Prevalence of and risk factor for community-onset third-generation cephalosporin-resistant Escherichia coli bacteremia at a medical center in Taiwan

Mortality and length of hospital stay after bloodstream infections caused by ESBL-producing compared to non-ESBL-producing E. coli

OBJECTIVE

To compare mortality and length of hospital stay between patients with ESBL-producing E. coli bloodstream infections (BSIs) and patients with non-ESBL E. coli BSIs. We also aimed at describing risk factors for ESBL-producing E. coli BSIs and time to effective antibiotic treatment for the two groups.

METHODS

A retrospective case-control study among adults admitted between 2014 and 2021 to a Norwegian University Hospital.

RESULTS

A total of 468 E. coli BSI episodes from 441 patients were included (234 BSIs each in the ESBL- and non-ESBL group). Among the ESBL-producing E. coli BSIs, 10.9% (25/230) deaths occurred within 30 days compared to 9.0% (21/234) in the non-ESBL group. The adjusted 30-day mortality OR was 1.6 (95% CI 0.7-3.7, p = 0.248). Effective antibiotic treatment was administered within 24 hours to 55.2% (129/234) in the ESBL-group compared to 86.8% (203/234) in the non-ESBL group. Among BSIs of urinary tract origin (n = 317), the median length of hospital stay increased by two days in the ESBL group (six versus four days, p < 0.001). No significant difference in the length of hospital stay was found for other sources of infection (n = 151), with a median of seven versus six days (p = 0.550) in the ESBL- and non-ESBL groups, respectively.

CONCLUSION

There was no statistically significant difference in 30-day mortality in ESBL-producing E. coli compared to non-ESBL E. coli BSI, despite a delay in the administration of an effective antibiotic in the former group. ESBL-production was associated with an increased length of stay in BSIs of urinary tract origin.

From Epidemiology of Community-Onset Bloodstream Infections to the Development of Empirical Antimicrobial Treatment-Decision Algorithm in a Region with High Burden of Antimicrobial Resistance

Antimicrobial-resistant (AMR) infections have increased in community settings. Our objectives were to study the epidemiology of community-onset bloodstream infections (BSIs), identify risk factors for AMR-BSI and mortality-related factors, and develop the empirical antimicrobial treatment-decision algorithm. All adult, positive blood cultures at the emergency room and outpatient clinics were evaluated from 08/2021 to 04/2022. AMR was defined as the resistance of organisms to an antimicrobial to which they were previously sensitive. A total of 1151 positive blood cultures were identified. There were 450 initial episodes of bacterial BSI, and 114 BSIs (25%) were AMR-BSI. Non-susceptibility to ceftriaxone was detected in 40.9% of 195 E. coli isolates and 16.4% among 67 K. pneumoniae isolates. A treatment-decision algorithm was developed using the independent risk factors for AMR-BSI: presence of multidrug-resistant organisms (MDROs) within 90 days (aOR 3.63), prior antimicrobial exposure within 90 days (aOR 1.94), and urinary source (aOR 1.79). The positive and negative predictive values were 53.3% and 83.2%, respectively. The C-statistic was 0.73. Factors significantly associated with 30-day all-cause mortality were Pitt bacteremia score (aHR 1.39), solid malignancy (aHR 2.61), and urinary source (aHR 0.30). In conclusion, one-fourth of community-onset BSI were antimicrobial-resistant, and one-third of Enterobacteriaceae were non-susceptible to ceftriaxone. Treatment-decision algorithms may reduce overly broad antimicrobial treatment.

Diagnostic Accuracy of Hospital Antibiograms in Predicting the Risk of Antimicrobial Resistance in Enterobacteriaceae Isolates: A Nationwide Multicenter Evaluation at the Veterans Health Administration

BACKGROUND

Many clinical guidelines recommend that clinicians use antibiograms to inform empiric antimicrobial therapy. However, hospital antibiograms are typically generated by crude aggregation of microbiologic data, and little is known about an antibiogram's reliability in predicting antimicrobial resistance (AMR) risk at the patient-level. We aimed to assess the diagnostic accuracy of antibiograms as a tool for selecting empiric therapy for Escherichia coli and Klebsiella spp. for individual patients.

