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Objective To describe Neisseria gonorrhoeae treatment failure to the recommended antimicrobial regimens (azithromycin, cefixime and ceftriaxone). Methods Our study was a longitudinal analysis of treatment failures from an observational open cohort of gonococcal infection cases collected in Québec, Canada (n  = 2547) between September 2015 and December 2019. Epidemiological and clinical data were collected using a self-administered questionnaire, direct case interviews and chart reviews. Antimicrobial susceptibility testing was performed using the agar dilution method. To be retained as a treatment failure, cases must have had (i) a laboratory-confirmed gonococcal infection; (ii) a documented treatment; (iii) a positive test of cure (TOC) performed within a defined period and (iv) no sexual contact (vaginal, oral or anal), even protected with a condom, between the beginning of treatment and the positive TOC. A broader definition, including suspected cases, was also examined. Results Among 1593 cases where a TOC was performed, 83 had a positive TOC: 11 were retained as treatment failure, and 6 were considered suspected cases (overall = 17/1593; 1.1%). Possible explanations for retained or suspected treatment failure included resistance to the antibiotics used for treatment (n  = 1), pharyngeal infection (n  = 9, of which 5 had been treated with ceftriaxone and 4 with other regimens); and azithromycin monotherapy (n  = 1). Some cases had more than one potential explanation. Conclusions Treatment failure occurred in 1.1% of cases of Neisseria gonorrhoeae infection for which a TOC was performed, including some cases of pharyngeal infection treated with ceftriaxone. [ABSTRACT FROM AUTHOR]

Background Effective management of drug–food interactions is crucial for enhancing antibiotics' efficacy/safety. Adhering to PRISMA guidelines, we conducted a systematic review to assess the impact of dietary interventions on the bioavailability of 15 macrolides and 10 tetracyclines. Methods We included studies examining the influence of food, beverages, antacids, and mineral supplements on the pharmacokinetic parameters of orally administered macrolides and tetracyclines. We searched Medline (via PubMed), Embase and Cochrane Library databases up to December 2022. Risk of bias was assessed using Cochrane and NIH tools. Quantitative analyses were conducted if two or more comparable food-effect studies were available; otherwise, a qualitative summary was provided. Results We included 120 studies from 97 reports. Meta-analyses were conducted for 8 macrolides and 4 tetracyclines, with qualitative synthesis for 10 and 9, respectively. About 64% of the studies were open-label, crossover designs. Our assessment found that 37% of the studies had a high risk of bias, while only 6% had low risk. Food significantly affected 10 of 13 macrolides (77%) and 6 of 7 tetracyclines (86%). High positive effects on bioavailability were seen with extended-release azithromycin and clarithromycin, and erythromycin estolate. High negative impacts were observed with erythromycin propionate and stearate, azithromycin capsules, demeclocycline and omadacycline. Antacids and mineral supplements significantly decreased tetracyclines absorption. Milk and grapefruit juice showed variable impacts on absorption. Discussion Interactions depend on antibiotics' physicochemical characteristics, intervention type, drug formulation and potential patient factors. The quality of evidence was rated low due to outdated studies, methodological diversity and unequal data availability. [ABSTRACT FROM AUTHOR]

Background Ceftolozane/tazobactam and ceftazidime/avibactam are commonly used in patients with MDR- Pseudomonas aeruginosa (PSA) pneumonia (PNA). This study compared outcomes between non-COVID-19 hospitalized patients with MDR-PSA PNA who received ceftolozane/tazobactam or ceftazidime/avibactam. Methods The study included non-COVID-19 adult hospitalized patients with MDR-PSA PNA in the PINC AI Healthcare Database (2016–22) who received ceftolozane/tazobactam or ceftazidime/avibactam within 3 days of index culture for ≥2 days. Outcomes were mortality, recurrent MDR-PSA PNA, discharge destination, post-index culture day length of stay (LOS) and costs (in US dollars, USD), and hospital readmission. Results The final sample included 197 patients (117 ceftolozane/tazobactam, 80 ceftazidime/avibactam). No significant differences were observed in mortality and post-index culture LOS and costs between groups. In the multivariable analyses, patients who received ceftolozane/tazobactam versus ceftazidime/avibactam had lower recurrent MDR-PSA PNA (7.9% versus 18.0%, P  = 0.03) and 60 day PNA-related readmissions (11.1% versus 28.5%, P  = 0.03) and were more likely to be discharged home (25.8% versus 9.8%, P  = 0.03). Compared with ceftazidime/avibactam patients, ceftolozane/tazobactam patients had lower adjusted median total antibiotic costs (5052 USD versus 8099 USD, P  = 0.003) and lower adjusted median comparator (ceftolozane/tazobactam or ceftazidime/avibactam) antibiotic costs (3938 USD versus 6441 USD, P  = 0.005). In the desirability of outcome ranking (DOOR) analysis, a ceftolozane/tazobactam-treated patient was more likely to have a more favourable outcome than a ceftazidime/avibactam-treated patient [DOOR probability: 59.6% (95% CI: 52.5%–66.8%)]. Conclusions Early treatment with ceftolozane/tazobactam may offer some clinical and cost benefits over ceftazidime/avibactam in patients with MDR-PSA PNA. Further large-scale studies are necessary to comprehensively understand the outcomes associated with these treatments for MDR-PSA PNA. [ABSTRACT FROM AUTHOR]

Objectives Patients with liver cirrhosis are prone to develop severe bacterial infections. Pharmacokinetics (PK) of antibiotics in cirrhosis are potentially affected by impaired biotransformation phases 0–3 and consequences of portal hypertension such as portovenous shunting, ascites formation and/or acute kidney injury (AKI). We aimed to elucidate to what extent PK of selected antibiotics and, therefore, dosage recommendations are affected in adults with cirrhosis. Methods We performed a systematic search in PubMed, Embase, Cochrane and CINAHL on effects of cirrhosis on PK profiles of ceftriaxone, fosfomycin, gentamicin, meropenem, nitrofurantoin, piperacillin/tazobactam and vancomycin in adults. Antibiotics were selected based on the lack of specific dosing recommendations for adults with cirrhosis. We included studies reporting on ≥1 of the following PK parameters: AUC, half-life (t ½), CL, volume of distribution (V d), peak (C max) or trough concentrations (C min). Results We identified 15 studies (ceftriaxone, n  = 5; gentamicin, n  = 3; meropenem n  = 5; vancomycin, n  = 2), including 379 patients with cirrhosis, of which two were of high quality. No eligible studies were identified for fosfomycin, nitrofurantoin or piperacillin/tazobactam. Ceftriaxone unbound concentration increased in cirrhosis, but was mitigated by increased renal CL. Gentamicin levels in ascitic fluid were comparable to those in plasma. Meropenem PK parameters were not altered in cirrhosis without AKI, but in the presence of AKI a decrease in CL was observed. In contrast, vancomycin CL decreased in advanced cirrhosis. Conclusions Available data in studies of mostly moderate quality suggest that PK of ceftriaxone, meropenem and vancomycin are altered in cirrhosis. More advanced PK studies are needed to provide specific dosing recommendations. [ABSTRACT FROM AUTHOR]

Objectives Bacterial persistence is a significant cause of the intractability of chronic and relapsing infections. Despite its importance, many of the underlying mechanisms are still not well understood. Methods Antibiotic-tolerant mutants of Burkholderia thailandensis were isolated through exposure to lethal doses of AMP or MEM, followed by whole-genome sequencing to identify mutations. Subsequently, these mutants underwent comprehensive characterization via killing curves, growth curves, and persistence-fraction plots. Northern blot analysis was employed to detect uncharged tRNA, while the generation of relA and spoT null mutations served to confirm the involvement of the stringent response in this persistence mechanism. Phenotypic reversion of the persistence mutation was demonstrated by incubating the mutants without antibiotics for 2 weeks. Results We have discovered a novel mechanism of persistence triggered by specific mutations at positions 32 or 38 within the anticodon loop of tRNAAsp. This leads to heightened persistence through a RelA-dependent stringent response. Notably, this persistence can be easily reverted to wild-type physiology by losing the mutant tRNA allele within the tRNA gene cluster when persistence is no longer essential for survival. Conclusions This distinct form of persistence underscores the novel function of tRNA mutations at positions 32 or 38 within the anticodon loop, as well as the significance of the tRNA gene cluster in conferring adaptability to regulate persistence for enhanced survival. [ABSTRACT FROM AUTHOR]

Background Burkholderia cepacia complex (Bcc) is a collection of intrinsically drug-resistant Gram-negative bacteria that cause life-threatening disease in people with cystic fibrosis (CF). Standard antimicrobial susceptibility testing methods have poor predictive value for clinical outcomes in Bcc infections, probably due in part to differences between in vitro testing conditions and the environment in which Bcc grow in the lungs of people with CF. Objectives To compare the activity of commonly used antibiotics under standard in vitro testing conditions with activity in conditions mimicking those found in vivo. Methods Two Bcc strains were grown alone and with six different antibiotics (minocycline, ceftazidime, meropenem, tobramycin, levofloxacin, trimethoprim-sulfamethoxazole) in two different media: standard cation-adjusted Mueller–Hinton broth and an artificial sputum medium designed to simulate the environment in the lungs of people with CF through addition of components including mucin, free DNA and amino acids. Two different starting conditions were used for time–kill assays: a standard ∼5 × 106 cfu/mL inoculum, and a high-density inoculum in which bacteria were grown for 72 hours before addition of antibiotics. Growth detection was performed by colony enumeration and by detection of resazurin reduction. Results There were major discrepancies between standard susceptibility results and activity in our models. Some antibiotics, including ceftazidime, showed minimal activity in all time–kill assays despite low minimal inhibitory concentrations, while others, notably tobramycin, were more active in high-density growth conditions than in standard time–kill assays. Conclusions This work underscores the urgent need to develop more clinically relevant susceptibility testing approaches for Bcc. [ABSTRACT FROM AUTHOR]

