Community-onset Urinary Tract Infections Research Articles

Urinary tract infections in older adults: associated factors for extended-spectrum beta-lactamase production.

Urinary tract infections (UTIs) due to extended-spectrum beta-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae are among the leading causes of morbidity and mortality in older adults. Identifying associated factors for ESBL production may contribute to more appropriate empirical treatment. This was a prospective observational study. Hospitalized patients of age > 65 with community-onset or hospital-acquired upper UTI due to E. coli or Klebsiella pneumoniae were included. A multivariate analysis was performed. A total of 97 patients were included. ESBL prevalence among UTIs with E. coli or Klebsiella pneumoniae was 69.1% (n = 67). CRP values at the time of UTI diagnosis were found to be significantly higher in the ESBL-producing group (p = 0.004). The multivariate analysis revealed that male gender (OR: 2.72, CI: 1.02-7.25), prior recurrent UTI (OR: 3.14, CI: 1.21-8.14), and the development of secondary bacteremia (OR: 4.95, CI: 1.03-23.89) were major associated factors for UTI in older adults due to ESBL-producing E. coli and Klebsiella pneumoniae. Severe UTI in older men with a history of recurrent UTI may be a warning to the clinician for ESBL production in the setting of high ESBL prevalence. Carbapenems may be prioritized in the empirical treatment of patients with known risk factors for ESBL.

2848. Risk factors for recurrence of community-onset urinary tract infections caused by extended spectrum cephalosporin-resistant Enterobacterales

Abstract Background Extended spectrum cephalosporin-resistant Enterobacterales (ESCR-E) are increasingly implicated in community-onset urinary tract infections (UTIs). In this study, we assessed risk factors for recurrence among patients with community-onset UTI caused by ESCR-E. Methods This retrospective cohort study included adult patients evaluated April 2018 – December 2021 in the Duke University Health System with community-onset ESCR-E UTI, defined as (1) ESCR-E in a urine culture obtained in an outpatient clinic, emergency department, or within 48 hours of hospital admission; (2) ≥10 leukocytes per high-power field on urine microscopy or urine dipstick positive for leukocyte esterase; and (3) new antibiotic administration or prescription. ESCR-E UTI recurrence was assessed 14 to 180 days after completion of antibiotic treatment for the index UTI. Patients were right censored at end of follow up period or upon death. Univariate Cox proportional hazards regression was performed to evaluate the relationships between candidate risk factors and time to recurrence. Results 1428 patients were included; 207 (14.5%) experienced recurrence. In unadjusted analyses, risk factors for recurrent ESCR-E UTI included diabetes mellitus (hazard ratio [HR] = 1.4, 95% confidence interval [CI]: 1.1 to 1.9, p = 0.01), chronic renal insufficiency (HR = 1.6, 95% CI: 1.2 to 2.1, p < 0.001), neurogenic bladder (HR = 2.1, 95% CI: 1.4 to 2.9, p < 0.001), previous UTI diagnosis within one year (HR = 2.6, 95% CI: 1.9 to 3.5, p < 0.001), fluoroquinolone non-susceptibility (HR = 1.6, 95% CI: 1.2 to 2.2, p = 0.004), and trimethoprim-sulfamethoxazole non-susceptibility (HR = 1.3, 95% CI: 1.0 to 1.8, p = 0.045). Patients with ESCR Klebsiella pneumoniae UTI had a 53% greater hazard of recurrence compared to patients with ESCR E. coli UTI (HR = 1.5, 95% CI: 1.1 to 2.1, p = 0.008). Conclusion ESCR-E UTI recurrence was common, and several clinical and microbiologic characteristics were associated with recurrence. Patients with these characteristics should receive particular consideration for aggressive UTI risk factor modification and other non-antibiotic prevention strategies. Future studies should evaluate strategies to reduce the risk of recurrence among patients with ESCR-E UTI. Disclosures All Authors: No reported disclosures

Assessing the impact of discordant antibiotic treatment on adverse outcomes in community-onset UTI: a retrospective cohort study.