METHODS

We retrospectively generated hospital antibiograms for the nationwide Veterans Health Administration (VHA) facilities from 2000 to 2019 using all clinical culture specimens positive for E. coli and Klebsiella spp., then assessed the diagnostic accuracy of an antibiogram to predict resistance for isolates in the following calendar year using logistic regression models and predefined 5-step interpretation thresholds.

RESULTS

Among 127 VHA facilities, 1 484 038 isolates from 704 779 patients for E. coli and 671 035 isolates from 340 504 patients for Klebsiella spp. were available for analysis. For E. coli and Klebsiella spp., the discrimination abilities of hospital-level antibiograms in predicting individual patient AMR were mostly poor, with the areas under the receiver operating curve at 0.686 and 0.715 for ceftriaxone, 0.637 and 0.675 for fluoroquinolones, and 0.576 and 0.624 for trimethoprim-sulfamethoxazole, respectively. The sensitivity and specificity of the antibiogram varied widely by antimicrobial groups and interpretation thresholds with substantial trade-offs.

CONCLUSIONS

Conventional hospital antibiograms for E. coli and Klebsiella spp. have limited performance in predicting AMR for individual patients, and their utility in guiding empiric therapy may be low.

Risk factors in acquiring multidrug-resistant Klebsiella pneumoniae infections in a hospital setting in Saudi Arabia

Over the last decades, the prevalence of multidrug-resistant (MDR) Klebsiella pneumoniae in clinical settings has increased progressively. This study determined the prevalence and risk factors associated with MDR K. pneumoniae infection among hospitalized patients in a referral hospital located in southern Saudi Arabia. A prospective cross-sectional study was conducted in King Abdullah Hospital from April 2021 to March 2022. K. pneumoniae (n = 211) bacteria were recovered from clinical samples of adult patients and examined for antibiotic susceptibility. Univariate and multivariate logistic regressions were applied to determine the factors associated with MDR K. pneumoniae infection. MDR K. pneumoniae strains was found in 66.8% (142/211) of the patients. Among MDR K. pneumoniae, the highest resistance rate was determined for ampicillin (100%), cefuroxime (97.9%), ceftriaxone (94.3%), and aztreonam (92.2%). The lowest resistance rate was determined for colistin (16.3%), and tigecycline (6.4%). Further, the patients' gender, age group, intensive care unit (ICU) admission, invasive medical devices, and chronic illness were found to be significantly associated with MDR K. pneumoniae infection. The independent risk factors associated with MDR K. pneumoniae infection were the male gender (adjusted odds ratio [AOR] 2.107, 95% confidence interval CI 1.125‒3.945, p = 0.02), patients ≥ 65 years of age (AOR 1.905; CI 1.003‒3.616, p = 0.049), ICU admission (AOR 1.963; CI 1.033‒3.732, p = 0.04), diabetes (AOR 1.95; CI 1.02‒3.727, p = 0.043) and chronic obstructive pulmonary disease (AOR 7.172; CI 1.557‒33.032, p = 0.011). The study offered a vision of MDR K. pneumoniae infection in our setting and provided essential indications for further studies that may lead to the prevention and reduction of MDR bacteria.

Risk for primary cephalosporin resistance in Gram-negative bacteremia

Objective

This study aimed to examine the clinical risk factors for cephalosporin resistance in patients with Gram-negative bacteremia caused by Escherichia coli (EC), Klebsiella pneumoniae (KP), Enterobacter cloacae (ENC), and Pseudomonas aeruginosa (PS).

Methods

This retrospective cohort study included 400 adults with Gram-negative bacteremia. The goal was to review 100 cases involving each species and approximately half resistant and half susceptible to first-line cephalosporins, ceftriaxone (EC or KP), or cefepime (ENC or PS). Logistic regression was used to identify factors predictive of resistance.

Results

A total of 378 cases of Gram-negative bacteremia were included in the analysis. Multivariate analysis identified significant risk factors for resistance, including admission from a chronic care hospital, skilled nursing facility, or having a history of infection within the prior 6 months (OR 3.00, P < .0001), requirement for mechanical ventilation (OR 3.76, P < .0001), presence of hemiplegia (OR 3.54, P = .0304), and presence of a connective tissue disease (OR 3.77, P = .0291).

Conclusions

Patients without the identified risk factors should be strongly considered for receiving ceftriaxone or cefepime rather than carbapenems and newer broad-spectrum agents.

