Selective reporting of antibiotic susceptibility testing results: a promising antibiotic stewardship tool

When less is more: the art of communicating clinical microbiology results

The clinical microbiology laboratory is capable of identifying microorganisms in clinical specimens faster and more accurately than ever before. At face value, this should enable patient care providers to make better-informed decisions and target antimicrobial therapies to deliver individualized care. Ironically, more complete and specific reporting of microorganisms isolated from specimens may result in overtreatment based on the presence of a pathogen, even in the absence of clear signs of clinical infection. This conundrum calls into question the role of the laboratory in contributing to care through selective or "exception" reporting whereby some results are selectively withheld when there is a low probability that laboratory findings correlate with the clinical infection. In a recent article published in the Journal of Clinical Microbiology, Bloomfield et al. (J Clin Microbiol 62:e00342-24, 2024, https://doi.org/10.1128/jcm.00342-24) examine the impact and safety of an exception reporting strategy applied to wound swab specimens. Canonical pathogens associated with skin and soft tissue infections including S. aureus and beta-hemolytic streptococci are withheld from the laboratory report if certain patient criteria are met that would put them at low risk of adverse outcomes if untreated, or if treated with guideline-recommended empiric therapy. Their central finding was an approximately 50% reduction in post-laboratory report antibiotic initiation without adverse events or increased 30-day admission rate (indicative of infection-related complications, e.g., disseminated disease). While effectively achieving their goal, the premise of exception reporting and other modified reporting strategies raises questions about the potential risk of underreporting and how to ensure that the message is being interpreted, and acted upon, by care providers as was intended by the laboratory.

Trends in infection incidence and antimicrobial resistance in the US Veterans Affairs Healthcare System: a nationwide retrospective cohort study (2007-22)

BACKGROUND

Antimicrobial resistance poses a major threat to public health. There are few comprehensive nationwide studies that quantify long-term trends in infection incidence and antimicrobial resistance for multiple pathogens. We aimed to analyse trends in inpatient infection incidence and antimicrobial resistance for nine pathogens over the past 15 years across the USA.

METHODS

In this US nationwide retrospective cohort study, we analysed clinical microbiology data from electronic health records from all patients admitted to all 138 Veterans Affairs (VA) Medical Centers with acute care wards across the USA from Feb 1, 2007, to March 31, 2022. We quantified inpatient antibiotic use as days of therapy (DOT) per 1000 patient-days and antimicrobial resistance by resistance proportion (proportion of incident isolates identified as resistant) and phenotypic incidence (incidence of infections per 1000 admissions classified as resistant, susceptible, or missing). To analyse trends before the COVID-19 pandemic and during the COVID-19 pandemic, we used generalised estimating equation models and reported average annual percentage changes (AAPC).

FINDINGS

We collected 991 527 30-day incident isolates from 507 760 patients in 138 VA Medical Centers and 50 states in the USA. Between Feb 1, 2007, and Dec 31, 2019, infection incidence and antimicrobial resistance declined for many pathogens and pathogen-drug combinations. The proportion of methicillin resistance in Staphylococcus aureus decreased from 57·7% (11 876 of 20 584 incident isolates) to 44·6% (5916 of 13 257) over these 13 years (AAPC -1·8%; 95% CI -2·4 to -1·2; p<0·0001), and vancomycin-resistant Enterococcus faecium infections decreased from 77·8% (2555 of 3285) to 65·1% (893 of 1371; AAPC -1·2%; 95% CI -2·5 to 0·0; p=0·052). Fluoroquinolone resistance declined in both proportion and incidence for most pathogens. These trends correlated with substantial reductions in fluoroquinolone use, from 125 DOT per 1000 patient-days to 20 DOT per 1000 patient-days. Third generation cephalosporin resistance increased steeply in Escherichia coli infections from 6·7% (942 of 14 042) in 2007 to 15·3% (2153 of 14 053) in 2019 (AAPC 8·5%; 95% CI 6·2 to 10·7; p<0·0001). Carbapenem resistance proportion increased in Enterobacter cloacae infections from 1·1% (30 of 2852) in 2007 to 7·3% (212 of 2919) in 2019 (AAPC 19·8%; 95% CI 13·7 to 26·2; p<0·0001), but remained low for Klebsiella pneumoniae and E coli. During the COVID-19 pandemic between Jan 1, 2020, and March 31, 2022, several pathogen-drug combinations increased in both incidence and resistance for hospital-associated infections. For some pathogen-drug combinations, trends in incidence of resistant and susceptible infections were divergent, whereas for other combinations, these trends were in the same direction.

