Secular trends in gram-negative resistance among urinary tract infection hospitalizations in the United States, 2000-2009

Clinical Outcomes in Patients Who Received a One-Time Aminoglycoside Dose for Extended-Spectrum Beta-Lactamase-Producing Enterobacterales or Pseudomonas aeruginosa Cystitis

The Infectious Diseases Society of America (IDSA) recommends a single dose of an aminoglycoside for uncomplicated cystitis caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E) and difficult-to-treat Pseudomonas aeruginosa. However, there is very little recent clinical evidence to support this recommendation. The objective of this study was to evaluate the safety and efficacy of a single-dose aminoglycoside for cystitis caused by ESBL-E or Pseudomonas aeruginosa. This was a multicenter, retrospective, cohort study. Patients who received ≥3 days of standard of care were compared to patients who received a one-time dose of an aminoglycoside with or without a short course of effective therapy before. The primary outcome was the rate of relapse defined as requiring escalation of antibiotics or starting new antibiotic therapy within 14 days after the completion of antibiotics. A total of 66 patients were included in this study, with 33 patients in each arm. There were more males and complicated cystitis patients in the standard-of-care group. There was no difference found in the rate of relapse. The length of stay was significantly shorter in the aminoglycoside group (4.5 ± 4.4 days vs. 14.1 ± 10.1 days, p < 0.0001). A one-time dose of an aminoglycoside did not increase the risk of relapse and was associated with a shorter length of stay when used to treat cystitis caused by ESBL-E or Pseudomonas aeruginosa.

Recurrent UTI in Women-Risk Factors and Management

Urinary tract infections (UTIs) are common in women; more than 50% of women will be diagnosed with a UTI in her lifetime. Many of these women will go on to develop recurrent UTI. Nevertheless, evidence-based prevention of recurrent UTI is under-utilized. Here, the authors provide detailed practical advice on UTI prevention with a thorough review of the evidence. Non-antibiotic prevention measures discussed include increased fluid intake, vaginal estrogen therapy, methenamine, and cranberry. Antibiotic prophyalxis for carefully selected patients is also discussed.

A novel multivariate logistic model for predicting risk factors of failed treatment with carbapenem-resistant Acinetobacter baumannii ventilator-associated pneumonia

Background

This study aimed to explore the risk factors for failed treatment of carbapenem-resistant Acinetobacter baumannii ventilator-associated pneumonia (CRAB-VAP) with tigecycline and to establish a predictive model to predict the incidence of failed treatment and the prognosis of CRAB-VAP.

Methods

A total of 189 CRAB-VAP patients were included in the safety analysis set from two Grade 3 A national-level hospitals between 1 January 2022 and 31 December 2022. The risk factors for failed treatment with CRAB-VAP were identified using univariate analysis, multivariate logistic analysis, and an independent nomogram to show the results.

Results

Of the 189 patients, 106 (56.1%) patients were in the successful treatment group, and 83 (43.9%) patients were in the failed treatment group. The multivariate logistic model analysis showed that age (OR = 1.04, 95% CI: 1.02, 1.07, p = 0.001), yes. of hypoproteinemia (OR = 2.43, 95% CI: 1.20, 4.90, p = 0.013), the daily dose of 200 mg (OR = 2.31, 95% CI: 1.07, 5.00, p = 0.034), yes. of medication within 14 days prior to surgical intervention (OR = 2.98, 95% CI: 1.19, 7.44, p = 0.019), and no. of microbial clearance (OR = 0.31, 95% CI: 0.14, 0.70, p = 0.005) were risk factors for the failure of tigecycline treatment. Receiver operating characteristic (ROC) analysis showed that the AUC area of the prediction model was 0.745 (0.675-0.815), and the decision curve analysis (DCA) showed that the model was effective in clinical practice.

Conclusion

Age, hypoproteinemia, daily dose, medication within 14 days prior to surgical intervention, and microbial clearance are all significant risk factors for failed treatment with CRAB-VAP, with the nomogram model indicating that high age was the most important factor. Because the failure rate of CRAB-VAP treatment with tigecycline was high, this prediction model can help doctors correct or avoid risk factors during clinical treatment.

Spectrum and antibiotic resistance in community- and hospital-acquired urinary tract infections among adults: Experience from a large tertiary care center in a developing country

BACKGROUND

It is important to note that the causative agents and patterns of antibiotic resistance vary between urinary tract infections (UTIs) acquired in the community and those acquired in a hospital setting. Therefore, the aim of this study was to compare the types of organisms and patterns of antibiotic resistance in adult patients with community-acquired urinary tract infections (CA-UTIs) and hospital-acquired urinary tract infections (HA-UTIs).

METHODS

Retrospectively, we collected urine samples from patients at An-Najah National University Hospital who experienced nonrecurring urinary tract infections (UTIs) between January 2019 and December 2020. The data were subsequently analyzed using IBM-SPSS® 21.0 software to determine the distribution of microorganisms and evaluate the rates of antibiotic resistance.

RESULTS

A total of 798 nonrepetitive UTI patients were included in our study, in which more than half of the UTIs occurred in female patients (472; 59.1%), and most of the UTIs were of community origin (611; 76.6%). Both community-acquired urinary tract infections (CA-UTIs) and hospital-acquired urinary tract infections (HA-UTIs) were more common in female patients (45.6% and 13.5%, respectively). Escherichia coli was the most commonly isolated urinary pathogen in both the CA-UTIs and HA-UTIs. The five most common isolated urinary pathogens were E. coli, Klebsiella pneumoniae, Enterococcus faecalis, E. faecium, and Pseudomonas aeruginosa. Among the isolated bacteria, 28.2% were extended-spectrum beta-lactamase (ESBL)-producing bacteria, 4.1% were carbapenem-resistant Enterobacterales (CRE), and 6.5% were vancomycin-resistant Enterococci. The most commonly isolated urinary pathogens from HA-UTIs showed higher resistance rates against all the tested antibiotics except for E. faecium, which showed greater resistance to tetracycline (42.5%) and quinupristin/dalfopristin (17.5%) in CA-UTIs.

CONCLUSIONS

There are similarities in the etiological profiles of CA-UTI and HA-UTI, but the resistance rates are high, and urine culture is essential for the correct treatment of individual cases, even in primary care.

Trends in hospitalisation for urinary tract infection in adults aged 18-65 by sex in Spain: 2000 to 2015

OBJECTIVE

To analyse trends in urinary tract infection (UTIs) hospitalisation among patients adults 18-65 aged in Spain from 2000-2015.

METHODS

Retrospective observational study using the Spanish Hospitalisation Minimum Data Set (CMBD), with codifications by the International Classification of Diseases (ICD-9). Variables: Type of UTIs (pyelonephritis, prostatitis, cystitis and non-specific-UTIs), sex, age (in 5 categories: 18-49 and 50-64 years in men, and 18-44, 45-55 and 56-64 years in women), comorbidity, length of stay, costs and mortality associated with admission. The incidence of hospitalisation was studied according to sex, age group and type of UTIs per 100,000. Trends were identified using Joinpoint regression.

RESULTS

From 2000-2015, we found 259,804 hospitalisations for UTIs (51.6% pyelonephritis, 7.5% prostatitis, 0.6% cystitis and 40.3% non-specific UTIs). Pyelonephritis predominated in women and non-specific UTIs in men. The hospital stay and the average cost (2,160 EUR (IQR 1,7872,540 were greater in men. Overall mortality (0.4%) was greater in non-specific UTIs. More women were admitted (rates of 79.4 to 81.7) than in men (30.2 to 41). The greatest increase was found in men aged 50-64 years (from 59.3 to 87). In the Joinpoint analysis, the incidence of pyelonephritis increased in women [AAPC 2.5(CI 95% 1.6;3.4)], and non-specific UTIs decreased [AAPC -2.2(CI 95% -3.3;-1.2)]. Pyelonephritis decreased in men [AAPC -0.5 (CI 95% -1.5;0.5)] and non-specific UTIs increased [AAPC 2.3 (CI 95% 1.9;2.6)] and prostatitis increased [AAPC 2.6 (CI 95% 1.4;3.7)].

CONCLUSIONS

The urinary infection-related hospitalisation rate in adults in Spain increased during the period 2000-2015. Pyelonephritis predominated in women and non-specific UTIs in men. The highest hospitalisation rates occurred in the women but the greatest increase was found in men aged 65-74. The lenght of stay and cost were higher in men.

Investigating the impact of the genetic variant CXCR1 (rs2234671) in individuals with urinary tract infections

BACKGROUND

Urinary tract infections (UTIs) are currently posing a worldwide health concern by affecting millions of people. The genetic variant rs2234671 in the CXCR1-interleukin-8 receptor is closely related to a raised UTI risk.

OBJECTIVES

In this work, the impact of CXCR1 (rs2234671) on UTI individuals was examined.

METHODS

The demographic features of 30 recurrent UTI patients and 20 controls were thoroughly investigated. Bacterial isolation and identification were performed by the implementation of cultural and biochemical methods. DNA extraction, purification of all samples from both patients and healthy people, and IL-8 rs2234671 (C/G) SNP genotyping using T-ARMS-PCR were performed. The significance of the results was evaluated by carrying out a statistical analysis.

FINDINGS

The patient's average age was 34.63 ± 11.44 years, and controls averaged 30.30 ± 8.59 years (P= 0.156). No significant gender difference existed (P= 0.804). Escherichia coli (63.3%) was predominant, followed by Proteus mirabilis (26.7%), Enterococcus faecalis (23.3%), Klebsiella pneumoniae (10.0%), and Pseudomonas aeruginosa (20.0%). No significant association was found between bacterial species frequency, age, or sex. From the CXCR1 (rs2234671) frequency comparison, a higher GG genotype incidence in UTI patients than controls was extracted (26.7% vs. 15.0%), though not statistically significant. Risk analysis revealed that GG homozygous and C/G heterozygous genotypes were not UTI risk factors (OR = 2.47 and OR = 1.85, respectively). Moreover, the allele frequencies displayed no significant difference between the patients and controls (G allele: 66.7% vs. 66.7%; C allele: 33.3% vs. 33.3%).

