other microorganisms—most commonly Staphylococcus aureus—were codetected. Only 10.2% of BF-PP GBS-positive specimens were culture positive for GBS. Conclusions While GBS is not an uncommon pneumonia pathogen, the clinical significance of its detection by BF-PP is uncertain in many cases.

Abstract Background Prolonged and recurrent fevers in pediatric outpatients often require specialist consultations, presenting a challenge in accurately triaging to the correct pediatric subspecialty. This study aims to develop an artificial intelligence (AI)-based model to accurately direct pediatric patients to appropriate subspecialties.Table 1.Patient characteristics and the department confirming the final diagnosis Table 1. Patient characteristics and the department confirming the final diagnosis Methods A retrospective study was conducted at the Mayo Clinic, Rochester, from December 1, 2020, to January 1, 2023, involving pediatric patients aged 0 to 18 referred for recurrent fever or fever of unknown origin. Six machine learning models, including gradient boosting, random forest, support vector machines (SVM), k-Nearest Neighbor (KNN), logistic regression (LR) and decision tree, were developed using 7 variables (demographics, chief complaints, referral sources, departments of same-day initial visit, and lab tests results within 30 days before initial visits). Data were extracted from external electronic health records (EHR) using Mayo Data Explorer and Lab Information Management Systems. Precision, Recall, F1 Score, and area under the curve (AUROC) were selected to measure the performance.Table 2.Performance of six machine learning models Table 2. Performance of six machine learning models Results The study evaluated 87 pediatric patients with a median age of 10.2 years (IQR: 4.6-13.8), including 43 (49%) females (Table 1). External provider referrals were noted in 40 (46%) patients. Musculoskeletal pain was the most common chief complaint, identified in 29 (33%) patients, in addition to prolonged or recurrent fever. Infectious disease and rheumatology divisions jointly saw 43 (49%) patients during the initial visit. Sub-optimal performance was observed in six machine learning models (Table 2). The random forest model showed the best results (Accuracy=0.39, Precision=0.34, Recall=0.39, F1 Score=0.35, AUROC=0.60) (Figure).Figure.ROC curves for various models Figure. ROC curves for various models Conclusion This study demonstrates the potential of AI-based models for outpatient triage prediction in pediatric patients with recurrent fever, using EHR data to optimize health resource utilization. This data serves as the groundwork to expand and refine this AI triage tool. Disclosures All Authors: No reported disclosures

Abstract Background 16S ribosomal RNA (rRNA) gene PCR and sequencing may serve as an adjunctive diagnostic tool in complex infections, identifying bacteria in patients on antibiotics whose cultures may be negative. Data on the optimal clinical settings for utilizing this type of testing are limited. This study reviews a single center's 16S rRNA PCR/sequencing experience in children to identify clinical syndromes and optimize specimen choice for higher yield, leading to testing of appropriate patients. Methods A retrospective study was performed at Mayo Clinic, Rochester involving children aged 0 to 18 years whose normally sterile tissue or fluid samples underwent 16S rRNA gene PCR/sequencing. The assay involved an up-front real-time PCR assay, reported as negative or submitted to Sanger or next-generation sequencing depending on Ct values. Data was collected on patient characteristics and results of 16S rRNA gene PCR/sequencing and conventional tests. Impact on clinical decision-making was assessed as to whether the advanced molecular diagnostic changed antimicrobial therapy. Results A total of 162 tests were performed on 124 patients, including 47% females (58/124) with a median age of 9.6 (range, 2.2-15.0) years. Overall, 33/162 (20%) of tests were positive in 24/124 (19%) patients. 58% of positive tests (19/33) were from samples with negative bacterial cultures. Cerebrospinal fluid was the most common specimen tested (n=38; 31%). Positive results were more likely from fluid compared to tissue samples (OR [95% CI]: 3.1 [1.3, 7.1], p=.007; OR [95% CI]: 0.3 [0.1, 0.8], p=.007, respectively). Testing was positive in 5/10 (50%) pleural fluids tested, a higher positivity rate than any other specimen type (OR [95% CI]: 5 [1.3, 19.0], p=.011). No significant changes in antibiotics were made within 24 hours of reporting positive 16S rRNA gene PCR/sequencing results. Conclusion This study highlights the importance of selecting appropriate sample types for 16S rRNA gene PCR/sequencing in pediatric patients. The assay is most likely to yield positive results in children with pleural effusion and in other fluid samples such as subdural and synovial fluid. Further implementation science research is needed to achieve impact on clinical practice. Disclosures Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria

Abstract Background Although infectious diseases present significant challenges in pediatric care, formal training in pediatric infectious diseases is not mandated in categorical pediatric residency training. This research seeks to examine the self-assessed confidence levels of general pediatric residents in Washington DC in managing common infectious diseases. The study specifically compares the confidence levels of residents who have undergone elective infectious diseases training with those who have not. Subjective Confidence in the Management of Common Infectious Diseases Encounters Methods A cross-sectional study was conducted using voluntary surveys distributed among pediatric residents from various programs in Washington DC. The surveys aimed to assess subjective confidence levels in managing common infectious disease conditions and to explore motivation to pursue infectious disease training. Effect of infectious diseases elective rotation on interest in infectious diseases as a career. Are you more or less likely to pursue infectious diseases fellowship? Results Analysis of 20 completed surveys revealed that residents who completed infectious diseases rotations demonstrated significantly higher confidence levels in managing infectious disease conditions compared to their counterparts (P: &lt; 0.001). Notably, residents with specialized training showed increased confidence in antibiotic selection and in their diagnostic abilities. Additionally, they exhibited enhanced confidence in managing specific presentations such as sexually transmitted diseases, fever of unknown origin, and central nervous system infections (all with P &lt; 0.05). Finally, 22% of respondents expressed an increased likelihood of pursuing a career in infectious diseases following their rotation. Effect of infectious diseases rotation on the confidence in the management of inpatient and outpatient infectious diseases encounters Conclusion These findings underscore the potential benefits of incorporating infectious diseases rotations into pediatric residency programs, as evidenced by improved skills in antibiotic selection, diagnosis, and management of specific infectious disease scenarios. Additionally, the observed increased interest in pursuing a career in infectious diseases among a subset of residents highlights the positive impact of such training on career trajectory and specialty choice. Investigators plan to distribute the questionnaire more broadly across the US to see if these results are more widespread. Disclosures All Authors: No reported disclosures

Abstract Craniofacial dermoid cysts are congenital anomalies that rarely have intracranial extension and can be associated with other anomalies. Common sites of these lesions are the lateral brow and parietal scalp. Presentation of the dermoid cyst in the occipital region with intracranial extension is extremely rare. We report a 2-year-old female with a presentation of an occipital dermoid cyst with intracranial extension and secondary cerebellar abscess. This case highlights the rarity of the presentation of an occipital dermoid cyst with intracranial extension and secondary infection and the importance of early imaging for suspected dermoid cysts in the occipital region for identification of intracranial extension.