Emergency Department Urinary Tract Infections Caused by Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae: Many Patients Have No Identifiable Risk Factor and Discordant Empiric Therapy Is Common

Co-resistance Among Escherichia coli and Klebsiella pneumoniae Urine Isolates from Female Outpatients with Presumed UTI: A Retrospective US Cohort Study

INTRODUCTION

Urinary tract infections (UTIs) caused by antimicrobial-resistant Enterobacterales are a global health threat. There are limited surveillance data available to characterize the prevalence of antimicrobial resistance among outpatients in the United States (US).

METHODS

This retrospective cohort (database) study investigated co-resistance among Escherichia coli and Klebsiella pneumoniae urinary isolates from US female outpatients aged ≥ 12 years with presumed uncomplicated UTI (uUTI), ≥ 3 months of data (2011-2019), and antimicrobial susceptibility testing results. Eligible isolates were the first urinary E. coli or K. pneumoniae isolate per patient collected within 30 days; classified as not susceptible (NS) if antimicrobial susceptibility testing results were intermediate or resistant to each antibiotic tested. Four resistance phenotypes were identified: NS to fluoroquinolones (FQ), trimethoprim/sulfamethoxazole (SXT), nitrofurantoin (NTF), and extended-spectrum β-lactamase+/third-generation cephalosporin (ESBL+/3GC NS). Co-resistance phenotypes included all possible combinations of resistance to ≥ 2 drug classes.

RESULTS

Of 1,513,882 E. coli isolates and 250,719 K. pneumoniae isolates, 856,918 and 187,459 isolates with ≥ 1 resistance phenotype were included in the analysis, respectively. The most common resistance phenotypes were SXT NS for the E. coli isolates (44.8%) and NTF NS for the K. pneumoniae isolates (75.5%), while ESBL+/3GC NS comprised 11.2 and 5.9%, respectively. Among ESBL+/3GC NS E. coli isolates, 72.4, 56.7, and 46.6% were co-resistant to FQ, SXT, and FQ + SXT, respectively. For ESBL+/3GC NS K. pneumoniae isolates, 65.7 and 45.7% were co-resistant to SXT and FQ + SXT.

CONCLUSION

Both species exhibited high rates of co-resistance, emphasizing the need to raise awareness of co-resistance and of the unmet need for effective treatment options for uUTI.

Multidrug resistance among uropathogenic clonal group A E. Coli isolates from Pakistani women with uncomplicated urinary tract infections

OBJECTIVE

Multi-drug resistance (MDR) has notably increased in community acquired uropathogens causing urinary tract infections (UTIs), predominantly Escherichia coli. Uropathogenic E. coli causes 80% of uncomplicated community acquired UTIs, particularly in pre-menopausal women. Considering this high prevalence and the potential to spread antimicrobial resistant genes, the current study was conducted to investigate the presence of clinically important strains of E. coli in Pakistani women having uncomplicated cystitis and pyelonephritis. Women belonging to low-income groups were exclusively included in the study. Seventy-four isolates from urine samples were processed, phylotyped, and screened for the presence of two Single Nucleotide Polymorphisms (SNPs) particularly associated with a clinically important clonal group A of E. coli (CgA) followed by antibiotic susceptibility testing and genome sequence analysis.

RESULTS

Phylogroup B2 was most prevalent in patients and 44% of isolates were positive for the presence of CgA specific SNPs in Fumarate hydratase and DNA gyrase subunit B genes. Antibiotic susceptibility testing showed widespread resistance to trimethoprim-sulfamethoxazole and extended-spectrum beta-lactamase production. The infection analysis revealed the phylogroup B2 to be more pathogenic as compared to the other groups. The genome sequence of E. coli strain U17 revealed genes encoding virulence, multidrug resistance, and host colonization mechanisms.

CONCLUSIONS

Our research findings not only validate the significant occurrence of multidrug-resistant clonal group A E. coli (CgA) in premenopausal Pakistani women suffering from cystitis and pyelonephritis but also reveal the presence of genes associated withvirulence, and drug efflux pumps. The detection of highly pathogenic, antimicrobial-resistant phylogroup B2 and CgA E. coli strains is likely to help in understanding the epidemiology of the pathogen and may ultimately help to reduce the impact of these strains on human health. Furthermore, the findings of this study will particularly help to reduce the prevalence of uncomplicated UTIs and the cost associated with their treatment in women belonging to low-income groups.

Design of a panel of indicators for antibiotic stewardship programs in the Emergency Department

OBJECTIVE

To develop a panel of indicators to monitor antimicrobial stewardship programs activity in the emergency department.

METHODS

A multidisciplinary group consisting of experts in the management of infection in emergency departments and the implementation of antimicrobial stewardship programs (ASP) evaluated a proposal of indicators using a modified Delphi methodology. In the first round, each expert classified the relevance of each proposed indicators in two dimensions (healthcare impact and ease of implementation) and two attributes (prioritization level and frequency). The second round was conducted based on the modified questionnaire according to the suggestions raised and new indicators suggested. Experts modified the prioritization order and rated the new indicators in the same manner as in the first round.

RESULTS

61 potential indicators divided into four groups were proposed: consumption indicators, microbiological indicators, process indicators, and outcome indicators. After analyzing the scores and comments from the first round, 31 indicators were classified as high priority, 25 as intermediate priority, and 5 as low priority. Moreover, 18 new indicators were generated. Following the second round, all 61 initially proposed indicators were retained, and 18 new indicators were incorporated: 11 classified as high priority, 3 as intermediate priority, and 4 as low priority.

CONCLUSIONS

The experts agreed on a panel of ASP indicators adapted to the emergency services prioritized by level of relevance. This is as a helpful tool for the development of these programs and will contribute to monitoring the appropriateness of the use of antimicrobials in these units.

[Translated article] Design of a panel of indicators for antibiotic stewardship programs in the Emergency Department

OBJECTIVE

To develop a panel of indicators to monitor antimicrobial stewardship programs activity in the emergency department.

METHODS

A multidisciplinary group consisting of experts in the management of infection in emergency departments and the implementation of antimicrobial stewardship programs (ASP) evaluated a proposal of indicators using a modified Delphi methodology. In the first round, each expert classified the relevance of each proposed indicators in two dimensions (healthcare impact and ease of implementation) and two attributes (prioritisation level and frequency). The second round was conducted based on the modified questionnaire according to the suggestions raised and new indicators suggested. Experts modified the prioritisation order and rated the new indicators in the same manner as in the first round.