MAIN CONCLUSIONS

Although no significant association between CXCR1 (rs2234671) and UTI was found, the GG genotype may point to the increasing probability of UTI risk. Additional research is required to confirm and expand these conclusions.

Enhancement and external validation of algorithms using diagnosis codes to identify invasive Escherichia coli disease

OBJECTIVE

To assess the predictive accuracy of code-based algorithms for identifying invasive Escherichia coli (E. coli) disease (IED) among inpatient encounters in US hospitals.

METHODS

The PINC AI Healthcare Database (10/01/2015-03/31/2020) was used to assess the performance of six published code-based algorithms to identify IED cases among inpatient encounters. Case-confirmed IEDs were identified based on microbiological confirmation of E. coli in a normally sterile body site (Group 1) or in urine with signs of sepsis (Group 2). Code-based algorithm performance was assessed overall, and separately for Group 1 and Group 2 based on sensitivity, specificity, positive and negative predictive value (PPV and NPV) and F1 score. The improvement in performance of refinements to the best-performing algorithm was also assessed.

RESULTS

Among 2,595,983 encounters, 97,453 (3.8%) were case-confirmed IED (Group 1: 60.9%; Group 2: 39.1%). Across algorithms, specificity and NPV were excellent (>97%) for all but one algorithm, but there was a trade-off between sensitivity and PPV. The algorithm with the most balanced performance characteristics included diagnosis codes for: (1) infectious disease due to E. coli OR (2) sepsis/bacteremia/organ dysfunction combined with unspecified E. coli infection and no other concomitant non-E. coli invasive disease (sensitivity: 56.9%; PPV: 56.4%). Across subgroups, the algorithms achieved lower algorithm performance for Group 2 (sensitivity: 9.9%-61.1%; PPV: 3.8%-16.0%).

CONCLUSIONS

This study assessed code-based algorithms to identify IED during inpatient encounters in a large US hospital database. Such algorithms could be useful to identify IED in healthcare databases that lack information on microbiology data.

Dominance of Escherichia coli sequence types ST73, ST95, ST127 and ST131 in Australian urine isolates: a genomic analysis of antimicrobial resistance and virulence linked to F plasmids

Extraintestinal pathogenic Escherichia coli (ExPEC) are the most frequent cause of urinary tract infections (UTIs) globally. Most studies of clinical E. coli isolates are selected based on their antimicrobial resistance (AMR) phenotypes; however, this selection bias may not provide an accurate portrayal of which sequence types (STs) cause the most disease. Here, whole genome sequencing (WGS) was performed on 320 E. coli isolates from urine samples sourced from a regional hospital in Australia in 2006. Most isolates (91%) were sourced from patients with UTIs and were not selected based on any AMR phenotypes. No significant differences were observed in AMR and virulence genes profiles across age sex, and uro-clinical syndromes. While 88 STs were identified, ST73, ST95, ST127 and ST131 dominated. F virulence plasmids carrying senB-cjrABC (126/231; 55%) virulence genes were a feature of this collection. These senB-cjrABC+ plasmids were split into two categories: pUTI89-like (F29:A-:B10 and/or >95 % identity to pUTI89) (n=73) and non-pUTI89-like (n=53). Compared to all other plasmid replicons, isolates with pUTI89-like plasmids carried fewer antibiotic resistance genes (ARGs), whilst isolates with senB-cjrABC+/non-pUTI89 plasmids had a significantly higher load of ARGs and class 1 integrons. F plasmids were not detected in 89 genomes, predominantly ST73. Our phylogenomic analyses identified closely related isolates from the same patient associated with different pathologies and evidence of strain-sharing events involving isolates sourced from companion and wild animals.

Antimicrobial activity of ceftibuten-avibactam against a global collection of Enterobacterales from patients with urinary tract infections (2021)

We evaluated the in vitro activity of ceftibuten-avibactam against Enterobacterales causing urinary tract infection (UTI). A total of 3216 isolates (1/patient) were consecutively collected from patients with UTI in 72 hospitals from 25 countries in 2021 then susceptibility tested by CLSI broth microdilution. Ceftibuten-susceptible breakpoints currently published by EUCAST (≤ 1 mg/L) and CLSI (≤ 8 mg/L) were applied to ceftibuten-avibactam for comparison. The most active agents were ceftibuten-avibactam (98.4%/99.6% inhibited at ≤ 1/ ≤ 8 mg/L), ceftazidime-avibactam (99.6% susceptible [S]), amikacin (99.1%S), and meropenem (98.2%S). Ceftibuten-avibactam (MIC_50/90, 0.03/0.06 mg/L) was fourfold more potent than ceftazidime-avibactam (MIC_50/90, 0.12/0.25 mg/L) based on MIC_50/90 values. The most active oral agents were ceftibuten (89.3%S; 79.5% inhibited at ≤ 1 mg/L), levofloxacin (75.4%S), and trimethoprim-sulfamethoxazole (TMP-SMX; 73.4%S). Ceftibuten-avibactam inhibited 97.6% of isolates with an extended-spectrum β-lactamase phenotype, 92.1% of multidrug-resistant isolates, and 73.7% of carbapenem-resistant Enterobacterales (CRE) at ≤ 1 mg/L. The second most active oral agent against CRE was TMP-SMX (24.6%S). Ceftazidime-avibactam was active against 77.2% of CRE isolates. In conclusion, ceftibuten-avibactam was highly active against a large collection of contemporary Enterobacterales isolated from patients with UTI and exhibited a similar spectrum to ceftazidime-avibactam. Ceftibuten-avibactam may represent a valuable option for oral treatment of UTI caused by multidrug-resistant Enterobacterales.

Comparison of antimicrobial resistance in patients with obstructive pyelonephritis associated with ureteral stones and uncomplicated pyelonephritis

This study aimed to investigate the clinical outcomes of causative microorganisms in obstructive pyelonephritis associated with ureteral stones (OPU) and their antibiotic susceptibilities. This retrospective cohort study included female patients diagnosed with community-acquired acute pyelonephritis (APN) at a tertiary-care hospital between 2008 and 2017. A comparison of APN cases associated with the obstruction of the upper urinary tract by ureteral stones and APN cases without complications was performed. Propensity score (PS) matching was used to adjust the heterogeneity within each group. Of the 588 female patients with community-acquired APN, 107 were diagnosed with OPU and 481 with uncomplicated APN. After PS matching, Enterobacteriaceae strains isolated from OPU cases were more resistant to fluoroquinolones (51.9% vs 16.0%, P < .001). Extended-spectrum β-lactamase was detected in 22.2% and 21.0% of the Enterobacteriaceae strains isolated from OPU and uncomplicated APN cases, respectively (P = 1.000). The treatment failure rate was similar in OPU and uncomplicated APN groups (16.0% vs 21.0%, P = .545). Patients with OPU may be empirically treated with antibiotics in accordance with the treatment protocol for general pyelonephritis. Clinicians should exercise caution in prescribing fluoroquinolones for treating OPU.

Epidemiological and Genetic Characteristics of Clinical Carbapenem-Resistant Acinetobacter baumannii Strains Collected Countrywide from Hospital Intensive Care Units (ICUs) in China

Acinetobacter baumannii is one of the key Gram-negative pathogens that can cause serious nosocomial infections. In China, a large proportion of clinical A. baumannii strains are multidrug resistant, among which strains resistant to carbapenems are particularly worrisome, as infections caused by such strains may limit the choice of existing antibiotics. We conducted a nationwide and genome-based surveillance on the prevalence and antibiotic susceptibility profile of carbapenem-resistant A. baumannii (CRAB) strains collected from intensive care units (ICUs) in hospitals in different provinces and investigated the routes of transmission and mechanism of resistance by whole-genome sequencing and phylogenetic analysis. We found that CRAB strains were prevalent in 71.4% (55/77) of the ICUs surveyed. Clonal spread of CRAB was found in 37.6% (29/77) of ICUs and a total of 22 different clones were identified. Most clones were transmissible within one ICU, but up to six clones could be detected in at least three hospitals. In addition, carbapenem-hydrolysing class D β-lactamases (CHDL) were found to be mainly responsible for carbapenem-resistance in A. baumannii and the ST2 global-clone is the predominant type of CRAB in China. Importantly, we found that CRAB isolates currently exhibited extremely low rate of resistance to colistin (0.4%) and tigecycline (2.5%), but a high rate of resistance to ceftazidime-avibactam (70.2%). Findings in this work shall facilitate development of appropriate antimicrobial regimens for treatment of CRAB infections. Further surveillance and research on the evolutionary and epidemiological features of clinical CRAB strains are necessary.

Oral Tebipenem Pivoxil Hydrobromide in Complicated Urinary Tract Infection

BACKGROUND

There is a need for oral antibiotic agents that are effective against multidrug-resistant gram-negative uropathogens. Tebipenem pivoxil hydrobromide is an orally bioavailable carbapenem with activity against uropathogenic Enterobacterales, including extended-spectrum beta-lactamase-producing and fluoroquinolone-resistant strains.