Objectives Neisseria gonorrhoeae strains associated with the high-level ceftriaxone-resistant FC428 clone or containing its main resistance determinant, penA allele 60.001, have shown global transmission. In Hangzhou, China, 10% of the isolates were associated with the FC428 clone in 2019. Here, we investigated ceftriaxone resistance and the prevalence of FC428-associated strains in Hangzhou in 2020–22. Methods A total of 209 gonococcal isolates were investigated for antimicrobial susceptibility to ceftriaxone and other antibiotics by agar dilution method. Sequence types and penA alleles were determined by PCR and sequence analysis. Results Resistance to ceftriaxone (MIC > 0.125 mg/L) was observed for 16% (33/209) of the isolates, whereas 6.7% (14/209) of the isolates displayed high-level ceftriaxone resistance (MIC = 1 mg/L). These 14 high-level ceftriaxone-resistant isolates and another isolate displaying an MIC = 0.25 mg/L contained penA allele 60.001, with eight of these isolates, all from 2020 to 2021 belonging to MLST ST1903, the sequence type commonly associated with the original FC428 clone. Importantly, the six penA allele 60.001-containing isolates from 2022 belonged to MLST ST8123, ST7365 and ST7367, which are among the most frequently encountered sequence types found in China. Therefore, these results indicate that endemic lineages in China have acquired penA allele 60.001. Conclusions Here, we report continued transmission of gonococcal strains associated with the FC428 clone or containing penA allele 60.001 in Hangzhou. A major concern for public health is the acquisition of penA allele 60.001 by successful endemic lineages, which might enhance the transmission of this high-level ceftriaxone resistance trait. [ABSTRACT FROM AUTHOR]

Mycobacterium abscessus complex is a group of rapidly growing non-tuberculous mycobacteria (NTM), increasingly emerging as opportunistic pathogens. Current treatment options for these microorganisms are limited and associated with a high rate of treatment failure, toxicity and recurrence. In search of new therapeutic strategies, interest has grown in dual β-lactam (DBL) therapy, as research recently discovered that M. abscessus cell wall synthesis is mainly regulated by two types of enzymes (d , d- transpeptidases and l , d- transpeptidases) differently susceptible to inhibition by distinct β-lactams. In vitro studies testing several DBL combinations have shown synergy in extracellular broth cultures as well as in the intracellular setting: cefoxitin/imipenem, ceftaroline/imipenem, ceftazidime/ceftaroline and ceftazidime/imipenem. The addition of specific β-lactamase inhibitors (BLIs) targeting M. abscessus β-lactamase did not significantly enhance the activity of DBL combinations. However, in vivo data are lacking. We reviewed the literature on DBL/DBL-BLI-based therapies for M. abscessus infections to raise greater attention on this promising yet overlooked treatment option and to guide future preclinical and clinical studies. [ABSTRACT FROM AUTHOR]

Background Procalcitonin (PCT) is a blood marker used to help diagnose bacterial infections and guide antibiotic treatment. PCT testing was widely used/adopted during the COVID-19 pandemic in the UK. Objectives Primary: to measure the difference in length of early (during first 7 days) antibiotic prescribing between patients with COVID-19 who did/did not have baseline PCT testing during the first wave of the pandemic. Secondary: to measure differences in length of hospital/ICU stay, mortality, total days of antibiotic prescribing and resistant bacterial infections between these groups. Methods Multi-centre, retrospective, observational, cohort study using patient-level clinical data from acute hospital Trusts/Health Boards in England/Wales. Inclusion: patients ≥16 years, admitted to participating Trusts/Health Boards and with a confirmed positive COVID-19 test between 1 February 2020 and 30 June 2020. Results Data from 5960 patients were analysed: 1548 (26.0%) had a baseline PCT test and 4412 (74.0%) did not. Using propensity-score matching, baseline PCT testing was associated with an average reduction in early antibiotic prescribing of 0.43 days [95% confidence interval (CI): 0.22–0.64 days, P  < 0.001) and of 0.72 days (95% CI: 0.06–1.38 days, P  = 0.03] in total antibiotic prescribing. Baseline PCT testing was not associated with increased mortality or hospital/ICU length of stay or with the rate of antimicrobial-resistant secondary bacterial infections. Conclusions Baseline PCT testing appears to have been an effective antimicrobial stewardship tool early in the pandemic: it reduced antibiotic prescribing without evidence of harm. Our study highlights the need for embedded, rapid evaluations of infection diagnostics in the National Health Service so that even in challenging circumstances, introduction into clinical practice is supported by evidence for clinical utility. Study registration number ISRCTN66682918. [ABSTRACT FROM AUTHOR]

Background Macrolides are recommended for treating the emerging enteropathogen Arcobacter butzleri ; nonetheless, this bacterium often exhibits highly variable resistance rates, and the mechanisms behind this resistance phenotype remain largely unexplored. Objectives To understand the phenotypic and genotypic consequences associated with the acquisition of erythromycin resistance in A. butzleri , as well as the effects on the fitness of this species. Methods Resistant strains resulting from spontaneous mutations and adaptive laboratory evolution under increasing erythromycin concentrations were examined regarding their cross-resistance and collateral susceptibility profiles. Genetic causes of phenotypic antibiotic resistance were analysed by sequencing and bioinformatics, with functional correlation through ethidium bromide accumulation assays. Growth profiles in the presence and absence of erythromycin, motility and biofilm formation abilities were assessed to detect potential changes in fitness and virulence. Results Clones from spontaneous mutation rate evolution demonstrated decreased susceptibility to erythromycin and other classes of antibiotics, associated with mutations in the transcriptional repressor areR , causing overexpression of the AreABC efflux pump. In turn, WGS analysis of the evolved strain showed additional mutations in the ribosomal proteins L4 and L22 and in the areR gene. Furthermore, the acquisition of macrolide resistance altered A. butzleri virulence and entailed a high biological cost. Conclusions The findings of this study have proved that efflux activity contributes synergistically with mutations in the ribosomal proteins L4 and L22 to A. butzleri 's high-level macrolide resistance. The results further suggest an impact on the bacterial physiology and virulence, with the increased fitness cost justifying the low worldwide prevalence of high-level resistant circulating strains. [ABSTRACT FROM AUTHOR]

This article discusses the recent regulatory restrictions on the use of fluoroquinolones and their impact on treating orthopaedic infections. We focus on the balance between the benefits and risks of fluoroquinolones in scenarios involving severe infections where alternative antibiotics may be less effective. The discussion includes a summary of recent evidence on adverse effects and the implications for clinical practice. [ABSTRACT FROM AUTHOR]

Objectives Pharmacodynamic parameters evaluated under conditions that simulate an infection site volume and microbial load might reveal hidden risks of resistance selection and subsequent treatment failure. The study aimed to investigate the predictive potential of MICs determined at various conditions on the antimicrobial effect and emergence of resistance. Methods We assessed meropenem MICs (microdilution: 0.2 mL, 5 × 105 cfu/mL; macrodilution: 2 mL, 5 × 105 cfu/mL), MICHVs (220 mL, 5 × 105 cfu/mL), MICHIs (0.2 mL, 5 × 107 cfu/mL) and MICHVIs (220 mL, 5 × 107 cfu/mL) for five Klebsiella pneumoniae strains and analysed these values alongside the results of experiments in a dynamic in vitro model. A clinically relevant meropenem dosing regimen was simulated and the starting bacterial inocula were 106 and 108 cfu/mL. Results The effectiveness of meropenem agreed with MICHVs for the 106 cfu/mL inoculum and with MICHIs or MICHVIs for the 108 cfu/mL inoculum. Strains characterized as resistant according to these values grew during meropenem exposure, and resistant mutants were selected. Conclusions Our results suggest that MICHV-based parameters may be suitable for predicting antibacterial effects and the risk of resistance development when the inoculum is 106 cfu/mL, while MICHI- or MICHVI-based parameters are suitable for these purposes when the inoculum is 108 cfu/mL. Also, the correlation between resistance selection and the MICHI-based parameter was as high as one that corresponds with a mutant prevention concentration (MPC)-based parameter; this suggests that the MPC can be replaced by the more easily determined alternative parameter MICHI. [ABSTRACT FROM AUTHOR]

Background Patient-reported penicillin allergy labels (PALs) are associated with adverse patient outcomes and inappropriate antibiotic prescribing. Removal of PALs via direct oral challenge (DOC) is associated with increased penicillin utilization post removal. Objectives To assess the impact of direct delabelling (allergy label removal via medical reconciliation alone) of type A adverse drug reaction (ADR) PALs on inpatient prescribing. Methods From January 2019 to December 2022 at two tertiary hospitals in Melbourne, patients aged ≥18 years with type A ADR PALs, as defined by the validated Antibiotic Allergy Assessment Tool, were offered direct delabelling or single-dose DOC. The primary endpoint was antibiotic use pre- and post-assessment (during index admission and 90 days post assessment). The secondary endpoint was the proportion of patients delabelled in the direct delabelling and DOC cohorts in the electronic medical record at 90 days post assessment. Results Allergy labels (n  = 4108) were assessed for 488 participants, with 490 individual type A ADR PAL assessments included. Three hundred and thirty-seven patients were directly delabelled, 69 underwent DOC and 84 were not delabelled. There was increased use of any penicillin following direct delabelling (OR 19.19, 95% CI 2.48–148.36) and DOC (OR 56.98, 95% CI 6.82–476.19) during the index admission, higher in the DOC group compared with direct delabelling (OR 2.97, 95% CI 1.39–6.37). Relabelling at 90 days was low with no statistically significant difference between direct delabelling (5/337; 1.5%) and DOC (0/69; 0%). Conclusions Both direct delabelling and DOC of type A ADR PALs increased penicillin usage; however, the impact was greatest with DOC. Most patients remain delabelled at 90 days. [ABSTRACT FROM AUTHOR]