Phenotypic and genotypic antibiotic susceptibility profiles of Gram-negative bacteria isolated from bloodstream infections at a referral hospital, Lusaka, Zambia

Bloodstream infections (BSI) caused by antimicrobial-resistant (AMR) Gram-negative bacteria (GNB) are a significant cause of morbidity and mortality. Third-generation cephalosporins (3GCs) have been used as empiric treatment for BSI and other invasive infections for years; however, their overuse could promote the emergence of extended-spectrum beta-lactamases (ESBLs). Thus, this study aimed to determine the epidemiological, clinical and microbiological features and the effects of antimicrobial resistance on the outcomes of BSIs at a referral hospital in Lusaka, Zambia. This was a six-month prospective facility-based study undertaken at a referral hospital in Lusaka, Zambia. As part of the routine diagnosis and patient care, blood samples for bacteriological culture were collected from patients presenting with fever and processed for pathogen identification and antimicrobial susceptibility testing using the VITEK 2 Compact instrument. ESBLs and plasmid-mediated quinolone resistance (PMQR) associated genes were determined using the polymerase chain reaction method. Patient information was collected using a structured data collection sheet and entered in CSpro 7.6. Data were analysed in WHOnet and STATA version 14. A total of 88 GNB were isolated, of which 76% were Enterobacterales, 14% Acinetobacter baumannii and 8% Pseudomonas aeruginosa. Resistance to third and fourth-generation cephalosporins was 75% and 32%, respectively. Noteworthy was the high prevalence (68%) of inappropriate empirical treatment, carbapenem resistance (7%), multi-drug resistance (83%) and ESBL-producers (76%). In comparison to E. coli as a causative agent of BSI, the odds of death were significantly higher among patients infected with Acinetobacter baumannii (OR = 3.8). The odds of death were also higher in patients that received 3GCs as empiric treatment than in those that received 4GCs or other (none cephalosporin) treatment options. Structured surveillance, yearly antibiogram updates, improved infection control and a well functional antimicrobial stewardship (AMS) program, are of utmost importance in improving appropriate antimicrobial treatment selection and favourable patient outcomes.

The Resistance Mechanisms and Clinical Impact of Resistance to the Third Generation Cephalosporins in Species of Enterobacter cloacae Complex in Taiwan

Enterobacter cloacae complex (ECC) is ubiquitous in the environment and is an important pathogen causing nosocomial infections. Because routine methods used in clinical laboratories cannot identify species within ECC, the clinical significance of each species within ECC is less known. We applied hsp60 gene sequencing to identify the species/clusters of ECC and detected β-lactamase genes and class 1 integrons with PCR for 184 clinical ECC isolates in Taiwan from 2013 to 2014 to investigate the clinical impact of species within ECC. The four most common clusters were E. hormaechei subsp. steigerwaltii (cluster VIII) (29.9%), E. hormaechei subsp. oharae (cluster VI) (20.1%), E. cloacae subsp. cloacae (cluster XI) (12%), and E. kobei (cluster II) (10.3%). E. hormaechei, which consisted of four clusters (clusters III, VI, VII, and VIII), is the predominant species and accounted for 57.1% of the isolates. The ceftazidime resistance rate was 27.2%, and the ceftriaxone resistance rate was 29.3%. Resistance to third generation cephalosporin was associated with a higher 30-day mortality rate. In total, 5 (2.7%), 24 (13.0%), and 1 (0.5%) isolates carried ESBL, AmpC, and carbapenemase genes, respectively. Class 1 integrons were present in 24.5% of the isolates, and most of the cassettes pertain to antibiotic resistance. Resistance to third generation cephalosporins, multidrug resistance, and class 1 integrons were significantly more in E. hormaechei (clusters III, VI, VII, and VIII) than in the other species. The 30-day mortality rate and 100-day mortality did not differ significantly between patients with E. hormaechei and those with infections with the other species. In conclusion, the distribution of third generation cephalosporin resistance, multidrug resistance, and class 1 integrons were uneven among Enterobacter species. The resistance to third generation cephalosporins possessed significant impact on patient outcome.