To investigate the risk of adverse outcomes following discordant antibiotic treatment (urinary organism resistant) for culture-confirmed community-onset lower urinary tract infection (UTI). Cohort study using routinely collected linked primary care, secondary care and microbiology data from patients with culture-confirmed community-onset lower UTI (COLUTI). Antibiotic treatment within ±3 days was considered concordant if the urinary organism was sensitive and discordant if resistant.The primary outcome was the proportion of patients experiencing urinary infection-related hospital admission (UHA) within 30 days. Secondary outcomes were the proportion of patients experiencing reconsultation within 30 days, and the odds of UHA and reconsultation following discordant treatment, adjusting for sex, age, risk factors for complicated UTI, previous antibiotic treatment, recurrent UTI and comorbidities. A total of 11 963 UTI episodes in 8324 patients were included, and 1686 episodes (14.1%, 95% CI 13.5%-14.7%) were discordant. UHA occurred in 212/10 277 concordant episodes (2.1%, 95% CI 1.8%-2.4%) and 88/1686 discordant episodes (5.2%, 95% CI 4.2%-6.4%). Reconsultation occurred in 3961 concordant (38.5%, 95% CI 37.6%-39.5%) and 1472 discordant episodes (87.3%, 95% CI 85.6%-88.8%). Discordant treatment compared with concordant was associated with increased odds of UHA (adjusted OR 2.31, 95% CI 1.77-3.0, P < 0.001) and reconsultation (adjusted OR 11.25, 95% CI 9.66-13.11, P < 0.001) on multivariable analysis. Chronic kidney disease and diabetes mellitus were also independently associated with increased odds of UHA. One in seven COLUTI episodes in primary care were treated with discordant antibiotics. In higher risk patients requiring urine culture, empirical antibiotic choice optimization could meaningfully reduce adverse outcomes.

Risk Factors for Recurrence of Community-Onset Urinary Tract Infections Caused by Extended-Spectrum Cephalosporin-Resistant Enterobacterales.

Extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) are an increasingly important cause of community-onset urinary tract infections (UTIs), including recurrent infections. We evaluated risk factors for recurrence among patients with community-onset ESCrE UTI. This retrospective cohort study included adults with community-onset ESCrE UTI in the Duke University Health System from April 2018 through December 2021. ESCrE UTI recurrence by the same species was assessed 14-180 days (ie, 6 months) after completion of antibiotic treatment. We evaluated the relationships between candidate risk factors and time to recurrence using Cox proportional hazards regression models. Among 1347 patients with community-onset ESCrE UTI, 202 (15.0%) experienced recurrent infection during the 6-month follow-up period. Independent risk factors for recurrence included neurogenic bladder (adjusted hazard ratio [aHR], 1.8 [95% confidence interval {CI}, 1.2-2.6]; P = .005), prior history of UTI (aHR, 2.4 [95% CI, 1.7-3.3]; P < .001), and fluoroquinolone nonsusceptibility of the index UTI (aHR, 1.5 [95% CI, 1.1-2.1]; P = .02). Klebsiella pneumoniae infection was associated with recurrence in univariate analysis (HR, 1.6 [95% CI, 1.1-2.1]; P = .007) but not multivariate analysis (aHR, 1.4 [95% CI, 1.0-1.9]; P = .06). Inappropriate initial or definitive antibiotic therapy was not predictive of ESCrE UTI recurrence. Recurrence of community-onset ESCrE UTI was common and associated with several patient and pathogen-level risk factors. Future studies should evaluate microbial risk factors for recurrence and improve the management of ESCrE UTI.

Hospital admission after primary care consultation for community-onset lower urinary tract infection: a cohort study of risks and predictors using linked data.

Urinary tract infections (UTIs) are a common indication for antibiotic prescriptions, reductions in which would reduce antimicrobial resistance (AMR). Risk stratification of patients allows reductions to be made safely. To identify risk factors for hospital admission following UTI, to inform targeted antibiotic stewardship. Retrospective cohort study of East London primary care patients. Hospital admission outcomes following primary care consultation for UTI were analysed using linked data from primary care, secondary care, and microbiology, from 1 April 2012 to 31 March 2017. The outcomes analysed were urinary infection-related hospital admission (UHA) and all-cause hospital admission (AHA) within 30 days of UTI in primary care. Odds ratios between specific variables (demographic characteristics, prior antibiotic exposure, and comorbidities) and the outcomes were predicted using generalised estimating equations, and fitted to a final multivariable model including all variables with a P-value <0.1 on univariable analysis. Of the 169 524 episodes of UTI, UHA occurred in 1336 cases (0.8%, 95% confidence interval [CI] = 0.7 to 0.8) and AHA in 6516 cases (3.8%, 95% CI = 3.8 to 3.9). On multivariable analysis, increased odds of UHA were seen in patients aged 55-74 years (adjusted odds ratio [AOR] 1.49) and ≥75 years (AOR 3.24), relative to adults aged 16-34 years. Increased odds of UHA were also associated with chronic kidney disease (CKD; AOR 1.55), urinary catheters (AOR 2.01), prior antibiotics (AOR 1.38 for ≥3 courses), recurrent UTI (AOR 1.33), faecal incontinence (FI; AOR 1.47), and diabetes mellitus (DM; AOR 1.37). Urinary infection-related hospital admission after primary care consultation for community-onset lower UTI was rare; however, increased odds for UHA were observed for some patient groups. Efforts to reduce antibiotic prescribing for suspected UTI should focus on patients aged <55 years without risk factors for complicated UTI, recurrent UTI, DM, or FI.