In Enterobacteriaceae, susceptibility to cephalosporins and carbapenems is often associated with membrane and enzymatic barrier resistance. For about 20 years, a large number of Klebsiella pneumoniae , Escherichia coli and Enterobacter cloacae presenting ß-lactam resistance have been isolated from medical clinics. In addition, some of the resistant isolates exhibited alterations in the outer membrane porin OmpC-OmpF orthologues, resulting in the complete absence of gene expression, replacement by another porin or mutations affecting channel properties. Interestingly, for mutations reported in OmpC-OmpF orthologues, major changes in pore function were found to be present in the gene encoding for OmpC. The alterations were located in the constriction region of the porin and the resulting amino acid substitutions were found to induce severe restriction of the lumen diameter and/or alteration of the electrostatic field that governs the diffusion of charged molecules. This functional adaptation through porins maintains the entry of solutes necessary for bacterial growth but critically controls the influx of harmful molecules such as β-lactams at a reduced cost. The data recently published show the importance of understanding the underlying parameters affecting the uptake of antibiotics by infectious bacteria. Furthermore, the development of reliable methods to measure the concentration of antibiotics within bacterial cells is key to combat impermeability-resistance mechanisms. [ABSTRACT FROM AUTHOR]

Background Over the years, reports have associated fluoroquinolones (FQ) with seizures. The incidence and whether FQ compared to non-epileptogenic antibiotic are associated with increased risk of seizures has yet to be examined. Methods A retrospective observational study of hospitalized patients treated with FQ (ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin) or macrolides (MA: azithromycin or roxithromycin) between January 2009 and January 2021 in a large tertiary academic medical centre. The outcome was the occurrence of a seizure during treatment. The Naranjo scale was used to assess causality between FQ treatment and seizures. Comparative analysis was conducted using propensity score matching to correct for possible bias due to non-random selection, followed by inverse probability weighting (IPW) to estimate the difference in seizure risk between FQ and MA. Results Overall, 52 722 patients were treated with FQ during a total of 178 982 days. Mean age was 65 (±19) years and 47% were females. Thirty-three patients (0.06%) experienced a seizure, yielding an incidence of 1:5422 treatment days. Causality was deemed probable and possible among 9/33 and 24/33, respectively. The MA group composed of 8522 patients treated during 17 954 treatment days. Mean age was 65 (±21) years, 49% were females. Six (0.07%) patients experienced each a single seizure. IPW estimated OR for seizures among the FQ versus MA group was 1.44 (95%CI 0.59–3.5, P  = 0.42). Discussion The incidence of FQ associated seizures among hospitalized patients is low and the risk did not significantly exceed that under macrolides. Our results provide evidence for clinicians and decision-makers when balancing fluoroquinolones risks and benefits. [ABSTRACT FROM AUTHOR]

Background Antibiotic overuse leads to the emergence of antibiotic resistance that threatens immunocompromised cancer patients. Infections caused by MDR Gram-negative pathogens are difficult to treat and associated with high mortality. Hence, empirical therapy with standard-of-care (SOC) antibiotics could be suboptimal in these vulnerable patients. New antibiotics covering potential resistant pathogens may be considered. Methods We conducted a randomized non-inferiority study comparing safety and efficacy of imipenem/cilastatin/relebactam (IPM/REL), a β-lactam/β-lactamase inhibitor combination, with SOC antibiotics (cefepime, piperacillin/tazobactam or meropenem) in cancer patients with febrile neutropenia. Patients received at least 48 h of IV antibiotics and were assessed at end-of-IV (EOIV) therapy, test of cure (TOC; Days 21–28), and late follow-up (LFU; Days 35–42). Results A total of 100 patients were enrolled (49 IPM/REL and 50 SOC). Demographics and rates of documented microbiological infections were similar in both groups. In the SOC arm, 86% of antibiotics consisted of cefepime. Patients on IPM/REL had a higher favourable clinical response at EOIV than those on SOC (90% versus 74%; P  = 0.042); however, responses were similar at TOC and LFU. Microbiological eradication was comparable at all three timepoints. Study drug-related adverse events and adverse events leading to drug discontinuation were similar in both groups, with no study drug-related mortality. Conclusions Our results suggest that compared with SOC antibiotics, predominantly cefepime, IPM/REL for empirical coverage of febrile neutropenia in cancer patients is generally safe and could be associated with a better clinical outcome at EOIV. The current SOC consisting mainly of agents that do not cover for ESBL-producing and carbapenem-resistant Enterobacterales bacteria should be reconsidered. [ABSTRACT FROM AUTHOR]

Background To guide antibiotic stewardship interventions, understanding for what indications antibiotics are used is essential. Methods In rural Burkina Faso, we measured antibiotic dispensing across all healthcare providers. From October 2021 to February 2022, we surveyed patients in Nanoro district, Burkina Faso, following visits to health centres (3), pharmacies (2), informal medicine vendors (5) and inpatients in health centres. We estimated prevalence of antibiotic use and the proportion of Watch group antibiotics by provider type and by clinical presentation, assessing compliance with WHO's AWaRe Antibiotic Book. We estimated per capita antibiotic use by multiplying prevalence of antibiotic use, mean DDD per adult treatment course, and the rate of healthcare visits per 1000 inhabitants per day, estimated from a prior household survey. Results Outpatient antibiotic use was more frequent after health centre visits (54.8%, of which 16.5% Watch, n  = 1249) than after visits to pharmacies (26.2%, 16.3% Watch, n  = 328) and informal medicine vendors (26.9%, 50.0% Watch, n  = 349). The frequency of antibiotic use was highest for bronchitis (79.9% antibiotic use, of which 12.6% Watch), malaria (31.9%, 23.1% Watch), gastroenteritis (76.0%, 31.7% Watch), rhinopharyngitis (40.4%, 8.3% Watch) and undifferentiated fever (77.0%, 44.8% Watch). Compliance with WHO AWaRe guidance could have averted at least 68.4% of all Watch antibiotic use in outpatients at health centres. Community-wide, 2.9 DDD (95% CI 1.9–3.9) were used per 1000 adult inhabitants per day. Conclusions Most Watch antibiotic use at community level or primary care deviated from WHO guidance. Antibiotic stewardship should focus on key clinical presentations and include primary care and self-medication. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (SA) is a leading cause of bloodstream infection. The liver represents the sentinel immune organ for clearance of bloodstream pathogens and eradication of intracellular SA from liver-resident macrophages (Kupffer cells, KCs) eliminates the likely pathogenic reservoir that contributes to persistent bacteraemia. Objectives We assessed antimicrobial activity at phagolysosome-mimicking pH, intracellular penetration, and SA eradication within KCs in vitro for clinically prescribed antistaphylococcal agents alone or in combination: vancomycin, daptomycin, ceftaroline, ceftobiprole, oritavancin, oxacillin, cefazolin; rifampin and fosfomycin. Methods pH-adjusted broth microdilution assays, intracellular bioaccumulation assays, and intracellular killing assays against clinical bloodstream isolates were performed using a murine KC line with study agents. Results Rifampin and β-lactams exhibited enhanced activity [2- to 16-fold minimum inhibitory concentrations (MIC) decrease] at phagolysosomal pH while vancomycin, oritavancin, daptomycin and fosfomycin demonstrated reduced activity (2- to 32-fold MIC increase in order of least to greatest potency reduction). All agents evaluated had poor to modest intracellular to extracellular concentration ratios (0.024–7.8), with exceptions of rifampin and oritavancin (intracellular to extracellular ratios of 17.4 and 78.2, respectively). Finally, we showed that the first-line treatment for SA bacteraemia (SAB), vancomycin, performed worse than all other tested antibiotics in eradicating intracellular SA at human C max concentration (0.20 log cfu decrease), while oritavancin performed better than all other agents alone (2.05 versus 1.06–1.36 log cfu decrease). Conclusions Our findings raise concerns about the efficacy of commonly prescribed antibiotics against intracellular SA reservoirs and emphasize the need to consider targeting pathogen eradication from the liver to achieve early control of SAB. [ABSTRACT FROM AUTHOR]

Antimicrobial susceptibility testing (AST) is a core function of the clinical microbiology laboratory and is critical to the management of patients with bloodstream infections (BSIs) to facilitate optimal antibiotic therapy selection. Recent technological advances have resulted in several rapid methods for determining susceptibility direct from positive blood culture that can provide turnaround times in under 8 h, which is considerably shorter than conventional culture-based methods. As diagnostic results do not directly produce a medical intervention, actionability is a primary determinant of the effect these technologies have on antibiotic use and ultimately patient outcomes. Randomized controlled trials and observational studies consistently show that rapid AST significantly reduces time to results and improves antimicrobial therapy for patients with BSI across various methods, patient populations and organisms. To date, the clinical impact of rapid AST has been demonstrated in some observational studies, but randomized controlled trials have not been sufficiently powered to validate many of these findings. This article reviews various metrics that have been described in the literature to measure the impact of rapid AST on actionability, antibiotic exposure and patient outcomes, as well as highlighting how implementation and workflow processes can affect these metrics. [ABSTRACT FROM AUTHOR]

Background Bloodstream infections are linked to heightened morbidity and mortality rates. The consequences of delayed antibiotic treatment can be detrimental. Effective management of bacteraemia hinges on rapid antimicrobial susceptibility testing. Objectives This retrospective study examined the influence of the VITEK® REVEAL™ Rapid AST system on positive blood culture (PBC) management in a French tertiary hospital. Materials and methods Between November 2021 and March 2022, 79 Gram-negative monomicrobial PBC cases underwent testing with both VITEK®REVEAL™ and VITEK®2 systems. Results The study found that VITEK®REVEAL™ yielded better results than the standard of care, significantly shortening the time to result (7.0 h compared to 9.6 h) as well as the turnaround time (15 h compared to 31.1 h) when applied for all isolates. Conclusions This study implies that the use of VITEK®REVEAL™ enables swift adaptations of antibiotic treatment strategies. By considerably minimizing the turnaround time, healthcare professionals can promptly make necessary adjustments to therapeutic regimens. Notably, these findings underscore the potential of VITEK®REVEAL™ in expediting appropriate antibiotic interventions, even in less ideal conditions. Further studies in varied laboratory contexts are required to validate these encouraging outcomes. [ABSTRACT FROM AUTHOR]

