Age-related Trends in Adults with Urinary Tract Infections Presenting to the Emergency Department: A 5-Year Experience

Adhesion of Klebsiella oxytoca to bladder or lung epithelial cells is promoted by the presence of other opportunistic pathogens

The intestinal and respiratory tracts of healthy individuals serve as habitats for a diverse array of microorganisms, among which Klebsiella oxytoca holds significance as a causative agent in numerous community- and hospital-acquired infections, often manifesting in polymicrobial contexts. In specific circumstances, K. oxytoca, alongside other constituents of the gut microbiota, undergoes translocation to distinct physiological niches. In these new environments, it engages in close interactions with other microbial community members. As this interaction may progress to co-infection where the virulence of involved pathogens may be promoted and enhance disease severity, we investigated how K. oxytoca affects the adhesion of commonly co-isolated bacteria and vice versa during co-incubation of different biotic and abiotic surfaces. Co-incubation was beneficial for the adhesion of at least one of the two co-cultured strains. K. oxytoca enhanced the adhesion of other enterobacteria strains to polystyrene and adhered more efficiently to bladder or lung epithelial cell lines in the presence of most enterobacteria strains and S. aureus. This effect was accompanied by bacterial coaggregation mediated by carbohydrate-protein interactions occurring between bacteria. These interactions occur only in sessile, but not planktonic populations, and depend on the features of the surface. The data are of particular importance for the risk assessment of the urinary and respiratory tract infections caused by K. oxytoca, including those device-associated. In this paper, we present the first report on K. oxytoca ability to acquire increased adhesive capacities on epithelial cells through interactions with common causal agents of urinary and respiratory tract infections.

New methodology to assess the excess burden of antibiotic resistance using country-specific parameters: a case study regarding E. coli urinary tract infections

OBJECTIVES

Antimicrobial resistant (AMR) infections are a major public health problem and the burden on population level is not yet clear. We developed a method to calculate the excess burden of resistance which uses country-specific parameter estimates and surveillance data to compare the mortality and morbidity due to resistant infection against a counterfactual (the expected burden if infection was antimicrobial susceptible). We illustrate this approach by estimating the excess burden for AMR (defined as having tested positive for extended-spectrum beta-lactamases) urinary tract infections (UTIs) caused by E. coli in the Netherlands in 2018, which has a relatively low prevalence of AMR E. coli, and in Italy in 2016, which has a relatively high prevalence.

DESIGN

Excess burden was estimated using the incidence-based disability-adjusted life-years (DALYs) measure. Incidence of AMR E. coli UTI in the Netherlands was derived from ISIS-AR, a national surveillance system that includes tested healthcare and community isolates, and the incidence in Italy was estimated using data reported in the literature. A systematic literature review was conducted to find country-specific parameter estimates for disability duration, risks of progression to bacteraemia and mortality.

RESULTS

The annual excess burden of AMR E. coli UTI was estimated at 3.89 and 99.27 DALY/100 0000 population and 39 and 2786 excess deaths for the Netherlands and Italy, respectively.

CONCLUSIONS

For the first time, we use country-specific and pathogen-specific parameters to estimate the excess burden of resistant infections. Given the large difference in excess burden due to resistance estimated for Italy and for the Netherlands, we emphasise the importance of using country-specific parameters describing the incidence and disease progression following AMR and susceptible infections that are pathogen specific, and unfortunately currently difficult to locate.

Risk factors for trimethoprim and sulfamethoxazole-resistant Escherichia coli in emergency department patients with urinary tract infections

BACKGROUND

While trimethoprim-sulfamethoxazole (TMP-SMX) is recommended as one of the first-line empiric therapies for treatment of acute uncomplicated cystitis, institutions that observe resistance rates exceeding 20% for Escherichia coli (E. coli) should utilize alternative empiric antibiotic therapy per the Infectious Diseases Society of America (IDSA). Identifying risk factors associated with TMP-SMX resistance in E. coli may help guide empiric antibiotic prescribing for urinary tract infections (UTIs).

METHODS

This multicenter, retrospective study included adult patients who were discharged from 12 emergency departments (EDs) with a urine culture positive for E. coli between January 1, 2019 and December 31, 2019. Logistic regression was used to assess the relationship between potential risk factors and TMP-SMX resistance. The overall institutional antimicrobial resistance rates for E. coli were compared to the rates seen in the study population of ED urinary isolates.

RESULTS

Among 427 patients included from a randomized sample of 500 with a urine culture positive for E. coli, 107 (25.1%) were resistant to TMP-SMX. Three predictors of TMP-SMX resistance were identified: recurrent UTI (OR 2.27 [95% CI 1.27-3.99]), genitourinary abnormalities (OR 2.31 [95% CI 1.17-4.49]), and TMP-SMX use within 90 days (OR 8.77 [95% CI 3.19-28.12]). When the antibiotic susceptibilities for this ED cohort were compared to the institutional antibiogram, the TMP-SMX resistance rate was found to be higher in the ED population (25.1% vs 20%).

CONCLUSIONS

TMP-SMX should likely be avoided as first-line therapy for UTI in patients who have recurrent UTIs, genitourinary abnormalities, or have previously received TMP-SMX within the past 90 days. The use of an ED-specific antibiogram should be considered for assessing local resistance rates in this population.