RESULTS

61 potential indicators divided into four groups were proposed: consumption indicators, microbiological indicators, process indicators, and outcome indicators. After analysing the scores and comments from the first round, 31 indicators were classified as high priority, 25 as intermediate priority, and 5 as low priority. Moreover, 18 new indicators were generated. Following the second round, all 61 initially proposed indicators were retained, and 18 new indicators were incorporated: 11 classified as high priority, 3 as intermediate priority, and 4 as low priority.

CONCLUSIONS

The experts agreed on a panel of ASP Indicators adapted to the emergency services prioritised by level of relevance. This is as a helpful tool for the development of these programs and will contribute to monitoring the appropriateness of the use of antimicrobials in these units.

The Interventions and Challenges of Antimicrobial Stewardship in the Emergency Department

Over the last decades, we have witnessed a constant increase in infections caused by multi-drug-resistant strains in emergency departments. Despite the demonstrated effectiveness of antimicrobial stewardship programs in antibiotic consumption and minimizing multi-drug-resistant bacterium development, the characteristics of emergency departments pose a challenge to their implementation. The inclusion of rapid diagnostic tests, tracking microbiological results upon discharge, conducting audits with feedback, and implementing multimodal educational interventions have proven to be effective tools for optimizing antibiotic use in these units. Nevertheless, future multicenter studies are essential to determine the best way to proceed and measure outcomes in this scenario.

Exposure to Non-Antimicrobial Drugs and Risk of Infection with Antibiotic-Resistant Enterobacteriaceae

Antimicrobial resistance (AMR) has consistently been linked to antibiotic use. However, the roles of commonly prescribed non-antimicrobial drugs as drivers of AMR may be under-appreciated. Here, we studied a cohort of patients with community-acquired pyelonephritis and assessed the association of exposure to non-antimicrobial drugs at the time of hospital admission with infection with drug-resistant organisms (DRO). Associations identified on bivariate analyses were tested using a treatment effects estimator that models both outcome and treatment probability. Exposure to proton-pump inhibitors, beta-blockers, and antimetabolites was significantly associated with multiple resistance phenotypes. Clopidogrel, selective serotonin reuptake inhibitors, and anti-Xa agents were associated with single-drug resistance phenotypes. Antibiotic exposure and indwelling urinary catheters were covariates associated with AMR. Exposure to non-antimicrobial drugs significantly increased the probability of AMR in patients with no other risk factors for resistance. Non-antimicrobial drugs may affect the risk of infection with DRO through multiple mechanisms. If corroborated using additional datasets, these findings offer novel directions for predicting and mitigating AMR.

PREDICTION OF MULTIDRUG-RESISTANT BACTERIA IN URINARY TRACT INFECTIONS IN THE EMERGENCY DEPARTMENT

BACKGROUND

Urinary tract infections (UTI) due to multidrug-resistant bacteria are a frequent reason for visiting the emergency department (ED).

OBJECTIVES

The aim of this study was to evaluate the applicability of a predictive model of infection by multidrug-resistant microorganisms in UTIs treated in an ED.

METHODS

This is a retrospective observational study. Adult patients admitted to an ED with a diagnosis of UTI and positive urine culture were included. The main objective was to evaluate the area under the curve of the receiver operating characteristic (AUC-ROC), the scale proposed by González-del-Castillo, considering infection by a resistant pathogen as the dependent variable and the scale score of the predictive model used as the independent variable.

RESULTS

The study included 414 patients with UTIs, 125 (30.2%) of which were caused by multidrug-resistant microorganisms. A total of 38.4% of patients were treated with antibiotics during the previous 3 months and a multidrug-resistant pathogen was isolated from 10.4% of the total during the previous 6 months. The AUC-ROC of the scale for predicting UTIs due to multidrug-resistant microorganisms was 0.79 (95% confidence interval 0.76-0.83), the optimal cut-off point being 9 points, with a sensitivity of 76.8% and a specificity of 71.6%.

CONCLUSIONS

The use of the predictive model evaluated is a useful tool in real clinical practice to improve the success of empirical treatment of patients presenting to the ED with a diagnosis of UTI and positive urine culture pending identification.

Antimicrobial Resistance in Urinary Tract Infections: Is There an Issue and Does It Matter?

Antimicrobial resistance (AMR) has increased substantially among community-acquired uropathogens that cause urinary tract infections (UTI), limiting the availability of effective oral antibiotic treatments. This review includes coverage of an expert-led Learning Lounge, symposium session, and several poster presentations, that took place between 20th–22nd October 2022 as part of IDWeek2022 in Washington, D.C., USA. An immersive Learning Lounge, sponsored by GSK, opened with Keith Kaye, Department of Medicine, Rutgers–Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA, who illuminated the concerns of AMR in community-acquired UTIs, delivering contemporary surveillance data, and outlined how in vitro data may translate into practical advice. This led fittingly to Erin McCreary, Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pennsylvania, USA, who enquired whether enough is being done in clinical practice regarding community-acquired infections, highlighting the importance of antimicrobial stewardship (AMS), and galvanising the audience to adapt healthcare settings to the changing landscape. The scientific programme also included three data-rich posters that showcased Kaye’s surveillance data on Escherichia coli and Klebsiella pneumoniae co-resistance, along with the geographical distribution of K. pneumoniae. An insightful poster by Claire Trennery, Value Evidence Outcomes, GSK, Brentford, UK, considered the patient perspective of UTI symptoms in defining antibiotic treatment success, and two posters presented by Rodrigo Mendes, JMI Laboratories, North Liberty, Iowa, USA, examined in vitro global surveillance data of emerging antimicrobial treatments.

Contemporary Evaluation of Tebipenem In Vitro Activity against Enterobacterales Clinical Isolates Causing Urinary Tract Infections in US Medical Centers (2019-2020)