Objectives To outline the procedural implementation and optimization of rapid diagnostic test (RDT) results for bloodstream infections (BSIs) and to evaluate the combination of RDTs with real-time antimicrobial stewardship team (AST) support plus clinical surveillance platform (CSP) software on time to appropriate therapy in BSIs at a single health system. Methods Blood culture reporting and communication were reported for four time periods: (i) a pre-BCID [BioFire® FilmArray® Blood Culture Identification (BCID) Panel] implementation period that consisted of literature review and blood culture notification procedure revision; (ii) a BCID implementation period that consisted of BCID implementation, real-time results notification via CSP, and creation of a treatment algorithm; (iii) a post-BCID implementation period; and (iv) a BCID2 implementation period. Time to appropriate therapy metrics was reported for the BCID2 time period. Results The mean time from BCID2 result to administration of effective antibiotics was 1.2 h (range 0–7.9 h) and time to optimal therapy was 7.6 h (range 0–113.8 h) during the BCID2 Panel implementation period. When comparing time to optimal antibiotic administration among patients growing ceftriaxone-resistant Enterobacterales, the BCID2 Panel group (mean 2.8 h) was significantly faster than the post-BCID Panel group (17.7 h; P  = 0.0041). Conclusions Challenges exist in communicating results to the appropriate personnel on the healthcare team who have the knowledge to act on these data and prescribe targeted therapy against the pathogen(s) identified. In this report, we outline the procedures for telephonic communication and CSP support that were implemented at our health system to distribute RDT data to individuals capable of assessing results, enabling timely optimization of antimicrobial therapy. [ABSTRACT FROM AUTHOR]

Background Bacterial RNA polymerase (RNAP) is a promising target for antimicrobial chemotherapy due to its indispensable role in bacterial growth and survival. Among its components, only the rpoB gene encoding the β-subunit is known for its association with rifampicin resistance. We recently identified a variant of the RNAP α-subunit (RpoA) in Pseudomonas aeruginosa, conferring heightened bacterial susceptibility to antimicrobials. This susceptibility was attributed to the specific down-regulation of the MexEF-OprN efflux pump. Objectives We asked how to distinguish antimicrobial-susceptible variant strains from clinical isolates. Methods In this study, we identified various P. aeruginosa RpoA variants from clinical sources. Using the sequence alignment of different bacterial RpoA species, we computed the positional conservation of substitutions in RpoA variants using Shannon Entropy. Results Our findings revealed that selective RpoA variant strains exhibited distinct profiles of antimicrobial susceptibility. Notably, RpoA variant strains, containing single-substitutions in the C-terminal domain (α-CTD) but not the N-terminal domain (α-NTD), showed attenuated MexEF-OprN expression and increased susceptibility to MexEF-OprN-specific antibiotics. Furthermore, we observed a close correlation between the susceptibility of these α-CTD RpoA variant strains to antibiotics and the conservation degrees of positional substitutions. Conclusions Our findings demonstrate the prevalence of antimicrobial-susceptible RpoA variant strains among P. aeruginosa clinical isolates. The identified positional conservation pattern in our study facilitates the rapid classification of RpoA variant strains with distinct drug resistances. Given the high conservation of RNAP across bacterial species, our findings open a new therapeutic perspective for precisely and efficiently combating pathogenic RpoA variant strains with specific antimicrobials. [ABSTRACT FROM AUTHOR]

Background MRSA is a major contributor to AMR-related deaths. The WHO's global action plan emphasizes a One Health approach, acknowledging the connection between humans and their companion animals. It is agreed on that comprehensive AMR surveillance is needed. Objectives This study provides a large-scale overview of MRSA occurrence in cats and dogs in Germany, serving as a foundation for continuous surveillance. Methods The study analysed all results of canine and feline bacterial diagnostic samples from a large laboratory, encompassing samples received from veterinary practices between January 2019 and December 2021. MRSA prevalence between host species, sample types and geographical distribution were compared. Additionally, data were contrasted with human MRSA surveillance data from Germany. Results Samples originated from 3491 German veterinary practices, representing 33.1% of practices and clinics nationally. Bacterial examination results from 175 171 samples were analysed, identifying S. aureus in 5526 of these samples (3.2% isolation rate). S. aureus in clinical samples was more prevalent in cats (5.6%) than dogs (2.0%). Methicillin resistance was found in 17.8% of S. aureus samples and was higher in dogs (20.4%, 95%CI 18.9–22.0) than cats (15.6%, 95%CI 14.3–17.0). The highest MRSA prevalence was found in canine wound samples (32%), compared to skin/soft tissue, respiratory tract and other (<23% respectively). Conclusion The study reveals a 17.8% MRSA prevalence, which is higher than the human outpatient MRSA prevalence (5.4%). Restriction and regulation of veterinary antibiotic use should be validated with AMR surveillance. Our study shows that this is feasible in companion animals with significant coverage. [ABSTRACT FROM AUTHOR]

Background The COVID-19 pandemic has resulted in great incertitude and overwhelming changes in healthcare that have had a direct impact on antibiotic prescription. However, the influence of this pandemic on antibiotic consumption in patients undergoing surgery has not yet been analysed. The goal of this study was to analyse antimicrobial consumption and prescription in the same period of 2019 (pre-COVID-19), 2020 (beginning of the COVID-19 pandemic) and 2021 (established COVID-19) according to the DDD system in surgical patients at a tertiary-level hospital. Methods A prospectively maintained database was analysed. All patients who underwent elective or emergency gastrointestinal surgery during the same period (2019, 2020 and 2021) were included. Those who received at least 1 of the 10 most frequently prescribed antimicrobials during those periods were analysed. Results A total of 2975 patients were included in this study. In 2020, the number of procedures performed decreased significantly (653 versus 1154 and 1168 in 2020 versus 2019 and 2021, respectively; P  = 0.005). Of all patients who underwent surgery during these periods, 45.08% received at least one of the antimicrobials studied (45.8% in 2020 versus 22.9% and 22.97% in 2019 and 2021, respectively; P  = 0.005). Of these, 22.97% of the patients received a combination of these antimicrobials, with ceftriaxone/metronidazole being the most frequent. Hepato-Pancreato-Biliary and Liver Transplant, Emergency Surgery and Colorectal Surgery units had higher antibiotic consumption. Conclusions The COVID-19 pandemic has resulted in a significant decrease in surgical activity and higher post-operative antimicrobial prescription compared with previous and subsequent years. [ABSTRACT FROM AUTHOR]

Objectives The measurement of VOCs release in the headspace of a bacterial culture represents a new approach to rapidly assess antimicrobial susceptibility. Herein, we evaluated the diagnostic performance of the VITEK® REVEAL™ system directly from a collection of Gram-negative positive blood cultures. Materials and methods One hundred and twenty-eight positive blood cultures were included in the analysis (Enterobacterales, n  = 95; Pseudomonas aeruginosa , n  = 21; Acinetobacter baumannii complex, n  = 12). Samples were processed using VITEK® REVEAL™ according to the manufacturer's recommendations, and MICs of 22 antimicrobials were compared with those obtained using reference methods. Categorical agreement (CA), essential agreement (EA) and categorical errors were calculated. Results Overall, 2220 strain/antibiotic pair combinations were analysed. Of these, most were classified as resistant by reference antimicrobial susceptibility testing (1091/2220; 48.7%). The overall CA and EA were 97.6% and 97.7%, respectively. CA ranged from 97.5% in Enterobacterales to 97.9% in both P. aeruginosa and A. baumannii complex. The overall number of categorical discrepancies were: 18 very major errors (1.6%), 13 major errors (1.2%) and 22 minor errors (2.4%). EA ranged from 95.2% in P. aeruginosa to 98.1% in Enterobacterales. Screening test for ESBL phenotype was positive, indeterminate and negative in 13.7%, 32.6% and 27.4% of Enterobacterales isolates tested by both VITEK® REVEAL™ and the reference method, showing 100% CA. Conclusions VITEK® REVEAL™ represents a reliable tool to obtain antimicrobial susceptibility results of the main Gram-negative species directly from positive blood cultures with time to results of less than 8 h. [ABSTRACT FROM AUTHOR]

Objectives Temocillin, a carbapenem-sparing β-lactam antibiotic, is commonly used at the standard 4 g/day dosage for treating complicated urinary tract infections (cUTIs). However, pharmacokinetic/pharmacodynamic (PK/PD) data supporting this regimen is limited. This study evaluated the plasma pharmacokinetics (PK) and PTA of temocillin in non-critically ill cUTI patients with varying degrees of renal insufficiency (RI). Methods In this single-centre clinical study, 22 cUTI patients received a fixed 4 g/day (2 g q12h, intravenously) temocillin dose, irrespective of renal function (no RI: n  = 5, mild RI: n  = 8, moderate RI: n  = 9). Plasma samples were collected post-dosing for LC-MS analysis of total and unbound temocillin levels. Monte Carlo simulations were performed based on the established PK/PD target of ≥35% f T > MIC (minimal inhibitory concentration). Results Among patients, the highest plasma drug exposure and PK/PD target attainment were observed in those with moderate RI (median AUC0–12h = 1143 h.mg/L and % f T > MIC = 68%), followed by mild RI patients (median AUC0–12h = 918 h.mg/L and % f T > MIC = 34%), and the lowest in those with healthy kidney function (median AUC0–12h = 692 h.mg/L and % f T > MIC = 26%). Simulations indicated that the 4 g/day temocillin dose achieves 90% PTA only for glomerular filtration rate < 60 mL/min and MIC ≤ 8 mg/L. Conclusion The standard temocillin dose may need to be increased from 4 to 6 g/day to treat non-critically ill cUTI patients, in line with recent EUCAST recommendations. For patients with moderate RI, who experience higher exposure due to reduced renal drug clearance, 4 g/day temocillin remains appropriate. [ABSTRACT FROM AUTHOR]