INTERPRETATION

Significant reductions in methicillin resistance in S aureus, vancomycin-resistant E faecium, and fluoroquinolone resistance across multiple pathogens suggest that control efforts have had an effect on resistance. The rise in extended-spectrum β-lactamases-producing Enterobacterales and recent surge in hospital-associated infections emphasise the need for ongoing surveillance and interventions. Our study highlights how coupling the analysis of phenotypic incidence with resistance proportion can enhance interpretation of antimicrobial resistance data.

FUNDING

US Centers for Disease Control and Prevention.

'When all you have is a hammer, everything has to be a nail': Managing diagnostic uncertainty in urinary tract infection

Diagnosis of urinary tract infections (UTI) is a routine part of medical work and yet is well recognised to be an area of high clinical uncertainty. Meanwhile, diagnosis of UTI is becoming increasingly important to policymakers globally due to concerns about antibiotic over-prescription. Drawing on Mol's concept of ontological multiplicity in clinical work, I explore how diagnostic uncertainty is co-ordinated into certainty by a UK national diagnostic algorithm for UTI. The diagnosis of UTI is produced or withheld as a post hoc rationalisation of a prior decision whether to prescribe antibiotics or not. Work in the sociology of diagnosis has already noted that diagnostic steps are often re-ordered by health-care professionals taking diverse actions in the best interest of their patients. This article contributes an argument that ordering diagnostic work around antimicrobial stewardship agendas has the effect of narrowing possible actions. Exploring the consequences and effects of doing diagnosis in this way for different groups, I argue that a greater creativity about what could be done to care for painful bladders could be found in a return to more clinical ways of working.

Impact of selective reporting of wound cultures on microbiology reports and antimicrobial-drug use on a wound-care ward in Finland: a retrospective cohort study

BACKGROUND

Selective reporting is a promising tool for antimicrobial stewardship, but in wound cultures, its effects on the use of antimicrobials are unknown. Our HUS Diagnostic Center Bacteriology laboratory refined its selective reporting protocol for wound cultures during 2017-2018. In this study we aimed to show our protocol's impact on the frequency of antimicrobial escalation.

METHODS

We performed a retrospective cohort study of patients in the wound-care ward of a primary-care hospital in Helsinki, Finland, from 2014 to 2016 (pre-intervention) and from 2019 to April 2021 (post-intervention). With the inclusion criterion being wound-culture collection, this provided us with 299 patients, of which 152 were in the pre-intervention group, and 147 were post-intervention. We collected the data from medical records and compared the pre-intervention- with the post-intervention group in terms of patient profiles, microbiology reports, antimicrobial treatment, and treatment outcomes.

FINDINGS

In the pre-intervention group 40% of the patients were male and 60% female and in the post-intervention group 49% and 51% respectively. The frequency of AST reported had decreased from 63% in the pre-intervention group to 37% post-intervention (OR 0.35, p < 0.001). The post-intervention group demonstrated lower frequencies of antimicrobial treatment 7 d after wound culture collection, 82% pre-intervention vs 58% post-intervention (OR 0.31, p < 0.001), and antimicrobial escalation, 42% vs 20% (OR 0.35, p < 0.001) respectively. Length of hospital stay, and all-cause mortality were similar between the groups.

INTERPRETATION

Selective reporting of wound cultures appears an effective and safe measure to reduce the use of antimicrobials.

FUNDING

HUS Diagnostic Center.

Antibiotic action and resistance: updated review of mechanisms, spread, influencing factors, and alternative approaches for combating resistance

Antibiotics represent a frequently employed therapeutic modality for the management of bacterial infections across diverse domains, including human health, agriculture, livestock breeding, and fish farming. The efficacy of antibiotics relies on four distinct mechanisms of action, which are discussed in detail in this review, along with accompanying diagrammatic illustrations. Despite their effectiveness, antibiotic resistance has emerged as a significant challenge to treating bacterial infections. Bacteria have developed defense mechanisms against antibiotics, rendering them ineffective. This review delves into the specific mechanisms that bacteria have developed to resist antibiotics, with the help of diagrammatic illustrations. Antibiotic resistance can spread among bacteria through various routes, resulting in previously susceptible bacteria becoming antibiotic-resistant. Multiple factors contribute to the worsening crisis of antibiotic resistance, including human misuse of antibiotics. This review also emphasizes alternative solutions proposed to mitigate the exacerbation of antibiotic resistance.