METHODS

In this phase 3, international, double-blind, double-dummy trial, we evaluated the efficacy and safety of orally administered tebipenem pivoxil hydrobromide as compared with intravenous ertapenem in patients with complicated urinary tract infection or acute pyelonephritis. Patients were randomly assigned, in a 1:1 ratio, to receive oral tebipenem pivoxil hydrobromide (at a dose of 600 mg every 8 hours) or intravenous ertapenem (at a dose of 1 g every 24 hours) for 7 to 10 days (or up to 14 days in patients with bacteremia). The primary efficacy end point was overall response (a composite of clinical cure and favorable microbiologic response) at a test-of-cure visit (on day 19, within a ±2-day window) in the microbiologic intention-to-treat population. The noninferiority margin was 12.5%.

RESULTS

A total of 1372 hospitalized adult patients were enrolled; 868 patients (63.3%) were included in the microbiologic intention-to-treat population (50.8% of whom had complicated urinary tract infections and 49.2% of whom had pyelonephritis). An overall response was seen in 264 of 449 patients (58.8%) who received tebipenem pivoxil hydrobromide, as compared with 258 of 419 patients (61.6%) who received ertapenem (weighted difference, -3.3 percentage points; 95% confidence interval [CI], -9.7 to 3.2). Clinical cure at the test-of-cure visit was observed in 93.1% of the patients in the microbiologic intention-to-treat population who received tebipenem pivoxil hydrobromide and 93.6% of patients who received ertapenem (weighted difference, -0.6 percentage point; 95% CI, -4.0 to 2.8); the majority of patients with microbiologic response failures at the test-of-cure visit were asymptomatic patients with recurrent bacteriuria. Secondary and subgroup analyses were supportive of the primary analysis. Adverse events were observed in 25.7% of patients who received tebipenem pivoxil hydrobromide and in 25.6% of patients who received ertapenem; the most common adverse events were mild diarrhea and headache.

CONCLUSIONS

Oral tebipenem pivoxil hydrobromide was noninferior to intravenous ertapenem in the treatment of complicated urinary tract infection and acute pyelonephritis and had a similar safety profile. (Funded by Spero Therapeutics and the Department of Health and Human Services; ADAPT-PO ClinicalTrials.gov number, NCT03788967.).

Treatment of UTIs Due to Klebsiella pneumoniae Carbapenemase-Producers: How to Use New Antibiotic Drugs? A Narrative Review

Background: K. pneumoniae is one of the bacteria most frequently causing health care-associated urinary tract infections, and increasingly incriminating Klebsiella pneumoniae carbapenemase producers (KPCp). Most infections caused by KPCp are nosocomial and might cause serious issues, even leading to death in half of the reported cases. Our aim was to identify the best strategy, based on available scientific data, for the use of new antibiotic treatments to manage KPCp UTIs. Methods: this narrative review of the literature was performed according to the criteria of preferred reporting items for systematic review and meta-analyses statement (PRISMA) (2020). Results and Conclusions: KPCp-UTIs are a real challenge for physicians. While cefiderocol, meropenem-vaborbactam, ceftazidim-avibactam, and imipenem-relebactam represent a major step forward in the treatment of these UTIs, no guidelines are currently available, in view of choosing the most appropriate treatment, in each specific case.

Trends in urinary tract infection hospitalization in older adults in Spain from 2000-2015

Objective

To analyze trends in urinary tract infection hospitalization (cystitis, pyelonephritis, prostatitis and non-specified UTI) among patients over 65 years in Spain from 2000–2015.

Methods

We conducted a retrospective observational study using the Spanish Hospitalization Minimum Data Set (CMBD), with codifications by the International Classification of Diseases (ICD-9). We collected data on sex, age, type of discharge, main diagnosis, comorbid diagnosis, length of stay, and global cost. All the hospitalizations were grouped by age into three categories: 65–74 years old, 75–84 years old, and 85 years old and above. In the descriptive statistical analysis, crude rates were defined as hospitalizations per 1,000 inhabitants aged ≥65. To identify trends over time, we performed a Joinpoint regression.

Results

From 2000–2015, we found 387,010 hospitalizations coded as UTIs (54,427 pyelonephritis, 15,869 prostatitis, 2643 cystitis and 314,071 non-specified UTI). The crude rate of hospitalization for UTIs between 2000 and 2015 ranged from 2.09 in 2000 to 4.33 in 2015 Rates of hospitalization were higher in men than in women, except with pyelonephritis. By age group, higher rates were observed in patients aged 85 years or older, barring prostatitis-related hospitalizations. Joinpoint analyses showed an average annual percentage increase (AAPC) in incidence rates of 4.9% (95% CI 3.2;6.1) in UTI hospitalizations. We observed two joinpoints, in 2010 and 2013, that found trends of 5.5% between 2000 and 2010 (95% CI 4.7;6.4), 1.5% between 2010 and 2013 (95% CI -6.0;9.6) and 6.8% between 2013 and 2015 (95% CI -0.3;14.4).

Conclusions

The urinary infection-related hospitalization rate in Spain doubled during the period 2000–2015. The highest hospitalization rates occurred in men, in the ≥85 years old age group, and in non-specified UTIs. There were increases in all types of urinary tract infection, with non-specified UTIs having the greatest growth. Understanding these changing trends can be useful for health planning.

Multidrug-Resistant Lineage of Enterotoxigenic Escherichia coli ST182 With Serotype O169:H41 in Airline Waste

Enterotoxigenic Escherichia coli (ETEC) is the primary aetiologic agent of traveller’s diarrhoea and a significant cause of diarrhoeal disease and death in developing countries. ETEC O169:H41 strains are known to cause both traveller’s diarrhoea and foodborne outbreaks in developed countries and are cause for concern. Here, whole-genome sequencing (WGS) was used to assemble 46 O169:H41 (ST182) E. coli draft genomes derived from two airplane waste samples sourced from a German international airport. The ST182 genomes were compared with all 84 publicly available, geographically diverse ST182 genomes to construct a core genome-based phylogenetic tree. ST182 isolates were all phylogroup E, the majority serotype O169:H41 (n = 121, 93%) and formed five major clades. The airplane waste isolates differed by an average of 15 core SNPs (range 0–45) but their accessory genome content was diverse. While uncommon in other ST182 genomes, all airplane-derived ST182 isolates carried: (i) extended-spectrum β-lactamase gene bla_CTX–M–15 notably lacking the typical adjacent ISEcp1; (ii) qnrS1 and the S83L mutation in gyrA, both conferring resistance to fluoroquinolones; and (iii) a class 1 integron structure (IS26-intI1_Δ648-dfrA17-aadA5-qacEΔ1-sul1-ORF-srpC-padR-IS6100-mphR-mrx-mphA-IS26) identified previously in major extraintestinal pathogenic E. coli STs but not in ETEC. ST182 isolates carried ETEC-specific virulence factors STp + CS6. Adhesin/invasin tia was identified in 89% of aircraft ST182 isolates (vs 23%) and was located on a putative genomic island within a hotspot region for various insertions including PAI I₅₃₆ and plasmid-associated transposons. The most common plasmid replicons in this collection were IncFII (100%; F2:A-:B-) and IncB/O/K/Z (89%). Our data suggest that potentially through travel, E. coli ST182 are evolving a multidrug-resistant profile through the acquisition of class 1 integrons and different plasmids.

Synergistic Antibacterial and Antibiofilm Activity of the MreB Inhibitor A22 Hydrochloride in Combination with Conventional Antibiotics against Pseudomonas aeruginosa and Escherichia coli Clinical Isolates

In the era of antibiotic resistance, the bacterial cytoskeletal protein MreB is presented as a potential target for the development of novel antimicrobials. Combined treatments of clinical antibiotics with anti-MreB compounds may be promising candidates in combating the resistance crisis, but also in preserving the potency of many conventional drugs. This study aimed to evaluate the synergistic antibacterial and antibiofilm activities of the MreB inhibitor A22 hydrochloride in combination with various antibiotics. The minimum inhibitory concentration (MIC) values of the individual compounds were determined by the broth microdilution method against 66 clinical isolates of Gram-negative bacteria. Synergy was assessed by the checkerboard assay. The fractional inhibitory concentration index was calculated for each of the A22-antibiotic combination. Bactericidal activity of the combinations was evaluated by time-kill curve assays. The antibiofilm activity of the most synergistic combinations was determined by crystal violet stain, methyl thiazol tetrazolium assay, and confocal laser scanning microscopy analysis. The combined cytotoxic and hemolytic activity was also evaluated toward human cells. According to our results, Pseudomonas aeruginosa and Escherichia coli isolates were resistant to conventional antibiotics to varying degrees. A22 inhibited the bacterial growth in a dose-dependent manner with MIC values ranging between 2 and 64 μg/mL. In combination studies, synergism occurred most frequently with A22-ceftazidime and A22-meropemen against Pseudomonas aeruginosa and A22-cefoxitin and A22-azithromycin against Escherichia coli. No antagonism was observed. In time-kill studies, synergism was observed with all expected combinations. Synergistic combinations even at the lowest tested concentrations were able to inhibit biofilm formation and eradicate mature biofilms in both strains. Cytotoxic and hemolytic effects of the same combinations toward human cells were not observed. The findings of the present study support previous research regarding the use of MreB as a novel antibiotic target. The obtained data expand the existing knowledge about the antimicrobial and antibiofilm activity of the A22 inhibitor, and they indicate that A22 can serve as a leading compound for studying potential synergism between MreB inhibitors and antibiotics in the future.

Bacterial uropathogens and susceptibility testing among patients diagnosed with urinary tract infections at Hiwot Fana Specialized University Hospital, Eastern Ethiopia

Background:

Urinary tract infection is a common infection posing a significant healthcare burden globally. Currently, it is becoming hard to manage due to the drug resistance of uropathogens. This study aimed to evaluate the rate of culture positivity and the susceptibility pattern of isolates among clinically diagnosed patients with urinary tract infection.

