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Background: Enterobacter spp. are opportunistic pathogens that cause nosocomial infections. Bacteriophages could be used to treat antibiotic-resistant Enterobacter infections. Materials and Methods: We used 10 genetically diverse clinical Enterobacter spp. isolates to identify lytic bacteriophages in hospital and municipal wastewater. Comparative genomics was performed on host bacterial isolates and isolated phages. Activity of each phage against all 10 host isolates was determined. We also tested phage activity against paired isolates from two patients who developed ceftazidime–avibactam resistance. Results: Bacteria belonged to three Enterobacter species and Klebsiella aerogenes. We isolated 12 bacteriophages, most of which belonged to the Myoviridae and Autographiviridae families. Most phages were able to lyse multiple bacterial isolates, and many lysed isolates of different species. Ceftazidime–avibactam-resistant isolates were still phage susceptible, and one isolate showed increased susceptibility compared with the parent isolate. Conclusion: The phages we isolated expand the diversity of Enterobacter- targeting phages, and could be useful for treating antibiotic-resistant Enterobacter infections.

Pseudomonas aeruginosa infections can be difficult to treat and new therapeutic approaches are needed. Bacteriophage therapy is a promising alternative to traditional antibiotics, but large numbers of isolated and characterized phages are lacking. We collected 23 genetically and phenotypically diverse P. aeruginosa isolates from people with cystic fibrosis (CF) and clinical infections, and characterized their genetic, phenotypic, and prophage diversity. We then used these isolates to screen and isolate 14 new P. aeruginosa-targeting phages from hospital wastewater. Phages were characterized with genome sequencing, comparative genomics, and lytic activity screening against all 23 bacterial host isolates. For four different phages, we evolved bacterial mutants that were resistant to phage infection. We then used genome sequencing and functional analysis of the resistant mutants to study their mechanisms of phage resistance as well as changes in virulence factor production and antibiotic resistance, which differed from corresponding parent bacterial isolates. Finally, we tested two phages for their ability to kill P. aeruginosa grown in biofilms in vitro, and observed that both phages reduced viable bacteria in biofilms by least one order of magnitude. One of these phages also showed activity against P. aeruginosa biofilms grown on CF airway epithelial cells. Overall, this study demonstrates how systematic genomic and phenotypic characterization can be deployed to develop bacteriophages as precision antibiotics.

Background and objectivesPain management for patients undergoing the Nuss procedure for treatment of pectus excavatum can be challenging. In an effort to improve pain management, our institution added bilateral single injection erector spinae plane (ESP) blocks to surgeon placed intercostal nerve cryoablation. We aimed to assess the efficacy of this practice change.MethodsRetrospective clinical data from a single academic medical center were evaluated. Due to an institutional change in clinical management, we were able to perform a before and after study. Twenty patients undergoing Nuss procedure who received bilateral ultrasound-guided single-shot T6 level ESP blocks and intercostal nerve cryoablation were compared with a historical control cohort of 20 patients who underwent Nuss procedure with intercostal nerve cryoablation alone. The primary outcome variables included postoperative pain scores, total hospital opioid use, and hospital length of stay.ResultsMedian total hospital intravenous morphine milligram equivalents was lower for the ESP group than for the control group (0.60 (IQR 0.35–0.88) vs 1.15 mg/kg (IQR 0.74–1.68), p<0.01). There was no difference in postoperative pain scores between the two groups. Mean hospital length of stay was 2.45 (SD 0.69) days for the control group and 1.95 (SD 0.69) days for the ESP group (p=0.03). No adverse events related to block placement were identified.ConclusionsIn a single-center academic practice, the addition of bilateral single injection ESP blocks at T6 to surgeon performed cryoablation reduced opioid consumption without a change in subjectively reported pain scores. The results from this pilot study can provide effect size estimates to guide the design of future randomized trials.