Improving antimicrobial use through better diagnosis: The relationship between diagnostic stewardship and antimicrobial stewardship

Antimicrobial stewardship programs (ASPs) exist to optimize antibiotic use, reduce selection for antimicrobial-resistant microorganisms, and improve patient outcomes. Rapid and accurate diagnosis is essential to optimal antibiotic use. Because diagnostic testing plays a significant role in diagnosing patients, it has one of the strongest influences on clinician antibiotic prescribing behaviors. Diagnostic stewardship, consequently, has emerged to improve clinician diagnostic testing and test result interpretation. Antimicrobial stewardship and diagnostic stewardship share common goals and are synergistic when used together. Although ASP requires a relationship with clinicians and focuses on person-to-person communication, diagnostic stewardship centers on a relationship with the laboratory and hardwiring testing changes into laboratory processes and the electronic health record. Here, we discuss how diagnostic stewardship can optimize the "Four Moments of Antibiotic Decision Making" created by the Agency for Healthcare Research and Quality and work synergistically with ASPs.

Post-report antibiotic initiation following community non-sterile-site microbiology results: an opportunity for labs to lead stewardship?

OBJECTIVES

Positive culture results from non-sterile sites (NSSs) are poorly predictive of clinical infection. Despite this, these results are often interpreted as an indication for antibiotics, even in patients with limited signs of infection. We sought to quantify the influence of NSS culture results on post-report antibiotic initiation (PRAI) in patients who had not been started on antibiotics pre-report.

METHODS

All community wound/skin swab and sputum cultures were matched to antibiotic dispensing records from February 2017 to July 2022. Prescribing behaviour was assessed pre- and post-report. Sampling without treatment pre-report was termed 'test-and-wait' (TaW). Following TaW, PRAI was identified if antibiotics were started within 5 days post-report.

RESULTS

There were 65 480 wound/skin swabs and 8126 sputum samples, with TaW occurring in 21 740 (35.1%) and 4185 (54.4%), respectively. Following a TaW approach PRAI occurred in 43.3% when an organism was reported, versus 10.8% (P < 0.01) for a 'no growth' report for wound/skin swabs. For the same comparison with sputum, PRAI occurred in 47.9% versus 10.8% (P < 0.01). On multivariate analysis reporting an organism remained strongly associated with PRAI.

CONCLUSIONS

Reporting an organism in those not already on antibiotics was strongly associated with PRAI. We hypothesize that for many patients TaW suggests limited evidence of infection (i.e. insufficient to justify antibiotic treatment at time of sampling), meaning positive NSS results may be driving a considerable volume of potentially unnecessary antibiotic use. Further study on this topic is required, but strategies to reduce PRAI may offer laboratories an opportunity to meaningfully impact antimicrobial stewardship efforts.

Short report: impact of selective reporting of antibiotic susceptibility testing on antibiotic use in patients with bloodstream infection with Enterococcus faecalis

INTRODUCTION

Bloodstream infections with Enterococcus faecalis are associated with relevant morbidity and mortality. Targeted antimicrobial therapy is essential. The choice of an adequate treatment may be challenging when susceptibility testing offers different options. Selective reporting of antibiotic susceptibility test results might lead to a more tailored antibiotic therapy and could therefore be an important antimicrobial stewardship program intervention. The aim of this study was to analyse whether the introduction of selective reporting of antibiotic test results leads to a more targeted antibiotic therapy in patients with bloodstream infection with Enterococcus faecalis.

METHODS

This study was performed as a retrospective cohort study at the University Hospital Regensburg, Germany. All patients with blood cultures positive for Enterococcus faecalis between March 2003 and March 2022 were analysed. In February 2014 selective reporting of antibiotic susceptibility test results omitting sensitivity results for agents not recommended was introduced.

RESULTS

263 patients with blood cultures positive for Enterococcus faecalis were included. After introduction of selective reporting of antibiotic tests (AI) significantly more patients received ampicillin than before introduction of selective reporting (BI) (9.6% BI vs. 34.6% AI, p < 0.001).

CONCLUSION

Selective reporting of antibiotic susceptibility test results led to a significantly higher use of ampicillin.

