Clinical characteristics of community-acquired acute pyelonephritis caused by ESBL-producing pathogens in South Korea

Economic Burden of Community-Acquired Antibiotic-Resistant Urinary Tract Infections: Systematic Review and Meta-Analysis

Background

Antibiotic resistance (ABR) poses a major burden to global health and economic systems. ABR in community-acquired urinary tract infections (CA-UTIs) has become increasingly prevalent. Accurate estimates of ABR's clinical and economic burden are needed to support medical resource prioritization and cost-effectiveness evaluations of urinary tract infection (UTI) interventions.

Objective

This study aims to systematically synthesize the evidence on the economic costs associated with ABR in CA-UTIs, using published studies comparing the costs of antibiotic-susceptible and antibiotic-resistant cases.

Methods

We searched the PubMed, Ovid MEDLINE and Embase, Cochrane Review Library, and Scopus databases. Studies published in English from January 1, 2008, to January 31, 2023, reporting the economic costs of ABR in CA-UTI of any microbe were included. Independent screening of titles/abstracts and full texts was performed based on prespecified criteria. A quality assessment was performed using the Integrated Quality Criteria for Review of Multiple Study Designs (ICROMS) tool. Data in UTI diagnosis criteria, patient characteristics, perspectives, resource costs, and patient and health economic outcomes, including mortality, hospital length of stay (LOS), and costs, were extracted and analyzed. Monetary costs were converted into 2023 US dollars.

Results

This review included 15 studies with a total of 57,251 CA-UTI cases. All studies were from high- or upper-middle-income countries. A total of 14 (93%) studies took a health system perspective, 13 (87%) focused on hospitalized patients, and 14 (93%) reported UTI pathogens. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa are the most prevalent organisms. A total of 12 (80%) studies reported mortality, of which, 7 reported increased mortality in the ABR group. Random effects meta-analyses estimated an odds ratio of 1.50 (95% CI 1.29-1.74) in the ABR CA-UTI cases. All 13 hospital-based studies reported LOS, of which, 11 reported significantly higher LOS in the ABR group. The meta-analysis of the reported median LOS estimated a pooled excess LOS ranging from 1.50 days (95% CI 0.71-4.00) to 2.00 days (95% CI 0.85-3.15). The meta-analysis of the reported mean LOS estimated a pooled excess LOS of 2.45 days (95% CI 0.51-4.39). A total of 8 (53%) studies reported costs in monetary terms-none discounted the costs. All 8 studies reported higher medical costs spent treating patients with ABR CA-UTI in hospitals. The highest excess cost was observed in UTIs caused by carbapenem-resistant Enterobacterales. No meta-analysis was performed for monetary costs due to heterogeneity.

Conclusions

ABR was attributed to increased mortality, hospital LOS, and economic costs among patients with CA-UTI. The findings of this review highlighted the scarcity of research in this area, particularly in patient morbidity and chronic sequelae and costs incurred in community health care. Future research calls for a cost-of-illness analysis of infections, standardizing therapy-pathogen combination comparators, medical resources, productivity loss, intangible costs to be captured, and data from community sectors and low-resource settings and countries.

Assessment of the presence of multidrug-resistant Escherichia coli, Salmonella and Staphylococcus in chicken meat, eggs and faeces in Mymensingh division of Bangladesh

The emergence of bacteria that is resistant to several drugs of clinical importance poses a threat to successful treatment, a phenomenon known as multidrug resistance that affects diverse classes of antibiotics. The purpose of this study was to evaluate the prevalence of multidrug-resistant Escherichia coli, Salmonella spp. and Staphylococcus aureus in chicken egg, meat and faeces from four districts of Bangladesh. A total of 120 chicken samples were collected from different poultry farms. Conventional culture and molecular detection methods were used for identification of bacterial isolates from the collected samples followed by antibiotic susceptibility test through the disc diffusion method, finally antibiotic resistant genes were detected by PCR. E. coli, Salmonella spp. and Staphylococcus aureus were detected in meat, egg and faecal samples. Antimicrobial susceptibility results revealed isolates from faeces were 100 % resistant to amoxicillin, while all S. aureus and Salmonella sp. from faeces were resistant to doxycycline, tetracycline and erythromycin. Salmonella spp. isolates from eggs indicated 100 % resistance to erythromycin, amoxycillin, while E. coli were 100 % resistant to erythromycin. E. coli and S. aureus from meat were 100 % resistant to amoxicillin and erythromycin. However, Salmonella spp. from eggs were 100 % susceptible to doxycycline, gentamicin, levofloxacin and tetracycline. The mecA and aac(3)-IV genes were only found in S. aureus and E. coli, respectively. The Sul1, tetB, and aadA1 were highest in Salmonella spp. and S. aureus, while the sul1, tetA and bla SHV were higher in E. coli. Isolates from all samples were multidrug resistant. These findings indicate a high risk of transmission of resistance genes from microbial contamination to food of animal origin. The study emphasizes the need for effective biosecurity measures, responsible antibiotic use, and strict regulations in poultry production to prevent the spread of antibiotic resistance.

Assessing Clinical Potential of Old Antibiotics against Severe Infections by Multi-Drug-Resistant Gram-Negative Bacteria Using In Silico Modelling

In the light of increasing antimicrobial resistance among gram-negative bacteria and the lack of new more potent antimicrobial agents, new strategies have been explored. Old antibiotics, such as colistin, temocillin, fosfomycin, mecillinam, nitrofurantoin, minocycline, and chloramphenicol, have attracted the attention since they often exhibit in vitro activity against multi-drug-resistant (MDR) gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The current review provides a summary of the in vitro activity, pharmacokinetics and PK/PD characteristics of old antibiotics. In silico modelling was then performed using Monte Carlo simulation in order to combine all preclinical data with human pharmacokinetics and determine the probability of target (1-log kill in thigh/lung infection animal models) attainment (PTA) of different dosing regimens. The potential of clinical efficacy of a drug against severe infections by MDR gram-negative bacteria was considered when PTA was >95% at the epidemiological cutoff values of corresponding species. In vitro potent activity against MDR gram-negative pathogens has been shown for colistin, polymyxin B, temocillin (against E. coli and K. pneumoniae), fosfomycin (against E. coli), mecillinam (against E. coli), minocycline (against E. coli, K. pneumoniae, A. baumannii), and chloramphenicol (against E. coli) with ECOFF or MIC90 ≤ 16 mg/L. When preclinical PK/PD targets were combined with human pharmacokinetics, Monte Carlo analysis showed that among the old antibiotics analyzed, there is clinical potential for polymyxin B against E. coli, K. pneumoniae, and A. baumannii; for temocillin against K. pneumoniae and E. coli; for fosfomycin against E. coli and K. pneumoniae; and for mecillinam against E. coli. Clinical studies are needed to verify the potential of those antibiotics to effectively treat infections by multi-drug resistant gram-negative bacteria.

