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Background In clinical practice, challenges in identifying patients with uncomplicated urinary tract infections (uUTIs) at risk of antibiotic nonsusceptibility may lead to inappropriate prescribing and contribute to antibiotic resistance. We developed predictive models to quantify risk of nonsusceptibility to 4 commonly prescribed antibiotic classes for uUTI, identify predictors of nonsusceptibility to each class, and construct a corresponding risk categorization framework for nonsusceptibility. Methods Eligible females aged ≥12 years with Escherichia coli– caused uUTI were identified from Optum's de-identified Electronic Health Record dataset (1 October 2015–29 February 2020). Four predictive models were developed to predict nonsusceptibility to each antibiotic class and a risk categorization framework was developed to classify patients' isolates as low, moderate, and high risk of nonsusceptibility to each antibiotic class. Results Predictive models were developed among 87 487 patients. Key predictors of having a nonsusceptible isolate to ≥3 antibiotic classes included number of previous UTI episodes, prior β-lactam nonsusceptibility, prior fluoroquinolone treatment, Census Bureau region, and race. The risk categorization framework classified 8.1%, 14.4%, 17.4%, and 6.3% of patients as having isolates at high risk of nonsusceptibility to nitrofurantoin, trimethoprim-sulfamethoxazole, β-lactams, and fluoroquinolones, respectively. Across classes, the proportion of patients categorized as having high-risk isolates was 3- to 12-fold higher among patients with nonsusceptible isolates versus susceptible isolates. Conclusions Our predictive models highlight factors that increase risk of nonsusceptibility to antibiotics for uUTIs, while the risk categorization framework contextualizes risk of nonsusceptibility to these treatments. Our findings provide valuable insight to clinicians treating uUTIs and may help inform empiric prescribing in this population. [ABSTRACT FROM AUTHOR]

Objectives To investigate clinical outcomes of patients with Pseudomonas endocarditis and identify factors associated with treatment failure. Methods Adult patients meeting definitive Duke's criteria for Pseudomonas endocarditis at 11 hospitals were identified between May 2000 and February 2024. Failure was defined as death or microbiological failure by day 42. First-line therapy consisted of cefepime, piperacillin/tazobactam, ceftazidime or ceftolozane/tazobactam alone or in combination. Results Forty-eight patients met inclusion criteria; 29% were persons who inject drugs and 13% were organ transplant recipients. Pseudomonas aeruginosa was the causative species in 98% of cases. Patients who experienced 42 day cure were more likely to be initially managed with first-line β-lactam agents compared with those who experienced clinical failure (97% versus 62%, P  = 0.004). Treatment with first-line β-lactams was associated with shorter time to treatment initiation and a lower likelihood of infection due to MDR Pseudomonas spp. In the univariate model, patients who experienced 90 day mortality were more likely to have prosthetic valve endocarditis (57% versus 24%, P  = 0.02), an intracardiac complication (36% versus 9%, P  = 0.04) and a higher median (IQR) Pitt bacteraemia score [2.5 (2–3.8) versus 1 (0–2), P  = 0.048]. Combination therapy did not improve clinical outcomes but did increase the rate of adverse effects resulting in drug discontinuation compared with monotherapy, (21% versus 0%, P  = 0.08). Conclusions This is the largest study of Pseudomona s endocarditis to date. We identified improved clinical outcomes when cefepime, piperacillin/tazobactam, ceftazidime or ceftolozane/tazobactam were used for initial treatment. We did not identify a clinical benefit for combination treatment. [ABSTRACT FROM AUTHOR]

Background Successful use of carbapenems in combination with cefazolin or oxacillin for treatment of MSSA bacteraemia has been described; however, comparative data to standard treatment approaches are lacking. Methods This was a multicentre, retrospective study of adult patients with MSSA bacteraemia for >48 h. Standard treatment was considered monotherapy with cefazolin, oxacillin or nafcillin. Combination therapy was defined as the addition of ertapenem or meropenem to standard treatment for at least 24 h. The primary outcome was duration of bacteraemia defined as time from administration of an antibiotic with in vitro activity to first negative blood culture. Time to blood culture sterilization was compared through risk-set matching with aid of a propensity score. Results Overall, 238 patients were included; 66% (157/238) received standard treatment and 34% (81/238) received combination therapy. The median (IQR) time to carbapenem initiation was 4.7 (3.63–6.5) days. Patients who received combination therapy were younger (P  = 0.012), more likely to have endocarditis (P  = 0.034) and had longer median duration of bacteraemia (P  < 0.001). After applying risk-set matching, patients who received combination therapy experienced faster time to blood culture sterilization compared with control patients [HR = 1.618 (95% CI; 1.119–2.339) P  = 0.011]. Using a paired hazard model, 90 day mortality rates were not statistically different among patients who received combination therapy versus matched controls [HR = 1.267 (95% CI; 0.610–2.678), P  = 0.608]. Discussion Carbapenem combination therapy resulted in faster time to blood culture sterilization, but no differences in overall mortality rates. Randomized trials are critical to determine the utility of carbapenem combination therapy. [ABSTRACT FROM AUTHOR]