Understanding and Implementing Diagnostic Stewardship: A Guide for Resident Physicians in the Era of Antimicrobial Resistance

Antimicrobial resistance (AMR) poses a significant global health challenge, exacerbated by the COVID-19 pandemic. Antimicrobial stewardship programs (ASPs) are crucial in managing this crisis, with diagnostic stewardship (DS) emerging as a key component. DS refers to the appropriate use of diagnostic tests to optimize patient outcomes, improve antimicrobial use, and combat multi-drug-resistant (MDR) organisms. Despite its potential, understanding and application of DS remain ambiguous in multiple respects, which, however, do not directly implicate the implementation of such initiatives. DS is particularly important for resident physicians who are often at the forefront of patient care and can significantly influence future AMR strategies. This review provides a comprehensive overview of DS, discussing its importance, potential challenges, and future directions. It emphasizes the need for resident physicians to understand DS principles and integrate them into their clinical practice from the beginning of their careers. The review also highlights the role of various stakeholders in implementing DS and the importance of continuous education and training. Ultimately, DS is not just a clinical tool but a philosophy of care, essential for a more responsive, humane, and effective healthcare system.

Impact of selective reporting of antibiotic susceptibility testing results for urinary tract infections in the outpatient setting: A prospective controlled before-after intervention study

OBJECTIVES

The use of selective reporting of antibiotic susceptibility testing (AST) results is a recommended antimicrobial stewardship strategy to improve the appropriateness of antibiotic prescriptions. We conducted a large, pragmatic, prospective, multicentre, controlled (selective reporting versus complete reporting) before-after intervention study to assess the impact of selective reporting of AST results for Escherichia coli-positive urine cultures on the prescription of broad-spectrum antibiotics carrying a higher risk of selection of resistance (i.e., amoxicillin-clavulanate, third-generation cephalosporins, and quinolones) in the outpatient setting. We also looked for possible unintended clinical consequences of the intervention leading to consultations and/or hospitalisations.

METHODS

We compared two groups of laboratories located in a French region. We collected data from the health insurance databases before (2017) and after the implementation of the intervention (2019). The primary outcome was the prescription proportions of broad-spectrum antibiotics.

RESULTS

We included 42,956 Escherichia coli-positive urine cultures with AST. The decrease of the proportion of broad-spectrum antibiotic prescriptions between 2017 and 2019 was significantly higher for selective reporting of AST, attributable to a decrease in the prescription proportion of third-generation cephalosporins (- 8.5% for selective reporting versus - 0.1% for complete reporting, p < 0.001). This impact was more marked for targeted therapy and female patients. Requests from clinicians for the complete reporting of AST results were infrequent (1.2% of all the selective AST results reported in 2019). No unintended consequences were observed.

CONCLUSION

The results showed a positive impact of the selective reporting of AST results, but room for improvement is still important.

REGISTRATION AT CLINICAL TRIALS

NCT03612297.

Antimicrobial susceptibility testing: An updated primer for clinicians in the era of antimicrobial resistance: Insights from the Society of Infectious Diseases Pharmacists

Antimicrobial susceptibility testing (AST) is a critical function of the clinical microbiology laboratory and is essential for optimizing care of patients with infectious diseases, monitoring antimicrobial resistance (AMR) trends, and informing public health initiatives. Several methods are available for performing AST including broth microdilution, agar dilution, and disk diffusion. Technological advances such as the development of commercial automated susceptibility testing platforms and the advent of rapid diagnostic tests have improved the rapidity, robustness, and clinical application of AST. Numerous accrediting and regulatory agencies are involved in the process of AST and setting and revising breakpoints, including the U.S. Food and Drug Administration and the Clinical and Laboratory Standards Institute. Challenges to optimizing AST include the emergence of new resistance mechanisms, the development of new antimicrobial agents, and generation of new data requiring updates and revisions to established methods and breakpoints. Together, the challenges in AST methods and their interpretation create important opportunities for well-informed clinicians to improve patient outcomes and provide value to antimicrobial stewardship programs, especially in the setting of rapidly changing and increasing AMR. Addressing AST challenges will involve continued development of new technologies along with collaboration between clinicians and the laboratory to facilitate optimal antimicrobial use, combat the increasing burden of AMR, and inform the development of novel antimicrobials. This updated primer serves to reinforce important principles of AST, and to provide guidance on their implementation and optimization.

Impact of selective reporting of antibiotic susceptibility testing results on meropenem prescriptions for the treatment of Pseudomonas aeruginosa infections after 2020 EUCAST criteria update: an observational study in a university hospital

BACKGROUND

We previously reported an increase in meropenem prescriptions for Pseudomonas aeruginosa infections in our hospital after the implementation of the 10th version of the EUCAST breakpoints table for P. aeruginosa in January 2020. As a consequence, antibiotic susceptibility testing results were adapted by masking meropenem for P. aeruginosa isolates susceptible to either ceftazidime, cefepime or piperacillin-tazobactam. We aimed to assess the changes in meropenem prescriptions after the implementation of the selective reporting.