Antimicrobial Resistance Profile of Common Foodborne Pathogens Recovered from Livestock and Poultry in Bangladesh

Multidrug-resistant (MDR) foodborne pathogens have created a great challenge to the supply and consumption of safe & healthy animal-source foods. The study was conducted to identify the common foodborne pathogens from animal-source foods & by-products with their antimicrobial drug susceptibility and resistance gene profile. The common foodborne pathogens Escherichia coli (E. coli), Salmonella, Streptococcus, Staphylococcus, and Campylobacter species were identified in livestock and poultry food products. The prevalence of foodborne pathogens was found higher in poultry food & by-product compared with livestock (p < 0.05). The antimicrobial drug susceptibility results revealed decreased susceptibility to penicillin, ampicillin, amoxicillin, levofloxacin, ciprofloxacin, tetracycline, neomycin, streptomycin, and sulfamethoxazole-trimethoprim whilst gentamicin was found comparatively more sensitive. Regardless of sources, the overall MDR pattern of E. coli, Salmonella, Staphylococcus, and Streptococcus were found to be 88.33%, 75%, 95%, and 100%, respectively. The genotypic resistance showed a prevalence of blaTEM, blaSHV, blaCMY, tetA, tetB, sul1, aadA1, aac(3)-IV, and ereA resistance genes. The phenotype and genotype resistance patterns of isolated pathogens from livestock and poultry had harmony and good concordance, and sul1 & tetA resistance genes had a higher prevalence. Good agricultural practices along with proper biosecurity may reduce the rampant use of antimicrobial drugs. In addition, proper handling, processing, storage, and transportation of foods may decline the spread of MDR foodborne pathogens in the food chain.

Relationship between the appropriateness of antibiotic treatment and clinical outcomes/medical costs of patients with community-acquired acute pyelonephritis: a multicenter prospective cohort study

BACKGROUND

Inappropriate use of antibiotics not only increases antibiotic resistance as collateral damage but also increases clinical failure rates and medical costs. The purpose of this study was to determine the relationship between the appropriateness of antibiotic prescription and outcomes of community-acquired acute pyelonephritis (CA-APN).

METHODS

A multicenter prospective cohort study was conducted at eight hospitals in Korea between September 2017 and August 2018. All hospitalized patients aged ≥ 19 years who were diagnosed with CA-APN on admission were recruited. The appropriateness of empirical and definitive antibiotics, as well as the appropriateness of antibiotic treatment duration and route of administration, was evaluated in accordance with the guideline and expert opinions. Clinical outcomes and medical costs were compared between patients who were administered antibiotics 'appropriately' and 'inappropriately.'

RESULTS

A total of 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of them, 10 (2.5%) and 18 (5.7%) were administered 'inappropriately' empirical and definitive antibiotics, respectively. Of the 119 patients whose use of both empirical and definitive antibiotics was classified as 'optimal,' 57 (47.9%) received antibiotics over a longer duration than that recommended; 67 (56.3%) did not change to oral antibiotics on day 7 of hospitalization, even after stabilization of the clinical symptoms. Patients who were administered empirical antibiotics 'appropriately' had shorter hospitalization days (8 vs. 10 days, P = 0.001) and lower medical costs (2381.9 vs. 3235.9 USD, P = 0.002) than those who were administered them 'inappropriately.' Similar findings were observed for patients administered both empirical and definitive antibiotics 'appropriately' and those administered either empirical or definitive antibiotics 'inappropriately'.

CONCLUSIONS

Appropriate use of antibiotics leads to better outcomes, including reduced hospitalization duration and medical costs.

Quantitative Evaluation of the Economic Impact of Antimicrobial Resistance on the Treatment of Community-Acquired Acute Pyelonephritis in Korea

Background

Materials and Methods

Results

Conclusion

Clinical and microbiological characteristics of men with nonobstructive acute pyelonephritis: A multicenter retrospective observational study

To investigate the differences in clinical and microbiological features in men hospitalized with community-acquired (CA) and healthcare-associated (HA) nonobstructive acute pyelonephritis (APN), as well as the predictive factors associated with bacteremia.Men discharged from urological centers with nonobstructive APN were identified using an electronic medical records system. We compared the clinical and microbiological data between subjects with CA-APN and HA-APN.Of the 245 men with nonobstructive APN, 175 had CA-APN, and 70 had HA-APN. The HA group was significantly older, had a longer hospital stay, and had more underlying diseases, bacteremia, and intensive care unit admissions than the CA group. The most commonly cultured microorganism was Escherichia coli. The susceptibility of the cultured bacteria to fluoroquinolone was 68.7% in the CA group and 45.3% in the HA group (P = .005). The proportion of extended-spectrum beta-lactamase-producing bacteria was 22.7% for CA and 53.5% for HA (P < .001). The sensitivity to piperacillin/tazobactam was 94.9% for CA and 90.0% for HA, and the sensitivity to amikacin was more than 95% for both groups. The multivariate analysis revealed that an age ≥65 years and chronic liver disease were independent predictive factors for bacteremia.The incidence of antibiotic resistance and bacteremia was higher in the HA group than in the CA group. However, resistance to fluoroquinolone and the presence of extended-spectrum beta-lactamase-producing bacteria were high in both groups. Piperacillin/tazobactam and amikacin may be suitable treatment options in men with nonobstructive APN.

Fluoroquinolone Can Be an Effective Treatment Option for Acute Pyelonephritis When the Minimum Inhibitory Concentration of Levofloxacin for the Causative Escherichia coli Is ≤16 mg/L

The purpose of this study was to determine whether the fluoroquinolone (FQ) minimum inhibitory concentration (MIC) for the causative agent Escherichia coli influences the clinical response of FQ treatment at 72 h in patients with community-acquired acute pyelonephritis (CA-APN). We prospectively collected the clinical data of women with CA-APN from 11 university hospitals from March 2010 to February 2012 as well as E. coli isolates from the urine or blood. In total, 78 patients included in this study received FQ during the initial 72 h, and the causative E. coli was detected. The clinical response at 72 h was significantly higher in patients with a levofloxacin MIC ≤ 16 mg/L than in those with an MIC > 16 mg/L (70.4% vs. 28.6%, p = 0.038). No difference was observed in clinical response at 72 h based on ciprofloxacin MIC. To summarize, FQ can be an effective treatment option for CA-APN when levofloxacin MIC against E. coli is ≤16 mg/L.