Methods:

An institution-based cross-sectional study was conducted on patients clinically diagnosed with urinary tract infections and received a drug prescription at Hiwot Fana Specialized University Hospital from August 2018 to June 2019. A clean-catch mid-stream urine specimen was collected and bacterial identification and susceptibility test were performed using standard microbiological methods. Data were entered into EpiInfo 7 and exported to STATA 15 for analysis. Data were analyzed using descriptive analysis and bi-variate and multivariate regression analyses and presented with graphs, frequency, and tables.

Results:

A total of 687 urine samples were collected from patients with clinically diagnosed urinary tract infections. The mean age was 31 years and 56.62% were female. 28.38% of the participants had a culture-positive result, of which 86.15% had monomicrobial infections. Inpatients (AOR = 3.8, 95% CI = (1.8–7.9)) and hypertensive patients (AOR = 2.1, 95% CI = (1.1–4.4)) had higher odds of culture-positive results. Staphylococcus species (35.3%), E. coli (25.34%), Pseudomonas species (6.8%), and other Enterobacterales are isolated. Most isolates showed resistance to more than one drug, and amikacin, gentamicin, and nitrofurantoin showed relatively higher activity against isolates.

Conclusion:

About one-third of the clinically diagnosed patients with urinary tract infection were culture-positive with many types of bacterial uropathogens. Inpatients and hypertensive patients had a higher risk of developing bacterial infections. Bacterial isolates showed different percentages of susceptibility to the tested antibiotics.

Multiple antimicrobial resistance and outcomes among hospitalized patients with complicated urinary tract infections in the US, 2013-2018: a retrospective cohort study

Background

Complicated urinary tract infection (cUTI) is common among hospitalized patients. Though carbapenems are an effective treatment in the face of rising resistance, overuse drives carbapenem resistance (CR). We hypothesized that resistance to routinely used antimicrobials is common, and, despite frequent use of carbapenems, associated with an increased risk of inappropriate empiric treatment (IET), which in turn worsens clinical outcomes.

Methods

We conducted a retrospective cohort study of patients hospitalized with a culture-positive non-CR cUTI. Triple resistance (TR) was defined as resistance to > 3 of the following: 3rd generation cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, fosfomycin, and nitrofurantoin. Multivariable models quantified the impact of TR and inappropriate empiric therapy (IET) on mortality, hospital LOS, and costs.

Results

Among 23,331 patients with cUTI, 3040 (13.0%) had a TR pathogen. Compared to patients with non-TR, those with TR were more likely male (57.6% vs. 47.7%, p < 0.001), black (17.9% vs. 13.6%, p < 0.001), and in the South (46.3% vs. 41.5%, p < 0.001). Patients with TR had higher chronic (median [IQR] Charlson score 3 [2, 4] vs. 2 [1, 4], p < 0.001) and acute (mechanical ventilation 7.0% vs. 5.0%, p < 0.001; ICU admission 22.3% vs. 18.6%, p < 0.001) disease burden. Despite greater prevalence of empiric carbapenem exposure (43.3% vs. 16.2%, p < 0.001), patient with TR were also more likely to receive IET (19.6% vs. 5.4%, p < 0.001) than those with non-TR. Although mortality was similar between groups, TR added 0.38 (95% CI 0.18, 0.49) days to LOS, and $754 (95% CI $406, $1103) to hospital costs. Both TR and IET impacted the outcomes among cUTI patients whose UTI was not catheter-associated (CAUTI), but had no effect on outcomes in CAUTI.

Conclusions

TR occurs in 1 in 8 patients hospitalized with cUTI. It is associated with an increase in the risk of IET exposure, as well as a modest attributable prolongation of LOS and increase in total costs, particularly in the setting of non-CAUTI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05842-0.

The Impact of COPD in Trends of Urinary Tract Infection Hospitalizations in Spain, 2001-2018: A Population-Based Study Using Administrative Data

(1) Background: To examine trends in incidence and outcomes of urinary tract infections (UTIs) among men and women with or without chronic obstructive pulmonary disease (COPD), and to identify the predictors for in-hospital mortality (IHM). (2) Methods: We included patients (aged ≥40 years) who were hospitalized with UTIs between 2001 and 2018. Data were collected from the Spanish National Hospital Discharge Database. (3) Results: We identified 748,458 UTI hospitalizations, 6.53% with COPD. The UTIs incidence increased over time. It was 1.55 times higher among men COPD patients than among non-COPD men (incidence rate ratio (IRR) 1.55; 95% CI 1.53-1.56). The opposite happened in women with COPD compared to non-COPD women (IRR 0.30; 95% CI 0.28-0.32). IHM was higher in men with COPD than non-COPD men (5.58% vs. 4.47%; p < 0.001) and the same happened in women (5.62% vs. 4.92%; p < 0.001). The risk of dying increased with age and comorbidity, but the urinary catheter was a protective factor among men (OR 0.75; 95% CI 0.64-0.89). Multivariable analysis showed a significant reduction in the IHM over time for men and women with COPD. Suffering from COPD only increased the risk of IHM among men (OR 1.07; 95% CI 1.01-1.13). (4) Conclusions: The incidence of UTIs increased over time. Suffering COPD increased the risk of IHM among men, but not among women.

Genomic analysis of trimethoprim-resistant extraintestinal pathogenic Escherichia coli and recurrent urinary tract infections

Urinary tract infections (UTIs) are the most common bacterial infections requiring medical attention and a leading justification for antibiotic prescription. Trimethoprim is prescribed empirically for uncomplicated cases. UTIs are primarily caused by extraintestinal pathogenic Escherichia coli (ExPEC) and ExPEC strains play a central role in disseminating antimicrobial-resistance genes worldwide. Here, we describe the whole-genome sequences of trimethoprim-resistant ExPEC and/or ExPEC from recurrent UTIs (67 in total) from patients attending a regional Australian hospital from 2006 to 2008. Twenty-three sequence types (STs) were observed, with ST131 predominating (28 %), then ST69 and ST73 (both 7 %). Co-occurrence of trimethoprim-resistance genes with genes conferring resistance to extended-spectrum β-lactams, heavy metals and quaternary ammonium ions was a feature of the ExPEC described here. Seven trimethoprim-resistance genes were identified, most commonly dfrA17 (38 %) and dfrA12 (18 %). An uncommon dfrB4 variant was also observed. Two blaCTX-M variants were identified - blaCTX-M-15 (16 %) and blaCTX-M-14 (10 %). The former was always associated with dfrA12, the latter with dfrA17, and all blaCTX-M genes co-occurred with chromate-resistance gene chrA. Eighteen class 1 integron structures were characterized, and chrA featured in eight structures; dfrA genes featured in seventeen. ST131 H30Rx isolates possessed distinct antimicrobial gene profiles comprising aac(3)-IIa, aac(6)-Ib-cr, aph(3')-Ia, aadA2, blaCTX-M-15, blaOXA-1 and dfrA12. The most common virulence-associated genes (VAGs) were fimH, fyuA, irp2 and sitA (all 91 %). Virulence profile clustering showed ST131 H30 isolates carried similar VAGs to ST73, ST405, ST550 and ST1193 isolates. The sole ST131 H27 isolate carried molecular predictors of enteroaggregative E. coli/ExPEC hybrid strains (aatA, aggR, fyuA). Seven isolates (10 %) carried VAGs suggesting ColV plasmid carriage. Finally, SNP analysis of serial UTI patients experiencing worsening sequelae demonstrated a high proportion of point mutations in virulence factors.

In vitro activity of omadacycline and levofloxacin against Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus in human urine supplemented with calcium and magnesium

BACKGROUND

Omadacycline, an aminomethylcycline, was approved in 2018 for the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. In a Phase Ib study, around 34% of the absorbed dose of omadacycline was shown to be excreted in urine-an important property for urinary tract infection (UTI) treatment. Therefore, omadacycline has been studied in two Phase II trials for the treatment of uncomplicated UTIs and acute pyelonephritis. The activity of omadacycline against UTI pathogens in human urine is important to understand in this context.

OBJECTIVES

To study the in vitro activity of omadacycline against UTI pathogens in human urine supplemented with calcium and magnesium.

METHODS

Omadacycline activity was compared with that of levofloxacin against the urinary pathogens Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus in standard medium, pooled normal human urine and neutral pH-adjusted pooled normal human urine spiked with calcium or magnesium at concentrations consistent with hypercalcaemia and hypermagnesaemia.

RESULTS

The activities of omadacycline and levofloxacin against these urinary pathogens were lower in urine relative to standard medium; addition of Mg2+ to broth and urine had a further negative impact on omadacycline activity, whereas the addition of Ca2+ had less of an impact. Levofloxacin activity was not substantially reduced in either broth or urine by the addition of divalent cations.

CONCLUSIONS

The activity of omadacycline against UTI organisms was lower in urine relative to standard medium and was negatively impacted by magnesium. Omadacycline displayed slightly reduced activity when excess calcium was present, but, overall, the differences were ≤2-fold. These observations should be considered along with the pharmacokinetics of the agent for clinical context.