Background β-lactam antibiotics, which inhibit penicillin-binding protein 3 (PBP3) that is required for cell division, play a key role in treating P. aeruginosa infections. Some sequence variations in PBP3 have been associated with β-lactam resistance but the effects of variations on antibiotic susceptibility and on cell division have not been quantified. Antibiotic efflux can also reduce susceptibility. Objectives To quantify the effects of PBP3 variations on β-lactam susceptibility and cell morphology in P. aeruginosa. Methods Nineteen PBP3 variants were expressed from a plasmid in the reference strain P. aeruginosa PAO1 and genome engineering was used to construct five mutants expressing PBP3 variants from the chromosome. The effects of the variations on β-lactam minimum inhibitory concentration (MIC) and cell morphology were measured. Results Some PBP3 variations reduced susceptibility to a variety of β-lactam antibiotics including meropenem, ceftazidime, cefepime and ticarcillin with different variations affecting different antibiotics. None of the tested variations reduced susceptibility to imipenem or piperacillin. Antibiotic susceptibility was further reduced when PBP3 variants were expressed in mutant bacteria overexpressing the MexAB-OprM efflux pump, with some variations conferring clinical levels of resistance. Some PBP3 variations, and sub-MIC levels of β-lactams, reduced bacterial growth rates and inhibited cell division, causing elongated cells. Conclusions PBP3 variations in P. aeruginosa can increase the MIC of multiple β-lactam antibiotics, although not imipenem or piperacillin. PBP3 variations, or the presence of sub-lethal levels of β-lactams, result in elongated cells indicating that variations reduce the activity of PBP3 and may reduce bacterial fitness. [ABSTRACT FROM AUTHOR]

Background Fosfomycin is gaining increasing attention for its activity against MDR or XDR pathogens. Currently, IV fosfomycin is a potential option for treating various infections, including urinary tract infections, pneumonia and skin infections when first-line treatments fail. Objectives To evaluate the demographic, clinical, microbiological and treatment modality of children received IV fosfomycin to treat infections caused by MDR pathogens since there are few data on the use of fosfomycin in children. Methods This study was conducted retrospectively with patients under 18 years of age who were treated with IV fosfomycin for at least 72 h due to infections caused by MDR pathogens between January 2019 and October 2023 at Marmara University Pendik Training and Research Hospital, İstanbul, Türkiye. Data on demographic and clinical features, microbiological findings, treatment modalities and side effects were evaluated. Results Twenty-five children, for a total of 32 cases of infection episodes, with a mean age of 11.4 ±   3.92 years who received IV fosfomycin were included. The most frequent comorbidity was chronic pulmonary diseases, and the most common infection needed for IV fosfomycin was MDR Pseudomonas aeruginosa pneumonia. In all cases, fosfomycin was administered in combination with other antibiotics, mainly meropenem–colistin (68.7%) or meropenem (15.6%). Twenty-two (71.9%) cases had favourable clinical responses at the end of therapy. Conclusions Our results suggest that IV fosfomycin may be an effective treatment option for MDR pathogens in the paediatric population. Nevertheless, careful stewardship is necessary to maintain efficacy and reduce antimicrobial resistance selection risk. [ABSTRACT FROM AUTHOR]

Background Clostridioides difficile infection (CDI), a leading cause of nosocomial deaths, is a microbiota-mediated disease. As such, the use of broader spectrum antibiotics, such as vancomycin and metronidazole, can prime the gastrointestinal tract to become more prone to CDI recurrences. Fidaxomicin, a narrow-spectrum antibiotic, has been demonstrated to be superior in preventing recurrence and in preserving the intestinal microbiota; however, widespread employment worldwide has been hindered due to high acquisition costs. Objectives To integrate the currently available guidelines on the management of CDI and to shed light on the timeliest employment of fidaxomicin. Methods An expert panel was gathered to obtain consensus using Delphi methodology on a series of statements regarding the management of CDI and on appropriate antibiotic use. Results Consensus was reached on 21 of the 25 statements addressing the management of CDI. Conclusions Delphi methodology was used to achieve consensus on the management of CDI, on the identification of patients at risk of recurrences or severe infection, and on the most appropriate use of fidaxomicin, with the final aim of fostering clinical practice application of treatment algorithms proposed by previous guidelines, in absolute synergy. It could be an important tool to promote more appropriate and cost-effective CDI treatments in European settings with limited resources, like Italy. [ABSTRACT FROM AUTHOR]

Objectives The quality of amoxicillin capsules, ceftriaxone for injection, and ciprofloxacin tablets was evaluated to determine whether there is any difference in quality when comparing the country of origin. This was undertaken because it has been claimed that antibiotics manufactured in Europe are of superior quality to those originating from Africa or Asia. Methods Samples of amoxicillin capsules, ceftriaxone for injection, and ciprofloxacin tablets were collected from three randomly selected wholesale pharmacies in each city, namely Arusha, Dar es Salaam and Mwanza, Tanzania. The collected samples of collected brands were subjected to quality control testing as per their respective pharmacopoeial monographs. Amoxil 250 mg capsules (Glaxo Wellcome, Mayenne, France), Rocephin (Roche, Switzerland) and Cipro-Denk 500 (Allphamed Pharbil Arzneimittel GmbH, Gottingen, Germany) were used as reference brands for the other generic brands of amoxicillin, ceftriaxone and ciprofloxacin, respectively. Results A total of 31 brands (10 different brands of amoxicillin capsules, 9 of ceftriaxone sodium injections, and 12 of ciprofloxacin tablets) were collected from the targeted regions and subjected to quality control testing. All samples of collected brands complied with the requirements of their respective pharmacopoeial monographs. Conclusions There was no significant difference in quality between brands of amoxicillin capsules, ceftriaxone for injection, and ciprofloxacin tablets manufactured in Africa and Asia against those manufactured in Europe in terms of compliance with the respective pharmacopoeial monographs. [ABSTRACT FROM AUTHOR]

Background A small proportion of Escherichia coli and Klebsiella pneumoniae demonstrate in vitro non-susceptibility to piperacillin/tazobactam but retain susceptibility to ceftriaxone. Uncertainty remains regarding how best to treat these isolates. Objectives We sought to compare clinical outcomes between patients with piperacillin/tazobactam-non-susceptible but ceftriaxone-susceptible E. coli or K. pneumoniae bloodstream infection receiving definitive therapy with ceftriaxone versus an alternative effective antibiotic. Methods We retrospectively identified patients with a positive blood culture for piperacillin/tazobactam-non-susceptible but ceftriaxone-susceptible E. coli or K. pneumoniae between 1 January 2013 and 31 December 2022. Patients were divided into one of two definitive treatment groups: ceftriaxone or alternative effective antibiotic. Our primary outcome was a composite of 90 day all-cause mortality, hospital readmission, or recurrence of infection. We used Cox proportional hazards models to compare time with the composite outcome between groups. Results Sixty-two patients were included in our analysis. Overall, median age was 63 years (IQR 49.5–71.0), the most common source of infection was intra-abdominal (25/62; 40.3%) and the median total duration of therapy was 12.0 days (IQR 9.0–16.8). A total of 9/22 (40.9%) patients in the ceftriaxone treatment group and 18/40 (45.0%) patients in the alternative effective antibiotic group met the composite endpoint. In an adjusted time-to-event analysis, there was no difference in the composite endpoint between groups (HR 0.67, 95% CI 0.30–1.50). The adjusted Bayesian posterior probability that the HR was less than or equal to 1 (i.e. ceftriaxone is as good or better than alternative therapy) was 85%. Conclusions These findings suggest that ceftriaxone can be used to effectively treat bloodstream infections with E. coli or K. pneumoniae that are non-susceptible to piperacillin/tazobactam but susceptible to ceftriaxone. [ABSTRACT FROM AUTHOR]

Background The increase in antibiotic resistance is a major public health issue. The development of rapid antimicrobial susceptibility testing (AST) methods is becoming a priority to ensure early and appropriate antibiotic therapy. Objectives To evaluate sedimentation field-flow fractionation (SdFFF) as a method for performing AST in less than 3 h. Methods SdFFF is based on the detection of early biophysical changes in bacteria, using a chromatographic-type technology. One hundred clinical Escherichia coli strains were studied. A calibrated bacterial suspension was incubated for 2 h at 37°C in the absence (untreated) or presence (treated) of five antibiotics used at EUCAST breakpoint concentrations. Bacterial suspensions were then injected into the SdFFF machine. For each E. coli isolate, retention times and elution profiles of antibiotic-treated bacteria were compared with retention times and elution profiles of untreated bacteria. Algorithms comparing retention times and elution profiles were used to determine if the strain was susceptible or resistant. Performance evaluation was done according to CLSI and the ISO standard 20776-2:2021 with broth microdilution used as the reference method. Results AST results from SdFFF were obtained in less than 3 h. SdFFF showed high categorical agreement (99.8%), sensitivity (99.5%) and specificity (100.0%) with broth microdilution. Results for each antimicrobial were also in agreement with the ISO 20776-2 recommendations, with sensitivity and specificity of ≥95.0%. Conclusions This study showed that SdFFF can be used as a rapid, accurate and reliable phenotypic AST method with a turnaround time of less than 3 h. [ABSTRACT FROM AUTHOR]