Tebipenem pivoxil is an oral broad-spectrum carbapenem. This study evaluated the activity of tebipenem and comparators against UTI Enterobacterales from US hospitals (2019-2020). 3,576 Enterobacterales causing UTI in 52 centers in 9 US Census Divisions were included. Susceptibility testing followed the CLSI broth microdilution method. Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis with an MIC of ≥2 μg/mL for ceftazidime, ceftriaxone, and/or aztreonam were designated ESBL. Isolates were also grouped based on MDR phenotype. Tebipenem, meropenem, and ertapenem had MIC₉₀ against Enterobacterales of 0.06 μg/mL, 0.06 μg/mL and 0.03 μg/mL, respectively. Low susceptibility results for aztreonam (87.1% susceptible), cefazidime (88.1%), ceftriaxone (84.8%), and other agents were observed. Tebipenem and ertapenem were equally potent (MIC₉₀, 0.015 to 0.03 μg/mL) against E. coli and K. pneumoniae, whereas ertapenem showed an MIC 8-fold lower than tebipenem against P. mirabilis. Oral agents, such as amoxicillin-clavulanate, levofloxacin, and trimethoprim-sulfamethoxazole, showed elevated nonsusceptibility rates in the Middle Atlantic region (26, 45, 47, and 41%, respectively). ESBL prevalence varied from 7% to 16%, except in the Middle Atlantic region (42%). The carbapenems were active against ESBL and MDR isolates (93.7 to 96.8% susceptible). Elevated rates of ESBL in UTI pathogens in US hospitals were noted as well as a uniform in vitro potency (MIC₉₀) of tebipenem and the intravenous carbapenems, regardless of phenotype. IMPORTANCE The occurrence of urinary-tract Enterobacterales pathogens producing ESBL enzymes in community and nosocomial settings continues to increase, as does the coresistance to fluoroquinolones, trimethoprim-sulfamethoxazole and nitrofurantoin often exhibited by these pathogens. This scenario complicates the clinical empirical and guided management of UTI by precluding the use of oral and many intravenous options. Oral options appear compromised even among some ESBL-negative isolates, against which the use of parenteral agents may be required. In addition, the interregional variability of susceptibility results of US UTI pathogens provides a less predictable susceptibility pattern to inform empirical treatment decisions. This study evaluated the in vitro activity of tebipenem against contemporary uropathogens, including those resistant to currently available oral options.

Effects of chronic exposure to arsenic on the fecal carriage of antibiotic-resistant Escherichia coli among people in rural Bangladesh

Antibiotic resistance is a leading cause of hospitalization and death worldwide. Heavy metals such as arsenic have been shown to drive co-selection of antibiotic resistance, suggesting arsenic-contaminated drinking water is a risk factor for antibiotic resistance carriage. This study aimed to determine the prevalence and abundance of antibiotic-resistant Escherichia coli (AR-Ec) among people and drinking water in high (Hajiganj, >100 μg/L) and low arsenic-contaminated (Matlab, <20 μg/L) areas in Bangladesh. Drinking water and stool from mothers and their children (<1 year) were collected from 50 households per area. AR-Ec was detected via selective culture plating and isolates were tested for antibiotic resistance, arsenic resistance, and diarrheagenic genes by PCR. Whole-genome sequencing (WGS) analysis was done for 30 E. coli isolates from 10 households. Prevalence of AR-Ec was significantly higher in water in Hajiganj (48%) compared to water in Matlab (22%, p <0.05) and among children in Hajiganj (94%) compared to children in Matlab (76%, p <0.05), but not among mothers. A significantly higher proportion of E. coli isolates from Hajiganj were multidrug-resistant (83%) compared to isolates from Matlab (71%, p <0.05). Co-resistance to arsenic and multiple antibiotics (MAR index >0.2) was observed in a higher proportion of water (78%) and child stool (100%) isolates in Hajiganj than in water (57%) and children (89%) in Matlab (p <0.05). The odds of arsenic-resistant bacteria being resistant to third-generation cephalosporin antibiotics were higher compared to arsenic-sensitive bacteria (odds ratios, OR 1.2-7.0, p <0.01). WGS-based phylogenetic analysis of E. coli isolates did not reveal any clustering based on arsenic exposure and no significant difference in resistome was found among the isolates between the two areas. The positive association detected between arsenic exposure and antibiotic resistance carriage among children in arsenic-affected areas in Bangladesh is an important public health concern that warrants redoubling efforts to reduce arsenic exposure.

High prevalence of fluoroquinolone-resistant UTI among US emergency department patients diagnosed with urinary tract infection, 2018-2020

BACKGROUND

Uropathogen resistance, fluoroquinolone-resistance (FQR), and extended spectrum beta-lactamase (ESBL), has been observed to be emerging worldwide with prevalences above recommended thresholds for routine empirical treatment. The primary aim of our study was to determine the prevalence of FQR from a geographically diverse sample of United States emergency departments (EDs).

METHODS

We conducted a multi-center, observational cohort study using a network of 15 geographically diverse US EDs. All patients ≥18 years of age with the primary or secondary diagnosis of urinary tract infection (UTI) in the ED identified using International Classification of Diseases (ICD-10) diagnosis code of cystitis, pyelonephritis, or UTI from 2018 to 2020 were included. We calculated descriptive statistics for uropathogens and susceptibilities. Logistic regression analysis was used to identify antimicrobial resistance risk factors associated with FQR Escherichia coli.

RESULTS

Among 3779 patients who met inclusion criteria, median age was 62.9 years (interquartile range [IQR]: 41-77.6) and 76.3% were female. The most common diagnoses were complicated (41.2%) and uncomplicated cystitis (40.3%). E. coli was the most common pathogen (63.2%), followed by Klebsiella pneumoniae (13.2%) and Enterococcus species (5.8%). Across all sites, overall E. coli FQ-resistance prevalence was 22.1%, ranging from 10.5 to 29.7% by site. The prevalence of ESBL-producing uropathogen was 7.4%, ranging from 3.6% to 11.6% by site. Previous IV or oral antimicrobial use in the past 90-days and history of a multi-drug resistant pathogen were associated with FQ-resistant E. coli (odds ratio [OR] 2.68, 95% confidence interval [CI]: 2.04-3.51, and OR 6.93, 95% CI: 4.95-9.70, respectively). Of the patients who had FQ-resistant E. coli or an ESBL-producing uropathogen isolated, 116 (37.1%) and 61 (36.7%) did not have any documented risk factors for resistance.

CONCLUSION

FQ-resistant E. coli is widely prevalent across US sites highlighting the need for ongoing monitoring of antimicrobial resistance and, at some locations, modification of empirical treatments.

Urinary Tract Infection as the Diagnosis for Admission Through the Emergency Department: Its Prevalence, Seasonality, Diagnostic Methods, and Diagnostic Decisions

Background

Urinary tract infections (UTIs) affect millions of people of all ages around the world. It constitutes one of the most common conditions encountered in emergency departments (EDs). In this study, we aimed to inquire into the prevalence of UTIs as the hospitalization primary diagnosis through the emergency department and to research the seasonal pattern, accuracy of the diagnostic methods used, and final diagnosis.

Methods

A retrospective cross-sectional study was undertaken that included all patients admitted with a primary diagnosis of UTIs through the ED over a four-month period (January, April, June, and September) in the emergency department of King Abdulaziz Medical City (KAMC) in Riyadh. The prevalence, diagnostics, and outcomes of UTIs were evaluated, and their association with seasonality was assessed after obtaining data from the Hospital Information System BestCare of King Abdullah National Guard Hospital. The variables that have been collected were analyzed using the Statistical Package for Social Sciences software version 26 (IBM Corp., Armonk, NY, USA).