Antimicrobial Susceptibility and Cross-Resistance Patterns among Common Complicated Urinary Tract Infections in U.S. Hospitals, 2013 to 2018

In the face of increasing rates of antimicrobial resistance in complicated urinary tract infections (cUTIs), clinicians need to understand cross-resistance patterns among commonly encountered pathogens. We performed a multicenter, retrospective cohort study in the Premier database of approximately 180 hospitals, from 2013 to 2018. Using an ICD-9/10-based algorithm, we identified all adult patients hospitalized with cUTIs and included those with a positive blood or urine culture. We examined the microbiology and susceptibilities to common cUTI antimicrobials (3rd-generation cephalosporin [C3], fluoroquinolones [FQ], trimethoprim-sulfamethoxazole [TMP/SMZ], fosfomycin [FFM], and nitrofurantoin [NFT]) singly and in groups of two. Among 28,057 organisms from 23,331 patients, the 3 most common pathogens were Escherichia coli (41.0%; C3^r, 15.1%), Klebsiella pneumoniae (12.1%; C3^r, 13.2%), and Pseudomonas aeruginosa (11.0%; C3^r, 12.0%). E. coli was most frequently resistant to FQ (43.5%) and least to NFT (6.7%). K. pneumoniae was most frequently resistant to NFT (60.8%) and least to FFM (0.1%). P. aeruginosa was most frequently resistant to FQ (34.4%) and least to TMP/SMZ (4.2%). Of the C3^r E. coli isolates, 87.1% were also FQ^r, 63.7% were TMP/SMZ^r, and 13.3% were NFT^r C3^r K. pneumoniae isolates had a 76.5% chance of being FQ^r, 78.1% were TMP/SMZ^r, and 77.6% were NFT^r C3^r P. aeruginosa coexisted with FQ^r in 47.3%, TMP/SMZ^r in 18.9%, and NFT^r in 28.7%. Among the most common pathogens isolated from hospitalized patients with cUTIs, the rates of single resistance to common treatments and of cross-resistance to these regimens are substantial. Knowing the patterns of cross-resistance may help clinicians tailor empirical therapy more precisely.

Analysis of drug resistance of extended-spectrum beta-lactamases-producing Escherichia coli and Klebsiella pneumoniae in children with urinary tract infection

Objectives:

To investigate the drug resistance of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K.pneumoniae) in children with urinary tract infection (UTI) and to provide the rationale for clinical use of antibiotics.

Methods:

This is a retrospective analysis of drug susceptibility in children with E. coli or K. pneumoniae-positive urine culture between August 2013 and August 2017, Shenzhen Children’s Hospital, Shenzhen, China. Drug resistance was statistically assessed using Fisher exact test and χ² test.

Results:

A total of 698 cases of E. coli, 426 of which were confirmed ESBL-producing strains, and 217 cases of K. pneumoniae, including 111 ESBL-producing strains, were detected, and the difference in proportion of positive ESBL-producing strains (61.03% versus 51.15%) was statistically significant (p=0.010). The average drug resistance rates of E. coli and K. pneumoniae to piperacillin/tazobactam, meropenem, ertapenem, imipenem, and amikacin were <15%. The average resistance rates of ESBL-producing E. coli and K. pneumoniae to cefpodoxime, cefixime, cefazolin, and ceftriaxone was >98%, while average resistance rates for non-ESBL-producing bacteria to the above 4 drugs was <20%.

Conclusion:

In southern China, the proportion of ESBL-producing strains and the drug resistance rates of E. coli and K. pneumoniae in UTI in children was high, but their resistance rates to carbapenems and β-lactamase inhibitor complexes containing tazobactam were low. Carbapenems are the most effective antibacterial drugs for the treatment of ESBL-producing bacteria.

Efficacy and safety of levofloxacin as a treatment for complicated urinary tract infections and pyelonephritis

INTRODUCTION

Urinary tract infections (UTIs) are among the most common causes of sepsis presenting to hospitals. Treating complicated UTIs is extremely important due to their potential mortality. Levofloxacin is a fluoroquinolone antibacterial that has become one of the cornerstones of antibiotic therapy of complicated UTIs and pyelonephritis since its introduction in the 1990s because of its exceptional pharmacokinetic (PK) and pharmacodynamic (PD) profile. However, the emergence of widespread fluoroquinolone resistance over the past decade has prompted investigators to reexamine its place in the treatment of UTI.

AREAS COVERED

This literature review summarizes data about the efficacy and the tolerability of levofloxacin in treating complicated UTIs and pyelonephritis.

EXPERT OPINION

In the early 2000s, fluoroquinolones became the most commonly prescribed antibiotic in the US. Since then, the resistance rate of Escherichia coli to fluoroquinolones has increased, largely hampering the use of this class of drugs. These data, in association with emerging data about inappropriate prescription and toxicity, have limited its clinical use. For these reasons, a judicious use of levofloxacin and other fluoroquinolones and a careful implementation of infection control procedures are the main available tools for the management of UTIs and pyelonephritis.

Carbapenem Treatment and Outcomes Among Patients With Culture-Positive Complicated Intra-abdominal Infections in US Hospitals: A Retrospective Cohort Study

BACKGROUND

Carbapenems are a frequent firstline therapy in complicated intra-abdominal infections (cIAIs). We examined the microbiology, epidemiology, and outcomes among patients hospitalized in the United States with culture-positive cIAIs in the context of their exposure to empiric carbapenem treatment (ECT).

METHODS

We performed a multicenter retrospective cohort study of Premier database of ~180 hospitals, 2013-2017. Using an International Classification of Diseases (ICD)-9/10-based algorithm, we identified all culture-positive adult patients hospitalized with cIAI and examined their microbiology, epidemiology, and outcomes.

RESULTS

Among 4453 patients with cIAIs, 3771 (84.7%) had a gram-negative (GN) and 1782 (40.0%) a gram-positive organism; 1185 (26.6%) received ECT. Compared with those on non-ECT, patients on ECT were less frequently admitted from home (82.5% vs 86.0%) or emergently (76.0% vs 81.4%; P < .05 for each); E. coli were less frequent, whereas P. aeruginosa and Enterococcus spp. were more prevalent and resistance to third-generation cephalosporins (C3R; 10.1% vs 5.1%; P < .001) and carbapenems (CR; 3.6% vs 1.2%; P < .001) was more common. In adjusted analyses, ECT was associated with no rise in mortality, shorter postinfection length of stay (-0.59 days; 95% confidence interval [CI], -1.15 to -0.03), but higher postinfection costs ($3844; 95% CI, $1921 to $5767) and risk of Clostridioides difficile (odds ratio, 2.15; 95% CI, 1.02 to 4.50).

CONCLUSIONS

Among patients hospitalized with cIAI, the majority were gram-negative. Despite a 10% prevalence of C3R, fully one-quarter of all empiric regimens contained a carbapenem. ECT was a marker for slightly lower postinfection length of stay, but higher costs and risk of hospital complications.

Clinical relevance of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin susceptible Staphylococcus aureus (MSSA) for mothers during pregnancy

PURPOSE

The impact of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin-sensitive Staphylococcus aureus (MSSA) of healthy pregnant women is not described in detail in Germany. In this study, we screened for MSSA and AMRB, especially for methicillin-resistant S. aureus (MRSA) as well as extended-spectrum beta-lactamase (ESBL)-producing E. coli. Potential risk factors for colonization with AMRB/MSSA and the potential effects of colonization with these on the obstetric population were investigated.

METHODS

From October 2013 until December 2015 pregnant women were screened before birth for colonization with AMRB/MSSA from the mammillae, nose, perianal and vaginal area. Before birth, the expectant mother was administered a standardized interview questionnaire by a trained interviewer. Data from the hospital admission records were also included.

RESULTS

Samples from 651 pregnant women were analyzed. Colonization with MSSA was detected in 14.3% (n = 93), AMRB in 3.5% [(n = 23); MRSA: n = 3/ESBL: n = 20]. Significantly more colonization of AMRB/MSSA could be detected in women who had previously given birth compared to women who were nulliparous (p < 0.05). MSSA colonization was significantly associated with self-reported respiratory diseases during pregnancy (p < 0.05), but AMRB/MSSA colonization was not statistically associated with other types of infection.

CONCLUSION

Our results demonstrate a low overall rate of colonization with AMRB/MSSA, as well as a low percentage of colonized pregnant women who developed infections. Multiparous women are at higher risk for colonization with MSSA/MRSA or ESBL. Because the prevalence of AMRB/MSSA is low, this study suggests that general screening of pregnant women without risk factors is not recommended.

Fosfomycin for treatment of multidrug-resistant pathogens causing urinary tract infection: A real-world perspective and review of the literature

Among 47 patients with urinary tract infections (UTIs) due to multidrug-resistant (MDR) bacteria, treatment with fosfomycin resulted in clinical cure rates of 87% and 94% at 48 hours and 14 days, respectively. Response rates did not vary across pathogens. Our retrospective, observational findings support fosfomycin treatment against MDR pathogens causing UTIs.

Joint Modeling of Resistance to Six Antimicrobials in Urinary Escherichia coli Isolates in Quebec, Canada

Empirical treatment of urinary tract infections should be based on susceptibility profiles specific to the locale and patient population. Additionally, these susceptibility profiles should account for correlations between resistance to different types of antimicrobials.

Empirical treatment of urinary tract infections should be based on susceptibility profiles specific to the locale and patient population. Additionally, these susceptibility profiles should account for correlations between resistance to different types of antimicrobials. We used hierarchical logistic regression models to investigate geographic, temporal, and demographic trends in resistance to six antimicrobials in community-acquired and nosocomial urinary E. coli isolates from three communities in the province of Quebec, Canada, procured between April 2010 and December 2017. A total of 74,986 community-acquired (patient age, ≥18 years) and 4,384 nosocomial isolates (patient age, ≥65 years) were analyzed. In both community-acquired and nosocomial isolates, we found geographic variation in the prevalence of resistance. Male sex (community-acquired hierarchical mean odds ratio [OR], 1.24; 95% credible interval [CI], 1.02 to 1.50; nosocomial hierarchical mean OR, 1.16, 95% CI, 0.92 to 1.41) and recent hospitalization (community-acquired hierarchical mean OR, 1.49; 95% CI, 1.33 to 1.66; nosocomial hierarchical mean OR, 1.31; 95% CI, 0.99 to 1.78) were associated with a higher risk of resistance to most types of antimicrobials. We found distinct seasonal trends in both community-acquired and nosocomial isolates, but only community-acquired isolates showed a consistent annual pattern. Ciprofloxacin resistance increased sharply with patient age. We found clinically relevant differences in antimicrobial resistance in urinary E. coli isolates between locales and patient populations in the province of Quebec. These results could help inform empirical treatment decisions for urinary tract infections. In the future, similar models integrating local, provincial, and national resistance data could be incorporated into decision support systems for clinicians.

