Impact of cascade reporting of antimicrobial susceptibility on fluoroquinolone and meropenem consumption at a Veterans' Affairs medical center.

OBJECTIVE: To determine whether cascade reporting is associated with a change in meropenem and fluoroquinolone consumption. DESIGN: A quasi-experimental study was conducted using an interrupted time series to compare antimicrobial consumption before and after the implementation of cascade reporting. SETTING: A 399-bed, tertiary-care, Veterans' Affairs medical center. PARTICIPANTS: Antimicrobial consumption data across 8 inpatient units were extracted from the Center for Disease Control and Prevention (CDC) National Health Safety Network (NHSN) antimicrobial use (AU) module from April 2017 through March 2019, reported as antimicrobial days of therapy (DOT) per 1,000 days present (DP). INTERVENTION: Cascade reporting is a strategy of reporting antimicrobial susceptibility test results in which secondary agents are only reported if an organism is resistant to primary, narrow-spectrum agents. A multidisciplinary team developed cascade reporting algorithms for gram-negative bacteria based on local antibiogram and infectious diseases practice guidelines, aimed at restricting the use of fluoroquinolones and carbapenems. The algorithms were implemented in March 2018. RESULTS: Following the implementation of cascade reporting, mean monthly meropenem (P =.005) and piperacillin/tazobactam (P = .002) consumption decreased and cefepime consumption increased (P < .001). Ciprofloxacin consumption decreased by 2.16 DOT per 1,000 DP per month (SE, 0.25; P < .001). Clostridioides difficile rates did not significantly change. CONCLUSION: Ciprofloxacin consumption significantly decreased after the implementation of cascade reporting. Mean meropenem consumption decreased after cascade reporting was implemented, but we observed no significant change in the slope of consumption. cascade reporting may be a useful strategy to optimize antimicrobial prescribing.

Variation in a novel antipseudomonal antimicrobial consumption metric across hospital inpatient units at a Veterans Affairs hospital: A retrospective cohort study.

A novel antimicrobial consumption metric designed to identify the proportion of carbapenem consumption (PoCC) among broad-spectrum antipseudomonal antimicrobials has been shown to vary significantly by US Census Bureau region. This retrospective surveillance study identified significant total PoCC variability (27%; P = .001) across 8 inpatient units from January 2017 through June 2018. This metric may be useful in identifying and comparing inpatient units that may be overusing antipseudomonal carbapenems.

The effectiveness of formulary restriction and preauthorization at an academic medical center.

The impact of formulary restriction and preauthorization (FRPA) on prescribing trends was examined over a 5-year period at an academic medical center. Ordinary least squares regression was used to identify hospital units demonstrating statistically significant trends in prescription of restricted agents. Significant decreases in restricted drug use were seen on 2 of 7 medicine units subject to FRPA, whereas a significant increase was seen in 1 of 4 surgical units subject to FRPA.

The Current State of Antimicrobial Stewardship: Challenges, Successes, and Future Directions.

PURPOSE OF REVIEW: The aim of this study is to examine the current state of the field of antimicrobial stewardship (AS) by highlighting key challenges and successes, as well as exciting future directions. RECENT FINDINGS: AS mandates from the Centers for Medicare and Medicaid (CMS) and the Joint Commission (TJC) will stimulate increased compliance with current AS standards, but overall compliance is currently poor. Key challenges to progress in the field of AS include insufficient workforce and monetary resources, poorly defined AS metrics, and much needed expansion beyond the inpatient hospital setting. Despite these challenges, massive progress has been made in the last two and a half decades since the field of AS emerged. AS metrics are rapidly evolving and transforming the way antimicrobial stewardship programs (ASPs) measure success. Rapid diagnostics and diagnostic test stewardship are proving to be extremely effective when coupled with an ASP. Telehealth may improve access to ASP expertise in resource poor settings, and the role of bedside nurses as ASP team members has the potential to greatly augment ASP efforts. Allergy testing as an ASP strategy remains largely underutilized. ASPs have made significant gains in the battle against antimicrobial resistance (AR), but considerable advancement is still needed. Awareness of current challenges is critical to ensure progress in the field. The field of AS is expanding and transforming rapidly through integration, technology, and improved processes.

Lactobacillus demonstrate thiol-independent metabolism of methylglyoxal: Implications toward browning prevention in Parmesan cheese.