Trends in the Rates of Extended-Spectrum-β-Lactamase-Producing Enterobacterales Isolated from Urine Cultures during the COVID-19 Pandemic in Ontario, Canada.

Worldwide, extended-spectrum β-lactamase (ESBL) rates are increasing at an alarming level with increasing rates of health care exposures, international travel, and antibiotic usage. In this study, we investigated whether enhanced social isolation, travel restrictions, and the reduced use of antibiotics in Ontario, Canada during coronavirus disease 2019 (COVID-19) pandemic had an impact on ESBL rates in urine cultures collected from the community and long-term-care (LTC) facilities across the province. Data from a total of 8.6 million urine cultures performed at LifeLabs Ontario from 2016 to 2021 were utilized for analysis. ESBL-producing Escherichia coli (ESBL Escherichia coli) and ESBL Klebsiella pneumoniae were identified using standard operating procedures. Data trends were estimated by interrupted time series (ITS) regression analysis. Among 2.3 million positive urine cultures, 48.9% and 7.2% grew E. coli and K. pneumoniae, of which 5.8% and 3.3% produced ESBLs, respectively. While the overall rate of ESBL isolation was higher in the pandemic period than in the prepandemic period, by ITS regression analysis of the monthly rates of ESBL isolation, decreasing trends were noted for ESBL E. coli in both the community and LTC facilities and for ESBL K. pneumoniae in the community. The ESBL K. pneumoniae rates in LTC facilities continued to increase throughout the COVID-19 period. By subgroup analysis for different genders, age groups, and local health integration network (LHIN) units, similar trends were seen in most cases (P < 0.05), except for a few densely populated LHINs where rate changes were not statistically significant. IMPORTANCE Community-onset urinary tract infections (UTIs) caused by ESBL-producing Enterobacterales, particularly E. coli and K. pneumoniae, are a major public health concern. In this study, we assessed the impact of COVID-19 on ESBL rates in urine cultures in Ontario, Canada. Our results show the recent epidemiology of ESBL-producing Enterobacterales in urine cultures from both the community and LTC facilities in Ontario, Canada, and the impact of COVID-19 restrictions on ESBL trends for the entire province as well as different subgroups of the population based on demographic and geographic characteristics. Our results may have important public health implications in the context of the gradual easing of COVID-19 restrictions.

Antimicrobial Susceptibility Patterns of Escherichia coli from Urine Isolates

Urinary tract infections (UTIs) are predominantly caused by Escherichia coli (E. coli). Increasing E. coli resistance to antibiotics is a major concern worldwide. Since UTIs are often treated by trial and error, measuring antimicrobial resistance (AMR) is important. However, there isn't much information about the rate of antimicrobial resistance to E. coli in the Libyan community. To determine rate of antimicrobial susceptibility patterns of E. coli urine isolates, in Al-Bayda, Libya. A retrospective study, in which 104 E. coli urine isolates were conducted using the antimicrobial susceptibility profile (antibiogram) of six different antibiotics against E. coli, isolates, were collected from several medical laboratories. Out of the 104 E. coli urine isolates, the MDR was 39.4%. The overall frequency of isolates resistant to ceftriaxone was 62.5%, trimethoprim-sulfamethoxazole (TMP-SMZ)(54.8%), Amoxicillin-Clavulanic acid (47.11%), ciprofloxacin (26%), nitrofurantoin (18.26%), and levofloxacin (15.4%). Prevalence of AMR among Libyan outpatient urine-isolated E. coli was high, with a high incidence of multidrug-resistance. The knowledge of antibiotic resistance rates in the region helps inform empiric treatment of community-onset UTI and highlights the antibiotic resistance profile to clinicians.