Results

A total of 315 patients were admitted with a diagnosis of UTI. The prevalence of UTI among patients admitted through the ED was 10.5% with a significantly higher prevalence noted in January (13.3%) than in April (8.5%) or September (8.8%) (Fisher’s exact test: 0.009 and 0.01, respectively). As would be expected, the cohort was made up of elderly individuals with a mean age of 70.6 years, and the male/female ratio was 1:2. UTI symptoms including dysuria, frequency, urgency, rigors, and loin pain were noted in only 41% of cases or less, and urinalysis was the basis of making the diagnosis (87.9% had positive leukocyte esterase (LE) and 90.5% had positive urine WBC/HPF). Furthermore, 4.4% required urgent treatment, and 3.1% required intensive care unit (ICU) admission. Urine culture was negative in 30.8% of the cases (30.8% false positives among those admitted with UTI). The commonest organisms isolated were Escherichia coli (33%), Klebsiella pneumoniae (14.3%), and Pseudomonas aeruginosa (5.1%). The median length of hospital stay (LOS) was 3.5 days, and the Charlson Comorbidity Index (CCI) score was 5.7. The mean hemoglobin (Hb), creatinine, C-reactive protein (CRP), procalcitonin, and lactic acid were 108 gm/L, 131.3 umol/L, 38.3 mg/L, 0.28 ng/mL, and 2.07 mmol/L, respectively.

Conclusion

This research found that the prevalence of UTI cases as an admission diagnosis through the emergency department was high, despite some cultures being negative or contaminated, thus probably indicating an increase in the rates of false positives. The admission rate is linked to factors such as oxygen saturation and RDW, but this is not entirely understood. In addition, the study also displayed a seasonal pattern linked to the highest number of confirmed cases in January, while the lowest was in April.

A multicenter analysis of trends in resistance in urinary Enterobacterales isolates from ambulatory patients in the United States: 2011-2020

BACKGROUND

Urinary tract infections (UTIs), which are usually caused by bacteria in the Enterobacterales family, are a common reason for outpatient visits. Appropriate empiric therapy for UTIs requires an understanding of antibiotic resistance in the community. In this nationwide study, we examined trends in antibiotic resistance in urinary Enterobacterales isolates from ambulatory patients in the United States (US).

METHODS

We analyzed the antimicrobial susceptibility profiles (extended-spectrum beta-lactamase [ESBL]-producing phenotype and not susceptible [NS] to beta-lactams, trimethoprim/sulfamethoxazole [TMP/SMX], fluoroquinolones [FQ], or nitrofurantoin [NFT]) of 30-day non-duplicate Enterobacterales isolates from urine cultures tested at ambulatory centers in the BD Insights Research Database (2011-2020). The outcome of interest was the percentage of resistant isolates by pathogen and year. Multi-variable generalized estimating equation models were used to assess trends in resistance over time and by additional covariates.

RESULTS

A total of 338 US facilities provided data for > 2.2 million urinary Enterobacterales isolates during the 10-year study. Almost three-quarters (72.8%) of Enterobacterales isolates were Escherichia coli. Overall unadjusted resistance rates in Enterobacterales isolates were 57.5%, 23.1%, 20.6%, and 20.2% for beta-lactams, TMP/SMX, FQ, and NFT, respectively, and 6.9% had an ESBL-producing phenotype. Resistance to two or more antibiotic classes occurred in 16.4% of isolates and 5.5% were resistant to three or more classes. Among isolates with an ESBL-producing phenotype, 70.1%, 59.9%, and 33.5% were NS to FQ, TMP/SMX, and NFT, respectively. In multivariable models, ESBL-producing and NFT NS Enterobacterales isolates increased significantly (both P < 0.001), while other categories of resistance decreased. High rates (≥ 50%) of beta-lactam and NFT resistance were observed in Klebsiella isolates and in non-E. coli, non-Klebsiella Enterobacterales isolates.

CONCLUSIONS

Antimicrobial resistance was common in urinary Enterobacterales isolates. Isolates with an ESBL-producing phenotype increased by about 30% between 2011 and 2020, and significant increases were also observed in NFT NS Enterobacterales isolates. Resistance rates for all four antibiotic classes were higher than thresholds recommended for use as empiric therapy. Non-E. coli Enterobacterales isolates showed high levels of resistance to commonly used empiric antibiotics, including NFT. These data may help inform empiric therapy choices for outpatients with UTIs.

Impact of Empirical Antibiotic Therapy on Outcomes of Outpatient Urinary Tract Infection Due to Nonsusceptible Enterobacterales

Resistance to oral antibiotics commonly used to treat outpatient urinary tract infections (UTIs) is increasing, but the implications of empirical treatment of resistant pathogens are not well described. Using an electronic records database, we reviewed the outcomes of patients >18 years of age who developed an outpatient UTI and had an outpatient urine culture result showing a member of the order Enterobacterales along with prescription data for an oral antibiotic filled on the day before, day of, or day after the culture was collected. Linear probability models were used to estimate partial effects of select clinical and demographic variables on the composite outcome. In all, 4,792 patients had 5,587 oral antibiotic prescriptions. Of 5,395 evaluable episodes, 22% of patients received an antibiotic to which the pathogen was resistant in vitro, and those patients were almost twice as likely to require a second prescription (34% versus 19%) or be hospitalized (15% versus 8%) within 28 days of the initial prescription fill compared to patients who received an antibiotic to which the pathogen was susceptible. Approximately 1% of Enterobacterales isolates were resistant to all commonly available classes of oral antibiotics. A greater risk of treatment failure was seen in patients over 60 years of age, patients with diabetes mellitus, men, and those treated with an antibiotic when prior culture identified an organism resistant to that class. The increasing resistance among members of Enterobacterales responsible for outpatient UTIs is limiting the effectiveness of empirical treatment with existing antibiotics, and consequently, outpatients with UTI are more likely to require additional courses of therapy or be hospitalized. IMPORTANCE Resistance rates for bacteria that cause urinary tract infections (UTIs) have increased dramatically. Regional rates of resistance to commonly prescribed antibiotics now exceed 20%, which is the threshold at which the Infectious Diseases Society of America recommends therapy be guided by culture. Our goals were to describe outcomes for outpatients with UTIs caused by bacteria resistant to empirically chosen antibiotics and to create a simple stratification schema for clinicians to identify UTI patients at increased risk of treatment failure due to antibiotic mismatch. These data are relevant to clinicians, given how common uncomplicated UTIs are, and highlight the need for clinicians to understand local resistance rates and the importance of culture-guided treatment, especially in vulnerable patients. These findings also showed that 1% of bacteria were resistant to all major classes of oral antibiotics, underscoring the need for new antibiotics to treat patients with UTIs due to resistant bacteria.