Introduction FebriDx® is a CE-marked, single-use point-of-care test with markers for bacterial [C-reactive protein (CRP)] and viral [myxovirus resistance protein A (MxA)] infection, using finger-prick blood samples. Results are available after 10–12 min. We explored the usability and potential impact of FebriDx® in reducing antibiotic prescriptions for lower respiratory tract infection (LRTI) in primary care, and the feasibility of conducting a randomized controlled trial (RCT). Methods Patients (aged ≥1 year) with LRTI deemed likely to receive antibiotic prescription were recruited at nine general practices and underwent FebriDx® testing. Data collection included FebriDx® results, antibiotic prescribing plan (before and after testing) and re-consultation rates. Staff completed System Usability Scale questionnaires. Results From 31 January 2023 to 9 June 2023, 162 participants participated (median age 57 years), with a median symptom duration of 7 days (IQR 5–14). A valid FebriDx® result was obtained in 97% (157/162). Of 155 patients with available results, 103 (66%) had no detectable CRP or MxA, 28 (18%) had CRP only, 5 (3%) had MxA only, and 19 (12%) had both CRP and MxA. The clinicians' stated management plan was to prescribe antibiotics for 86% (134/155) before testing and 45% (69/155) after testing, meaning a 41% (95% CI: 31%, 51%) difference after testing, without evidence of increased re-consultation rates. Ease-of-use questionnaires showed 'good' user-friendliness. Conclusions Use of FebriDx® to guide antibiotic prescribing for LRTI in primary care was associated with a substantial reduction in prescribing intentions. These results support a fully powered RCT to confirm its impact and safety. [ABSTRACT FROM AUTHOR]

Objectives To assess the effectiveness of shortened regimens of vancomycin or fidaxomicin in the treatment of Clostridioides difficile infection (CDI). Methods Adult patients with CDI hospitalized from January 2022 to May 2023 were included in this observational study. In patients with CDI treated with vancomycin or fidaxomicin, antibiotic treatment was discontinued after either 5 or 7 days of vancomycin or 5 days of fidaxomicin if there was a clinical response and improvement in laboratory parameters. The control cohort was treated with the standard 10 day regimen of either vancomycin or fidaxomicin. The follow-up was 60 days. Causative C. difficile strains were characterized by ribotyping and toxin gene detection when available. Results Twenty-five patients (median age 76 years) received shortened treatment with vancomycin (n  = 21), or fidaxomicin (n  = 4). Five cases fulfilled the criteria for severe CDI. Twenty-three patients completed follow-up; two died from causes other than CDI, and two developed recurrent CDI (8.0%). Ribotypes (RTs) 001 and 014 were the most prevalent with 20% each. In two C. difficile isolates, binary toxin genes were detected (RTs 078 and 023). In the control group of 22 patients recurrent CDI developed in 5 patients (22.7%). No statistically significant differences were found between the groups. Conclusions Shortened treatment regimens for CDI with vancomycin and fidaxomicin were shown to be effective in our cohort of patients compared with 10 days of treatment. The recurrence rate was lower in the study group. A larger, prospective, double-blind, randomized, multicentre study is needed to support our findings. [ABSTRACT FROM AUTHOR]

Background Riemerella anatipestifer encodes an iron acquisition system, but whether it encodes the iron efflux pump and its role in antibiotic resistance are largely unknown. Objectives To screen and identify an iron efflux gene in R. anatipestifer and determine whether and how the iron efflux gene is involved in antibiotic resistance. Methods In this study, gene knockout, streptonigrin susceptibility assay and inductively coupled plasma mass spectrometry were used to screen for the iron efflux gene ietA. The MIC measurements, scanning electron microscopy and reactive oxygen species (ROS) detection were used to verify the role of IetA in aztreonam resistance and its mechanism. Mortality and colonization assay were used to investigate the role of IetA in virulence. Results The deletion mutant Δ ietA showed heightened susceptibility to streptonigrin, and prominent intracellular iron accumulation was observed in Δ fur Δ ietA under excess iron conditions. Additionally, Δ ietA exhibited increased sensitivity to H2O2-produced oxidative stress. Under aerobic conditions with abundant iron, Δ ietA displayed increased susceptibility to the β-lactam antibiotic aztreonam due to heightened ROS production. However, the killing efficacy of aztreonam was diminished in both WT and Δ ietA under anaerobic or iron restriction conditions. Further experiments demonstrated that the efficiency of aztreonam against Δ ietA was dependent on respiratory complexes Ⅰ and Ⅱ. Finally, in a duckling model, Δ ietA had reduced virulence compared with the WT. Conclusion Iron efflux is critical to alleviate oxidative stress damage and β-lactam aztreonam killing in R. anatipestifer , which is linked by cellular respiration. [ABSTRACT FROM AUTHOR]

Background It is crucial to understand the trends in paediatric antibiotic prescribing and serious and nonserious infections to improve antibiotic prescribing practices for children in ambulatory care. Objectives Assessing trends in paediatric antibiotic prescribing and infection incidence in general practice from 2002 to 2022. Methods In this retrospective cohort study using INTEGO network data from 162 507 patients in Flanders (Belgium), we calculated antibiotic prescribing rates and proportions alongside incidence rates of serious and nonserious infections, stratified by age (0–1, 2–6, 7–12 years) and municipality. We performed autoregressive moving average time-series analyses and seasonality analyses. Results From 2002 to 2022, antibiotic prescribing rate decreased significantly: 584/1000 person-years (PY) (95% CI 571–597) to 484/1000PY (95% CI 478–491); so did antibiotic overall prescribing proportion: 46.3% (95% CI 45.1–47.6) to 23.3% (95% CI 22.9–23.7) (59.3% amoxicillin and 17.8% broad spectrum). Prescribing proportions dropped significantly for nonserious (45.6% to 20.9%) and increased for serious infections (64.1% to 69.8%). Proportions significantly dropped for acute suppurative otitis media (74.7% to 64.1%), upper respiratory tract infections (44.9% to 16.6%), bronchitis/bronchiolitis (73.6% to 44.1%) and acute tonsillopharyngitis (59.5% to 21.7%), while significantly increasing for pneumonia (65.2% to 80.2%). Nonserious and serious infection incidence rates increased from 785/1000PY and 34.2/1000PY to 1223/1000PY and 64.1/1000PY, respectively. Blood and CRP testing proportions increased significantly. Conclusions Antibiotic prescribing in general practice for children declined from 2002 to 2022. Further targeted antibiotic stewardship initiatives are needed to reduce the use of broad-spectrum antibiotics and antibiotic prescribing for conditions such as otitis media and bronchitis/bronchiolitis. [ABSTRACT FROM AUTHOR]

Objectives To identify and assess the effectiveness of national antibiotic optimization interventions in primary and secondary care in England (2013–2022). Methods A systematic scoping review was conducted. Literature databases (Embase and Medline) were used to identify interventions and evaluations. Reports included the UK AMR Strategy (2013–2018), National Action Plan (2019–2024) and English Surveillance Programme for Antimicrobial Utilisation and Resistance (ESPAUR) reports (2014–2022). The design, focus and quality of evaluations and the interventions' effectiveness were extracted. Findings Four hundred and seventy-seven peer-reviewed studies and 13 reports were screened. One hundred and three studies were included for review, identifying 109 interventions in eight categories: policy and commissioning (n  = 9); classifications (n  = 1); guidance and toolkits (n  = 22); monitoring and feedback (n  = 17); professional engagement and training (n  = 19); prescriber tools (n  = 12); public awareness (n  = 17); workforce and governance (n  = 12). Most interventions lack high-quality effectiveness evidence. Evaluations mainly focused on clinical, microbiological or antibiotic use outcomes, or intervention implementation, often assessing how interventions were perceived to affect behaviour. Only 16 interventions had studies that quantified effects on prescribing, of which six reported reductions. The largest reduction was reported with structural-level interventions and attributed to a policy and commissioning intervention (primary care financial incentives). Behavioural interventions (guidance and toolkits) reported the greatest impact in hospitals. Conclusions Many interventions have targeted antibiotic use, each pulling different levers across the health system simultaneously. On the basis of these studies, structural-level interventions may have the greatest impact. Collectively, the combination of interventions may explain England's decline in prescribing but direct evidence of causality is unavailable. [ABSTRACT FROM AUTHOR]

Background Antibiotic exposure increases antimicrobial resistance and has also been associated with long-term harms, including allergies, inflammatory diseases and weight gain. We assessed antibiotic exposure in the first 2 years of life in Australian children, the factors influencing this and its appropriateness. Methods Data from 1201 participants in the MIS BAIR randomized controlled trial were used. Multivariable logistic regression was used to identify factors associated with antibiotic exposure. Results At 1 and 2 years of age, exposure to at least one course of antibiotics was 43% and 67%, with the highest first antibiotic prescription rate between 9 and 18 months. Amoxicillin was the most frequently used antibiotic (59%), followed by cefalexin (7%). The most common diagnoses for which antibiotics were prescribed were respiratory tract infections from 0 to 6 months of age and otitis media from 6 to 12 months. Factors associated with antibiotic exposure from 0 to 12 months of age were delivery by Caesarean section (adjusted odd-ratio (aOR) 1.5, 95%CI 1.1–1.9), birth in winter (aOR 1.7, 95%CI 1.2–2.4), maternal antibiotic exposure during the last trimester of pregnancy (aOR 1.6, 95%CI 1.1–2.3), cessation of breastfeeding by 6 months of age (aOR 1.5, 95%CI 1.1–2.0) and day-care attendance (aOR 1.4, 95%CI 1.1–1.8). Based on parent-reported questionnaires, 27% of infants were treated in the first year of life for conditions unlikely to need antibiotic treatment. Conclusion At least two-thirds of children were prescribed antibiotics in the first 2 years of life, and more than a quarter of these exposures may have been unnecessary. [ABSTRACT FROM AUTHOR]