Changes in Clinical Characteristics of Community-Acquired Acute Pyelonephritis and Antimicrobial Resistance of Uropathogenic Escherichia coli in South Korea in the Past Decade

This study examined changes in the clinical characteristics of community-acquired acute pyelonephritis (CA-APN) in South Korea between the period 2010–2011 and 2017–2018. We recruited all CA-APN patients aged ≥19 years who visited eight hospitals in South Korea from September 2017 to August 2018, prospectively. Data collected were compared with those from the previous study in 2010–2012, with the same design and participation from 11 hospitals. A total of 617 patients were enrolled and compared to 818 patients’ data collected in 2010–2011. Escherichia coli was the most common causative pathogen of CA-APN in both periods (87.3% vs. 86.5%, p = 0.680). E. coli isolates showed significantly higher antimicrobial resistance against fluoroquinolone (32.0% vs. 21.6%, p < 0.001), cefotaxime (33.6% vs. 8.3%, p < 0.001), and trimethoprim/sulfamethoxazole (37.5% vs. 29.2%, p = 0.013) in 2017–2018 than in 2010–2011. Total duration of antibiotic treatment increased from 16.55 ± 9.68 days in 2010–2011 to 19.12 ± 9.90 days in 2017–2018 (p < 0.001); the duration of carbapenem usage increased from 0.59 ± 2.87 days in 2010–2011 to 1.79 ± 4.89 days in 2010–2011 (p < 0.001). The median hospitalization was higher for patients in 2017–2018 than in 2010–2011 (9 vs. 7 days, p < 0.001). In conclusion, antimicrobial resistance of E. coli to almost all antibiotic classes, especially third generation cephalosporin, increased significantly in CA-APN in South Korea. Consequently, total duration of antibiotic treatment, including carbapenem usage, increased.

Differences in antibiotic usage patterns for acute pyelonephritis according to hospital type and region in the Republic of Korea: A population-based study

This study aimed to determine the differences in antibiotic usage patterns in the treatment of acute pyelonephritis according to hospital type and region in Korea.The claims database of the Health Insurance Review and Assessment Service in Korea was used to select patients with the International Classification of Diseases, Tenth Revision code N10 (acute tubulo-interstitial nephritis) or N12 (tubulo-interstitial nephritis, neither acute nor chronic) as the primary discharge diagnosis in 2010-2014. Usage of each class of antibiotics was expressed as the defined daily dose (DDD)/event.The average antibiotic usage per inpatient event was 11.3 DDD. The average antibiotic usage was the highest among patients admitted to tertiary hospitals (13.8 DDD), followed by those admitted to secondary hospitals (11.5 DDD), clinics (10.0 DDD), and primary hospitals (9.8 DDD). According to the geographic analyses, third-generation cephalosporins were highly prescribed in some southern regions; fluoroquinolones and aminoglycosides were highly prescribed in some centrally located regions of the Korean peninsula. The hotspots for carbapenem usage included Seoul and Gyeonggi province cluster and Busan cluster: these regions include the capital city and the second biggest city in Korea, respectively.In conclusion, the antibiotic usage patterns for acute pyelonephritis in Korea differ according to the hospital type and region.

Whole-Genome Sequencing-Based Characteristics in Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolated from Retail Meats in Korea

The spread of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) has posed a critical health risk to both humans and animals, because resistance to beta-lactam antibiotics makes treatment for commonly infectious diseases more complicated. In this study, we report the prevalence and genetic characteristics of ESBL-ECs isolated from retail meat samples in Korea. A total of 1205 E. coli strains were isolated from 3234 raw meat samples, purchased from nationwide retail stores between 2015 and 2018. Antimicrobial susceptibility testing was performed for all isolates by a broth microdilution method, and the ESBL phenotype was determined according to the Clinical and Laboratory Standards Institute (CLSI) confirmatory method. All ESBL-EC isolates (n = 29) were subjected to whole-genome sequencing (WGS). The antimicrobial resistance genes, plasmid incompatibility types, E. coli phylogroups, and phylogenetic relations were investigated based on the WGS data. The prevalence of ESBL-ECs in chicken was significantly higher than that in other meat samples. The results in this study demonstrate that clonally diverse ESBL-ECs with a multidrug resistance phenotype were distributed nationwide, although their prevalence from retail meat was 0.9%. The dissemination of ESBL-ECs from retail meat poses a potential risk to consumers and food-handlers, suggesting that the continuous surveillance of ESBL-ECs in retail meat should be conducted at the national level.

Prolonged fever is not a reason to change antibiotics among patients with uncomplicated community-acquired acute pyelonephritis

The study aimed to determine the pattern of fever resolution among febrile patients undergoing treatment for acute pyelonephritis (APN) and prove that switching therapy based solely on persistent fever beyond 72 hours of antibiotics treatment may be unwarranted.For the purpose of this study, non-responders were defined as those patients who had a persistent fever over 72 hours after the initiation of antibiotic therapy. Responders were defined as those patients who became afebrile in less than 72 hours after the initiation of antibiotic therapy. Clinical cure was defined as the complete resolution of all symptoms during antibiotic therapy without recurrence during the follow-up period.A total of 843 female patients with uncomplicated community-acquired APN met all inclusion criteria. The non-responder group comprised of 248 patients (29%), and the remaining patients constituted the responder group. The median initial C-reactive protein level was higher (15.6 mg/dl vs 12.6 md/dl, P < .001) and bacteremia was more frequent (31% vs 40%, P = .001) in the non-responder group. Escherichia coli (E. coli) was the most common pathogen in both groups; there was no significant difference between the groups in the etiology of APN. Antimicrobial resistance and extended spectrum β-lactamase producing strains had an increasing trend in the non-responder group but there was no significant difference between the groups.This study shows that it is difficult to identify patients at risk of uncomplicated community-acquired APN by antibiotic-resistant pathogens based exclusively on persistent fever. Patients with a prolonged fever for more than 72 hours show similar antibiotic susceptibility patterns and are not associated with adverse treatment outcomes. Therefore, switching of current antibiotics to broad-spectrum antibiotics should be reserved in this patient population until antibiotic susceptibility test results are available.

Change in the Annual Antibiotic Susceptibility of Escherichia coli in Community-Onset Urinary Tract Infection between 2008 and 2017 in a Tertiary Care Hospital in Korea

The susceptibility of Escherichia coli from community onset urinary tract infection (UTI) was evaluated by dividing community onset UTI into the simple community acquired-UTI (CA-UTI) and healthcare associated UTI (HCA-UTI) groups for a period of 10 years. The susceptibility of E. coli to most antibiotics, except amikacin and imipenem, continued to decrease. In the CA-UTI group, the susceptibility to cefotaxime was 88% in 2015, but rapidly decreased to 79.3% in 2017. The susceptibility to cefepime and piperacillin-tazobactam were 88.8% and 90.5% in 2017, respectively. In the HCA-UTI group, the susceptibility to most antibiotics markedly decreased to less than 60% by 2017. The incidence of ESBL-producing E. coli increased to 23.3% in the CA-UTI group in 2017.

