Evaluation of a successful fluoroquinolone restriction intervention among high-risk patients: A mixed-methods study

Comparison of Different Antibiotics and the Risk for Community-Associated Clostridioides difficile Infection: A Case-Control Study

Background

Antibiotics are the greatest risk factor for Clostridioides difficile infection (CDI). Risk for CDI varies across antibiotic types and classes. Optimal prescribing and stewardship recommendations require comparisons of risk across antibiotics. However, many prior studies rely on aggregated antibiotic categories or are underpowered to detect significant differences across antibiotic types. Using a large database of real-world data, we evaluate community-associated CDI risk across individual antibiotic types.

Methods

We conducted a matched case-control study using a large database of insurance claims capturing longitudinal health care encounters and medications. Case patients with community-associated CDI were matched to 5 control patients by age, sex, and enrollment period. Antibiotics prescribed within 30 days before the CDI diagnosis along with other risk factors, including comorbidities, health care exposures, and gastric acid suppression were considered. Conditional logistic regression and a Bayesian analysis were used to compare risk across individual antibiotics. A sensitivity analysis of antibiotic exposure windows between 30 and 180 days was conducted.

Results

We identified 159 404 cases and 797 020 controls. Antibiotics with the greatest risk for CDI included clindamycin and later-generation cephalosporins, and those with the lowest risk included minocycline and doxycycline. We were able to differentiate and order individual antibiotics in terms of their relative level of associated risk for CDI. Risk estimates varied considerably with different exposure windows considered.

Conclusions

We found wide variation in CDI risk within and between classes of antibiotics. These findings ordering the level of associated risk across antibiotics can help inform tradeoffs in antibiotic prescribing decisions and stewardship efforts.

Omadacycline and Clostridioides difficile: A Systematic Review of Preclinical and Clinical Evidence

OBJECTIVE

The objective of this systematic review is to summarize in vitro, preclinical, and human data related to omadacycline and Clostridioides difficile infection (CDI).

DATA SOURCES

PubMed and Google Scholar were searched for "omadacycline" AND ("Clostridium difficile" OR "C difficile" OR "Clostridioides difficile") for any studies published before February 15, 2022. The US Food and Drug Administration (FDA) Adverse Events Reporting System (AERS) was searched for omadacycline (for reports including "C. difficile" or "CDI" or "gastrointestinal infection"). The publications list publicly available at Paratek Pharmaceuticals, Inc. Web site was reviewed.

STUDY SELECTION AND DATA EXTRACTION

Publications presenting primary data on omadacycline and C. difficile published in English were included.

DATA SYNTHESIS

Preclinical and clinical evidence was extracted from 14 studies. No case reports in indexed literature and no reports on FDA AERS were found. Omadacycline has potent in vitro activity against many C. difficile clinical strains and diverse ribotypes. In phase 3 studies, there were no reports of CDI in patients who received omadacycline for either community-acquired bacterial pneumonia or acute bacterial skin and skin structure infection.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Omadacycline should be considered a low-risk antibiotic regarding its propensity to cause CDI.

CONCLUSIONS

Reducing the burden of CDI on patients and the health care system should be a priority. Patients with appropriate indications who are at heightened risk of CDI may be suitable candidates for omadacycline therapy. In these patients, omadacycline may be preferable to antibiotics with a high CDI risk.

Characterizing barriers to antibiotic stewardship for skin and soft-tissue infections in the emergency department using a systems engineering framework

OBJECTIVE

Skin and soft-tissue infections (SSTIs) account for 3% of all emergency department (ED) encounters and are frequently associated with inappropriate antibiotic prescribing. We characterized barriers and facilitators to optimal antibiotic use for SSTIs in the ED using a systems engineering framework and matched them with targeted stewardship interventions.

DESIGN AND PARTICIPANTS

We conducted semistructured interviews with a purposefully selected sample of emergency physicians.

METHODS

An interview guide was developed using the Systems Engineering Initiative for Patient Safety (SEIPS) framework. Interviews were recorded, transcribed, and analyzed iteratively until conceptual saturation was achieved. Themes were identified using deductive directed content analysis guided by the SEIPS model.

RESULTS

We conducted 20 interviews with physicians of varying experience and from different practice settings. Identified barriers to optimal antibiotic prescribing for SSTIs included poor access to follow-up (organization), need for definitive diagnostic tools (tools and technology) and fear over adverse outcomes related to missed infections (person). Identified potential interventions included programs to enhance follow-up care; diagnostic aides (eg, rapid MRSA assays for purulent infections and surface thermal imaging for cellulitis); and shared decision-making tools.

CONCLUSIONS

Using a systems engineering informed qualitative approach, we successfully characterized barriers and developed targeted antibiotic stewardship interventions for SSTIs managed in the ED work system. The interventions span multiple components of the ED work system and should inform future efforts to improve antibiotic stewardship for SSTIs in this challenging care setting.

A Non-Restrictive Approach to Fluoroquinolone Stewardship at Two Community Hospitals

Background

Fluoroquinolones are one of the most prescribed antimicrobials in the United States and have been increasingly used in inpatient and outpatient settings to treat various infectious diseases syndromes. Due to the unwanted collateral effects on antibiotic resistance, poor susceptibility rates among Gram-negative pathogens, and adverse effects, fluoroquinolones are often targeted by hospital antimicrobial stewardship programs to prevent overutilization. This study describes the association of nonrestrictive antimicrobial stewardship interventions at 2 nonacademic community hospitals on levofloxacin utilization, prescribing patterns on alternative antibiotics, and Pseudomonas aeruginosa nonsusceptibility rates to levofloxacin.