Antibiotic resistance and siderophores production by clinical Escherichia coli strains

The phenomenon of antibiotic resistance has dramatically increased in the last few decades, especially in enterobacterial pathogens. Different strains of Escherichia coli have been reported to produce a variety of structurally different siderophores. In the present study, 32 E. coli strains were collected from different clinical settings in Cairo, Egypt and subjected to the antibiotic susceptibility test by using 19 antibiotics belonging to 7 classes of chemical groups. The results indicated that 31 strains could be considered as extensively drug-resistant and only one strain as pan drug-resistant. Siderophores production by all the tested E. coli strains was determined qualitatively and quantitatively. Two E. coli strains coded 21 and 49 were found to be the most potent siderophores producers, with 79.9 and 46.62%, respectively. Bacterial colonies with cured plasmids derived from strain 49 showed susceptibility to all the tested antibiotics. Furthermore, E. coli DH5α cells transformed with the plasmid isolated from E. coli strain 21 or E. coli strain 49 were found to be susceptible to ansamycins, quinolones, and sulfonamide groups of antibiotics. In contrast, both plasmid-cured and plasmid-transformed strains did not produce siderophores, indicating that the genes responsible for siderophores production were located on plasmids and regulated by genes located on the chromosome. On the basis of the obtained results, it could be concluded that there is a positive correlation between antibiotic resistance, especially to quinolones and sulfonamide groups, and siderophores production by E. coli strains used in this study.

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

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

Clinical Characteristics of Patients and Whole Genome Sequencing-Based Surveillance of Escherichia coli Community-Onset Bloodstream Infections at a Non-tertiary Hospital in CHINA

Background:Escherichia coli is the most common pathogens in patients with community-onset blood stream infections (COBSI). Knowledge of the epidemiology of this disease is crucial to improve allocation of health resources, formulate isolation strategies that prevent transmission, and guide empirical antibiotic therapy.

Methods: This retrospective observational study examined patients with E. coli COBSI (EC-COBSI) at a non-tertiary hospital in China. Whole-genome sequencing and analysis of the isolates was performed. The relationships of clinical variables with antimicrobial resistance and the genetic background of the isolates were examined.

Results: There were 148 isolates in patients with EC-COBSI. All isolates were susceptible to ceftazidime/avibactam, carbapenems, and tigecycline; 35.1% were positive for extended spectrum β-lactamase (ESBL+); and bla_CTX–M–14 was the most common ESBL gene. Patients with ESBL- isolates were more likely to receive appropriate empiric treatment than those with ESBL+ isolates (61.5% vs. 91.4%, p < 0.001), but these two groups had similar mortality rates. The overall 30-day mortality rate was 9.5%. Phylogenetic analysis showed that the isolates were diverse, and that the main sequence types (STs) were ST95, ST131, and ST69. Intra-abdominal infection was the primary source of disease, and isolates from these patients had lower frequencies of virulence genes.

Conclusion: The mortality rate of patients with EC-COBSI was unrelated to ESBL status of the isolates. Most isolates had low resistance to most of the tested antimicrobial agents. The isolates were diverse, and multiple strains were related. Prevention and control of EC-COBSI should target prevention of patient colonization and the living environment.

Trends of major antimicrobial resistance phenotypes in enterobacterales and gram-negative non-fermenters from ATLAS and EARS-net surveillance systems: Italian vs. European and global data, 2008-2018

Antimicrobial resistance (AMR) is a growing health concern over the recent years. High AMR levels have been reported in Italy among European countries. Here, we analyze longitudinally the AMR trends observed in Italy for Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Enterobacter cloacae and Pseudomonas aeruginosa from the Antimicrobial Testing Leadership and Surveillance database, in comparison with data from the European Antimicrobial Resistance Surveillance Network (2008-2018). We also compare these longitudinal data from Italy with those from Europe and globally. Data analysis revealed highest resistance rates for carbapenems and difficult-to-treat resistance in A. baumannii (82.4% and 83.6%, respectively) followed by third-generation cephalosporin-resistant K. pneumoniae in Italy (≥50%). Resistance rates in Italy were higher compared to Europe and globally, as observed in both Antimicrobial Testing Leadership and Surveillance and European Antimicrobial Resistance Surveillance Network. These findings further substantiate the high AMR rates in Italy and aim to support informed decision making at a national level.