Inappropriate empirical antibiotic therapy does not adversely affect the clinical outcomes of patients with acute pyelonephritis caused by extended-spectrum β-lactamase-producing Enterobacteriales

Extended-spectrum β-lactamase-producing Enterobacteriales (ESBL-PE) are often associated with inappropriate empirical therapy (IAT). The aim of this study was to investigate whether IAT of acute pyelonephritis (APN) caused by ESBL-PE is related to adverse outcomes. A retrospective cohort study was performed at a tertiary-care hospital from 2014 through 2016. Patients who had APN caused by ESBL-PE and were definitely treated with appropriate antibiotics for at least 7 days were enrolled. IAT was defined as when inappropriate empirical antibiotics were given 48 h or longer after initial diagnosis of APN. Primary endpoint was treatment failure defined as clinical and/or microbiologic failure. Secondary endpoints were length of hospital stay and recurrence of APN. Propensity score matching was used to adjust heterogeneity of each group. Among 175 eligible cases, 59 patients received IAT and 116 patients received appropriate empirical antimicrobial therapy (AT). Treatment failure was observed in five (8.4%) patients and nine (7.8%) patients in each group, respectively. After matching, the treatment failure rate was similar between both groups (adjusted odd ratio [aOR] 1.05; 95% confidence index [CI] 0.26-4.15). The length of hospital stay (median 11 days in the IAT group versus 11 days in the AT group; P = 0.717) and absence of recurrence within 2 months (90.3% in IAT and 86.7% in AT; P = 0.642) were also similar. IAT did not adversely affect the clinical outcome. In this regard, clinicians should be more cautious about indiscriminate prescription of broad-spectrum antibiotics such as carbapenem empirically for treatment of APN possibly caused by ESBL-PE.

Does urinary tract infection caused by extended-spectrum β-lactamase-producing Escherichia coli show same antibiotic resistance when it recurs?

This study was performed to evaluate what percentage of urinary tract infections (UTIs) caused by extended spectrum β-lactamase (ESBL)-producing strains recurs with ESBL-producing strains during follow up and to assess the risk factors for recurrence with ESBL-producing Escherichia coli strains on subsequent first recurrence episode. We enrolled female patients with UTIs caused by ESBL-producing E. coli between May 2012 and December 2015, who were longitudinally followed up for at least 24 months. Among the 206 patients with ESBL positive UTI, 180 completed the study. 60 (60/180, 33.3%) of patient with first episode of UTI caused by ESBL-producing E. coli experienced recurrent UTIs during follow up. Of 60 patients, 43 (43/60, 71.7%) recurred with ESBL-producing E. coli on the first UTI recurrence episode. On multivariate analysis, the time to recurrence and history of cephalosporin usage in the last 6 months were identified as risk factors for recurrence with ESBL-producing E. coli per se (odds ratio [OR] = 0.9, 95% confidence interval [CI] 0.8-1.0, p = 0.030 and OR = 27.0, 95% CI 2.4-299.8, p = 0.007, respectively). These findings show that high proportion of patient with UTI caused by ESBL-producing E. coli recurs with ESBL-producing E. coli on subsequent recurrence episode. While result of antibiotic susceptibility cannot be identified on the visit day empirical treatment should be referred to the antecedent antibiotic resistance profile in patients whose previous UTIs were due to ESBL-producing strains.

Descriptive Epidemiology of Acute Pyelonephritis in Korea, 2010-2014: Population-based Study

BACKGROUND

Acute pyelonephritis (APN) is one of the most common community-acquired bacterial infections. Recent increases of antimicrobial resistance in urinary pathogens might have changed the other epidemiologic characteristics of APN. The objective of this study was to describe the current epidemiology of APN in Korea, using the entire population.

METHODS

From the claims database of the Health Insurance Review and Assessment Service in Korea, the patients with International Classification of Diseases, 10th Revision codes N10 (acute tubulo-interstitial nephritis) or N12 (tubulo-interstitial nephritis, neither acute nor chronic) as the primary discharge diagnosis during 2010-2014 were analyzed, with two or more claims during a 14-day period considered as a single episode.

RESULTS

The annual incidence rate of APN per 10,000 persons was 39.1 and was on the increase year to year (35.6 in 2010; 36.7 in 2011; 38.9 in 2012; 40.1 in 2013; 43.8 in 2014, P = 0.004). The increasing trend was observed in both inpatients (P = 0.014) and outpatients (P = 0.004); in both men (P = 0.042) and women (P = 0.003); and those aged under 55 years (P = 0.014) and 55 years or higher (P = 0.003). Eleven times more women were diagnosed and treated with APN than men (men vs. women, 6.5 vs. 71.3), and one of every 4.1 patients was hospitalized (inpatients vs. outpatients, 9.6 vs. 29.4). The recurrence rate was 15.8%, and the median duration from a sporadic episode (i.e., no episode in the preceding 12 months) to the first recurrence was 44 days. The recurrence probability increased with the number of previous recurrences. The average medical cost per inpatient episode was USD 1,144, which was 12.9 times higher than that per outpatient episode (USD 89).

CONCLUSION

The epidemiology of APN in Korea has been changing with an increasing incidence rate.

Factors associated with the recurrence of acute pyelonephritis caused by extended-spectrum β-lactamase-producing Escherichia coli: the importance of infectious disease consultation

To investigate factors for the recurrence of acute pyelonephritis (APN) caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-PE), a retrospective cohort study was performed at a tertiary-care hospital from 2014 through 2016. Among 135 patients who had recovered from APN caused by ESBL-PE, the 1-year cumulative recurrence rates of APN caused by any pathogen or by ESBL-PE specifically were 35.6% and 22.1%, respectively. In a multivariate analysis, infectious disease (ID) consultation was associated with decreased recurrence (95% confidence interval [CI] = 0.24-0.96, P = 0.038 for recurrence caused by any pathogen; and 95% CI = 0.15-0.84, P = 0.019 for recurrence caused by ESBL-PE). History of APN within 1 year was a risk factor for recurrent APN caused by any pathogen (P = 0.011). Microbiological cure was a preventive factor for recurrent APN caused by ESBL-PE (P = 0.024). In conclusion, our data show that ID consultation protects against APN recurrence caused by ESBL-PE.

Antibiotic-resistant clones in Gram-negative pathogens: presence of global clones in Korea

Antibiotic resistance is a global concern in public health. Antibiotic-resistant clones can spread nationally, internationally, and globally. This review considers representative antibiotic-resistant Gram-negative bacterial clones-CTX-M- 15-producing ST131 in Escherichia coli, extended-spectrum ß-lactamase-producing ST11 and KPC-producing ST258 in Klebsiella pneumoniae, IMP-6-producing, carbapenem-resistant ST235 in Pseudomonas aeruginosa, and OXA-23-producing global clone 2 in Acinetobacter baumannii-that have disseminated worldwide, including in Korea. The findings highlight the urgency for systematic monitoring and international cooperation to suppress the emergence and propagation of antibiotic resistance.

Community-Acquired Urinary Tract Infection by Escherichia coli in the Era of Antibiotic Resistance

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are the most common types of infections in women. The antibiotic resistance of E. coli is increasing rapidly, causing physicians to hesitate when selecting oral antibiotics. In this review, our objective is to ensure that clinicians understand the current seriousness of antibiotic-resistant E. coli, the mechanisms by which resistance is selected for, and methods that can be used to prevent antibiotic resistance.