An evaluation of multidrug-resistant (MDR) bacteria in patients with urinary stone disease: data from a high-volume stone management center

PURPOSE

To investigate the prevalence of MDR bacteria in patients with urinary stones and the risk factors for its formation.

METHODS

A retrospective study was performed among patients with urinary stones in Beijing Tsinghua Changgung Hospital from December 2014 to May 2018. Patients with positive urinary cultures and drug sensitivity results were included. MDR were defined as any bacteria that have resistance to at least one agent in at least three classes of antibiotics. Bacteria distribution and resistance patterns were calculated.

RESULTS

1655 patients with urinary stones were eligible for analysis, among which 367 patients had positive urinary culture, yielding 457 isolates of 45 species. Escherichia coli remained the most common organism with a prevalence of 29.3%, followed by Enterococcus faecalis (12.0%), Proteus mirabilis (10.5%), and Klebsiella pneumonia (6.8%). 44.4% isolates were identified as MDR. The three most common Gram-negative bacteria were Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae, with a MDR rate of 84.33%, 62.5%, and 48.39%, respectively. Drug-resistant rates were different between MDR and non-MDR in ampicillin, cefazolin, ceftriaxone, cefepime, gentamicin, amikacin, and levofloxacin (all with p value < 0.05). In multivariate analysis, indwelling catheters (OR 3.1, 95% CI 1.07-8.98) and antibiotics use in the last 3 months (OR 2.14, 95% CI 1.04-4.38) were significantly associated with MDR formation.

CONCLUSIONS

MDR bacteria were common among patients with urinary stones in our center and achieved high drug-resistant rates in ampicillin, first-generation and part of third-generation cephalosporins, and fluoroquinolones. Indwelling catheters and antibiotics used in the last 3 months were independent risk factors for MDR formation. Tailored antibacterial strategies still should be established according to the local bacterial spectrum and patient condition.

Description of carbapenemase-producing Enterobacteriaceae isolates in a Spanish tertiary hospital. Epidemiological analysis and clinical impact

OBJECTIVE

The aim of the study was to carry out an epidemiological analysis of patients with carbapenemase-producing Enterobacteriaceae (CPE) isolations in our hospital as well as to perform a description of the genotypic temporal evolution of CPE isolated.

METHODS

An observational prospective cohort study was performed involving all patients with CPE isolates from clinical samples during November 2014 to November 2016 in a Spanish teaching hospital. Patients were clinically evaluated and classified either as infected or colonized. Information on the consumption of carbapenems in the hospital during the study period was also analyzed. PCR was used for identification of the carbapenemase genes blaKPC, blaVIM, and blaOXA-48.

RESULTS

A total of 301 CPE isolates were obtained (107 in 2014, 89 in 2015 and 105 in 2016). Klebsiella pneumoniae (73.4%) was the most prevalent microorganism. Hundred and seventy (56.7%) of carbapenemases detected were blaOXA-48, 73 (24.3%) were blaKPC and 57 (19%) were blaVIM. In year 2014 KPC was predominant while in 2016 OXA-48 predominated. In 2014 we observed a significant association between the medical wards and the ICU with a higher prevalence of OXA-48 (OR 4.15; P<0.001) and VIM (OR 7.40; P<0.001) in the univariate analysis, in the following years there was no association. Regarding the clinical significance of microbiological results after assessing our patients, 60% of isolates represented infection and 40% behaved as colonizers. One third of hospitalized patients with CPE isolation died within 30 days, regardless of whether they were colonized or infected.

CONCLUSIONS

We have observed an epidemiological change in the genotypes of our isolates along the study period. A thorough knowledge of the CPE's epidemiological distribution in each hospital is fundamental for optimizing antimicrobial chemotherapy.

Risk factors and prognosis of complicated urinary tract infections caused by Pseudomonas aeruginosa in hospitalized patients: a retrospective multicenter cohort study

Purpose

Complicated urinary tract infections (cUTIs) are among the most frequent health-care-associated infections. In patients with cUTI, Pseudomonas aeruginosa deserves special attention, since it can affect patients with serious underlying conditions. Our aim was to gain insight into the risk factors and prognosis of P. aeruginosa cUTIs in a scenario of increasing multidrug resistance (MDR).

Methods

This was a multinational, retrospective, observational study at 20 hospitals in south and southeastern Europe, Turkey, and Israel including consecutive patients with cUTI hospitalized between January 2013 and December 2014. A mixed-effect logistic regression model was performed to assess risk factors for P. aeruginosa and MDR P. aeruginosa cUTI.

Results

Of 1,007 episodes of cUTI, 97 (9.6%) were due to P. aeruginosa. Resistance rates of P. aeruginosa were: antipseudomonal cephalosporins 35 of 97 (36.1%), aminoglycosides 30 of 97 (30.9%), piperacillin-tazobactam 21 of 97 (21.6%), fluoroquinolones 43 of 97 (44.3%), and carbapenems 28 of 97 (28.8%). The MDR rate was 28 of 97 (28.8%). Independent risk factors for P. aeruginosa cUTI were male sex (OR 2.61, 95% CI 1.60-4.27), steroid therapy (OR 2.40, 95% CI 1.10-5.27), bedridden functional status (OR 1.79, 95% CI 0.99-3.25), antibiotic treatment within the previous 30 days (OR 2.34, 95% CI 1.38-3.94), indwelling urinary catheter (OR 2.41, 95% CI 1.43-4.08), and procedures that anatomically modified the urinary tract (OR 2.01, 95% CI 1.04-3.87). Independent risk factors for MDR P. aeruginosa cUTI were age (OR 0.96, 95% CI 0.93-0.99) and anatomical urinary tract modification (OR 4.75, 95% CI 1.06-21.26). Readmission was higher in P. aeruginosa cUTI patients than in other etiologies (23 of 97 [23.7%] vs 144 of 910 [15.8%], P=0.04), while 30-day mortality was not significantly different (seven of 97 [7.2%] vs 77 of 910 [8.5%], P=0.6).

Conclusion

Patients with P. aeruginosa cUTI had characteristically a serious baseline condition and manipulation of the urinary tract, although their mortality was not higher than that of patients with cUTI caused by other etiologies.

Potential targets for next generation antimicrobial glycoconjugate vaccines

Cell surface carbohydrates have been proven optimal targets for vaccine development. Conjugation of polysaccharides to a carrier protein triggers a T-cell-dependent immune response to the glycan moiety. Licensed glycoconjugate vaccines are produced by chemical conjugation of capsular polysaccharides to prevent meningitis caused by meningococcus, pneumococcus and Haemophilus influenzae type b. However, other classes of carbohydrates (O-antigens, exopolysaccharides, wall/teichoic acids) represent attractive targets for developing vaccines. Recent analysis from WHO/CHO underpins alarming concern toward antibiotic-resistant bacteria, such as the so called ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) and additional pathogens such as Clostridium difficile and Group A Streptococcus. Fungal infections are also becoming increasingly invasive for immunocompromised patients or hospitalized individuals. Other emergencies could derive from bacteria which spread during environmental calamities (Vibrio cholerae) or with potential as bioterrorism weapons (Burkholderia pseudomallei and mallei, Francisella tularensis). Vaccination could aid reducing the use of broad-spectrum antibiotics and provide protection by herd immunity also to individuals who are not vaccinated.

This review analyzes structural and functional differences of the polysaccharides exposed on the surface of emerging pathogenic bacteria, combined with medical need and technological feasibility of corresponding glycoconjugate vaccines.

A systematic review of the association between delayed appropriate therapy and mortality among patients hospitalized with infections due to Klebsiella pneumoniae or Escherichia coli: how long is too long?

Background

Temporal relationships between the time to appropriate antibiotic therapy and outcomes are not well described.

Methods

A systematic literature review and meta-analysis was performed to examine this relationship in patients hospitalized with Klebsiella pneumoniae or Escherichia coli infections.

Results

Twenty identified studies contained data for patients who received delayed appropriate therapy (DAT) versus appropriate antibiotic therapy for these pathogens. Of the 20 included studies, the majority (19/20) focused on patients with bloodstream infections, and only 1 study evaluated patients with pneumonia. When all DAT results were combined (any delay > 24 h from culture collection or any delay after culture and susceptibility reporting [C& SR]), there was an increased risk of mortality (odds ratio [OR], 1.60 [95% CI, 1.25–2.50]). The risk of mortality was greater when DAT > 48 h from culture collection or DAT > C&SR results were combined (OR, 1.76 [95% CI, 1.27–2.44]).

Conclusions

Our findings suggest there is a need to shift current treatment practices away from antibiotic escalation strategies that contribute to delayed appropriate therapy and toward early, relatively aggressive and comprehensive, antibiotic therapy, especially among patients with bloodstream infections due to K. pneumoniae or E. coli.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3524-8) contains supplementary material, which is available to authorized users.