Mortality associated with third generation cephalosporin-resistance in Enterobacteriaceae infections: a multicenter cohort study in Southern China

Background: Emerging third-generation cephalosporin-resistant Enterobacteriaceae (3GCR-EB) pose global healthcare concern. This study assessed the in-hospital mortality attributed to 3GCR-EB.Methods: The study cohort comprised inpatients with community-onset or healthcare-associated infection caused by Enterobacteriaceae in three tertiary-care public hospitals in 2017. In-hospital mortality was compared between 3GCR-EB infected patients and third-generation cephalosporin-susceptible Enterobacteriaceae (3GCS-EB) infected patients using competing risk survival models.Results: Of 2,343 study patients (median age 60 years; 45.2% male), 1,481 (63.2%) had 3GCS-EB and 862 (36.8%) 3GCR-EB infection. 494 (57.0%) 3GCR-EB isolates were co-resistant to fluoroquinolones and 15 (1.7%) to carbapenems. In-hospital mortality was similar in 3GCS-EB and 3GCR-EB infections (2.4% vs. 2.8%; p = 0.601). No increase in the hazard of in-hospital mortality was detected for 3GCR-EB compared to 3GCS-EB infection (sub-distribution hazard ratio [HR] 0.80; 95%CI, 0.41-1.55) adjusting for patient age, sex, intensive care admission, origin of infection and site of infection. Analysis of cause-specific hazards showed that 3GCR-EB infections significantly decreased the daily rate of hospital discharge (cause-specific HR = 0.84; 95%CI, 0.76-0.92) leading to lengthier hospitalizations.Conclusion: 3GCR-EB infection per se was not associated with increased in-hospital mortality in this study, but placed significant healthcare burden by increasing the length of hospitalization.

Impact of Prior Antibiotic Use in Primary Care on Escherichia coli Resistance to Third Generation Cephalosporins: A Case-Control Study

Research is lacking on the reversibility of antimicrobial resistance (AMR). Thus, we aimed to determine the influence of previous antibiotic use on the development and decay over time of third generation cephalosporin (3GC)-resistance of E. coli. Using the database of hospital laboratories of the Autonomous Province of Bolzano/Bozen (Italy), anonymously linked to the database of outpatient pharmaceutical prescriptions and the hospital discharge record database, this matched case-control study was conducted including as cases all those who have had a positive culture from any site for 3GC resistant E. coli (3GCREC) during a 2016 hospital stay. Data were analyzed by conditional logistic regression. 244 cases were matched to 1553 controls by the date of the first isolate. Male sex (OR 1.49, 95% CI 1.10–2.01), older age (OR 1.11, 95% CI 1.02–1.21), the number of different antibiotics taken in the previous five years (OR 1.20, 95% CI 1.08–1.33), at least one antibiotic prescription in the previous year (OR 1.92, 95% CI 1.36–2.71), and the diagnosis of diabetes (OR 1.57, 95% CI 1.08–2.30) were independent risk factors for 3GCREC colonization/infection. Patients who last received an antibiotic prescription two years or three to five years before hospitalization showed non-significant differences with controls (OR 0.97, 95% CI 0.68–1.38 and OR 0.85, 95% CI 0.59–1.24), compared to an OR of 1.92 (95% CI 1.36–2.71) in those receiving antibiotics in the year preceding hospitalization. The effect of previous antibiotic use on 3GC-resistance of E. coli is highest after greater cumulative exposure to any antibiotic as well as to 3GCs and in the first 12 months after antibiotics are taken and then decreases progressively.

Clinical Impact and Risk Factors of Nonsusceptibility to Third-Generation Cephalosporins Among Hospitalized Adults with Monomicrobial Enterobacteriaceae Bacteremia in Southern Taiwan: A Multicenter Study

Background

Reducing the effectiveness of broad-spectrum cephalosporins against Enterobacteriaceae infections has been recognized. This study aimed to investigate risk factors and clinical significance of third-generation cephalosporin nonsusceptibility (3GC-NS) among the cases of monomicrobial Enterobacteriaceae bacteremia (mEB) at regional or district hospitals.

Methods

The study was conducted at three hospitals in southern Taiwan between Jan. 2017 and Oct. 2019. Only the first episode of mEB from each adult (aged ≥20 years) was included. The primary outcome was in-hospital crude mortality.