2229. Antibiotic Resistance in Gram-Negative Community-Onset Urinary Tract Infections Among Adults Presenting to Hospitals, United States, 2012-2020

Abstract Background Choosing empiric therapy for patients with community-onset urinary tract infections (CO-UTI) presenting to hospitals for treatment is challenging without understanding local antimicrobial susceptibility patterns. We investigated changes over time in antimicrobial resistance among CO-UTI pathogens and identified patient-level factors associated with higher levels of resistance. Methods We used non-duplicate positive urine cultures in the 2012-2020 Premier Healthcare Database as a proxy for CO-UTI in patients ≥ 18 years old presenting to hospitals receiving care categorized as community-onset inpatient (CO-INPT) or observation/emergency department (OBS/ED). We included cultures positive for Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa obtained within 3 days of admission. Phenotypes investigated include resistance to extended-spectrum cephalosporins (ESC), fluoroquinolones (FLQ), and trimethoprim-sulfamethoxazole (TMP-SX). Logistic regression analyses were performed. Results Among 1,987,605 urine cultures meeting study criteria from 432 hospitals, &amp;gt; 66% were E. coli. Antibiotic resistance (AR) was highest to FLQ among CO-INPT E. coli (31.7%) and P. mirabilis (29.3%) in 2020. ESC resistance increased from 2012 to 2020 among E. coli and K. pneumoniae in both CO-INPT and OBS/ED (p&amp;lt; 0.001). TMP-SX resistance remained &amp;gt; 20% among E. coli in CO-INPT and OBS/ED and P. mirabilis in CO-INPT throughout the study period. All AR phenotypes were significantly higher among CO-INPT than OBS/ED (p&amp;lt; 0.001), and higher among males than females (p&amp;lt; 0.001). FLQ resistance among E. coli, P. mirabilis, and P. aeruginosa was &amp;gt; 20% among males (28.2%, 30.4%, 21.9% respectively) but not females (17.5%, 15.1%, 14.5%) in OBS/ED, while it was &amp;gt; 20% among both males (37.2%, 37.3%, 24.6%) and females (31.2%, 33.9%, 21.9%) in CO-INPT. Figure 1.% Resistance to extended-spectrum cephalosporins by year and acute care setting.Figure 2.% Resistance to fluoroquinolones by year and acute care setting.Figure 3.% Resistance to trimethoprim-sulfamethoxazole by year and acute care setting. Conclusion Resistance to TMP-SX in both CO-INPT and OBS/ED, and FLQ in CO-INPT, was elevated suggesting alternative empiric therapy might be necessary for CO-UTI presenting to hospitals. Increasing resistance to ESC among pathogens in CO-INPT cultures warrants further evaluation of local resistance levels. Gender and need for inpatient therapy are factors to consider in developing local treatment recommendations. Disclosures All Authors: No reported disclosures.

From Pathophysiological Hypotheses to Case-Control Study Design: Resistance from Antibiotic Exposure in Community-Onset Infections.

Antimicrobial resistance is a global public health concern, at least partly due to the misuse of antibiotics. The increasing prevalence of antibiotic-resistant infections in the community has shifted at-risk populations into the general population. Numerous case–control studies attempt to better understand the link between antibiotic use and antibiotic-resistant community-onset infections. We review the designs of such studies, focusing on community-onset bloodstream and urinary tract infections. We highlight their methodological heterogeneity in the key points related to the antibiotic exposure, the population and design. We show the impact of this heterogeneity on study results, through the example of extended-spectrum β-lactamases producing Enterobacteriaceae. Finally, we emphasize the need for the greater standardization of such studies and discuss how the definition of a pathophysiological hypothesis specific to the bacteria–resistance pair studied is an important prerequisite to clarify the design of future studies.

Impact of restriction of over-the-counter sales of antimicrobials on antimicrobial resistance in Escherichia coli from community-onset urinary tract infections in inner São Paulo State, Brazil.

Antimicrobial resistance in community-associated infections is an increasing worldwide concern. In low-to-middle income countries, over-the-counter (OTC) sales of antimicrobials without medical prescription have been blamed for increasing consumption and resistance. We studied the impact of restriction of OTC sales of antimicrobials in Brazil (instituted in October 2010) on resistance trends of Escherichia coli from community-onset urinary tract infections. We analyzed monthly resistance trend of Escherichia coli from community-onset urinary tract infections from 2005 through 2018. The data were submitted to interrupted time series analysis in both linear and Poisson regression models. We found impact on cefazolin (p<0.001) and amikacin (p<0.001) resistance as immediate impact of the intervention, and no beneficial impact on resistance to ciprofloxacin, ceftriaxone or sulfamethoxazole-trimethoprim. At the present study, we found that OTC sales restriction did not generally impact on antimicrobial resistance.