Clinical Practice Guidelines for the Antibiotic Treatment of Community-Acquired Urinary Tract Infections

Urinary tract infections (UTIs) are infectious diseases that commonly occur in communities. Although several international guidelines for the management of UTIs have been available, clinical characteristics, etiology and antimicrobial susceptibility patterns may differ from country to country. This work represents an update of the 2011 Korean guideline for UTIs. The current guideline was developed by the update and adaptation method. This clinical practice guideline provides recommendations for the diagnosis and management of UTIs, including asymptomatic bacteriuria, acute uncomplicated cystitis, acute uncomplicated pyelonephritis, complicated pyelonephritis related to urinary tract obstruction, and acute bacterial prostatitis. This guideline targets community-acquired UTIs occurring among adult patients. Healthcare-associated UTIs, catheter-associated UTIs, and infections in immunocompromised patients were not included in this guideline.

Prospective cohort study of risk factors for extended-spectrum ß-lactamase-producing Escherichia coli urinary tract infections in elderly patients admitted to hospital

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are currently common in community-onset infections, limiting therapeutic options. In this work we aim to identify the prevalence of and risk factors for ESBL-producing E. coli in elderly patients with urinary tract infections (UTI) admitted to hospital.

METHODS

Prospective cohort study on elderly patients with E. coli UTI admitted to a university hospital in Spain, from January 2013 to December 2015. Clinical features, microbiology and outcomes were recorded from the electronic medical records and reviewed by two researchers. Cases were segregated according to ESBL-producing E. coli. Risk factors for ESBL-producing E. coli were analysed by multivariate analysis.

RESULTS

The prevalence of ESBL-producing E. coli was 27.4% (85/310). Healthcare-associated UTI was the only risk factor for ESBL-producing E. coli (OR 6.79; 95% CI 3.22-14.31, P < .001) by multivariate analysis. ESBL-producing E. coli was 43.9% in the healthcare-associated UTI group and 8.9% in the community-acquired UTI group (P < .001). Inadequate empirical antibiotic therapy and length of stay in hospital were higher in the ESBL-producing E. coli group than in the non-ESBL-producing E. coli group (62.3% vs 5.3% and 6.60 ± 3.69 days vs 5.61 ± 3.16 days, respectively). Mortality was not significantly different between groups (13% in ESBL-producing E. coli group vs 7.5% in non-ESBL-producing E. coli group, P = .140).

SUMMARY

Healthcare-associated UTI was a risk factor for ESBL-producing E. coli in elderly patients with UTI admitted to hospital. Our results might help clinicians in choosing empirical antibiotics in an overall high rate setting of ESBL-producing E. coli.

Activity of temocillin and 15 other agents, including fosfomycin and colistin, against Enterobacteriaceae in Hong Kong

Limited data are available on temocillin susceptibilities in Enterobacteriaceae from Asian countries where antimicrobial resistance is prevalent. The in vitro activities of temocillin and 15 commonly used antimicrobials against 613 non-duplicate blood (n = 310) and urine (with clinically significant bacteriuria; n = 303) isolates of Enterobacteriaceae from patients who attended 3 out of 7 clusters of public hospitals of the Hospital Authority, Hong Kong, during 2015/2016 were tested. Minimum inhibitory concentrations (MICs) were determined by Clinical and Laboratory Standards Institute (CLSI) microbroth dilution (agar dilution with fosfomycin). For temocillin, MICs were also obtained using the British Society of Antimicrobial Chemotherapy (BSAC) microbroth dilution method and interpreted using the BSAC breakpoints. Overall, 93.0% (570) isolates were susceptible to temocillin using BSAC systemic breakpoint (≤8 mg/L) and all except 2 isolates were susceptible using the urinary breakpoint (≤32 mg/L). The extended spectrum beta-lactamase (ESBL) positivity rate was 23.2% (118 out of 508 E. coli, Klebsiella spp., Proteus spp.). Temocillin resistance rate to ESBL-positive isolates was 16.1% using the systemic breakpoint of ≤8 mg/L (MIC₅₀ and MIC₉₀ were 8 mg/L and 16 mg/L respectively). Two isolates (1 E. coli, temocillin MIC 64 mg/L, 1 Klebsiella sp., MIC 32 mg/mL) were resistant to meropenem and possessed the NDM-5 and KPC-2 genes respectively. Other susceptibility rates were: amoxicillin/clavulanate (59.1%), trimethoprim/sulfamethoxazole (62.5%), ciprofloxacin (71.5%), ceftriaxone (75.4%), nitrofurantoin (76.4%), gentamicin (78.3%), cefepime (81.1%), ceftazidime (83.5%), piperacillin/tazobactam (86%), colistin (88.8%), tigecycline (89.4%), fosfomycin (92.8%), ertapenem (99.0%), amikacin (99.2%) and meropenem (99.7%). Temocillin may be a useful alternative for the treatment of infections caused by ESBL and multi-drug-resistant Enterobacteriaceae in Hong Kong, particularly as resistance rates to ciprofloxacin, nitrofurantoin and piperacillin/tazobactam are high.

Childhood urinary tract infection caused by extended-spectrum β-lactamase-producing bacteria: Risk factors and empiric therapy

BACKGROUND

This study investigated risk factors of childhood urinary tract infection (UTI) associated with extended-spectrum β-lactamase (ESBL)-producing bacteria (ESBL-positive UTI) and evaluated antimicrobial resistance as well as empiric treatment of childhood UTI.

METHODS

The records of children with positive urine culture between 1 January 2008 and 31 December 2012 were evaluated. Patients with positive urine culture for ESBL-producing bacteria were defined as the ESBL-positive group, whereas patients of the same gender and similar age with positive urine culture for non-ESBL-producing bacteria were defined as the ESBL-negative group. Each ESBL-positive patient was matched with two ESBL-negative patients.

RESULTS

The ESBL-positive and negative groups consisted of 154 and 308 patients, respectively. Potential risk factors for ESBL-positive UTI were identified as presence of underlying disease, clean intermittent catheterization (CIC), hospitalization, use of any antibiotic and history of infection in the last 3 months (P < 0.05). On logistic regression analysis, CIC, hospitalization and history of infection in the last 3 months were identified as independent risk factors. In the present study, 324 of 462 patients had empiric therapy. Empiric therapy was inappropriate in 90.3% of the ESBL-positive group and in 4.5% of the ESBL-negative group. Resistance to nitrofurantoin was similar between groups (5.1% vs 1.2%, P = 0.072); resistance to amikacin was low in the ESBL-positive group (2.6%) and there was no resistance in the ESBL-negative group.

CONCLUSIONS

Clean intermittent catheterization, hospitalization and history of infection in the last 3 months should be considered as risk factors for ESBL-positive UTI. The combination of ampicillin plus amikacin should be taken into consideration for empiric therapy in patients with acute pyelonephritis who have the risk factors for ESBL-positive UTI. Nitrofurantoin seems to be a logical choice for the empiric therapy of cystitis.

Antimicrobial Susceptibilities of Enterobacteriaceae in Community-Acquired Urinary Tract Infections during a 5-year Period: A Single Hospital Study in Korea

Background

Through investigating antimicrobial susceptibility patterns of Enterobacteriaceae in community-acquired urinary tract infection (CA-UTI), we provide basic evidence for the use of empirical antibiotics in CA-UTI.