Endogenous production of α-dicarbonyls by lactic acid bacteria can influence the quality and consistency of fermented foods and beverages. Methylglyoxal (MG) in Parmesan cheese can contribute toward undesired browning during low temperature ripening and storage conditions, leading to the economic depreciation of affected cheeses. We demonstrate the effects of exogenously added MG on browning and volatile formation using a Parmesan cheese extract (PCE). To determine the influence of Lactobacillus on α-dicarbonyls, strains were screened for their ability to modulate concentrations of MG, glyoxal, and diacetyl in PCE. It was found that a major metabolic pathway of MG in Lactobacillus is a thiol-independent reduction, whereby MG is partially or fully reduced to acetol and 1,2-propanediol, respectively. The majority of lactobacilli grown in PCE accumulated the intermediate acetol, whereas Lactobacillus brevis 367 formed exclusively 1,2-propanediol and Lactobacillus fermentum 14931 formed both metabolites. In addition, we determined the inherent tolerance to bacteriostatic concentrations of MG among lactobacilli grown in rich media. It was found that L. brevis 367 reduces MG exclusively to 1,2-propanediol, which correlates to both its ability to significantly decrease MG concentrations in PCE, as well as its significantly higher tolerance to MG, in comparison to other lactobacilli screened. These findings have broader implications toward lactobacilli as a viable solution for reducing MG-mediated browning of Parmesan cheese.

De-escalating Antibiotic Use in the Inpatient Setting: Strategies, Controversies, and Challenges.

PURPOSE OF REVIEW: Antibiotic de-escalation (ADE) is widely accepted as an integral strategy to curtail the global antibiotic resistance crisis. However, there is significant uncertainty regarding the ideal ADE strategy and its true impact on antibiotic resistance. Rapid diagnostic testing has the potential to enhance ADE strategies. Herein, we aim to discuss the current strategies, controversies, and challenges of ADE in the inpatient setting. RECENT FINDINGS: A consensus definition of ADE remains elusive at this time. Preliminary studies utilizing rapid diagnostic tests including matrix-assisted laser desorption/ionization time of flight (MALDI-TOF), procalcitonin, and other molecular techniques have demonstrated the potential to support ADE strategies. In the absence of evidence-based, highly specific ADE protocols, the likelihood that individual providers will make consistent, often challenging, decisions to de-escalate antibiotic therapy is low. Antimicrobial stewardship programs should support local physicians with ADE and develop innovative ways to integrate ADE into the broader construct of antimicrobial stewardship programs. The evolving field of rapid diagnostics has significant potential to improve ADE strategies, but more research is needed to fully realize this goal.

A survey to optimize the design of an antimicrobial stewardship smartphone app at an academic medical center.

Mobile medical apps are commonly used by health care professionals and could be used by antimicrobial stewardship programs to enhance adherence to local recommendations. We conducted a survey of health care workers to inform the design of an antimicrobial stewardship smartphone app.

Cytokines in the perinatal period - Part I.

Successful pregnancy requires a state of immune homeostasis. Maternal tolerance of the genetically distinct fetoplacental unit is in part mediated by maternal and fetal pro- and anti-inflammatory cytokines; these cytokines have also been implicated in different pregnancy-related pathologic states. This two-part series seeks to provide anesthesiologists with an overview on selected perinatal cytokines in an effort to identify opportunities for research and improvements in clinical care. In part one, we review basic and pregnancy-related elements of the immune system, with an emphasis on the role of cytokines. From this foundation, we offer a perspective of a unique phenomenon witnessed within obstetric anesthesia - maternal temperature elevation associated with labor epidural analgesia.

Cytokines in the perinatal period - Part II.

A contemporary, robust immunologic explanation for common obstetric conditions remains elusive; why some pregnant women are more susceptible to developing preeclampsia or preterm labor is not completely understood. We explore the immunology behind four important and commonly encountered pregnancy-related conditions: preeclampsia, recurrent miscarriage, preterm labor and gestational diabetes. For each condition, we summarize the current understanding of cytokines implicated in the pathogenesis, discuss the impact of anesthesia and analgesia on selected cytokine profiles, and suggest potential opportunities for clinical and research interventions.

Identification and characterization of a divalent metal ion-dependent cleavage site in the hammerhead ribozyme.