Clinical Outcome of Discordant Empirical Therapy and Risk Factors Associated to Treatment Failure in Children Hospitalized for Urinary Tract Infections

With the spread of antibiotic resistance in pediatric urinary tract infections (UTIs), more patients are likely to be started empirically on antibiotics to which pathogens are later found to be resistant (discordant therapy). However, in-vivo effectiveness may be different from in-vitro susceptibility. Aims of this study were to describe clinical outcomes of discordant empirical treatments in pediatric UTIs and to investigate risk factors associated to treatment failure. This observational, retrospective study was conducted on children hospitalized for febrile UTIs with positive urine culture and started on discordant empirical therapy. Failure rates of discordant treatments and associated risk factors were investigated. A total of 142/1600 (8.9%) patients were treated with inadequate empirical antibiotics. Clinical failure was observed in 67/142 (47.2%) patients, with no fatal events. Higher failure rates were observed for combinations of penicillin and beta-lactamase inhibitors (57.1%). Significant risk factors for failure of discordant treatment were history of recurrent UTIs (95% CI: 1.13–9.98, OR: 3.23, p < 0.05), recent use of antibiotics (95% CI: 1.46–21.82, OR: 5.02, p < 0.01), infections caused by Pseudomonas aeruginosa (95% CI: 1.85–62.10, OR: 7.30, p < 0.05), and empirical treatment with combinations of penicillin and beta-lactamase inhibitors (95% CI: 0.94–4.03, OR: 1.94, p = 0.05). This study showed that discordant empirical treatments may still be effective in more than half of pediatric UTIs. Clinical effectiveness varies between different discordant antibiotics in pediatric UTIs, and patients presenting risk factors for treatment failure may need a differentiated empirical approach.

A global perspective on improving patient care in uncomplicated urinary tract infection: Expert consensus and practical guidance

BACKGROUND

Uncomplicated urinary tract infections (uUTIs) are a common problem in women. Management is mainly based on empirical prescribing, but there are concerns about overtreatment and antimicrobial resistance (AMR), especially in patients with recurrent uUTIs.

METHODS

A multidisciplinary panel of experts met to discuss diagnosis, treatment, prevention, guidelines, AMR, clinical trial design, and the impact of COVID-19 on clinical practice.

RESULTS

Symptoms remain the cornerstone of uUTI diagnosis, and urine culture is necessary only when empirical treatment fails, or rapid recurrence of symptoms or AMR is suspected. Specific antimicrobials are first-line therapy (typically nitrofurantoin, fosfomycin, trimethoprim-sulfamethoxazole, and pivmecillinam; dependent on availability and local resistance data). Fluoroquinolones are not first-line options for uUTIs due primarily to safety concerns, but also rising resistance rates. High-quality data to support most non-antimicrobial approaches are lacking. Local AMR data specific to community-acquired uUTIs are needed, but representative information is difficult to obtain; instead, identification of risk factors for AMR can provide a basis to guide empirical antimicrobial prescribing. The COVID-19 pandemic has impacted management of uUTIs in some countries and may have long-lasting implications for future models of care.

CONCLUSIONS

The management of uUTIs in women can be improved without increasing complexity, including simplified diagnosis, and empirical antimicrobial prescribing based on patient characteristics, including review of recent antimicrobial use and past pathogen resistance profiles, drug availability, and guidelines. Current data for non-antimicrobial approaches are limited. The influence of COVID-19 on telehealth could provide an opportunity to enhance patient care in the long term.

Advances in novel antibiotics to treat multidrug-resistant gram-negative bacterial infections

Antimicrobial resistance is a growing threat to public health and an increasingly common problem for acute care physicians to confront. Several novel antibiotics have been approved in the past decade to combat these infections; however, physicians may be unfamiliar with how to appropriately utilize them. The purpose of this review is to evaluate novel antibiotics active against resistant gram-negative bacteria and highlight clinical information regarding their use in the acute care setting. This review focuses on novel antibiotics useful in the treatment of infections caused by resistant gram-negative organisms that may be seen in the acute care setting. These novel antibiotics include ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilistatin/relebactam, cefiderocol, plazomicin, eravacycline, and omadacycline. Acute care physicians should be familiar with these novel antibiotics so they can utilize them appropriately.

The prevalence and predictors of extended spectrum B-lactamase urinary tract infections among emergency department patients: A retrospective chart review

BACKGROUND AND IMPORTANCE

Inadequate initial antibiotic treatment of ESBL urinary tract infections (UTI) can lead to increase in the number of antibiotics used, return visits, longer hospitalizations, increased morbidity and mortality and increased costs. Given the important health implications on patients, this study aimed to examine the prevalence and predictors of ESBL UTIs among Emergency Department (ED) patients of a tertiary care center in Beirut, Lebanon.

DESIGN, SETTING AND PARTICIPANTS

Single-center retrospective observational study involving all adult UTI patients who presented to the ED of the American University of Beirut Medical Center, a tertiary care center between August 2019 and August 2020.

RESULTS

Out of the 886 patients that were included, 24.9% had an ESBL organism identified by urine culture. They had higher bladder catheter use within the previous 90 days, antibiotic use within last 90 days, and were more likely to have a history of an ESBL producing isolate from any body site in the last year. Antibiotic use in the last 90 days and a history of ESBL producing isolate at any site in the previous year were significantly associated with developing an ESBL UTI (OR = 1.66, p = 0.001 and OR = 2.53, p < 0.001 respectively). Patients diagnosed with cystitis were less likely to have an ESBL organism (OR = 0.4 95%CI [0.20-0.81], p = 0.01) CONCLUSION: The prevalence of ESBL organisms was found to be 24.9% in urinary tract infections. The predictors of an ESBL UTI infection were antibiotic use in the last 90 days, a history of ESBL producing isolate at any site in the previous year. Based on the findings of our study, we can consider modifying initial empiric antibiotic treatment for patients presenting with a UTI with the above stated risk factors.

