Broad Antimicrobial Resistance in a Case of Relapsing Babesiosis Successfully Treated With Tafenoquine.

We describe a case of relapsing babesiosis in an immunocompromised patient. A point mutation in the Babesia microti 23S rRNA gene predicted resistance to azithromycin and clindamycin, whereas an amino acid change in the parasite cytochrome b predicted resistance to atovaquone. Following initiation of tafenoquine, symptoms and parasitemia resolved.

Impact of medication bedside delivery program on hospital readmission rates.

BACKGROUND: Since the establishment of the Hospital Readmission Reduction Program by the Centers for Medicare and Medicaid Services, reducing readmission rates has been a priority for health care institutions. Many institutions have developed services to combat high readmission rates, including bedside medication delivery programs, which have demonstrated reductions in 30-day readmission rates in patients who used these services. OBJECTIVE: To evaluate the impact of health system-based bedside medication delivery programs on readmission rates in patients at a low to moderate risk of hospital readmission. METHODS: A single-center retrospective cohort study conducted on adult patients of low-to moderate-transitions of care (TOC) risk status with unplanned admissions to a large academic medical center between January 1, 2017, and January 1, 2019 who used the medication bedside delivery service or an outside pharmacy. The TOC risk status was defined using historic institutional definitions. Patients with at least a 2-day hospital stay and who were discharged to home from select primary medical services were included. The primary outcome was 30-day readmission rates between the 2 groups. Secondary outcomes included 60- and 90-day readmission rates and readmission rates stratified by primary medical service and TOC status. Coarsened exact matching was used to account for variation between groups. RESULTS: The study evaluated 6583 patients discharged with a total of 3905 patients and corresponding index admissions meeting inclusion criteria for analysis. No statistically significant difference between readmission rates at 30 days after the index admission was found between the medication bedside delivery group and the outside pharmacy group, 7.97% and 10.09%, respectively (P = 0.136). However, the readmission rate of the medication bedside delivery group was statistically significantly lower than that of the outside pharmacy group at 60 and 90 days. CONCLUSIONS: This study suggests that bedside medication delivery programs do not significantly reduce readmission rates at 30 days but may do so at 60 and 90 days.

Structural Patching Fosters Divergence of Mitochondrial Ribosomes.

Mitochondrial ribosomes (mitoribosomes) are essential components of all mitochondria that synthesize proteins encoded by the mitochondrial genome. Unlike other ribosomes, mitoribosomes are highly variable across species. The basis for this diversity is not known. Here, we examine the composition and evolutionary history of mitoribosomes across the phylogenetic tree by combining three-dimensional structural information with a comparative analysis of the secondary structures of mitochondrial rRNAs (mt-rRNAs) and available proteomic data. We generate a map of the acquisition of structural variation and reconstruct the fundamental stages that shaped the evolution of the mitoribosomal large subunit and led to this diversity. Our analysis suggests a critical role for ablation and expansion of rapidly evolving mt-rRNA. These changes cause structural instabilities that are "patched" by the acquisition of pre-existing compensatory elements, thus providing opportunities for rapid evolution. This mechanism underlies the incorporation of mt-tRNA into the central protuberance of the mammalian mitoribosome, and the altered path of the polypeptide exit tunnel of the yeast mitoribosome. We propose that since the toolkits of elements utilized for structural patching differ between mitochondria of different species, it fosters the growing divergence of mitoribosomes.

History of the ribosome and the origin of translation.

We present a molecular-level model for the origin and evolution of the translation system, using a 3D comparative method. In this model, the ribosome evolved by accretion, recursively adding expansion segments, iteratively growing, subsuming, and freezing the rRNA. Functions of expansion segments in the ancestral ribosome are assigned by correspondence with their functions in the extant ribosome. The model explains the evolution of the large ribosomal subunit, the small ribosomal subunit, tRNA, and mRNA. Prokaryotic ribosomes evolved in six phases, sequentially acquiring capabilities for RNA folding, catalysis, subunit association, correlated evolution, decoding, energy-driven translocation, and surface proteinization. Two additional phases exclusive to eukaryotes led to tentacle-like rRNA expansions. In this model, ribosomal proteinization was a driving force for the broad adoption of proteins in other biological processes. The exit tunnel was clearly a central theme of all phases of ribosomal evolution and was continuously extended and rigidified. In the primitive noncoding ribosome, proto-mRNA and the small ribosomal subunit acted as cofactors, positioning the activated ends of tRNAs within the peptidyl transferase center. This association linked the evolution of the large and small ribosomal subunits, proto-mRNA, and tRNA.