Materials and Methods

We retrospectively reviewed the medical records of patients over the age of 19 years who visited a hospital in Seoul between January 2012 and December 2016 for a CA-UTI. Urine cultures were used to identify causative organisms. We investigated extended-spectrum β-lactamase (ESBL) production and the antimicrobial susceptibility of Enterobactereiaceae. We evaluated recommended empirical antibiotics numerically by calculating the syndrome-specific likelihood of inadequate therapy (LIT) for the last 2 years (interpretation of the LIT A value: 1 out of A people is likely to receive inadequate empirical antibiotics).

Results

Urine cultures were performed in 1,605 out of 2,208 patients who were diagnosed with CA-UTI, and causative pathogens were identified in 1,134 (70.7%) cases. There were 998 (88.0%) cases of Enterobacteriaceae and Escherichia coli was the most common pathogen, accounting for 80.3% of cases (911 cases). The overall resistance rates to trimethoprim-sulfamethoxazole, fluoroquinolones, and cefotaxime were 31.7%, 23.2%, and 13.5%, respectively. There were 128 (10.8%) cases of ESBL-producing Entererobacteriaceae with an increasing but non-significant trend (P = 0.255). The LIT for CA-UTI in the past two years was highest for ertapenem and imipenem. Fluoroquinolones ranked 11th, with a LIT of 8.2, and cefotaxime ranked higher, at 10.5. In ESBL-producing Enterobacteriaceae, except for carbapenems, amikacin and piperacillin-tazobactam showed the highest susceptibility rates at 99.2% and 94.3%, respectively.

Conclusion

Empiric treatment with fluoroquinolones in CA-UTI should be carefully considered, given the high resistance rate. The proportion of ESBL-producing Entererobacteriaceae in CA-UTI has increased to a high level in Korea. Amikacin and piperacillin-tazobactam could be considered for empiric treatment in patients at risk for ESBL-producing Entererobacteriaceae when considering alternatives to carbapenems.

Characteristics of Extended-Spectrum β-Lactamases-Producing Escherichia coli in Fecal Samples of Inpatients of Beijing Tongren Hospital

We aimed to investigate the prevalence of extended-spectrum β-lactamases (ESBL)-producing Escherichia coli in Beijing Tongren hospital and to identify a possible relation between colonization and infection. The clinical data on 650 inpatients between March 2012 and July 2012 were retrospectively reviewed. The prevalence of ESBL-producing E. coli among the inpatients was 25.7% (167/650), with the highest level (50.0%) in the rheumatology ward and the lowest (10.0%) in intensive care units. Hospital stay more than 2 years prior to infection, the use of antibiotics within 3 months of infection, and the use of glucocorticoids or immunosuppressive drugs were found to be significantly associated with carriage of ESBL-producing E. coli (P < 0.05). In total, 76 sequence types (STs) were revealed by multilocus sequence typing. ST38 (n = 12, 7.2%) was the most common ST, followed by ST10 (n = 10, 6.0%) and ST131 and ST167 (n = 9 and 5.4% each). Among the fecal carriers, only one patient had an active infection, which was caused by an ST38 strain. In conclusion, in Beijing Tongren hospital, the prevalence of ESBL-producing E. coli was not high. The risk factors of carriage of ESBL-producing E. coli are hospitalization and use of antibiotics, glucocorticoids, or immunosuppressive drugs. ST38, ST10, ST131, and ST167 are the prominent genotypes, but almost 50.0% of STs were scarcely distributed.

Epidemic potential of Escherichia coli ST131 and Klebsiella pneumoniae ST258: a systematic review and meta-analysis

OBJECTIVES

Observational studies have suggested that Escherichia coli sequence type (ST) 131 and Klebsiella pneumoniae ST258 have hyperendemic properties. This would be obvious from continuously high incidence and/or prevalence of carriage or infection with these bacteria in specific patient populations. Hyperendemicity could result from increased transmissibility, longer duration of infectiousness, and/or higher pathogenic potential as compared with other lineages of the same species. The aim of our research is to quantitatively estimate these critical parameters for E. coli ST131 and K. pneumoniae ST258, in order to investigate whether E. coli ST131 and K. pneumoniae ST258 are truly hyperendemic clones.

PRIMARY OUTCOME MEASURES

A systematic literature search was performed to assess the evidence of transmissibility, duration of infectiousness, and pathogenicity for E. coli ST131 and K. pneumoniae ST258. Meta-regression was performed to quantify these characteristics.

RESULTS

The systematic literature search yielded 639 articles, of which 19 data sources provided information on transmissibility (E. coli ST131 n=9; K. pneumoniae ST258 n=10)), 2 on duration of infectiousness (E. coli ST131 n=2), and 324 on pathogenicity (E. coli ST131 n=285; K. pneumoniae ST258 n=39). Available data on duration of carriage and on transmissibility were insufficient for quantitative assessment. In multivariable meta-regression E. coli isolates causing infection were associated with ST131, compared to isolates only causing colonisation, suggesting that E. coli ST131 can be considered more pathogenic than non-ST131 isolates. Date of isolation, location and resistance mechanism also influenced the prevalence of ST131. E. coli ST131 was 3.2 (95% CI 2.0 to 5.0) times more pathogenic than non-ST131. For K. pneumoniae ST258 there were not enough data for meta-regression assessing the influence of colonisation versus infection on ST258 prevalence.

CONCLUSIONS

With the currently available data, it cannot be confirmed nor rejected, that E. coli ST131 or K. pneumoniae ST258 are hyperendemic clones.

Community-Onset Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Invasive Infections in Children in a University Hospital in France

Limited data is available on pediatric community-onset infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), but such infections may affect both the efficacy of empiric antibiotic therapy and the rational use of antibiotics.We retrospectively analyzed data from 2007 to 2012 for all children ≤16 years old with a positive ESBL-PE strain from usually sterile sites within 48 hours of admission in a tertiary hospital in France. We analyzed healthcare- and community-associated infections among community-onset infections. In total, 3612 Enterobacteriaceae isolates were collected; the prevalence of ESBL-PE infection increased over the study period, from 2.4% to 5.1% (P < 0.001). Among the 90 children with a first community-onset ESBL-PE infection, 58% (n = 52) had a healthcare-associated infection, and 87% of isolates were susceptible to amikacin. As compared with patients with community-associated infections, those with healthcare-associated infections had fewer urinary tract infections (UTIs) (86% vs 97%) and Escherichia coli infections (35% vs 84%) and more Klebsiella pneumoniae infections (46% vs 8%). Inappropriate empiric treatment was prescribed for 54 patients (64%), but a favorable outcome was observed in 46 of 49 (94%) and 1 of 5 (20%) patients with UTIs and non-UTIs, respectively (P < 0.001). Among patients with community-associated infections, 85% had at least 1 risk factor for ESBL-PE infections. In conclusion, the prevalence of community-onset ESBL-PE infections doubled during the study period. These infections mainly occurred among children with healthcare-associated criteria or identified risk factors. Amikacin is an alternative to carbapenems for empiric treatment because most of these infections involved urinary tract and susceptible isolates.