We describe a new RNA cleavage motif, found in the hammerhead ribozyme. Cleavage occurs between nucleotides G8 and A9, yielding a free 5'-hydroxyl group and a 2',3'-cyclic phosphate. This cleavage is dependent upon divalent metal ions and is the first evidence for a metalloribozyme known to show preference for Zn(2+). Cleavage is also observed in the presence of Ni(2+), Co(2+), Mn(2+), Cd(2+), and Pb(2+), while negligible cleavage was detected in the presence of the alkaline-earth metal ions Mg(2+), Ca(2+), Sr(2+), and Ba(2+). A linear relationship between the logarithm of the rate and pH was observed for the Zn(2+)-dependent cleavage, which is indicative of proton loss in the cleavage mechanism, either prior to or in the rate-determining step. We postulate that a zinc hydroxide complex, bound to the known A9/G10.1 metal ion binding site, abstracts the proton from the 2'-hydroxyl group of G8, which attacks the A9 phosphate and initiates cleavage. This hypothesis is supported by a previously reported crystal structure [Murray, J. B., Terwey, D. P., Maloney, L., Karpeisky, A., Usman, N., Beigelman, L., and Scott, W. G. (1998) Cell 92, 665-673], which shows the conformation required for RNA cleavage and proximity of the 2'-hydroxyl group to the metal ion complex.

Natural J-coupling analysis: interpretation of scalar J-couplings in terms of natural bond orbitals.

The natural J-coupling (NJC) method presented here analyzes the Fermi contact portion of J-coupling in the framework of finite perturbation theory applied to ab initio/density function theory (DFT) wave functions, to compute individual and pairwise orbital contributions to the net J-coupling. The approach is based on the concepts and formalisms of natural bond orbital (NBO) methods. Computed coupling contributions can be classified as Lewis (individual orbital contributions corresponding to the natural Lewis structure of the molecule), delocalization (resulting from pairwise donor-acceptor interactions), and residual repolarization (corresponding to correlation-like interactions). This approach is illustrated by an analysis of the angular and distance dependences of the contributions to vicinal (3)J(HH) couplings in ethane and to the long-range (6)J(HH) couplings in pentane. The results indicate that approximately 70% or more of the net J-coupling is propagated by steric exchange antisymmetry interactions between Lewis orbitals (predominantly sigma bonding orbitals). Hyperconjugative sigma to sigma delocalization interactions account for the remainder of the coupling. Calculated pairwise-steric and hyperconjugative-delocalization energies provide a means for relating coupling mechanisms to molecular energetics. In this way, J-coupling contributions can be related directly to the localized features of the molecular electronic structure in order to explain measured J-coupling patterns and to predict J-coupling trends that have yet to be measured.

Monomeric solution structure of the prototypical 'C' chemokine lymphotactin.

Lymphotactin, the sole identified member of the C class of chemokines, specifically attracts T lymphocytes and natural killer cells. This 93-residue protein lacks 2 of the 4 conserved cysteine residues characteristic of the other 3 classes of chemokines and possesses an extended carboxyl terminus, which is required for chemotactic activity. We have determined the three-dimensional solution structure of recombinant human lymphotactin by NMR spectroscopy. Under the conditions used for the structure determination, lymphotactin was predominantly monomeric; however, pulsed field gradient NMR self-diffusion measurements and analytical ultracentrifugation revealed evidence of dimer formation. Sequence-specific chemical shift assignments were determined through analysis of two- and three-dimensional NMR spectra of (15)N- and (13)C/(15)N-enriched protein samples. Input for the torsion angle dynamics calculations used in determining the structure included 1258 unique NOE-derived distance constraints and 60 dihedral angle constraints obtained from chemical-shift-based searching of a protein conformational database. The ensemble of 20 structures chosen to represent the structure had backbone and heavy atom rms deviations of 0.46 +/- 0.11 and 1.02 +/- 0.14 A, respectively. The results revealed that human lymphotactin adopts the conserved chemokine fold, which is characterized by a three-stranded antiparallel beta-sheet and a C-terminal alpha-helix. Two regions are dynamically disordered as evidenced by (1)H and (13)C chemical shifts and [(15)N]-(1)H NOEs: residues 1-9 of the amino terminus and residues 69-93 of the C-terminal extension. A functional role for the C-terminal extension, which is unique to lymphotactin, remains to be elucidated.

Incorporation of 2'-deoxy-5-(trifluoromethyl)uridine and 5-cyano-2'-deoxyuridine into DNA.

In an attempt to synthesize DNA containing 2'-deoxy-5-(trifluoromethyl)uridine (1) using previously published protocols, we found that the trifluoromethyl group converted into a cyano group, resulting in DNA containing 5-cyano-2'-deoxyuridine (3). We show that nucleoside 1 can be incorporated into DNA using phosphoramidite 2 in combination with acetyl-protected deoxycytidine and phenoxyacetyl-protected purine phosphoramidites. Replacing thymidine in DNA with 1 caused a slight decrease in DNA duplex stability at pH 6.9.