Background Antimicrobial resistance (AMR) is a major threat to global health. By 2050, it is forecast that AMR will cause 10 million deaths and cost 100 trillion USD annually. Point-of-care tests (POCTs) may represent a cost-effective approach to reduce AMR. Objectives We systematically reviewed which POCTs addressing AMR have undergone economic evaluation in primary and secondary healthcare globally, how these POCTs have been economically evaluated, and which are cost-effective in reducing antimicrobial prescribing or the burden of AMR. Clinical cost-effectiveness was additionally addressed. Methods This systematic review, accordant with PRISMA guidelines, was pre-registered on PROSPERO (CRD42022315192). MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched from 2000 to 2023 for relevant publications. Quality assessment was performed using the Consensus of Health Economic Criteria. Results The search strategy identified 1421 studies, of which 20 met the inclusion criteria. The most common POCTs assessed were for respiratory infections (n  = 10), STIs (n  = 3), and febrile patients in low- and middle-income countries (n  = 3). All studies assessed costs from a healthcare provider perspective; five additionally considered the societal cost of AMR. Eighteen studies identified POCT strategies that reduced antimicrobial prescribing. Of these, 10 identified POCTs that would be considered cost-effective at a willingness-to-pay (WTP) threshold of £33.80 per antibiotic prescription avoided. Most POCT strategies improved clinical outcomes (n  = 14); the remainder were clinically neutral. Conclusions There is evidence that some POCTs are cost-effective in reducing antimicrobial prescribing, with potential concomitant clinical benefits. Such interventions—especially CRP POCTs in both high- and low-income settings—merit further, large-scale clinical evaluation. [ABSTRACT FROM AUTHOR]

Objectives This study aims to elucidate the genomic dynamics driving the emergence of antimicrobial resistance (AMR), with a specific focus on the interplay between AMR and antimicrobial usage. Methods We conducted a comprehensive analysis using a ST239 methicillin-resistant Staphylococcus aureus (MRSA) dataset over a continuous 12-year period from a single hospital. Genomic analyses were performed tracking the changes in MRSA populations, particularly the emergence of reduced vancomycin susceptibility, and assessing the impact of glycopeptide use on these emergence events. Results Our findings reveal a significant correlation between hospital glycopeptide usage and the selection of MRSA strains with reduced vancomycin susceptibility. Genomic analyses provided insights into the molecular mechanisms driving resistance emergence, including the slowing of the molecular clock rate in response to heightened antimicrobial consumption. Conclusions In conclusion, this study the highlights the complex dynamics between AMR and antimicrobial use at the hospital level. The observed correlation between antimicrobial consumption and the development of less susceptible MRSA strains underscores the importance of antimicrobial stewardship programmes and the establishment of optimal consumption thresholds for mitigating AMR effectively. [ABSTRACT FROM AUTHOR]

Introduction Studies may underestimate the impact of antibiotics on bacterial resistance when correlating hospital antibiotic use with resistance rates (RRs) that exclude duplicate cultures as duplicates usually include more resistant isolates. Comparing correlations between antibiotic consumption and RRs resulting from different strategies for excluding duplicates could help explore how their exclusion affects such correlations. Methods We obtained antibiotics consumption and Pseudomonas aeruginosa susceptibility data from 2017 to 2021 for seven antibiotics and for carbapenems as a group in a university hospital. We calculated RRs using seven different time criteria for excluding duplicates. We assessed the correlations of antibiotic consumption to the same-year and next-year RR rates for the three most distinct rates. Results Duplicate cultures represented 53.45% of total cultures. RRs were higher when duplicates were included. We compared RRs resulting from excluding all duplicates, excluding duplicates monthly or admitting one culture per day. All antibiotics except meropenem showed a correlation with same-year RRs, either positive or negative, whereas all antibiotics showed a positive correlation with next-year RRs. For same-year and next-year correlations, the criteria with fewer duplicates (and therefore fewer resistant strains) found more correlations. However, the inclusion of duplicates taken at least 1 month apart found the most correlations. Admitting one culture per day found the fewest correlations. Conclusions Excluding duplicates from RRs affects the correlation of antibiotics consumption with RRs in P. aeruginosa. Including at least some duplicate cultures in correlation analyses, such as those taken 1 month apart, should be considered. [ABSTRACT FROM AUTHOR]

Objective To develop and validate an UPLC–MS/MS assay for simultaneous determination of the total concentration of ceftazidime, ciprofloxacin, flucloxacillin, piperacillin, tazobactam, sulfamethoxazole, N -acetyl sulfamethoxazole and trimethoprim, and the protein-unbound concentration of flucloxacillin, in human plasma to be used for research and clinical practice. Methods Sample pretreatment included protein precipitation with methanol. For the measurement of protein-unbound flucloxacillin, ultrafiltration was performed at physiological temperature. For all compounds, a stable isotopically labelled internal standard was used. Reliability of the results was assessed by participation in an international quality control programme. Results The assay was successfully validated according to the EMA guidelines over a concentration range of 0.5–100 mg/L for ceftazidime, 0.05–10 mg/L for ciprofloxacin, 0.4–125 mg/L for flucloxacillin, 0.2–60 mg/L for piperacillin, 0.15–30 mg/L for tazobactam, 1–200 mg/L for sulfamethoxazole and N -acetyl sulfamethoxazole, 0.05–10 mg/L for trimethoprim and 0.10–50 mg/L for unbound flucloxacillin. For measurement of total concentrations, the within- and between-day accuracy ranged from 90.0% to 109%, and 93.4% to 108%, respectively. Within- and between-day precision (variation coefficients, CVs) ranged from 1.70% to 11.2%, and 0.290% to 5.30%, respectively. For unbound flucloxacillin, within-day accuracy ranged from 103% to 106% and between-day accuracy from 102% to 105%. The within- and between-day CVs ranged from 1.92% to 7.11%. Results of the international quality control programme showed that the assay is reliable. Conclusions The method provided reliable, precise and accurate measurement of seven commonly prescribed antibiotics, including the unbound concentration of flucloxacillin. This method is now routinely applied in research and clinical practice. [ABSTRACT FROM AUTHOR]

Objectives To compare the differences in antibiotic use between COPD and non-COPD residents, and to explore the effect of COPD on antibiotic use. Methods Participants aged 40 years old or over from the Songjiang Adult Cohort were included. Information on prescription and baseline survey was collected based on the health information system. A logit-negative binomial Hurdle model was used to explore correlations between COPD and percentage of antibiotic use and average rate of antibiotic prescribing of different types of antibiotic. Multinomial logistic regression was used to assess the association between COPD and antimicrobial combination therapy and routes of administration. Results A total of 34576 individuals were included and 1594 (4.6%) were COPD patients. During the 6 years' follow-up, the percentage of antibiotic use for COPD patients was 98.4%, which was 7.88 (95%CI: 5.24–11.85) times of that for non-COPD patients after adjusting for potential confounders. The prescribing rate was 3220 prescriptions (95%CI: 3063.6–3385.2) per 1000 person-years for COPD patients, which was 1.96 (95%CI: 1.87–2.06) times of that for non-COPD patients. Other beta-lactam antibacterials, Macrolides, lincosamides and streptogramins, and quinolone antibacterials were the most commonly used types of antibiotic. Except for aminoglycoside antibacterials, both percentage of antibiotic use and rate of antibiotic prescription were increased in COPD patients. COPD patients were more likely to be prescribed a maximum of two antibiotics (OR=1.34, 95%CI: 1.20–1.50); and were more likely to use antibiotics intravenously (OR=2.77, 95%CI: 2.47–3.11). Conclusion COPD patients were more likely to have increased antibiotic use in a large-scale population-based adult cohort, suggesting COPD patients are a high-priority group for the management of antibiotic use in communities. [ABSTRACT FROM AUTHOR]

Objectives An Escherichia coli isolate, WGS1363, showed resistance to piperacillin/tazobactam but susceptibility to cephalosporins and contained a previously unrecognized β-lactamase, CTX-M-255, as the only acquired β-lactamase. CTX-M-255 was identical to CTX-M-27 except for a G239S substitution. Here, we characterize the hydrolytic spectrum of CTX-M-255 and a previously reported β-lactamase, CTX-M-178, also containing a G239S substitution and compare it to their respective parental enzymes, CTX-M-27 and CTX-M-15. Methods All β-lactamase genes were expressed in E. coli TOP10 and MICs to representative β-lactam-antibiotics were determined. Furthermore, bla CTX-M-15,   bla CTX-M-27, bla CTX-M-178 and bla CTX-M-255 with C-terminal His-tag fusions were affinity purified for enzyme kinetic assays determining Michaelis–Menten kinetic parameters against representative β-lactam-antibiotics and IC50s of clavulanate, sulbactam, tazobactam and avibactam. Results TOP10-transformants expressing bla CTX-M-178 and bla CTX-M-255 showed resistance to penicillin/β-lactamase combinations and susceptibility to cephalothin and cefotaxime in contrast to transformants expressing bla CTX-M-15 and bla CTX-M-27. Determination of enzyme kinetic parameters showed that CTX-M-178 and CTX-M-255 both lacked hydrolytic activity against cephalosporins and showed impaired hydrolytic efficiency against penicillin antibiotics compared to their parental enzymes. Both enzymes appeared more active against piperacillin compared to benzylpenicillin and ampicillin. Compared to their parental enzymes, IC50s of β-lactamase-inhibitors were increased more than 1000-fold for CTX-M-178 and CTX-M-255. Conclusions CTX-M-178 and CTX-M-255, both containing a G239S substitution, conferred resistance to piperacillin/tazobactam and may be characterized as inhibitor-resistant CTX-M β-lactamases. Inhibitor resistance was accompanied by loss of activity against cephalosporins and monobactams. These findings add to the necessary knowledge base for predicting antibiotic susceptibility from genotypic data. [ABSTRACT FROM AUTHOR]