METHODS

In this retrospective single-centre observational study, we analysed antimicrobial therapies prescribed for P. aeruginosa infections after the susceptibility testing results have been made available over three periods: "before EUCAST update", "after EUCAST update without selective reporting" and "after EUCAST update with selective reporting", at Lausanne University Hospital, Switzerland. We collected epidemiological, microbiological and clinical data. The primary outcome was the prescription of meropenem to treat P. aeruginosa infections after the release of susceptibility testing results. Secondary outcomes were the use of increased dosage of non-meropenem anti-pseudomonal drugs, and IDs' consultations rates after the release of susceptibility testing results.

RESULTS

Among the 457 patients included, 65 (14.2%) received meropenem: 5/148 (3.4%) before EUCAST update, 51/202 (25.3%) after EUCAST update without selective reporting, and 9/107 (8.4%) after EUCAST update with selective reporting. Supervision and counselling from IDs as well as the use of increased dosages of non-carbapenem antibiotics increased in both periods after EUCAST update, compared to the first period, respectively: 40.5% (60/148) versus 61.4% (124/202) versus 51.4% (55/107) (P < 0.001), and 57.9% (84/148) versus 91.1% (183/202) versus 90.7% (97/107) (P < 0.001).

CONCLUSIONS

Selective reporting of antibiotic susceptibility testing results might decrease unnecessary meropenem prescriptions for the treatment of P. aeruginosa infections and could be part of multimodal antibiotic stewardship interventions.

Oral ciprofloxacin activity against ceftriaxone-resistant Escherichia coli in an in vitro bladder infection model

OBJECTIVES

Pharmacodynamic profiling of oral ciprofloxacin dosing for urinary tract infections caused by ceftriaxone-resistant Escherichia coli isolates with ciprofloxacin MIC ≥ 0.25 mg/L.

BACKGROUND

Urine-specific breakpoints for ciprofloxacin do not exist. However, high urinary concentrations may promote efficacy in isolates with low-level resistance.

METHODS

Ceftriaxone-resistant E. coli urinary isolates were screened for ciprofloxacin susceptibility. Fifteen representative strains were selected and tested using a dynamic bladder infection model. Oral ciprofloxacin dosing was simulated over 3 days (250 mg daily, 500 mg daily, 250 mg 12 hourly, 500 mg 12 hourly and 750 mg 12 hourly). The model was run for 96 h. Primary endpoint was change in bacterial density at 72 h. Secondary endpoints were follow-up change in bacterial density at 96 h and area-under-bacterial-kill-curve. Bacterial response was related to exposure (AUC0-24/MIC; Cmax/MIC). PTA was determined using Monte-Carlo simulation.

RESULTS

Ninety-three clinical isolates demonstrated a trimodal ciprofloxacin MIC distribution (modal MICs at 0.016, 0.25 and 32 mg/L). Fifteen selected clinical isolates (ciprofloxacin MIC 0.25-512 mg/L) had a broad range of quinolone-resistance genes. Following ciprofloxacin exposure, E. coli ATCC 25922 (MIC 0.008 mg/L) was killed in all dosing experiments. Six isolates (MIC ≥ 16 mg/L) regrew in all experiments. Remaining isolates (MIC 0.25-8 mg/L) regrew variably after an initial period of killing, depending on simulated ciprofloxacin dose. A >95% PTA, using AUC0-24/MIC targets, supported 250 mg 12 hourly for susceptible isolates (MIC ≤ 0.25 mg/L). For isolates with MIC ≤ 1 mg/L, 750 mg 12 hourly promoted 3 log10 kill at the end of treatment (72 h), 1 log10 kill at follow-up (96 h) and 90% maximal activity (AUBKC0-96).

CONCLUSIONS

Bladder infection modelling supports oral ciprofloxacin activity against E. coli with low-level resistance (ciprofloxacin MIC ≤ 1 mg/L) when using high dose therapy (750 mg 12 hourly).