Results

Overall there were 499 episodes of adults with mEB included, and their mean age was 74.5 years. Female predominated, accounting for 53% of all patients. Escherichia coli (62%) and Klebsiella pneumoniae (21%) were two major causative species. The overall mortality rate was 15% (73/499), and patients infected by 3GC-NS isolates (34%, 172/499) had a higher mortality rate than those by 3GC-susceptible isolates (66%, 327/499) (21% vs 11%, P=0.005). By the multivariate analysis, 3GC-NS was the only independent prognostic determinant (adjusted odds ratio [AOR], 1.78; P=0.04). Of note, male (AOR 2.02, P=0.001), nosocomial-acquired bacteremia (AOR 2.77, P<0.001), and usage of nasogastric tube (AOR 2.01, P=0.002) were positively associated with 3GC-NS, but P. mirabilis bacteremia (AOR 0.28, P=0.01) and age (AOR 0.98, P=0.04) negatively with 3GC-NS.

Conclusion

For adults with Enterobacteriaceae bacteremia, 3GC-NS signifies a significant prognostic impact. Efforts to rapid identification of such antimicrobial resistance profiles should be incorporated into antimicrobial stewardship programs to achieve favorable outcomes.

National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored bla _KPC (n = 17), bla _OXA-48 (n = 2), and bla _VIM (n = 1) genes.

Trends in Antimicrobial Susceptibility of Escherichia coli Isolates in a Taiwanese Child Cohort with Urinary Tract Infections between 2004 and 2018

The aim of this study was to investigate the annual incidence of Escherichia coli isolates in urinary tract infections (UTIs) and the antimicrobial resistance of the third-generation cephalosporin (3GCs) to E. coli, including the factors associated with the resistance in hospitalized children in Taiwan. A large electronic database of medical records combining hospital admission and microbiological data during 2004–2018 was used to study childhood UTIs in Taiwan. Annual incidence rate ratios (IRR) of E. coli in children with UTIs and its resistant rate to the 3GCs and other antibiotics were estimated by linear Poisson regression. Factors associated with E. coli resistance to 3GCs were assessed through multivariable logistic regression analysis. E. coli UTIs occurred in 10,756 unique individuals among 41,879 hospitalized children, with 92.58% being community associated based on urine culture results reported within four days after the hospitalization. The overall IRR E. coli UTI was 1.01 (95% confidence interval (CI) 0.99–1.02) in community-associated (CA) and 0.96 (0.90–1.02) in healthcare-associated infections. The trend in 3GCs against E. coli increased (IRR 1.18, 95% CI 1.13–1.24) over time in CA-UTIs. Complex chronic disease (adjusted odds ratio (aOR), 2.04; 95% CI, 1.47–2.83) and antibiotics therapy ≤ 3 months prior (aOR, 1.49; 95% CI, 1.15–1.94) were associated with increased risk of 3GCs resistance to E. coli. The study results suggested little or no change in the trend of E. coli UTIs in Taiwanese youths over the past 15 years. Nevertheless, the increase in 3GCs-resistant E. coli was substantial. Interventions for children with complex chronic comorbidities and prior antibiotic treatment could be effective in reducing the incidence of 3GCs-resistant E. coli in CA-UTIs in this region and more generally.

Clinical Utilization of Blood and Urine Cultures and Incidences of Bacteremia and Bacteriuria in a Hospital in Thailand

Background

To effectively treat sepsis and urinary tract infection (UTI), blood and urine cultures should be used appropriately and relative to incidences of bacteremia and bacteriuria. This study aimed to investigate the use of blood and urine cultures and incidences of bacteremia and bacteriuria in a hospital in Thailand.

Material/Methods

Medical records of patients admitted from 2016 to 2018 were randomly selected and data in the records were anonymously extracted for investigation.

Results

From 12 000 records, data on blood and urine cultures were extracted from 9% and 4% of them, respectively. The negative rate of blood culture was 87.48%. Bacteremia was detected in 10.22%. The positive rate of urine culture was 27.38% and the contamination rate was 31.26%. Escherichia coli was the most common cause of community-onset bacteremia and bacteriuria. Methicillin-resistant coagulase-negative staphylococci and Acinetobacter baumannii were the most common cause of hospital-acquired bacteremia while yeasts were the most common cause of hospital-acquired UTI.

Conclusions

A high negative rate of blood culture may result not only from its low sensitivity but also from liberal test use to identify sepsis in some conditions. Improper urine collection is the main problem with use of urine culture.