High Prevalence of bla NDM Variants Among Carbapenem-Resistant Escherichia coli in Northern Jiangsu Province, China

The continuous emergence of carbapenem-resistant Escherichia coli (CRECO) presents a great challenge to public health. New Delhi metallo-lactamase (NDM) variants are widely disseminated in China, so the research on the prevalence and transmission of diverse bla_NDM variants is urgently needed. In the present study, 54 CRECO isolates were collected from 1,185 Escherichia coli isolates in five hospitals in Northern Jiangsu Province, China from September 2015 to August 2016. Antimicrobial susceptibility tests, PCR detection of resistance determinants, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to characterize these strains. Plasmid conjugation experiments were carried out to determine the transferability of resistant genes from selected isolates. PCR-based replicon typing (PBRT), S1 nuclease-PFGE, and Southern blotting were conducted for plasmid profiling. Carbapenemase genes were detectable in all CRECO isolates, among which thirty-one CRECO isolates were found to carry bla_NDM−5 (54.7%), while, bla_NDM−1, bla_NDM−7, bla_NDM−4, bla_NDM−9, and bla_KPC−2 were identified in 14, five, two, one, and one isolates, respectively. MLST results revealed 15 different STs and four new STs were first reported to be linked with NDM-producing isolates. PFGE typing showed that no more than two isolates with the same ST appeared to the same band pattern except three ST410 isolates. Twenty-six selected NDM-producing isolates were successfully transferred to E. coli J53 by conjugation experiments. Notably, 50.0% (13/26) of bla_NDM variants were found to be carried by ~55 kb IncX3 plasmid. Our study reported a high prevalence of bla_NDM variants, especially bla_NDM−5, in Northern Jiangsu province, China. Diverse bla_NDM variants were mainly carried by ~55 kb IncX3 plasmids, suggesting that the fast evolution and high transferability of this kind of plasmid promote the high prevalence of bla_NDM variants. Therefore, large-scale surveillance and effective infection control measures are also urgently needed to prevent diverse bla_NDM variants from becoming epidemic in the future.

The rates of quinolone, trimethoprim/sulfamethoxazole and aminoglycoside resistance among Enterobacteriaceae isolated from urinary tract infections in Azerbaijan, Iran

Aim: Antibiotic susceptibility patterns help to select appropriate empirical treatments of urinary tract infections (UTIs). This study aimed to investigate antibiotic resistance among Enterobacteriaceae isolated from UTIs in Azerbaijan, Iran. Methods: This study was carried out during 2016 in hospitals located in Tabriz, Urmia, and Khoy. Midstream urine specimens were cultured and identified by the standard methods. Susceptibility testing was carried out using the disk diffusion agar method for cefotaxime, ceftazidime, ceftriaxone, cefoxitin, imipenem, meropenem, ertapenem, cefepime, ampicillin, cefazolin, cefuroxime, aztreonam, nitrofurantoin, and fosfomycin and the agar dilution method for MIC determination of aminoglycosides, quinolones, sulfamethoxazole, and trimethoprim. Results: A total of 219 non-duplicated Enterobacteriaceae were isolated from UTIs. According to the agar dilution assay, the following resistance rates were determined: trimethoprim/sulfamethoxazole (co-trimoxazole) 69.8%, nalidixic acid 68.9%, ciprofloxacin 66.2%, levofloxacin 58.5%, tobramycin 47.9%, kanamycin 39.3%, gentamicin 27.8%, and amikacin 5.5%. High levels of resistance were observed to trimethoprim (78.5%), sulfamethoxazole (88.1%), ampicillin (86.3%), and cephazoline (79.4%). Conclusion: The most effective agents against Enterobacteriaceae were fosfomycin, carbapenems, and amikacin. Quinolones, trimethoprim and sulfamethoxazole are not appropriate for empirical therapy due to high levels of resistance. Amikacin is more effective among aminoglycosides and may be more effective, in complicated cases, when used in combination with fosfomycin and carbapenems.

Global research output in antimicrobial resistance among uropathogens: A bibliometric analysis (2002-2016)

OBJECTIVES

Antimicrobial resistance (AMR) among uropathogens contributes to treatment failure. Research in AMR among uropathogens is important to establish treatment options. This study assessed global research trends in AMR among uropathogens.

METHODS

SciVerse Scopus was used to retrieve relevant documents for the period 2002-2016. Only journal articles were included in the analysis. Analysis of author keywords was carried out using VOSviewer.

RESULTS

A total of 1087 journal articles were retrieved with an h-index of 50. The number of publications increased noticeably in the past decade. Analysis of subject areas of retrieved documents showed that 275 (25.3%) articles were in molecular biology/genetics/microbiology/immunology, 197 (18.1%) were in pharmacological/therapeutic approaches for treatment of urinary tract infections and 615 (56.6%) were in epidemiology/public health. Terms such as multidrug-resistant and extended-spectrum β-lactamases (ESBLs) appeared more frequently in documents published in the period 2012-2016. The mean number of authors per article was 5.3. Most active authors in this field were from Japan. The USA ranked first with 148 documents (13.6%), followed by India (97; 8.9%) and Iran (84; 7.7%). The top productive institution was Tehran University of Medical Sciences (21 publications), followed by Kobe University in Japan (20 publications). The Journal of Antimicrobial Chemotherapy ranked first with 33 publications.

CONCLUSION

Research in AMR among uropathogens showed a noticeable increase in the past decade. Reports of increasing incidence of resistance among uropathogens were published from different parts of the world. Empirical therapy should be based on updated research in AMR.

The analysis of microbial spectrum and antibiotic resistance of uropathogens isolated from patients with urinary stones

PURPOSE

The characteristics and resistance patterns of urine bacteriology in patients with urinary tract stones have not been extensively studied. This study aims to investigate the microbial spectrum and antibiotic resistance of uropathogens isolated from urinary tract infections in patients with urinary stones and provide a basis for appropriate antimicrobial treatments.

METHODS

The results of positive bladder midstream urine cultures and their antimicrobial susceptibility were retrospectively analysed from hospitalised patients with diagnosis of urinary calculi and urinary tract infections between January 2010 and December 2015.

RESULTS

A total of 3892 samples were analysed during the study period: 2201 were female patients (56.6%) and 1691 were male patients (43.4%). The 4 most common uropathogens were Escherichia coli (48.7%), Klebsiella pneumoniae (10.4%), Enterococcus faecalis (8.7%) and Proteus mirabilis (5.2%). Both E. coli (60.8%) and Proteus mirabilis (7.5%) were higher in female patients than in male patients (32.8%; 2.3%; P < .05). ESBL-positive E. coli accounted for 59.5% of total number of E. coli, while ESBL-positive K. pneumoniae comprised 42.0% of total K. pneumoniae. The majority of uropathogens in patients with stones had high resistance to fluoroquinolones, ceftriaxone, ceftazidime, cefepime, penicillins, sulfonamides and monobactams (resistance >20%).

CONCLUSIONS

The microbial spectrum in patients with urinary stones had a complex pattern. The uropathogens showed marked multidrug resistance and a large proportion of the uropathogens were able to produce β-lactamase.

Warmer weather as a risk factor for hospitalisations due to urinary tract infections

The incidence of urinary tract infections (UTIs) is seasonal, and this seasonality may be explained by changes in weather, specifically, temperature. Using data from the Nationwide Inpatient Sample, we identified the geographic location for 581 813 hospital admissions with the primary diagnosis of a UTI and 56 630 773 non-UTI hospitalisations in the United States. Next, we used data from the National Climatic Data Center to estimate the monthly average temperature for each location. Using a case-control design, we modelled the odds of a hospital admission having a primary diagnosis of UTI as a function of demographics, payer, location, patient severity, admission month, year and the average temperature for the admission month. We found, after controlling for patient factors and month of admission, the odds of a UTI diagnosis increased with higher temperatures in a dose-dependent manner. For example, relative to months with average temperatures of 5-7.5 °C, an admission in a month with an average temperature of 27.5-30 °C has 20% higher odds of a primary diagnosis of UTI. However, in months with extremely high average temperatures (above 30 °C), the odds of a UTI admissions decrease, perhaps due to changes in behaviour. Thus, at a population level, UTI-related hospitalisations are associated with warmer weather.

30-day readmission, antibiotics costs and costs of delay to adequate treatment of Enterobacteriaceae UTI, pneumonia, and sepsis: a retrospective cohort study

Background

Enterobacteriaceae are common pathogens in pneumonia, sepsis and urinary tract infection (UTI). Though rare, carbapenem resistance (CRE) among these organisms complicates efforts to ensure adequate empiric antimicrobial therapy. In turn this negatively impacts such outcomes as mortality and hospital costs. We explored proportion of total costs represented by antibiotics, 30-day readmission rates, and per-day costs of inadequate antimicrobial coverage among patients with Enterobacteriaceae pneumonia, sepsis and/or UTI in the context of inappropriate (IET) vs. appropriate empiric (non-IET) therapy and carbapenem resistance (CRE) vs. susceptibility (CSE).

Methods

We conducted a retrospective cohort study in the Premier Research database (2009–2013) of 175 US hospitals. We included all adult patients admitted with a culture-confirmed UTI, pneumonia, or sepsis as principal diagnosis, or as a secondary diagnosis in the setting of respiratory failure. Patients with hospital acquired infections or transfers from other acute facilities were excluded. IET was defined as failure to administer an antibiotic therapy in vitro active against the culture-confirmed pathogen within 2 days of admission.

Results

Among 40,137 patients with Enterobacteriaceae infections (54.2% UTI), 4984 (13.2%) received IET. CRE (3.1%) was more frequent in patients given IET (13.0%) than non-IET (1.6%, p < 0.001). The proportions of total costs represented by antibiotics were similar in IET and non-IET (3.3% vs. 3.4%, p = 0.01), and higher among the group with CRE than CSE (4.2% vs. 3.4%, p < 0.001). The 30-day readmission rates were higher in both IET than non-IET (25.6% vs. 21.1%, p < 0.001) and CRE than CSE (29.7% vs. 21.5%, p < 0.001) groups. Each additional day of inadequate therapy cost an additional $766 (95% CI $661, $870, p < 0.001) relative to adequate treatment.