Methods

Nonrestrictive antimicrobial stewardship interventions included monitoring and reporting of fluoroquinolone susceptibility trends to physician groups, performing medication use evaluations of levofloxacin accompanied with prescriber detailing, daily prospective audit and feedback, implementation of beta-lactam-based institutional guidelines for empiric therapy in various infectious disease syndromes, review and adjustment of electronic medical record order sets containing fluoroquinolones, and intensive prescriber education. No preauthorization of levofloxacin was used during this study period. Antibiotic utilization data were collected for the time periods of August 2015 through January 2021. Correlation between levofloxacin and other broad-spectrum antibiotc use was investigated as well as the impact on Pseudomonas aeruginosa levofloxacin nonsusceptibility rates.

Results

Both hospitals showed an overall downward trend in the prescribing of levofloxacin during the time period of August 2015 to January 2021. There was a significant negative correlation between monthly ceftriaxone and levofloxacin days of therapy for both hospitals (P < .0001). There was a positive correlation between levofloxacin days of therapy and P aeruginosa nonsusceptibility (P < .02 at both hospitals).

Conclusions

Our results demonstrate that a nonrestrictive approach to fluoroquinolone stewardship interventions had a significant impact on reducing levofloxacin utilization, increasing ceftriaxone utilization, and improving P aeruginosa levofloxacin susceptibility.

Mechanisms and impact of antimicrobial resistance in Clostridioides difficile

The evolution of antimicrobial resistance in Clostridioides difficile has markedly shaped its epidemiology and detrimentally impacted patient care. C. difficile exhibits resistance to multiple classes of antimicrobials, due to accumulation of horizontally acquired resistance genes and de novo mutations to drug targets. Particularly worrying is that declines in clinical success of firstline CDI antimicrobials coincide with the spread of strains that are more resistant to these drugs. Yet, there is still much to learn regarding the prevalence of genetic elements in clinical isolates, their molecular mechanisms, and the extent to which this information can be translated to develop molecular diagnostics that improve antimicrobial prescribing and antimicrobial stewardship approaches for CDI. Thus, this perspective discusses current understanding and knowledge gaps of antimicrobial resistance mechanisms in C. difficile, emphasizing on CDI therapies.

Synthesis of gemifloxacin conjugated silver nanoparticles, their amplified bacterial efficacy against human pathogen and their morphological study via TEM analysis

Drug-loaded nanoparticles (NPs) allow specific accumulation and controlled release of drugs to infected tissues with minimal cytotoxicity. In this study, gemifloxacin conjugated silver nanoparticles (Gemi-AgNPs) were synthesized, and the amplification of their antibacterial potential against the human pathogen as well as their stability was monitored under physiological conditions. Fourier transform infrared spectroscopy (FTIR) analysis demonstrated the interaction between -NH₂ and -OH functional moiety and the metal surface. The morphological analyses via transmission electron microscopy revealed that Gemi-AgNPs has a round oval shape and average particle size of 22.23 ± 2 nm. The antibacterial and antibiofilm activities of these NPS showed that Gemi-AgNPs exhibit excellent antimicrobial and biofilm inhibition activity against human pathogens, namely, Proteus mirabilis (P. mirabilis) and methicillin-resistant Staphylococcus aureus (MRSA). A significant increase in the antibiofilm activity of Gemi-AgNPs was confirmed by crystal violet, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining, and microscopic analysis. Gemi-AgNPs exhibited the ability to inhibit urease with an IC₅₀ value of 57.4 ± 0.72 µg/mL. The changes in the bacterial cell morphology were analyzed via TEM, which revealed that cell membranes disrupted and completely destroyed the cell morphology by the treatment of Gemi-AgNPs.

Antibiotic utilization variability among training services at an academic medical center: An observational study

OBJECTIVE

Evaluate the difference in antibiotic prescribing between various levels of resident training or attending types.

DESIGN

Observational, retrospective study.

SETTING

Tertiary-care, academic medical center in Madison, Wisconsin.

METHODS

We measured antibiotic utilization from January 1, 2016, through December 31, 2018, in our general medicine (GM) and hospitalist services. The GM1 service is staffed by outpatient internal medicine physicians, the GM2 service is staffed by geriatricians and hospitalists, and the GM3 service is staffed by only hospitalists. The GMA service is led by junior resident physicians, and the GMB service is led by senior resident physicians. We measured utilization using days of therapy (DOT) per 1,000 patient days (PD). In a secondary analysis based on antibiotic spectrum, we used average DOT per 1,000 PD.

RESULTS

Teaching services prescribed more antibiotics than nonteaching services (671.6 vs 575.2 DOT per 1,000 PD; P < .0001). Junior resident-led services used more antibiotics than senior resident-led services (740.9 vs 510.0 DOT per 1,000 PD; P < .0001). Overall, antibiotic prescribing was numerically similar between various attending physician backgrounds. A secondary analysis showed that GM services prescribed more broad-spectrum, anti-MRSA, and anti-pseudomonal antibiotics than the hospitalist services. GM junior resident-led services prescribed more broad-spectrum, anti-MRSA, and antipseudomonal therapy compared to their senior counterparts.

CONCLUSIONS

Antibiotics were prescribed at a significantly higher rate in services associated with trainees than those without. Services led by a junior resident physician prescribed antibiotics at a significantly higher rate than services led by a senior resident. Interventions to reduce unnecessary antibiotic exposure should be targeted toward resident physicians, especially junior trainees.