Evolution of the ribosome at atomic resolution.

The origins and evolution of the ribosome, 3-4 billion years ago, remain imprinted in the biochemistry of extant life and in the structure of the ribosome. Processes of ribosomal RNA (rRNA) expansion can be "observed" by comparing 3D rRNA structures of bacteria (small), yeast (medium), and metazoans (large). rRNA size correlates well with species complexity. Differences in ribosomes across species reveal that rRNA expansion segments have been added to rRNAs without perturbing the preexisting core. Here we show that rRNA growth occurs by a limited number of processes that include inserting a branch helix onto a preexisting trunk helix and elongation of a helix. rRNA expansions can leave distinctive atomic resolution fingerprints, which we call "insertion fingerprints." Observation of insertion fingerprints in the ribosomal common core allows identification of probable ancestral expansion segments. Conceptually reversing these expansions allows extrapolation backward in time to generate models of primordial ribosomes. The approach presented here provides insight to the structure of pre-last universal common ancestor rRNAs and the subsequent expansions that shaped the peptidyl transferase center and the conserved core. We infer distinct phases of ribosomal evolution through which ribosomal particles evolve, acquiring coding and translocation, and extending and elaborating the exit tunnel.

Combination of a Rapid Diagnostic Assay and Antimicrobial Stewardship Intervention for Gram-Negative Bacteremia.

Background: Traditional blood cultures for gram-negative bacteremia can take up to 72 hours or more to return results, prolonging the duration of empiric broad-spectrum intravenous antibiotics. The Accelerate Pheno system provides rapid identification and susceptibilities for blood cultures in gram-negative bacteremia. Current data on its clinical utility are mixed overall, so the system requires further research. Methods: A multicenter, retrospective quasi-experimental study was conducted comparing the Accelerate Pheno rapid diagnostic system with antimicrobial stewardship intervention and traditional blood cultures alone. Results: A total of 264 patients with blood cultures with gram-negative bacteria growth were included in the final analysis (102 pre-intervention, 162 post-intervention). The antimicrobial stewardship team made 364 recommendations in 152/162 (93.8%) patients in the post group. Duration of intravenous therapy was shorter (P < .001) for the post-intervention group (median, 4.0 days) compared with the pre-intervention group (median, 7.5 days). Hospital length of stay was also shorter (P < .001) for the post-intervention group (median, 5.1 days) compared with the pre-intervention group (median, 7.0 days). Readmission rates within 30 days were reduced (P = .042) post-intervention (13.0%) compared with pre-intervention (22.6%). In the post-intervention group, a larger proportion of patients were transitioned to oral therapy at any point (126/162, 77.8%) compared with pre-intervention (62/102, 60.8%; P < .001). Conclusions: These results suggest that the Accelerate Pheno system, with active review and intervention by a multidisciplinary antimicrobial stewardship team, is a useful tool in improving both patient-centric and antimicrobial stewardship outcomes.

Evaluation of Voriconazole and Posaconazole Dosing in Patients With Thermal Burn Injuries.

Fungal infections are a recognized cause of increased morbidity and mortality in thermal burn patients. Adequate treatment regimens remain a challenge due to unpredictable pharmacokinetic/pharmacodynamic changes caused by a hypermetabolic state and individual patient factors. A retrospective evaluation of adult thermal burn patients from April 2014 to April 2020 was conducted to assess voriconazole and posaconazole antifungal dosing regimens. The primary outcome was the incidence of attaining a therapeutic steady-state trough level on the patient's initial voriconazole or posaconazole regimen. Of the 33 patients analyzed, 26 (78.8%) patients achieved a therapeutic level during azole therapy. However, only 11 (33.3%) patients achieved a therapeutic level on their first azole regimen. The median time to therapeutic level was 8.0 + 21.8 days from the start of azole therapy. Optimal dosing strategies for azole therapy in patients with thermal burns remain undefined. Further assessment is needed to delineate patient-specific factors that can contribute to subtherapeutic azole levels in thermal burn patients and the overall clinical impact of population-specific dosing regimens.