Antimicrobial resistance in patients with suspected urinary tract infections in primary care in Assam, India.

ObjectivesWe investigated the prevalence and diversity of antimicrobial resistance in bacteria isolated from urine samples of community-onset urinary tract infection (UTI) patients in southern Assam, India.MethodsFreshly voided midstream urine samples were collected from patients attending primary healthcare centres, with the patients’ epidemiological data also recorded. Species identification was confirmed using a VITEK 2 compact automated system. Phenotypic confirmation of ESBLs was performed using the combined disc diffusion method (CLSI 2017) and carbapenemase production was phenotypically characterized using a modified Hodge test. Common ESBLs and carbapenem-resistance mechanisms were determined in Escherichia coli isolates using PCR assays. Incompatibility typing of the conjugable plasmids was determined by PCR-based replicon typing; the phylotypes and MLSTs were also analysed.ResultsA total of 301 (59.7%) samples showed significant bacteriuria along with symptoms of UTI and among them 103 isolates were identified as E. coli of multiple STs (ST3268, ST3430, ST4671 and others). Among them, 26.2% (27/103) were phenotypically ESBL producers whereas 12.6% (13/103) were carbapenemase producers. This study describes the occurrence of diverse ESBL genes—blaCTX-M-15, blaSHV-148, blaPER-1 and blaTEM—and two E. coli isolates carrying the blaNDM-1 carbapenemase gene. ESBL genes were located within transconjugable plasmids of IncP and IncF type whereas blaNDM-1 was carried in an IncFrepB type plasmid.ConclusionsThis study illustrates the high rate of MDR in E. coli causing UTI in primary care in rural Assam. UTIs caused by ESBL- or MBL-producing bacteria are very difficult to treat and can often lead to treatment failure. Thus, future research should focus on rapid diagnostics to enable targeted treatment options and reduce the treatment failure likely to occur with commonly prescribed antibiotics, which will help to combat antimicrobial resistance and the burden of UTIs.

Etiology and prevalence of ESBLs in adult community-onset urinary tract infections in East China: A prospective multicenter study

ObjectivesCommunity onset urinary tract infections (COUTIs) drew attention recently owing to their increased prevalence and associations with resistant pathogens. The study is aimed at investigating the etiology of COUTIs as well as prevalence and the related risk factors of extended-spectrum β-lactamase (ESBL) in COUTIs in China. MethodsThe prospective study was performed in nineteen hospitals during November 1, 2017 and August 31, 2019. Non-duplicated isolates from COUTIs were included. The ESBL phenotypic confirmation test was performed and whole genomes were sequenced for all the ESBL-positive bacteria for further analysis. The risk factors for ESBL-producing bacterial infections were analyzed using binary logistic regression. ResultsA total of 1760 COUTI cases were included in this study. Escherichia coli (1332, 75.7%), Klebsiella pneumoniae (110, 6.3%) and Enterococcus faecalis (52, 3.0%) were the top three common pathogens of COUTIs in China. The overall positive rate of ESBLs in Enterobacterales was 37.2% (562/1512). The age (OR=1.007, P = 0.041), solid malignant tumor (OR=1.668, P = 0.016), prostate diseases (OR=2.035, P = 0.010), history of lithotripsy for urinary calculi (OR=2.009, P = 0.030), history of urological surgery (OR=1.869, P = 0.009) and cephalosporin use within 3 months (OR=1.503, P = 0.025) were independent risk factors for ESBL-producing organisms causing COUTIs. The predominant ESBL types were CTX-Ms, among which CTX-M-14, CTX-M-55 and CTX-M-27 were the most common subtypes. ST131 and ST1193 were the predominant sequence types of ESBL-producing E. coli (ESBL-EC). Most of the tested antimicrobial agents showed significantly higher non-susceptible rates in the ESBL positive group as compared with ESBL-negative group (P < 0.05). ConclusionsEnterobacterales, especially E. coli, is the most common pathogen in COUTIs in China and ESBL-producers are highly prevalent. Thus, early prediction depending on risk factors seems to be crucial to determine the appropriate empirical therapy for infections caused by ESBL-producing pathogens.

Clinical and Economic Impact of Community-Onset Urinary Tract Infections Caused by ESBL-Producing Klebsiella pneumoniae Requiring Hospitalization in Spain: An Observational Cohort Study.