Colonization With Multidrug-Resistant Organisms Among Healthy Adults in the Community Setting: Prevalence, Risk Factors, and Composition of Gut Microbiome

BACKGROUND

The prevalence of colonization with multidrug-resistant organisms (MDROs) among healthy adults in the community is largely unknown. This study investigated the colonization rate of multidrug-resistant Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE) in the community in Taiwan, and compared the gut microbiota between MDRO carriers and non-carriers.

METHODS

This prospective cohort study was conducted from March 2017 to February 2018 at the Hsin-Chu and Jin-Shan branches of National Taiwan University Hospital. Nasal swabs and stool samples were obtained from healthy adults attending a health examination to screen for MDROs. Bacteria isolates of MDROs were tested for antibiotic susceptibility and resistant genes. Relevant data were collected using a standardized questionnaire to evaluate the risk factors for MDROs carriage, and 16S rRNA metagenomics sequencing was performed to analyze gut microbiota.

RESULTS

Among 187 participants, 4.6% (8/174) carried MRSA and 41.4% (77/186) carried third-generation cephalosporin-resistant (3GC-R) Escherichia coli or Klebsiella pneumoniae. The carriage rate of AmpC beta-lactamases and ESBL-producing strains were 16.1 and 27.4%, respectively. No carbapenem-resistant Enterobacteriaceae (CRE) or VRE were detected. The dominant resistant gene of E. coli isolates was CTX-M-type (73%), while that of K. pneumoniae was AmpC beta-lactamases (80%). In the multivariate analysis, the significant risk factors for carrying 3GC-R E. coli or K. pneumoniae were being an employee of technology company A [adjusted odds ratio (aOR) 4.127; 95% confidence interval (CI) 1.824-9.336; p = 0.001], and traveling to Southeast Asia in the past year (aOR 6.545; 95% CI 1.071-40.001; p = 0.042). The gut microbiota analysis showed that the phylum Proteobacteria and the family Enterobacteriaceae were significantly more abundant in 3GC-R E. coli and K. pneumoniae carriers.

CONCLUSION

A high rate of Taiwanese adults in the community carried 3GC-R Enterobacteriaceae, while no CRE or VRE colonization was noted. Compared with non-carriers, an expansion of Enterobacteriaceae in gut microbiota was found among 3GC-R Enterobacteriaceae carriers.

Antimicrobial resistance of bacteraemia in the emergency department of a German university hospital (2013-2018): potential carbapenem-sparing empiric treatment options in light of the new EUCAST recommendations

Background

This study investigated predominant microorganisms causing community-onset bacteraemia at the medical emergency department (ED) of a tertiary-care university hospital in Germany from 2013 to 2018 and their antimicrobial susceptibility patterns.

Methods

Antimicrobial resistance patterns in patients with positive blood cultures presenting to an internal medicine ED were retrospectively analysed.

Results

Blood cultures were obtained at 5191 of 66,879 ED encounters, with 1013 (19.5%) positive results, and true positive results at 740 encounters (diagnostic yield, 14.3%). The most frequently isolated relevant microorganisms were Enterobacterales (n = 439, 59.3%), Staphylococcus aureus (n = 92, 12.4%), Streptococcus pneumoniae (n = 34, 4.6%), Pseudomonas aeruginosa (n = 32, 4.3%), Streptococcus pyogenes (n = 16, 2.2%), Enterococcus faecalis (n = 18, 2.4%), and Enterococcus faecium (n = 12, 1.6%). Antimicrobial susceptibility testing revealed a high proportion of resistance against ampicillin-sulbactam in Enterobacterales (42.2%). The rate of methicillin-resistant Staphylococcus aureus was low (0.4%).

Piperacillin-tazobactam therapy provided coverage for 83.2% of all relevant pathogens using conventional breakpoints. Application of the new European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations increased the percentage of susceptible isolates to high-dose piperacillin-tazobactam to 92.8% (p < 0.001). Broad-spectrum carbapenems would only cover an additional 4.8%. The addition of vancomycin or linezolid extended coverage by just 1.7%.

Conclusions

Using an ureidopenicillin-beta-lactamase inhibitor combination at the high dose suggested by the new EUCAST recommendations provided nearly 93% coverage for relevant pathogens in patients with suspected bloodstream infection in our cohort. This might offer a safe option to reduce the empiric use of carbapenems. Our data support the absence of a general need for glycopeptides or oxazolidinones in empiric treatment.