Antimicrobial Resistance Trends in Urine Escherichia coli Isolates From Adult and Adolescent Females in the United States From 2011-2019: Rising ESBL Strains and Impact on Patient Management

Background

Uncomplicated urinary tract infection (uUTI) is predominantly caused by Escherichia coli, which has increasing antimicrobial resistance (AMR) at the United States (US)-community level. As uUTI is often treated empirically, assessing AMR is challenging, and there are limited contemporary data characterizing period prevalence in the US.

Methods

This was a retrospective study of AMR using Becton, Dickinson and Company Insights Research Database (Franklin Lakes, New Jersey, US) data collected 2011–2019. Thirty-day, nonduplicate Escherichia coli urine isolates from US female outpatients (aged ≥12 years) were included. Isolates were evaluated for nonsusceptibility (intermediate/resistant) to trimethoprim-sulfamethoxazole, fluoroquinolones, or nitrofurantoin, and assessed for extended-spectrum β-lactamase production (ESBL+) and for ≥2 or ≥3 drug-resistance phenotypes. Generalized estimating equations were used to model AMR trends over time and by US census region.

Results

Among 1 513 882 E. coli isolates, the overall prevalence of isolates nonsusceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, and nitrofurantoin was 25.4%, 21.1%, and 3.8%, respectively. Among the isolates, 6.4% were ESBL+, 14.4% had ≥2 drug-resistance phenotypes, and 3.8% had ≥3. Modeling demonstrated a relative average yearly increase of 7.7% (95% confidence interval [CI], 7.2–8.2%) for ESBL+ isolates and 2.7% (95% CI, 2.2–3.2%) for ≥3 drug-phenotypes (both P < .0001). Modeling also demonstrated significant variation in AMR prevalence between US census regions (P < .001).

Conclusions

Period prevalence of AMR among US outpatient urine-isolated E. coli was high, and for multidrug-resistance phenotypes increased during the study period with significant variation between census regions. Knowledge of regional AMR rates helps inform empiric treatment of community-onset uUTI and highlights the AMR burden to physicians.

Third-Generation Cephalosporin Resistance and Associated Discordant Antibiotic Treatment in Emergency Department Febrile Urinary Tract Infections

STUDY OBJECTIVE

Third-generation cephalosporin-resistant (3GCR) Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis (EKP) are an increasingly common cause of community-onset urinary tract infections (UTIs) in the United States. The 3GCR antimicrobial resistance pattern in these Enterobacterales species is most commonly due to production of extended-spectrum β-lactamases. We sought to provide contemporary, emergency department (ED)-focused data on 3GCR-EKP UTI regional prevalence, presentation, antibiotic susceptibility, and empiric treatment patterns, and outcomes.

METHODS

We performed a retrospective cohort study of all adults admitted with a febrile UTI at 21 Kaiser Permanente Northern California EDs between January 2017 and June 2019. Inclusion criteria included fever; admitting diagnosis of UTI, pyelonephritis, or sepsis; and ED urine culture with greater than 100,000 colony-forming units/mL of an EKP species. 3GCR was defined as in vitro resistance to ceftriaxone, ceftazidime, or both. 3GCR-EKP cases were compared with non-3GCR-EKP controls for the following: demographics, comorbidities, presenting clinical features, urinary isolate antimicrobial susceptibility, treatment, and clinical outcomes. The primary outcome measure was the rate of discordant initial empiric antibiotic treatment (administered within 6 hours of ED arrival) when compared with antimicrobial susceptibility testing. Secondary outcomes included hospital length of stay and 90-day mortality, adjusted for comorbidities and severity of illness.

RESULTS

There were 4,107 patients (median age 73 years and 35% men) who met study inclusion criteria. Of these patients, 530 (12.9%) had a 3GCR-EKP urinary tract infection. The proportion of subjects possessing risk factors for a health care-associated or extended-spectrum β-lactamase infection was 92.8% of case patients and 86.1% of controls. When comparing 3GCR-EKP case and non-3GCR-EKP control isolates, ciprofloxacin susceptibility rates were 21% versus 88%, and piperacillin/tazobactam susceptibility rates were 89% versus 97%, respectively. Initial empiric antibiotic therapy was discordant with antimicrobial susceptibility testing results in 63% of case patients versus 7% of controls (odds ratio 21.0; 95% confidence interval 16.9 to 26.0). The hospital length of stay was longer for 3GCR-EKP case patients, with an adjusted mean difference of 29.7 hours (95% CI 19.0 to 40.4). Ninety-day mortality was 12% in case patients versus 8% in controls (adjusted odds ratio 1.56; 95% confidence interval 1.07 to 2.28).

CONCLUSION

In this large, 2017 to 2019 Northern California ED study, nearly 13% of febrile EKP UTIs requiring hospitalization were caused by 3GCR-EKP, and in these cases, initial empiric therapy was often discordant with antimicrobial susceptibility testing. 3GCR-EKP infections were associated with a longer hospital length of stay and higher 90-day mortality. Similar data from other regions and for outpatient UTIs are needed.

Contemporary Management of Urinary Tract Infection in Children

Urinary tract infection (UTI) is common in children, and girls are at a significantly higher risk, as compared to boys, except in early infancy. Most cases are caused by Escherichia coli Collection of an uncontaminated urine specimen is essential for accurate diagnosis. Oral antibiotic therapy for 7 to 10 days is adequate for uncomplicated cases that respond well to the treatment. A renal ultrasound examination is advised in all young children with first febrile UTI and in older children with recurrent UTI. Most children with first febrile UTI do not need a voiding cystourethrogram; it may be considered after the first UTI in children with abnormal renal and bladder ultrasound examination or a UTI caused by atypical pathogen, complex clinical course, or known renal scarring. Long-term antibiotic prophylaxis is used selectively in high-risk patients. Few patients diagnosed with vesicoureteral reflux after a UTI need surgical correction. The most consequential long-term complication of acute pyelonephritis is renal scarring, which may increase the risk of hypertension or chronic kidney disease later in life. Treatment of acute pyelonephritis with an appropriate antibiotic within 48 hours of fever onset and prevention of recurrent UTI lowers the risk of renal scarring. Pathogens causing UTI are increasingly becoming resistant to commonly used antibiotics, and their indiscriminate use in doubtful cases of UTI must be discouraged.

Characterization of predictors of ESBL-producing enterobacteriaceae in urine cultures of emergency department patients

STUDY OBJECTIVE

With increasing prevalence of extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBLE), more reliable identification of predictors for ESBLE urinary tract infection (UTI) in the emergency department (ED) is needed. Our objective was to evaluate risk factors and their predictive ability for ED patients with ESBLE UTI.