Objectives To investigate the genomic diversity and β-lactam susceptibilities of Enterococcus faecalis collected from patients with infective endocarditis (IE). Methods We collected 60 contemporary E. faecalis isolates from definite or probable IE cases identified between 2018 and 2021 at the University of Pittsburgh Medical Center. We used whole-genome sequencing to study bacterial genomic diversity and employed antibiotic checkerboard assays and a one-compartment pharmacokinetic–pharmacodynamic (PK/PD) model to investigate bacterial susceptibility to ampicillin and ceftriaxone both alone and in combination. Results Genetically diverse E. faecalis were collected, however, isolates belonging to two STs, ST6 and ST179, were collected from 21/60 (35%) IE patients. All ST6 isolates encoded a previously described mutation upstream of penicillin-binding protein 4 (pbp4) that is associated with pbp4 overexpression. ST6 isolates had higher ceftriaxone MICs and higher fractional inhibitory concentration index values for ampicillin and ceftriaxone (AC) compared to other isolates, suggesting diminished in vitro AC synergy against this lineage. Introduction of the pbp4 upstream mutation found among ST6 isolates caused increased ceftriaxone resistance in a laboratory E. faecalis isolate. PK/PD testing showed that a representative ST6 isolate exhibited attenuated efficacy of AC combination therapy at humanized antibiotic exposures. Conclusions We find evidence for diminished in vitro AC activity among a subset of E. faecalis IE isolates with increased pbp4 expression. These findings suggest that alternate antibiotic combinations against diverse contemporary E. faecalis IE isolates should be evaluated. [ABSTRACT FROM AUTHOR]

This article provides an overview of the progress and challenges in combatting antimicrobial resistance (AMR) from the perspective of an infectious diseases pharmacist. The Centers for Disease Control and Prevention (CDC) identified 18 urgent and serious antimicrobial-resistant pathogens in 2013, and since then, there have been advancements in diagnosis, treatment, and prevention, resulting in a reduction in deaths caused by AMR pathogens. However, new challenges have emerged, such as increasing rates of hospital-acquired infections caused by drug-resistant bacteria. The COVID-19 pandemic has further exacerbated the AMR crisis, leading to a need for continued efforts in infection prevention and control, investments in alternative therapeutics and vaccine development, and innovative research to understand resistance mechanisms and develop new treatment approaches. The article emphasizes the importance of a multifaceted approach involving various stakeholders to address the urgent need to combat AMR. [Extracted from the article]

Background Diagnosis of invasive candidiasis (IC) is limited by insensitivity and slow turnaround of cultures. Our objectives were to define the performance of T2Candida, a nonculture test, under guidance of a diagnostic stewardship program, and evaluate impact on time to antifungal initiation and antifungal utilization. Methods This was a retrospective study of adult medical intensive care unit (MICU) patients with septic shock for whom T2Candida testing was performed from March 2017 to March 2020. Patients with positive T2Candida results during this period were compared to MICU patients who did not undergo T2Candida testing but had septic shock and blood cultures positive for Candida from January 2016 through March 2020. Results Overall, 155 T2Candida tests from 143 patients were included. Nine percent of T2Candida tests were positive compared to 4.5% of blood cultures. Sensitivity, specificity, positive predictive value, and negative predictive value of T2Candida for proven and probable IC were 78%, 95%, 50%, and 99%, respectively. Patients who tested positive for T2Candida (n = 14) were diagnosed earlier and initiated on antifungal therapy sooner than patients with IC (n = 14) diagnosed by blood culture alone (median, 5.6 vs 60 hours; P <.0001). Median antifungal days of therapy/1000 patient-days were 23.3/month preimplementation and 15/month postimplementation (P   =.007). Following a negative T2Candida result, empiric antifungals were either not administered in 58% or discontinued within 72 hours in 96% of patients. Conclusions Diagnostic stewardship guided T2Candida testing resulted in reduced time to IC diagnosis, faster initiation of antifungal therapy, and lower antifungal usage among MICU patients with septic shock. [ABSTRACT FROM AUTHOR]