Optimizing antimicrobial therapy in urinary tract infections: A focus on urine culture and sensitivity testing

Objectives: This cross-sectional study was conducted at Jordan university hospital to evaluate the impact of microbial culture data and sensitivity results on optimizing UTI treatment. Methods: All positive urine cultures requested for adult patients (≥18 years) admitted to Jordan University Hospital (JUH) within the period from January 2019-July 2021 were evaluated. The antibiotics prescribed before and after culture data and sensitivity results were compared to evaluate the impact of these diagnostic measures on optimizing UTI treatment. Results: During the study period, 2400 urine cultures revealed positive results. Among those patients, 1,600 (66.7%) were discharged before the availability of culture results and excluded. Of the remaining 800 patients, 701 patients (87.6%) received empiric treatment. After culture and sensitivity results were available, overall, 84 (10.5%) patients had optimization (improvement) in their UTI management after culture results were known, while 6 (0.8%) patients had a worsening in their treatments. Based on the culture results, we found that only 12.4% of patients were appropriately treated before and after the culture results. Moreover, our results revealed that 31.9% were inappropriately treated for their UTIs before and after culture results. Conclusion: This study revealed an alarmingly high rate of inappropriate treatment of UTIs despite the availability of urine culture and sensitivity data, and that culture results were not used to optimize treatment strategies for UTI. This practice can potentially result in poor health-related outcomes and adversely affects efforts to battle AMR. Multifaceted strategies must be implemented to help clinicians follow the best current evidence and current guidelines in their selection of antibiotics for the management of UTIs.

Establishment of RCPA national guidelines for selective reporting of antimicrobials: processes, challenges and measuring the impact

OBJECTIVES

In 2016, The Royal College of Pathologists of Australasia (RCPA) initiated the formation of a working group comprising medical microbiologists to establish guidelines to assist Australian laboratories to implement selective and cascade reporting of antimicrobials-the first guidelines of this type in the world.

METHODS

A 2017 audit of antimicrobial reporting in Australian and New Zealand laboratories identified significant opportunities for improvement and standardization of selective reporting.

RESULTS

The first draft of the RCPA Selective Reporting Guidelines was circulated to all RCPA Microbiology fellows for feedback in August 2018 and the first version was published in February 2019. Subsequently, version two of the guidelines has recently been published in Australia, and New Zealand adapted these guidelines for formulation of their own national guidelines to accommodate local needs.

CONCLUSIONS

Here we describe the processes, acceptance and challenges associated with the establishment of these guidelines and measurement of their impact.

Multiplexed and Rapid AST for Escherichia coli Infection by Simultaneously Pyrosequencing Multiple Barcodes Each Specific to an Antibiotic Exposed to a Sample

Antimicrobial susceptibility testing (AST) is an effective way to guide antibiotic selection. However, conventional culture-based phenotypic AST is time-consuming. The key point to shorten the test is to quantify the small change in the bacterial number after the antibiotic exposure. To achieve rapid AST, we proposed a combination of multiplexed PCR with barcoded pyrosequencing to significantly shorten the time for antibiotic exposure. First, bacteria exposed to each antibiotic were labeled with a unique barcode. Then, the pool of the barcoded products was amplified by PCR with a universal primer pair. Finally, barcodes in the amplicons were individually and quantitatively decoded by pyrosequencing. As pyrosequencing is able to discriminate as low as 5% variation in target concentrations, as short as 7.5 min was enough for cultivation to detect the susceptibility of Escherichia coli to an antibiotic. The barcodes enable more than six kinds of drugs or six kinds of concentrations of a drug to be tested at a time. The susceptibility of 6 antibiotics to 43 E. coli-positive samples from 482 clinical urine samples showed a consistency of 99.3% for drug-resistant samples and of 95.7% for drug-sensitive samples in comparison with the conventional method. In addition, the minimum inhibitory concentration (MIC) of 29 E. coli samples was successfully measured. The proposed AST is dye free (pyrosequencing), multiplexed (six antibiotics), fast (a half-working day for reporting the results), and able to detect the MIC, thus having a great potential for clinical use in quick antibiotic selection.

The Appropriateness of Empiric Treatment of Urinary Tract Infections in a Tertiary Teaching Hospital in Joran: A Cross-Sectional Study

This is a cross-sectional study that was conducted at Jordan University Hospital (JUH) to evaluate the appropriateness of Urinary Tract Infection (UTI) empiric treatment based on microbial culture data and susceptibility testing. All urine cultures requested for adult patients (≥18 years) admitted to JUH within the period from January 2019–July 2021 were reviewed and only those cultures with positive episodes of infection were considered. In this study, 6950 urine culture episodes were screened; among them, 34.5% (n = 2400) revealed positive results. Among those patients with positive culture episodes, 1600 patients (66.7%) were discharged before the availability of culture results and were excluded. Of the remaining eligible 800 patients, 701 (87.6%) received empiric treatment. In 26.8% of the eligible cases (n = 214), the prescribed empiric agents failed to have appropriate coverage of the identified pathogens, and in 14.6% of the cases (n = 117) the identified microorganisms were reported as resistant to the prescribed empiric agents. Furthermore, only 13.4% of the patients (n = 107) were appropriately treated for their UTI with empiric antibacterial agents. We were not able to judge the appropriateness of UTI treatment for one third (n = 263, 32.9%) of the patients, because they did not have susceptibility reports performed. This study revealed an alarmingly high rate of inappropriate treatment of UTIs, which encourages the emergence of bacterial resistance and affects health-related outcomes negatively. Therefore, antimicrobial stewardship programs must be applied to optimize antibiotic consumption in hospital settings.