Objective: To analyze the clinical and economic impact of community-onset urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae requiring hospitalization. Methods: A retrospective cohort study that included all adults with a UTI caused by K. pneumoniae that were admitted to a tertiary care hospital in Barcelona, Spain, between 2011 and 2015. Demographic, clinical, and economic data were analyzed. Results: One hundred and seventy-three episodes of UTIs caused by K. pneumoniae were studied; 112 were non-ESBL-producing and 61 were ESBL-producing. Multivariate analysis identified ESBL production, acute confusional state associated with UTI, shock, and the time taken to obtain adequate treatment as risk factors for clinical failure during the first seven days. An economic analysis showed differences between ESBL-producing and non-ESBL-producing K. pneumoniae for the total cost of hospitalization per episode (mean EUR 6718 vs EUR 3688, respectively). Multivariate analysis of the higher costs of UTI episodes found statistically significant differences for ESBL production and the time taken to obtain adequate treatment. Conclusion: UTIs caused by ESBL-producing K. pneumoniae requiring hospitalization and the time taken to obtain adequate antimicrobial therapy are associated with worse clinical and economic outcomes.

Risk Factors for Amoxicillin-Clavulanate Resistance in Community-Onset Urinary Tract Infections Caused by Escherichia coli or Klebsiella pneumoniae: The Role of Prior Exposure to Fluoroquinolones.

Background: High rates of amoxicillin-clavulanate (AMC) resistance among Enterobacterales isolated from urinary tract infections (UTIs) were observed in our area. The aim of this study was to identify risk factors associated with AMC resistance in patients with community-onset UTI in emergency departments (EDs). Methods: A retrospective study was performed of all ED patients with positive urine cultures for Escherichia coli or Klebsiella pneumoniae in a Spanish tertiary-care hospital. Results: 330 urine cultures in all were included: 261 (79.1%) for E. coli and 69 (20.90%) for K. pneumonia. Rates of AMC resistance were 14.94% and 34.78%, respectively. UTI was clinically confirmed in 212 (64.24%) cases. Previous antimicrobial exposure was independently associated with AMC resistance development in E. coli and K. pneumoniae urinary isolates (OR = 2.94, 95% CI = 1.55–5.58). Analyses of infected patients revealed that previous exposure to fluoroquinolones (OR = 3.33, 95% CI = 1.10–10.12, p = 0.034) and to AMC (OR = 5.68, 95% CI = 1.97–16.44, p = 0.001) was significantly associated with isolation of AMC-resistant strains. Conclusions: Prior antibiotic exposure, particularly to AMC or fluoroquinolones, was the only independent risk factor associated with development of AMC resistance in E. coli and K. pneumoniae urinary isolates from patients attending the ED.

Population structure and uropathogenic potential of extended-spectrum cephalosporin-resistant Escherichia coli from retail chicken meat

BackgroundFood-producing animals and their products are considered a source for human acquisition of antimicrobial resistant (AMR) bacteria, and poultry are suggested to be a reservoir for Escherichia coli resistant to extended-spectrum cephalosporins (ESC), a group of antimicrobials used to treat community-onset urinary tract infections in humans. However, the zoonotic potential of ESC-resistant E. coli from poultry and their role as extraintestinal pathogens, including uropathogens, have been debated. The aim of this study was to characterize ESC-resistant E. coli isolated from domestically produced retail chicken meat regarding their population genetic structure, the presence of virulence-associated geno- and phenotypes as well as their carriage of antimicrobial resistance genes, in order to evaluate their uropathogenic potential.ResultsA collection of 141 ESC-resistant E. coli isolates from retail chicken in the Norwegian monitoring program for antimicrobial resistance in bacteria from food, feed and animals (NORM-VET) in 2012, 2014 and 2016 (n = 141) were whole genome sequenced and analyzed. The 141 isolates, all containing the beta-lactamase encoding gene blaCMY-2, were genetically diverse, grouping into 19 different sequence types (STs), and temporal variations in the distribution of STs were observed. Generally, a limited number of virulence-associated genes were identified in the isolates. Eighteen isolates were selected for further analysis of uropathogen-associated virulence traits including expression of type 1 fimbriae, motility, ability to form biofilm, serum resistance, adhesion- and invasion of eukaryotic cells and colicin production. These isolates demonstrated a high diversity in virulence-associated phenotypes suggesting that the uropathogenicity of ESC-resistant E. coli from chicken meat is correspondingly highly variable. For some isolates, there was a discrepancy between the presence of virulence-associated genes and corresponding expected phenotype, suggesting that mutations or regulatory mechanisms could influence their pathogenic potential.ConclusionOur results indicate that the ESC-resistant E. coli from chicken meat have a low uropathogenic potential to humans, which is important knowledge for improvement of future risk assessments of AMR in the food chains.