Empirical therapies among adults hospitalized for community-acquired upper urinary tract infections: A decision-tree analysis of mortality, costs, and resistance

BACKGROUND

Poor outcomes occur when patients with serious infections receive antibiotics to which the organisms are resistant.

METHODS

Decision trees simulated in-hospital mortality, costs, incremental cost-effectiveness ratio per life year saved, and carbapenem resistance according to 3 empirical antibiotic strategies among adults hospitalized for community-acquired (CA) upper urinary tract infections (UTIs): ceftriaxone (CRO) plus gentamicin (GM) in the intensive care unit (ICU), imipenem (IMP), and individualized choice (IMP or CRO) based on clinical risk factors for CA- extended-spectrum β-lactamase (ESBL).

RESULTS

The estimated prevalence of CA-ESBL on admission was 5% (range, 1.3%-17.6%); 3% and 97% were admitted to the ICU and medical ward (MW), respectively. In the ICU, CRO plus GM was dominated; IMP was cost-effective (incremental cost-effectiveness ratio: €4,400 per life year saved compared with individualized choice). In the MW, IMP had no impact on mortality and was less costly (-€142 per patient vs CRO, -€38 vs individualized choice). The dominance of IMP was consistent in sensitivity analyses. Compared with CRO, colonization by carbapenem-resistant pathogens increased by an odds ratio of 4.5 in the IMP strategy.

CONCLUSION

Among the ICU patients, empirical IMP therapy reduces mortality at an acceptable cost. Among MW patients, individualized choice or CRO is preferred to limit carbapenem resistance at a reasonable cost.

Febrile urinary tract infection in the emergency room

PURPOSE OF REVIEW

To review the recent advances in the diagnostic and therapeutic approach to adults presenting with febrile urinary tract infection (UTI) in the emergency department (ED).

RECENT FINDINGS

Recent research suggests overdiagnosis and therefore overtreatment of UTI in the ED, especially in the elderly. Antimicrobial pretreatment, an indwelling catheter, and malignancy are independent risk factors for bacteremia with uropathogens that cannot be cultured from urine. A simple clinical prediction rule can predict clinically relevant radiologic findings in patients with invasive UTI. Procalcitonin is a marker for bacteremia; pro-adrenomedullin predicts a complicated course and 30-day mortality in complicated UTI. Several reports have identified the risk factors for resistant uropathogens in community-acquired febrile UTI. Adherence to the guidelines and early culture-guided intravenous-to-oral switch reduces the length of hospitalization.

SUMMARY

An effective strategy is needed to improve the diagnosis of UTIs in acute care. Further research regarding biomarker-guided triage might improve the management of patients with febrile UTI. Future efforts should be directed toward the improvement of adherence to UTI treatment guidelines.

Antimicrobial susceptibilities of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in health care-associated urinary tract infection: focus on susceptibility to fosfomycin

PURPOSE

The appearance of extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria in urinary tract infection (UTI) constitutes an important therapeutic challenge. The aim of this study was to describe drug susceptibility profiles of ESBL-producing bacteria isolated from urine samples. We also determined the antimicrobial co-resistance to several agents, including fosfomycin.

METHODS

The computerized database was used to identify ESBL-positive urine samples. We analyzed E. coli and Klebsiella isolates obtained from urine cultures, and duplicate isolates and isolates not tested against fosfomycin were excluded. The cases were further categorized according to UTI definition [community-acquired (CoA) UTI, community-onset health care-associated (HCA) UTI, and hospital-acquired (HA) UTI]. ESBL isolates were stratified according to their origin into two groups: urology and non-urology isolates.

RESULTS

Antimicrobial susceptibilities of the strains to fosfomycin were tested in 277 ESBL-positive strains, 217 ESBL-EC strains, and 60 ESBL-KP strains. The most effective agents were carbapenems, such as imipenem and meropenem. The least active substances were ciprofloxacin (20.7 %), levofloxacin (22.7 %), trimethoprim-sulfamethoxazole (34.3 %), and ampicillin-clavulanate (42.9 %). Overall, 243 out of the 277 (87.7 %) isolates tested were susceptible to fosfomycin. Higher fosfomycin sensitivity was observed in E. coli (94.9 %) compared to Klebsiella (61.7 %) (p = 0.001). ESBL-positive isolates from urological (68 isolates) and non-urological patients (209 isolates) showed similar susceptibility profiles. Other than carbapenems, isolates from CoA-UTI showed higher sensitivity to fosfomycin (100 %) and nitrofurantoin (93.1 %), isolates from HCA-UTI showed higher sensitivity to amikacin (94.1 %), and isolates from HA-UTI showed overall poor sensitivity to antibiotics.

CONCLUSIONS

Fosfomycin could be an alternative treatment option for UTIs related to ESBL-producing E. coli spp. and CoA-UTI, but not for UTIs related to ESBL-producing Klebsiella spp. Antimicrobial susceptibilities of ESBL-producing strains were different according to the UTI classification. Fosfomycin showed decreased activity against isolates from HCA-UTI and HA-UTI. However, further clinical verification is required to assess the clinical efficacy of fosfomycin for the treatment of UTIs caused by ESBL-producing E. coli isolates.

A comparison of the clinical characteristics of elderly and non-elderly women with community-onset, non-obstructive acute pyelonephritis

BACKGROUND/AIMS

Acute pyelonephritis (APN) is the most common cause of community-onset bacteremia in hospitalized elderly patients. The objectives of this study were to investigate the differences in the clinical and microbiological data of hospitalized elderly and non-elderly women with community-onset APN.

METHODS

Women with community-onset APN as a discharge diagnosis were identified from January 2004 to December 2013 using an electronic medical records system. We compared the clinical and microbiologic data in elderly and non-elderly women with community-onset APN due to Enterobacteriaceae.

RESULTS

Of the 1,134 women with community-onset APN caused by Enterobacteriaceae, 443 were elderly and 691 were non-elderly women. The elderly group had a lower frequency of upper and lower urinary tract symptoms/signs than the non-elderly. The incidence of bacteremia, extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, patients with a C-reactive protein (CRP) level ≥ 15 mg/dL, and patients with a leukocyte count ≥ 15,000/mm(3) in the blood, were significantly higher in the elderly group than in the non-elderly group. The proportion of patients requiring hospitalization for 10 days or more was significantly higher in the elderly group compared to the non-elderly group (51.5% vs. 26.2%, p < 0.001). The clinical cure rates at 4 to 14 days after the end of therapy were 98.3% (338/344) and 97.4% (519/533) in the elderly and non-elderly groups, respectively (p = 0.393).