METHODS

This was a retrospective case-control study at an urban academic medical center. Microbiology reports identified adult ED patients with positive urine cultures from 2015-2018. Inclusion criteria were diagnosis of UTI with monomicrobial enterobacteriaceae culture growth. Exclusions were cultures with carbapenemase-resistant enterobacteriaceae or urinary colonization. Collected variables included demographics, comorbidities, and recent medical history. Patient disposition, urine culture susceptibilities, presence of ESBLE, empiric antibiotics, and therapy modifications were collected. Patients were stratified based on ESBLE status and analyzed via descriptive statistics. The data were divided into 2 parts: the first used to identify possible predictors of ESBLE UTI and the second used to validate an additive scoring system.

RESULTS

Of 466 patients, 16.3% had ESBLE urine culture growth and 83.7% did not; 39.5% of ESBLE patients required antibiotic therapy modification, as compared to 6.4% of ESBLE negative patients (odds ratio [OR] 9.5; confidence interval [CI] 8.9-10.1). Independent predictors of ESBLE UTI were IV antibiotics within 1 year (OR 5.4; CI 2.1-12.8), surgery within 90 days (OR 6.4; CI 1.5-27.8), and current refractory UTI (OR 8.5; CI 2.0-36.6).

CONCLUSION

Independent predictors of ESBLE UTI in emergency department patients included IV antibiotics within 1 year, surgery within 90 days, and current refractory UTI.

Critically Ill Health Care-Associated Urinary Tract Infection: Broad vs. Narrow Antibiotics in the Emergency Department Have Similar Outcomes

BACKGROUND

Urinary tract infection (UTI) is the second most common infection requiring intensive care unit (ICU) admission in emergency department (ED) patients. Optimal empiric management for health care-associated (HCA) UTI is unclear, particularly in the critically ill.

OBJECTIVE

To compare clinical failure of broad vs. narrow antibiotic selection in the ED for patients presenting with HCA UTI admitted to the ICU.

METHODS

Observational cohort of patients started on empiric antibiotic for UTI with at least one HCA risk factor (recurrent UTI, chronic urinary catheter or dialysis, urologic procedures, previous antibiotic exposure, hospitalization, or group facility residence). Broad antibiotics covered Pseudomonas spp. and extended-spectrum beta-lactamase. Clinical failure was a composite of multiorgan dysfunction (MODS) by day 2 and in-hospital mortality. Secondary outcomes were length of stay (LOS), readmission, recurrent infection, development of multidrug-resistant organisms, and Clostridium difficile infection. Associations were reported with odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

There were 272 patients included; 196 (72.1%) received broad and 76 (27.9%) received narrow therapy. There was no association between antibiotic selection and clinical failure (OR 1.05, 95% CI 0.5-2.25, p = 0.89) or between antibiotic selection and number of HCA risk factors (OR 0.98, 95% CI 0.73-1.31, p = 0.87). There was an association between clinical failure and MODS on ICU admission (OR 9.14, 95% CI 4.70-17.78, p < 0.001). Hospital LOS and readmission did not differ between antibiotic groups.

CONCLUSION

Initial empiric broad or narrow antibiotic coverage in HCA UTI patients who presented to the ED and required ICU admission had similar clinical outcomes.

Prevalence and Antibiotic Resistance of ESKAPE Pathogens Isolated in the Emergency Department of a Tertiary Care Teaching Hospital in Hungary: A 5-Year Retrospective Survey

Antibiotic treatments initiated on Emergency Departments (ED) are empirical. Therefore, knowledge of local susceptibility patterns is important. Despite this, data on expected pathogens and their resistance profile are scarce from EDs internationally. The study aim was to assess the epidemiology and resistance patterns of bacterial isolates from a tertiary-care ED over 5 years, focusing on ESKAPE bacteria (including the Enterobacterales group). After removal of duplicates, n = 6887 individual bacterial isolates were recovered, out of which n = 4974 (72.22%) were ESKAPE isolates. E. coli was the most frequent isolate (2193, 44.1%), followed by the Klebsiella genus (664; 13.4%). The third most frequent isolate was S. aureus (561, 11.3%). In total, multi-drug resistance (MDR) was present in 23.8% and was most prevalent in A. baumanii (65.5%), P. mirabilis (42.7%), and K. pneumoniae (32.6%). MRSA was isolated in 19.6%, while ESBL-producing Enterobacterales in 17.7%, and these were associated with remarkably higher resistance to other antibacterials as well. Difficult-to-treat resistance (DTR) was detected in 0.5%. The frequent isolation of some ESKAPE bacteria and the detected considerable acquired resistance among ED patients raise concern. The revealed data identified problematic pathogens and will guide us to set up the optimal empiric antibiotic protocol for clinicians.

Differential Trends in Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Infections in Four Health Care Facilities in a Single Metropolitan Area: A Retrospective Analysis

Background: Prevalence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) is increasing worldwide, but greatly varies geographically. We compared the prevalence of ESBL-E. coli infections at four distinct health care facilities in San Francisco, California. Methods: Antimicrobial susceptibility reports were obtained for E. coli isolates from (1) a county hospital, (2) a public skilled nursing facility, (3) a university hospital, and (4) a Veterans Affairs (VA) Medical Center. We compared change in frequency of ESBL-E. coli and antimicrobial resistance to trimethoprim-sulfamethoxazole between 2012 and 2018. Results: From 2012 to 2018, frequency of ESBL-E. coli increased in urine and nonurine isolates from the county hospital (urine: 1.1% per year, 95% confidence interval [CI]: 0.5-1.6, p < 0.01; nonurine: 1.9% per year, 95% CI: 0.9-2.9, p < 0.01) and in urine isolates from the VA hospital (0.9% per year, 95% CI: 0.3-1.4, p < 0.01). The frequency of trimethoprim-sulfamethoxazole resistance fluctuated in all facilities. Conclusions: At the skilled nursing facility, the prevalence of ESBL-E. coli was highest, but remained stable over time, while the prevalence of ESBL-E. coli increased among urine and nonurine isolates at the county hospital and urine isolates at the VA hospital. The temporal trend of ESBL-E. coli infections, even within one city, varied by health care facility.

