Walter, Emmanuel B.

Antibiotic resistance is a major threat to public health. Treatment strategies involving shorter antibiotic courses have been proposed as a strategy to lower the potential for antibiotic resistance.

Abstract Antibiotic-associated diarrhea (AAD) is a common side effect of antibiotics. We examined the gastrointestinal microbiota in children treated with β-lactams for community-acquired pneumonia. Data were from 66 children (n = 198 samples), aged 6–71 months, enrolled in the SCOUT-CAP trial (NCT02891915). AAD was defined as ≥1 day of diarrhea. Stool samples were collected on study days 1, 6–10, and 19–25. Samples were analyzed using 16S ribosomal RNA gene sequencing to identify associations between patient characteristics, microbiota characteristics, and AAD (yes/no). Nineteen (29%) children developed AAD. Microbiota compositional profiles differed between AAD groups (permutational multivariate analysis of variance, P < .03) and across visits (P < .001). Children with higher baseline relative abundances of 2 Bacteroides species were less likely to experience AAD. Higher baseline abundance of Lachnospiraceae and amino acid biosynthesis pathways were associated with AAD. Children in the AAD group experienced prolonged dysbiosis (P < .05). Specific gastrointestinal microbiota profiles are associated with AAD in children.

Abstract Background Community-acquired pneumonia (CAP) in children is usually treated with 10 days of antibiotics. Shorter antibiotic courses may be beneficial if proven effective, with potentially fewer antibiotic adverse effects and decreased antibiotic exposure. Methods This randomized, double-blind, placebo-controlled superiority trial (NCT02891915) compared a strategy of short vs standard course ß-lactam therapy for outpatient CAP in children ages 6–71 months. Children demonstrating clinical improvement by day 3–5 of initial therapy were considered for enrollment. Enrolled children were randomized 1:1 to receive either 5 additional days of the originally prescribed antibiotic (standard) or matching placebo (short). The Desirability of Outcome Ranking (DOOR; PMID: 26113652) was the primary outcome, and was defined by classifying the global experience of children into an ordinal clinical response (OCR) that combined the response to CAP treatment and antibiotic adverse effects 11–15 days after the start of therapy. For those subjects with equivalent OCR, documented days of antibiotic administration was used to further rank the desirability of the outcome with the a priori assumption that shorter antibiotic exposure was more desirable. The OCR was a secondary outcome. The intention to treat population was used to estimate the probability of a more desirable outcome for the strategy of short vs. standard course therapy for both outcomes. Results 385 children were enrolled; 380 had complete data for analysis. Baseline characteristics were similar between the two strategies. In both strategies, > 90% of children had an adequate response to CAP treatment and most antibiotic adverse effects were minor (Table). In the OCR analysis, short course therapy had a 48% probability (95% CI: 42%-53%) of a more desirable outcome. In the DOOR analysis, short course therapy was superior to standard therapy with a 69% probability (95% CI: 63%-72%; p< 0.001) of a more desirable outcome. Conclusion Among children with CAP demonstrating initial clinical improvement with outpatient therapy, both strategies had a similar response to CAP treatment and antibiotic adverse effects, but short course therapy was superior in our a priori defined outcome that incorporated decreased antibiotic exposure. Disclosures Emmanuel B. Walter, MD, MPH, Moderna (Grant/Research Support)Pfizer (Grant/Research Support) Jason Newland, MD, MEd, FPIDS, Merck (Grant/Research Support)Pfizer (Other Financial or Material Support, Industry funded clinical trial) Vance G. Fowler, Jr., MD, MHS, Achaogen (Consultant)Actavis (Grant/Research Support)Advanced Liquid Logics (Grant/Research Support)Affinergy (Consultant, Research Grant or Support)Affinium (Consultant)Allergan (Grant/Research Support)Ampliphi Biosciences (Consultant)Basilea (Consultant, Research Grant or Support)Bayer (Consultant)C3J (Consultant)Cerexa (Consultant, Research Grant or Support)Contrafect (Consultant, Research Grant or Support)Cubist (Grant/Research Support)Debiopharm (Consultant)Destiny (Consultant)Durata (Consultant)Forest (Grant/Research Support)Genentech (Consultant, Research Grant or Support)Integrated Biotherapeutics (Consultant)Janssen (Consultant, Research Grant or Support)Karius (Grant/Research Support)Locus (Grant/Research Support)Medical Biosurfaces (Grant/Research Support)Medicines Co. (Consultant)Medimmune (Consultant, Research Grant or Support)Merck (Consultant, Research Grant or Support)NIH (Grant/Research Support)Novadigm (Consultant)Novartis (Consultant, Research Grant or Support)Pfizer (Grant/Research Support)Regeneron (Consultant, Research Grant or Support)Tetraphase (Consultant)Theravance (Consultant, Research Grant or Support)Trius (Consultant)xBiotech (Consultant) W. Charles Huskins, MD, MSc, ADMA Biologics (Consultant)Pfizer, Inc (Consultant)