Antimicrobial Susceptibility Testing: A Comprehensive Review of Currently Used Methods

Antimicrobial resistance (AMR) has emerged as a major threat to public health globally. Accurate and rapid detection of resistance to antimicrobial drugs, and subsequent appropriate antimicrobial treatment, combined with antimicrobial stewardship, are essential for controlling the emergence and spread of AMR. This article reviews common antimicrobial susceptibility testing (AST) methods and relevant issues concerning the advantages and disadvantages of each method. Although accurate, classic technologies used in clinical microbiology to profile antimicrobial susceptibility are time-consuming and relatively expensive. As a result, physicians often prescribe empirical antimicrobial therapies and broad-spectrum antibiotics. Although recently developed AST systems have shown advantages over traditional methods in terms of testing speed and the potential for providing a deeper insight into resistance mechanisms, extensive validation is required to translate these methodologies to clinical practice. With a continuous increase in antimicrobial resistance, additional efforts are needed to develop innovative, rapid, accurate, and portable diagnostic tools for AST. The wide implementation of novel devices would enable the identification of the optimal treatment approaches and the surveillance of antibiotic resistance in health, agriculture, and the environment, allowing monitoring and better tackling the emergence of AMR.

Effects of cascade reporting of susceptibility profiles for Enterobacterales on broad-spectrum antibiotics use and resistance

OBJECTIVE

To reduce the inappropriate use of broad-spectrum antibiotics in a 1000+ bed acute tertiary care hospital by the introduction of cascade antimicrobial susceptibility reporting for Enterobacterales.

METHODS

Over a 1-year period, we selectively suppressed reporting of susceptibility to the broad-spectrum antibiotics piperacillin-tazobactam (TZP) and meropenem (MEM) for Enterobacterales strains susceptible to amoxicillin-clavulanic acid (AMC) and negative for extended-spectrum β-lactamase (ESBL). We measured the effects on hospital-wide antibiotic consumption (defined daily doses/1000 admissions) and resistance of Escherichia coli and Klebsiella pneumoniae on two levels. First, we compared resistance and antibiotic use for the antibiotics impacted by the intervention (AMC, TZP and MEM) with control antibiotics that were consistently reported (fluoroquinolones, trimethoprim-sulfamethoxazole and third-generation cephalosporins). Second, we compared the resistance for TZP and MEM with a control pathogen (Pseudomonas aeruginosa) and studied the impact on rate of Clostridioides difficile-associated diarrhoea in our hospital.

RESULTS

We observed an overall increased use of AMC relative to overall antibiotic consumption (20.0%, p<0.0001) together with a decreased use of TZP (-11.9%, p=0.049) and unchanged use of MEM (p=0.68) relative to overall antibiotic consumption. As for resistance, the number of ESBL-positive K. pneumoniae strains diminished by 5.9% (p<0.0001). When focusing on intensive care units, the carbapenemase-producing Enterobacterales (CPE) rate also decreased by 4.5% (p=0.0091). For E. coli, no significant difference in ESBL (p=0.33) and CPE (p=0.48) rates were observed. No significant difference in the rate of C. difficile infections was observed (p=0.40).

CONCLUSIONS

Restricted susceptibility reporting of TZP and MEM was associated with a significant increased use of AMC and decreased use of TZP relative to overall antibiotic consumption and significant reduction in ESBL- and CPE-positive K. pneumoniae strains.

Impact of antibiotic susceptibility reporting on broad spectrum antibiotic use in serratia and morganella bacteremia

To minimize broad-spectrum antibiotic use, our microbiology laboratory changed antibiotic susceptibility reporting for AmpC-beta-lactamase producing Serratia marcescens and Morganella morganii in blood cultures to include results of narrow spectrum 3rd generation cephalosporins. We assessed the impact of this change on broad-spectrum antibiotic use and clinical outcomes. All adult patients with Serratia marcescens or Morganella morganii in blood culture 2 years pre- and post-change of susceptibility reporting were retrospectively reviewed. Exclusion: more than one pathogen isolated in their blood culture, did not receive antibiotics or died within 48 hours of positive blood culture. Outcomes: Rates of broad-spectrum antibiotic use, in-hospital mortality, clinical response and microbiologic success. There were 30 patients pre-change and 46 patients post-change of reporting. Cefepime use (broad-spectrum) decreased from 46.7% to 6.5% (p < 0.001) and 3^rd generation cephalosporin (narrow-spectrum) use increased (3.3% vs 34.8%, p = 0.0013) in the post-change cohort. This demonstrates the potential role of selective susceptibility reporting in antimicrobial stewardship.