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

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. 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 invitro 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. 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). 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.

1686. Microbiology of Community-Onset Urinary Tract Infections in the United States, 2012-2017

BackgroundCommunity-onset urinary tract infections (coUTIs) are one of the most common indications for antibiotic prescribing. It is important to understand patient demographic factors associated with microorganisms causing coUTI and their antibiotic resistance profiles, to tailor antibiotic prescribing practices. We analyzed microbiology data to understand factors associated with coUTI in the United States (US).MethodsCoUTIs were identified in the Premier Healthcare Database and Cerner Health Facts among patients treated at participating healthcare facilities in the US between 2012-2017. Cases were defined by urine cultures yielding a bacterial organism and were collected in outpatient settings or within three days of hospitalization. Only the first specimen for each encounter was included in the analysis. Data on the organisms isolated, patient’s age, sex, and US census regions of the submitting facilities were described and compared using chi-square tests for associations. Encounters were classified as inpatient (INPT), observation (OBS), emergency department (ED), and outpatient (OTPT) based on the setting in which the culture was submitted.ResultsUsing data from 637 acute care hospitals, urine samples from 3,291,561 encounters were included, with 776,653 (25.7%) INPT, 1,063,219 (34.8%) ED, 107,760 (3.5%) OBS, and 1,092,658 (35.8%) OTPT. The pathogens most frequently associated with coUTIs were Escherichia coli (57.3%), Klebsiella pneumoniae (9.7%), Enterococcus faecalis (5.1%), Proteus mirabilis (4.9%), and Pseudomonas aeruginosa (2.9%). Female sex, age < 65y and OTPT and ED settings were associated with higher relative frequency of E. coli (all p < 0.0001). Male sex, INPT setting and age >65 y were associated with higher relative frequency of P. aeruginosa, P. mirabilis and E. faecalis (all p < 0.0001, Figure). K. pneumoniae was found at higher relative frequency in those >45y, and in INPT and OBS settings (all p < 0.0001).Figure. Distribution of pathogens most frequently associated with community onset urinary tract infections ConclusionUnderstanding patient factors associated with the microbiology of coUTIs is an important step in developing treatment recommendations and antibiotic stewardship efforts. Further analyses will include assessing the impact of major antibiotic resistance phenotypes, geographic and healthcare settings.Disclosures All Authors: No reported disclosures

Virulence genotypes and phylogenetic distribution of the community-onset Escherichia coli

Background: The concept that not all E. coli are equally able to cause UTI, and that the uropathogenic E. coli (UPEC) strains possess distinctive traits that confer enhanced virulence potential compared to other source E. coli, is supported by abundant epidemiologic and experimental evidence. Virulence factors (VFs) are the specific genes encoding a diverse array of specialized properties that are postulated to contribute to virulence. The aim of this study was to find the prevalence difference of virulence genes and phylogenetic lineages between E. coli from community-onset urinary tract infection (CO-UPEC) and hepatobiliary infection (CO-HBEC) compared to rectal commensal E. coli (RCEC) in a healthy population. Methods and materials: We conducted a case-control study of patients with positive UPEC & HBEC between 2006 and 2008 at a teaching hospital in South Korea. Community-onset (CO) was the isolated from the patients from whom the specimen was obtained within 2 calendar days of hospitalization or at outpatient department. We also collected the rectal commensal E. coli (RCEC) of healthy people. All isolates underwent PCR-based microarray for phylotyping and detection of 11 VFs, including adhesins (prf, sfa, drb, prsGj96, papGad), toxins (hly, cnf1), siderophores (iroN, aer), capsule (kpsMT), and other (ompT). The virulence score was defined as the number of virulence genes identified. Results: A total of 548 CO-UPEC and 140 HBEC with 486 CREC isolates were collected. Compared with CREC, CO-UPEC showed higher VFs (3.92 ± 2.22 vs. 2.28 ± 1.90, p < 0.001) and CO-HBEC averaged fewer VFs (1.56 ± 1.64 vs. 2.28 ± 1.90, p < 0.001). Overall distribution of phylogenic group were B2(52.5%) and D(33%) in CO-UPEC, A(37.9%) and D(31.4%) in CO-HBEC and A(38.3%) and B2(29%) in RCEC. Conclusion: In conclusion, we observed the differences of VFs between clones from community- onset UPECs and HBECs compared to RCEC, and this result explain that UPECs would be more virulent than HBECs which could be less virulent than RCECs considering only VFs distribution. In phylogenetic analysis, each group of E. coli showed different phylogenic distribution, which imply group B E. coli might be more specifically associated with uropathogenecity.