A risk prediction model of urinary tract infections for patients with neurogenic bladder

Objectives: To develop a nomogram to evaluate the risk of urinary tract infections (UTI) in patients with neurogenic bladder (NGB)Methods: A retrospective analysis was conducted on 337 patients with NGB admitted to three hospitals. Collected data included clinical symptoms, patients' general characteristics, laboratory examinations and imaging findings. Multivariate logistic regression analysis was conducted to develop the risk prediction nomogram of UTIs for NGB patients. C index was used for the internal and external validation of that model.Results: The occurrence of UTIs was 45.7% (154 of 337), 52.6% (102 of 194), and 36.4% (52 of 143) in the overall, training and validation data sets, respectively. The prediction nomogram was developed with 5 prognostic factors which included white blood cell (WBC) in blood, Leukocyte (LEU) in urine, Urinary pH, length of stay and urination mode. The nomogram presented good discrimination with a C-index value of 0.921 (95% confidence interval: 0.87396 - 0.96804) and good calibration. The C-index values of the interval validation and external validation were 0.8905541 and 0.817, respectively. The results of decision curve analysis (DCA) demonstrated that the model was clinically useful.Conclusions: The prediction nomogram we developed is a simple and accurate tool for early prediction of UTIs in patients with NGB. This tool can assess risk of UTIs early, allowing for timely initiation of appropriate preventive measures.

Carbapenem and Cephalosporin Resistance among Enterobacteriaceae in Healthcare-Associated Infections, California, USA1

We analyzed antimicrobial susceptibility test results reported in healthcare-associated infections by California hospitals during 2014-2017. Approximately 3.2% of Enterobacteriaceae reported in healthcare-associated infections were resistant to carbapenems and 26.9% were resistant to cephalosporins. The proportion of cephalosporin-resistant Escherichia coli increased 7% (risk ratio 1.07, 95% CI 1.04-1.11) per year during 2014-2017.

Trends and impact of antimicrobial resistance on older inpatients with urinary tract infections (UTIs): A national retrospective observational study

Urinary tract infections (UTIs) are one of the most common infections in older people and are associated with increased morbidity and mortality. UTIs are also associated with increased risk of antimicrobial resistance (AR). This study examined changes in AR among older inpatients with a primary diagnosis of UTIs in the United States over an 8-year period and the impact of AR on clinical outcomes and hospital costs. Data were obtained from the longitudinal hospital HCUP-NIS database from 2009 to 2016 for inpatient episodes that involved those aged 65+ years. The ICD-9 and ICD-10 codes were used to identify episodes with a primary diagnosis of UTIs, comorbidities, AR status and age-adjusted Deyo-Charlson comorbidity index (ACCI) for the patient concerned. Weighted multivariable regression was used to examine the impact of AR on all-cause inpatient mortality, discharge destination, length of stay and hospital expenditures, adjusted for socio-demographic and clinical covariates. The proportion of admissions with AR increased, from 3.64% in 2009 to 6.88% in 2016 (p<0.001), with distinct patterns for different types of resistance. The likelihood of AR was higher in admissions with high ACCI scores and admissions to hospitals in urban areas. Admissions with AR were more likely to be discharged to healthcare facilities (e.g. care homes) compared to routine discharge (OR 1.81; 95%CI, 1.75–1.86), had increased length of stay (1.12 days; 95%CI, 1.06–1.18) and hospital costs (1259 USD; 95%CI, 1178–1340). Resistance due to MRSA was specifically associated with increased hospital mortality (OR 1.33; 95%CI, 1.15–1.53). Our findings suggest that the prevalence of AR has increased among older inpatients with UTIs in the USA. The study highlights the impact of AR among older inpatients with a primary diagnosis of UTIs on clinical outcomes and hospital costs. These relationships and their implications for the care homes to which patients are frequently discharged warrant further research.

National prevalence estimates for resistant Enterobacteriaceae and Acinetobacter species in hospitalized patients in the United States

OBJECTIVES

To determine antimicrobial nonsusceptibility rates for Enterobacteriaceae and Acinetobacter spp. in US hospitals.

METHODS

We analyzed antimicrobial susceptibilities of non-duplicate Enterobacteriaceae and Acinetobacter spp. isolates reported in 2017 from 375 US hospitals in the BD Insights Research Database. Logistic and Poisson regression modeling methods were used to estimate proportions of resistant isolates and rates per 1000 hospital admissions. National projections were generated based on raking (weighting) methods.

RESULTS

The nationwide proportions of resistant isolates in inpatients were an estimated 12.6%, 6.6%, and 1.2% for Enterobacteriaceae with extended-spectrum beta-lactamase (ESBL), multidrug resistant (MDR), and carbapenem-nonsusceptible (Carb-NS) phenotypes, respectively, and 42.4% and 34.5% for Acinetobacter spp. with MDR and Carb-NS phenotypes. Resistance varied by geographic region and hospital size/type. Estimated nationwide rates per 1000 hospital admissions ranged from a high of 7.1 for ESBL Enterobacteriaceae to a low of 0.3 for Carb-NS Acinetobacter spp. The estimated number of isolates occurring in US inpatients each year was 290,220 ESBL, 173,984 MDR, and 30,194 Carb-NS for Enterobacteriaceae and 12,274 MDR and 9,991 Carb-NS for Acinetobacter spp.

CONCLUSIONS

National prevalence estimates suggest high levels of antimicrobial resistance and a substantial number of patients with resistant Enterobacteriaceae and Acinetobacter spp. in US hospitals.

A Systematic Review of Single-Dose Aminoglycoside Therapy for Urinary Tract Infection: Is It Time To Resurrect an Old Strategy?

Increasing bacterial resistance and poor patient adherence rates limit the effectiveness of conventional antibiotic therapies for urinary tract infection (UTI). The objective of this study was to investigate whether a single aminoglycoside dose adequately treated UTI. A systematic search of PubMed/MEDLINE and Google Scholar databases was performed through September 2018 for English language original research articles assessing the efficacy of one-time parenteral aminoglycoside as UTI monotherapy. Of 252 potentially relevant studies, 13 studies met the inclusion criteria, representing 13,804 patients. Patient ages ranged from 2 weeks to >70 years; both inpatient and outpatient settings were represented. Cystitis was more common than pyelonephritis, and more females were represented than males. Escherichia coli was the most commonly isolated uropathogen. The pooled microbiologic cure rate with single-dose aminoglycoside therapy was 94.5% ± 4.3%. Cure was sustained (no recurrence) for 73.4% ± 9.6% of patients at day 30. Lower cure rates were observed among patients with radiographic urinary tract abnormality (chi-square P < 0.01). Across all studies, 63/13,804 (0.5%) cases of nephrotoxicity, vestibular toxicity, or injection site reaction were reported; no hearing loss was observed. Single-dose aminoglycoside therapy appears to be an effective treatment option for lower UTI in nonseptic patients, with minimal toxicity. Additional studies would be beneficial to confirm efficacy for pyelonephritis. When resistance to first-line UTI agents is endemic, aminoglycosides may serve as β-lactam- and fluoroquinolone-sparing options.