Diagnostic Stewardship as a Team Sport: Interdisciplinary Perspectives on Improved Implementation of Interventions and Effect Measurement

Diagnostic stewardship aims to deliver the right test to the right patient at the right time and is optimally combined with antimicrobial stewardship to allow for the right interpretation to translate into the right antimicrobial at the right time. Laboratorians, physicians, pharmacists, and other healthcare providers have an opportunity to improve the effectiveness of diagnostics through collaborative activities around pre-analytical and post-analytical periods of diagnostic testing. Additionally, special considerations should be given to measuring the effectiveness of diagnostics over time. Herein, we perform a narrative review of the literature on these potential optimization opportunities and the temporal factors that can yield changes in diagnostic effectiveness. Our objective is to inform on these considerations to ensure enhanced value through improved implementation and measurement of effectiveness for local stakeholder metrics and/or clinical outcomes research.

Guidelines on Implementing Antimicrobial Stewardship Programs in Korea

These guidelines were developed as a part of the 2021 Academic R&D Service Project of the Korea Disease Control and Prevention Agency in response to requests from healthcare professionals in clinical practice for guidance on developing antimicrobial stewardship programs (ASPs). These guidelines were developed by means of a systematic literature review and a summary of recent literature, in which evidence-based intervention methods were used to address key questions about the appropriate use of antimicrobial agents and ASP expansion. These guidelines also provide evidence of the effectiveness of ASPs and describe intervention methods applicable in Korea.

Optimizing rapid diagnostics and diagnostic stewardship in Gram-negative bacteremia

Antimicrobial resistance remains a high global concern, as it is associated with prolonged hospitalizations, increased morbidity and mortality, and escalating healthcare-related costs. Rapid diagnostic technology (RDT) has become the cornerstone in achieving prompt blood culture results providing a quicker initiation of optimal therapy, decreased mortality, and decreased spread of resistance. To maximize the benefits of RDTs, antimicrobial stewardship programs must implement a diagnostic stewardship (DS) subgroup to optimize communication, education, and interpretation of RDT results within the healthcare system. The DS subgroup is necessary to evaluate the technologies available, better integrate the selected technologies into the healthcare system, and develop innovative and appropriate use to improve patient outcomes.

AI-based mobile application to fight antibiotic resistance

Antimicrobial resistance is a major global health threat and its development is promoted by antibiotic misuse. While disk diffusion antibiotic susceptibility testing (AST, also called antibiogram) is broadly used to test for antibiotic resistance in bacterial infections, it faces strong criticism because of inter-operator variability and the complexity of interpretative reading. Automatic reading systems address these issues, but are not always adapted or available to resource-limited settings. We present an artificial intelligence (AI)-based, offline smartphone application for antibiogram analysis. The application captures images with the phone’s camera, and the user is guided throughout the analysis on the same device by a user-friendly graphical interface. An embedded expert system validates the coherence of the antibiogram data and provides interpreted results. The fully automatic measurement procedure of our application’s reading system achieves an overall agreement of 90% on susceptibility categorization against a hospital-standard automatic system and 98% against manual measurement (gold standard), with reduced inter-operator variability. The application’s performance showed that the automatic reading of antibiotic resistance testing is entirely feasible on a smartphone. Moreover our application is suited for resource-limited settings, and therefore has the potential to significantly increase patients’ access to AST worldwide.

Antimicrobial resistance is a major global health threat and its development is promoted by antibiotic misuse. Here, the authors present an offline smartphone application for automated and standardized antibiotic susceptibility testing, to be deployed in resource-limited settings.

Minimal impact of selective susceptibility reporting on the use of piperacillin-tazobactam for Escherichia coli and Klebsiella bacteremia

Selective cascade reporting of antibiotic susceptibilities did not have a significant impact on de-escalation from piperacillin-tazobactam (PT), duration of PT use, length of stay, or rates of acute kidney injury and Clostridioides difficile infection in patients with positive monomicrobial blood cultures with either Escherichia coli or Klebsiella spp.