Antibiotic prescribing for lower UTI in elderly patients in primary care and risk of bloodstream infection: A cohort study using electronic health records in England

Research has questioned the safety of delaying or withholding antibiotics for suspected urinary tract infection (UTI) in older patients. We evaluated the association between antibiotic treatment for lower UTI and risk of bloodstream infection (BSI) in adults aged ≥65 years in primary care. We analyzed primary care records from patients aged ≥65 years in England with community-onset UTI using the Clinical Practice Research Datalink (2007-2015) linked to Hospital Episode Statistics and census data. The primary outcome was BSI within 60 days, comparing patients treated immediately with antibiotics and those not treated immediately. Crude and adjusted associations between exposure and outcome were estimated using generalized estimating equations. A total of 147,334 patients were included representing 280,462 episodes of lower UTI. BSI occurred in 0.4% (1,025/244,963) of UTI episodes with immediate antibiotics versus 0.6% (228/35,499) of episodes without immediate antibiotics. After adjusting for patient demographics, year of consultation, comorbidities, smoking status, recent hospitalizations, recent accident and emergency (A&E) attendances, recent antibiotic prescribing, and home visits, the odds of BSI were equivalent in patients who were not treated with antibiotics immediately and those who were treated on the date of their UTI consultation (adjusted odds ratio [aOR] 1.13, 95% CI 0.97-1.32, p-value = 0.105). Delaying or withholding antibiotics was associated with increased odds of death in the subsequent 60 days (aOR 1.17, 95% CI 1.09-1.26, p-value < 0.001), but there was limited evidence that increased deaths were attributable to urinary-source BSI. Limitations include overlap between the categories of immediate and delayed antibiotic prescribing, residual confounding underlying differences between patients who were/were not treated with antibiotics, and lack of microbiological diagnosis for BSI. In this study, we observed that delaying or withholding antibiotics in older adults with suspected UTI did not increase patients' risk of BSI, in contrast with a previous study that analyzed the same dataset, but mortality was increased. Our findings highlight uncertainty around the risks of delaying or withholding antibiotic treatment, which is exacerbated by systematic differences between patients who were and were not treated immediately with antibiotics. Overall, our findings emphasize the need for improved diagnostic/risk prediction strategies to guide antibiotic prescribing for suspected UTI in older adults.

Genomic features of a carbapenem-resistant OXA-219-positive Acinetobacter baumannii of international ST15 (CC15) from a patient with community-onset urinary tract infection in Chilean Patagonia

ObjectiveCarbapenemase-producing Acinetobacter baumannii has been recognized as a critical priority pathogen by the World Health Organization. We hereby report the identification and the draft genome sequence of a carbapenem-resistant A. baumannii isolated from a patient with community-onset urinary tract infection, in a Chilean Patagonian city. MethodsThe whole genome was sequenced on an Illumina NextSeq platform and de novo assembled using Unicycler v.0.4. Resistome analysis and epidemiological investigation (based on MLST data and Pasteur scheme) were performed using bioinformatics tools available from the Center for Genomic Epidemiology. ResultsThe genome size was calculated at 3890824 bp, with a GC content of 39.1%, comprising 3864 total genes, 30 tRNAs, 3 rRNAs, 4 ncRNAs, and 109 pseudogenes. Carbapenem-resistant A. baumannii Ab3_Ch strain belonged to the international sequence type ST15 (clonal complex, CC15), and harboured the ISAba-1-blaOXA-219 gene array, along to blaTEM-1B and blaADC-6 β-lactamase genes, and aac(3)-IIa and aph(3′)-VIa aminoglycoside resistance genes. Additionally, efflux pump encoding genes (abaF, abaQ, abeS, adeI, adeK, adeL, adeN, adeR, adeS, and amvA) were identified, and mutations in the quinolone resistance-determining region of gyrA (Ser81Leu) and parC (Ser84Leu) were considered responsible for fluoroquinolone resistance. ConclusionThis genome sequence data could be used for comparative genomic studies of critical priority A. baumannii strains, as well as to understand the specific features of hospital-associated A. baumannii lineages of international clonal complexes emerging in community settings.