Introduction Antimicrobial resistance in Neisseria gonorrhoeae compromises gonorrhoea treatment and rapid antimicrobial susceptibility testing (AST) would be valuable. We have developed a rapid and accurate flow cytometry method (FCM) for AST of gonococci. Methods The 2016 WHO gonococcal reference strains, and WHO Q, R and S (n  = 17) were tested against seven clinically relevant antibiotics (ceftriaxone, cefixime, azithromycin, spectinomycin, ciprofloxacin, tetracycline and gentamicin). After 4.5 h incubation of inoculated broth, the fluorescent dye Syto™ 9 was added, followed by FCM analysis. After gating, the relative remaining population of gonococci, compared with unexposed growth control samples, was plotted against antimicrobial concentration, followed by non-linear curve regression analysis. Furthermore, the response at one single concentration/tested antibiotic was evaluated with the intention to use as a screening test for detection of resistant gonococci. Results A dose-dependent response was seen in susceptible isolates for all tested antimicrobials. There was a clear separation between susceptible/WT and resistant/non-WT isolates for ceftriaxone, cefixime, spectinomycin, ciprofloxacin and tetracycline. In contrast, for azithromycin, only high-level-resistant isolates were distinguished, while resistant isolates with MICs of 4 mg/L were indistinguishable from WT (MIC ≤ 1 mg/L) isolates. For gentamicin, all tested 17 isolates were WT and FCM analysis resulted in uniform dose–response curves. Using a single antibiotic concentration and a 50% remaining cell population cut-off, the overall sensitivity and specificity for resistance detection were 93% and 99%, respectively. Conclusions By providing results in <5 h for gonococcal isolates, FCM-based AST can become a rapid screening method for antimicrobial resistance or antimicrobial susceptibility in gonococci. [ABSTRACT FROM AUTHOR]

Background Managing drug–food interactions may help to achieve the optimal action and safety profile of β-lactam antibiotics. Methods We conducted a systematic review with meta-analyses in adherence to PRISMA guidelines for 32 β-lactams. We included 166 studies assessing the impact of food, beverages, antacids or mineral supplements on the pharmacokinetic (PK) parameters or PK/pharmacodynamic (PK/PD) indices. Results Eighteen of 25 β-lactams for which data on food impact were available had clinically important interactions. We observed the highest negative influence of food (AUC or C max decreased by >40%) for ampicillin, cefaclor (immediate-release formulations), cefroxadine, cefradine, cloxacillin, oxacillin, penicillin V (liquid formulations and tablets) and sultamicillin, whereas the highest positive influence (AUC or C max increased by >45%) for cefditoren pivoxil, cefuroxime and tebipenem pivoxil (extended-release tablets). Significantly lower bioavailability in the presence of antacids or mineral supplements occurred for 4 of 13 analysed β-lactams, with the highest negative impact for cefdinir (with iron salts) and moderate for cefpodoxime proxetil (with antacids). Data on beverage impact were limited to 11 antibiotics. With milk, the extent of absorption was decreased by >40% for cefalexin, cefradine, penicillin G and penicillin V, whereas it was moderately increased for cefuroxime. No significant interaction occurred with cranberry juice for two tested drugs (amoxicillin and cefaclor). Conclusions Factors such as physicochemical features of antibiotics, drug formulation, type of intervention, and patient's health state may influence interactions. Due to the poor actuality and diverse methodology of included studies and unproportionate data availability for individual drugs, we judged the quality of evidence as low. [ABSTRACT FROM AUTHOR]

Background Quality indicators (QIs) can be used to obtain valuable insights into prescribing quality. Five quantitative and nine diagnosis-linked QIs, aiming to provide general practitioners (GP) with feedback on their antibiotic prescribing quantity and quality, were previously developed and evaluated in a controlled study. Objective To confirm, in a larger non-controlled study, the feasibility of using routinely collected and extracted electronic patient records to calculate the diagnosis-linked QI outcomes for antibiotic prescribing, and their reliability and validity. Methods Retrospective study involving 299 Dutch general practices using routine care data (2018–2020). QIs describe total antibiotic and subgroup prescribing, prescribing percentages and first-choice prescribing for several clinical diagnoses. Practice variation in QI outcomes, inter-QI outcome correlations and sensitivity of QI outcomes to pandemic-induced change were determined. Results QI outcomes were successfully obtained for 278/299 practices. With respect to reliability, outcomes for 2018 and 2019 were comparable, between-practice variation in outcomes was similar to the controlled pilot, and inter-QI outcome correlations were as expected, for example: high prescribing of second choice antibiotics with low first-choice prescribing for clinical diagnoses. Validity was confirmed by their sensitivity to pandemic-induced change: total antibiotic prescribing decreased from 282 prescriptions/1000 registered patients in 2018 to 216 in 2020, with a decrease in prescribing percentages for upper and lower respiratory infections, from 26% to 18.5%, and from 28% to 16%. Conclusions This study confirmed the fit-for-purpose (feasibility, reliability and validity) of the antibiotic prescribing QIs (including clinical diagnosis-linked ones) using routinely registered primary health care data as a source. This feedback can therefore be used in antibiotic stewardship programmes to improve GPs' prescribing routines. [ABSTRACT FROM AUTHOR]

Background Risk factors for ciprofloxacin or MDR in primary care urine specimens are not well defined. Objectives We created a primary care-specific antibiogram for Escherichia coli isolates from cases with complicated and uncomplicated urinary tract infection (UTI) and evaluated risk factors for ciprofloxacin, trimethoprim/sulfamethoxazole and MDR among Enterobacterales. Methods We conducted a cross-sectional study to determine resistance and risk factors by collecting urine cultures from all patients (≥18 years) presenting with provider-suspected UTI at two primary care, safety-net clinics in Houston, TX, USA between November 2018 and March 2020. Results Among 1262 cultures, 308 cultures grew 339 uropathogens. Patients with Enterobacterales (n  = 199) were mostly female (93.5%) with a mean age of 48.5 years. E. coli was the predominant uropathogen isolated (n  = 187/339; 55%) and had elevated trimethoprim/sulfamethoxazole (43.6%) and ciprofloxacin (29.5%) resistance, low nitrofurantoin (1.8%) resistance, and no fosfomycin resistance. Among E. coli , 10.6% were ESBL positive and 24.9% had MDR. Birth outside the U.S.A. prior (2 year) trimethoprim/sulfamethoxazole resistance, and diabetes mellitus were associated with trimethoprim/sulfamethoxazole resistance. Prior (60 day) fluoroquinolone use, prior ciprofloxacin resistance and both diabetes mellitus and hypertension were strongly associated with ciprofloxacin resistance. Prior fluoroquinolone use and a history of resistance to any studied antibiotic were associated with MDR, while pregnancy was protective. Conclusions We found elevated resistance to UTI-relevant antimicrobials and novel factors associated with resistance; these data can be incorporated into clinical decision tools to improve organism and drug concordance. [ABSTRACT FROM AUTHOR]

Background Antibiotics and proton pump inhibitors (PPI) are recognized risk factors for acquisition and recurrence of Clostridioides difficile infection (CDI), yet combined effects remain unclear. Objectives To assess the short- and long-term effects of antibiotics and PPIs on CDI risk and recurrence. Methods Population-based study including all 43 152 patients diagnosed with CDI in Sweden (2006–2019), and 355 172 matched population controls without CDI. The impact of antibiotics and PPIs on CDI risk and recurrence was explored for recent (0–30 days) and preceding (31–180 days) use prior to their first CDI diagnosis, using multivariable conditional logistic regression presented as odds ratios (ORs) and 95% confidence interval, adjusted for demographics, comorbidities and other drugs. Results Compared to controls, the combined effect of recent PPIs and antibiotics [ORAB+PPI = 17.51 (17.48–17.53)] on CDI risk was stronger than the individual effects [ORAB = 15.37 (14.83–15.93); ORPPI = 2.65 (2.54–2.76)]. Results were less pronounced for exposure during the preceding months. Dose–response analyses showed increasing exposure correlated with CDI risk [recent use: ORAB = 6.32 (6.15–6.49); ORPPI = 1.65 (1.62–1.68) per prescription increase]. Compared to individuals without recurrence (rCDI), recent [ORAB = 1.30 (1.23–1.38)] and preceding [ORAB = 1.23 (1.16–1.31); ORPPI = 1.12 (1.03–1.21)] use also affected the risk of recurrence yet without significant interaction between both. Recent macrolides/lincosamides/streptogramins; other antibacterials including nitroimidazole derivates; non-penicillin beta lactams and quinolones showed the strongest association with CDI risk and recurrence, particularly for recent use. PPI use, both recent and preceding, further increased the CDI risk associated with almost all antibiotic classes. Conclusion Recent and less recent use of PPIs and systemic antibiotics was associated with an increased risk of CDI, particularly in combination. [ABSTRACT FROM AUTHOR]

Background Antimicrobial resistance is a worldwide threat, exacerbated by inappropriate prescribing. Most antibiotic prescribing occurs in primary care. Early-career GPs are important for the future of antibiotic prescribing and curbing antimicrobial resistance. Objectives To determine antibiotic prescribing patterns by early-career GPs for common acute infections. Methods A systematic literature search was conducted using PubMed, Embase and Scopus. Two authors independently screened abstracts and full texts for inclusion. Primary outcomes were antibiotic prescribing rates for common acute infections by GPs with experience of 10 years or less. Secondary outcomes were any associations between working experience and antibiotic prescribing. Results Of 1483 records retrieved, we identified 41 relevant studies. Early-career GPs were less likely to prescribe antibiotics compared with their more experienced colleagues (OR range 0.23–0.67). Their antibiotic prescribing rates for 'any respiratory condition' ranged from 14.6% to 52%, and for upper respiratory tract infections from 13.5% to 33%. Prescribing for acute bronchitis varied by country, from 15.9% in Sweden to 26% in the USA and 63%–73% in Australia. Condition-specific data for all other included acute infections, such as sinusitis and acute otitis media, were limited to the Australian context. Conclusions Early-career GPs prescribe fewer antibiotics than later-career GPs. However, there are still significant improvements to be made for common acute conditions, as their prescribing is higher than recommended benchmarks. Addressing antimicrobial resistance requires an ongoing worldwide effort and early-career GPs should be the target for long-term change. [ABSTRACT FROM AUTHOR]