CONCLUSIONS

Elderly women with APN exhibit higher serum CRP levels, a higher frequency of bacteremia, a higher proportion of ESBL-producing uropathogens, and require a longer hospitalization than non-elderly women, although these patients may not complain of typical urinary symptoms.

Impact of extended-spectrum β-lactamase production on treatment outcomes of acute pyelonephritis caused by escherichia coli in patients without health care-associated risk factors

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused by E. coli at a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3; P = 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38; P = 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65; P = 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused by E. coli showed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30; P = 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12; P = 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associated E. coli APN.

Temocillin (6 g daily) in critically ill patients: continuous infusion versus three times daily administration

OBJECTIVES

The growing incidence of infections caused by Enterobacteriaceae producing ESBLs has led to increased use of carbapenems. Temocillin, which resists most β-lactamases, may be a useful alternative. The aim of this study was to assess the pharmacokinetics and target attainment rates of 6 g of temocillin daily divided into three administrations every 8 h (three times daily) or administered by continuous infusion in critically ill patients.

PATIENTS AND METHODS

This was a prospective, two-centre, randomized, controlled study in patients with intra-abdominal or lower respiratory tract infections caused by Enterobacteriaceae.

RESULTS

Thirty-two patients were included and analysed for clinical efficacy, and pharmacokinetics were measured in 29 of them. Four patients undergoing continuous veno-venous haemofiltration (CVVH) were analysed separately. Mean, median and range of percentages of the dosing interval during which the free drug concentration remained >16 mg/L were 76.4, 98 and 18.7-98.9 in patients treated three times daily and 98.9, 89.7 and 36.4-99.9 in patients with continuous infusion, respectively. Clinical cure rates were 79% and 93% in each of these groups, respectively (not significant). Patients with CVVH received a daily dose of 750 mg given by continuous infusion and had a mean free drug concentration of only 13.8 ± 1.9 mg/L. No adverse event attributable to temocillin was observed.

CONCLUSIONS

Temocillin (6 g daily) given by continuous infusion allows a larger proportion of critically ill patients to have free drug serum concentrations covering infections caused by Enterobacteriaceae with an MIC of 16 mg/L compared with administration three times daily. Clinical efficacy compared with carbapenems in documented severe infections needs to be further studied.

Factors associated with ciprofloxacin- and cefotaxime-resistant Escherichia coli in women with acute pyelonephritis in the emergency department

BACKGROUND

High rates of antimicrobial resistance in Escherichia coli isolated from patients with urinary tract infections have been reported worldwide. The aim of this study was to identify risk factors for resistance to ciprofloxacin (CIP) and cefotaxime (CTX) in E. coli isolated from patients with acute pyelonephritis (APN).

METHODS

We prospectively identified women over 18 y of age who visited the emergency department of one of 10 hospitals with APN and whose urine culture grew E. coli. The study was conducted from April 16 to June 10, 2012.

RESULTS

Of the 229 patients identified, 173 (75.5%) had community-associated (CA) infections and 56 (24.5%) had healthcare-associated (HCA) infections. Sixty-seven isolates (29.3%) were resistant to CIP, 45 (19.7%) to CTX, and 29 (12.7%) to both CIP and CTX. Multivariate analyses revealed that hematologic disease, chronic kidney disease, a bed-ridden state, indwelling urinary catheter, antibiotic treatment in the preceding 3 months, and isolation of CIP-resistant E. coli in the urine within the preceding 3 months, were significantly associated with resistance to both CIP and CTX.

CONCLUSIONS

Chronic conditions and healthcare-associated factors were related to resistance to both fluoroquinolones and third-generation cephalosporins in women with APN. Continued and vigilant surveillance is necessary to monitor the dissemination of antimicrobial resistance in uropathogens.

Impact of extended-spectrum beta-lactamase on acute pyelonephritis treated with empirical ceftriaxone

BACKGROUND

Ceftriaxone is frequently administered empirically for hospitalized patients with acute pyelonephritis (APN) due to prevalent quinolone resistance in our hospital; however, its use is inappropriate for extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, an increasing problem.

METHODS

A retrospective, 1:2 matched cohort study was performed to evaluate the impact of ESBL on APN treated with empirical ceftriaxone. Each patient in ESBL group was matched with two patients in the non-ESBL group, using a 16-point scoring system, which included age, sex, bacteremia, simplified acute physiology score 2, Charlson comorbidity index and APN severity score.

RESULTS

From 2009 to 2011, among 1,322 community-onset cases of the E. coli bacteriuria with 212 (16%) ESBL producers, 261 patients with APN were treated empirically with ceftriaxone in a secondary care hospital. Among these 261 cases, twenty-six patients in the ESBL group and 52 matched patients in the non-ESBL group (1:2) were included. Mean time to defervescence was 4.6±2.2 days in the ESBL group and 2.6±1.3 days in the non-ESBL group (p<0.01). Rate of microbiological resolution within 5 days after antibiotic treatment was 77% (17/22) in the ESBL group and 100% (45/45) in the non-ESBL group (p=0.01). The duration of hospitalization was 13.3±8.2 days in the ESBL group and 7.3±3.5 days in the non-ESBL group (p<0.01). No patient died in either group.

CONCLUSION

Empirical ceftriaxone therapy for APN caused by ESBL-producing E. coli is inappropriate, and consequently can delay recovery and result in longer hospitalization.

Risk factors for community-acquired urinary tract infections caused by ESBL-producing enterobacteriaceae--a case-control study in a low prevalence country

Community-acquired urinary tract infection (CA-UTI) is the most common infection caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, but the clinical epidemiology of these infections in low prevalence countries is largely unknown. A population based case-control study was conducted to assess risk factors for CA-UTI caused by ESBL-producing E. coli or K. pneumoniae. The study was carried out in a source population in Eastern Norway, a country with a low prevalence of infections caused by ESBL-producing Enterobacteriaceae. The study population comprised 100 cases and 190 controls with CA-UTI caused by ESBL-producing and non-ESBL-producing E. coli or K. pneumoniae, respectively. The following independent risk factors of ESBL-positive UTIs were identified: Travel to Asia, The Middle East or Africa either during the past six weeks (Odds ratio (OR) = 21; 95% confidence interval (CI): 4.5–97) or during the past 6 weeks to 24 months (OR = 2.3; 95% CI: 1.1–4.4), recent use of fluoroquinolones (OR = 16; 95% CI: 3.2–80) and β-lactams (except mecillinam) (OR = 5.0; 95% CI: 2.1–12), diabetes mellitus (OR = 3.2; 95% CI: 1.0–11) and recreational freshwater swimming the past year (OR = 2.1; 95% CI: 1.0–4.0). Factors associated with decreased risk were increasing number of fish meals per week (OR = 0.68 per fish meal; 95% CI: 0.51–0.90) and age (OR = 0.89 per 5 year increase; 95% CI: 0.82–0.97). In conclusion, we have identified risk factors that elucidate mechanisms and routes for dissemination of ESBL-producing Enterobacteriaceae in a low prevalence country, which can be used to guide appropriate treatment of CA-UTI and targeted infection control measures.