Conclusions

In this large US cohort of Enterobacteriaceae infections, the cost of antibiotics was a small component of total costs, irrespective of whether empiric treatment was appropriate or whether a CRE was isolated. In contrast, each extra day of inadequate treatment added >$750 to hospital costs. Both CRE and IET were associated with an increased risk of readmission within 30 days.

Electronic supplementary material

The online version of this article (10.1186/s13756-017-0286-9) contains supplementary material, which is available to authorized users.

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal inflammation and fibrosis ultimately resulting in declining kidney function. Before improved clinical management and prevention of pyelonephritis can be instituted, a reliable animal model must be established in order to study the mechanisms of progression, recurrence, and therapeutic efficacy. The transurethral infection model closely mimics human pyelonephritis but exhibits considerable variation due to its reliance on urethral reflux to transport the bacteria to the kidney. Herein, a detailed surgical protocol for performing bacterial injections into the rat renal pelvis is provided and confirmed by non-invasive Magnetic Resonance Imaging (MRI). Using this protocol, animals receive direct exposure to a desired concentration of E. coli bacteria and can fully recover from the surgical procedure with adequate post-operative care. This facilitates subsequent longitudinal MRI assessments of the experimental animal models for comparison with saline (sham) controls. Using this direct delivery approach, the severity of infection is controllable and applicable for mechanistic studies of progression as well as development of novel treatment strategies.

Nationwide Surveillance of Clinical Carbapenem-resistant Enterobacteriaceae (CRE) Strains in China

The increasing incidence of carbapenem-resistant Enterobacteriaceae (CRE) - mediated hospital infections in China prompted a need to investigate the genetic basis of emergence of such strains. A nationwide survey was conducted in China covering a total of 1105 CRE strains collected from 25 geographical locales with results showing that acquisition of two carbapenemase genes, bla_KPC-2 and bla_NDM, was responsible for phenotypic resistance in 90% of the CRE strains tested (58% and 32% respectively), among which several major strain types, such as ST11 of K. pneumoniae and ST131/ST167 of E. coli, were identified, suggesting that dissemination of specific resistant clones is mainly responsible for emergence of new CRE strains. Prevalence of the fosA3 gene which mediates fosfomycin resistance, was high, while the colistin resistance determinant mcr-1 was rarely present in these isolates. Consistently, the majority of the bla_NDM-bearing plasmids recoverable from the test strains belonged to IncX3, which contained a common core structure, bla_NDM-blaMBL-trpF. Likewise, the core structure of ISKpn27-bla_KPC-2-ISKpn2 was observed among plasmids harboring the bla_KPC-2 gene, although they were genetically more divergent. In conclusion, the increasing prevalence of CRE strains in China is attributed to dissemination of conservative mobile elements carrying bla_NDM or bla_KPC-2 on conjugative and non-conjugative plasmids.

Carbapenem resistance, inappropriate empiric treatment and outcomes among patients hospitalized with Enterobacteriaceae urinary tract infection, pneumonia and sepsis

Background

Drug resistance among gram-negative pathogens is a risk factor for inappropriate empiric treatment (IET), which in turn increases the risk for mortality. We explored the impact of carbapenem-resistant Enterobacteriaceae (CRE) on the risk of IET and of IET on outcomes in patients with Enterobacteriaceae infections.

Methods

We conducted a retrospective cohort study in Premier Perspective database (2009–2013) of 175 US hospitals. We included all adult patients with community-onset culture-positive urinary tract infection (UTI), pneumonia, or sepsis as a principal diagnosis, or as a secondary diagnosis in the setting of respiratory failure, treated with antibiotics within 2 days of admission. We employed regression modeling to compute adjusted association of presence of CRE with risk of receiving IET, and of IET on hospital mortality, length of stay (LOS) and costs.

Results

Among 40,137 patients presenting to the hospital with an Enterobacteriaceae UTI, pneumonia or sepsis, 1227 (3.1%) were CRE. In both groups, the majority of the cases were UTI (51.4% CRE and 54.3% non-CRE). Those with CRE were younger (66.6+/−15.3 vs. 69.1+/−15.9 years, p < 0.001), and more likely to be African-American (19.7% vs. 14.0%, p < 0.001) than those with non-CRE. Both chronic (Charlson score 2.0+/−2.0 vs. 1.9+/−2.1, p = 0.009) and acute (by day 2: ICU 56.3% vs. 30.4%, p < 0.001, and mechanical ventilation 35.8% vs. 11.7%, p < 0.001) illness burdens were higher among CRE than non-CRE subjects, respectively. CRE patients were 3× more likely to receive IET than non-CRE (46.5% vs. 11.8%, p < 0.001). In a regression model CRE was a strong predictor of receiving IET (adjusted relative risk ratio 3.95, 95% confidence interval 3.5 to 4.5, p < 0.001). In turn, IET was associated with an adjusted rise in mortality of 12% (95% confidence interval 3% to 23%), and an excess of 5.2 days (95% confidence interval 4.8, 5.6, p < 0.001) LOS and $10,312 (95% confidence interval $9497, $11,126, p < 0.001) in costs.

Conclusions

In this large US database, the prevalence of CRE among patients with Enterobacteriaceae UTI, pneumonia or sepsis was comparable to other national estimates. Infection with CRE was associated with a four-fold increased risk of receiving IET, which in turn increased mortality, LOS and costs.

A population genomics approach to exploiting the accessory 'resistome' of Escherichia coli

The emergence of antibiotic resistance is a defining challenge, and Escherichia coli is recognized as one of the leading species resistant to the antimicrobials used in human or veterinary medicine. Here, we analyse the distribution of 2172 antimicrobial-resistance (AMR) genes in 4022 E. coli to provide a population-level view of resistance in this species. By separating the resistance determinants into 'core' (those found in all strains) and 'accessory' (those variably present) determinants, we have found that, surprisingly, almost half of all E. coli do not encode any accessory resistance determinants. However, those strains that do encode accessory resistance are significantly more likely to be resistant to multiple antibiotic classes than would be expected by chance. Furthermore, by studying the available date of isolation for the E. coli genomes, we have visualized an expanding, highly interconnected network that describes how resistances to antimicrobials have co-associated within genomes over time. These data can be exploited to reveal antimicrobial combinations that are less likely to be found together, and so if used in combination may present an increased chance of suppressing the growth of bacteria and reduce the rate at which resistance factors are spread. Our study provides a complex picture of AMR in the E. coli population. Although the incidence of resistance to all studied antibiotic classes has increased dramatically over time, there exist combinations of antibiotics that could, in theory, attack the entirety of E. coli, effectively removing the possibility that discrete AMR genes will increase in frequency in the population.

Effect of prior receipt of antibiotics on the pathogen distribution and antibiotic resistance profile of key Gram-negative pathogens among patients with hospital-onset urinary tract infections

BACKGROUND

This retrospective cohort study characterized the impact of prior antibiotic exposure on distribution and nonsusceptibility profiles of Gram-negative pathogens causing hospital-onset urinary tract infections (UTI).

METHODS

Hospital patients with positive urine culture for Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae ≥3 days after hospital admission were included. Assessment outcomes included the distribution of bacteria in urine cultures, antibiotic susceptibility patterns, and the effect of prior antibiotic exposure, defined as 0, 1, or ≥2 prior antibiotics, on the distribution and antibiotic susceptibility profiles of the Gram-negative organisms.

RESULTS

The most commonly isolated pathogens from 5574 unique UTI episodes (2027 with and 3547 without prior antibiotic exposure) were E. coli (49.5%), K. pneumoniae (17.1%), and P. aeruginosa (8.2%). P. aeruginosa was significantly more commonly isolated in patients with ≥2 prior antibiotic exposures (12.6%) compared with no exposure (8.2%; p = 0.036) or 1 prior exposure (7.9%; p = 0.025). Two or more prior antibiotic exposures were associated with slightly higher incidences of fluoroquinolone nonsusceptibility, multidrug resistance, and extended-spectrum β-lactamase phenotype compared with 0 or 1 exposure, suggesting an increased risk for resistant Gram-negative pathogens among hospital patients with urinary tract infections occurring ≥3 days after admission.

CONCLUSIONS

Clinicians should critically assess prior antibiotic exposure when selecting empirical therapy for patients with hospital-onset urinary tract infections caused by Gram-negative pathogens.

The Increase in Hospitalizations for Urinary Tract Infections and the Associated Costs in the United States, 1998-2011

Background

Outpatient therapies for urinary tract infections (UTIs) are becoming limited due to antimicrobial resistance. The purpose of this paper is to report how the incidence of hospitalizations for UTIs have varied over time in both men and women and across age groups. We also explore how the severity for UTI hospitalizations has changed and describe the seasonality of UTI hospitalizations.

Methods

Using the Nationwide Inpatient Sample, we compute a time-series of UTI incidence and subdivide the series by age and sex. We fit a collection of time-series models to explore how the trend and seasonal intensity varies by age and sex. We modeled changes in severity using regression with available confounders.

Results

In 2011, there were approximately 400000 hospitalizations for UTIs with an estimated cost of $2.8 billion. Incidence increased by 52% between 1998 and 2011. The rate of increase was larger among both women and older patients. We found that the seasonal intensity (summer peaks and winter troughs) increased over time among women while decreasing among men. For both men and women, seasonality decreased with advancing age. Relative to controls and adjusted for demographics, we found that costs among UTI patients grew more slowly, patients left the hospital earlier, and patients had lower odds of death.

Conclusions

Incidence of UTI hospitalization is increasing and is seasonal, peaking in the summer. However, the severity of UTI admissions seems to be decreasing, indicating that patients previously treated as outpatients may now be admitted to the hospital due to increasing antimicrobial resistance.