Urinary Tract Infections due to Multidrug-Resistant Enterobacteriaceae: Prevalence and Risk Factors in a Chicago Emergency Department

Apirhabdus apintestini gen. nov., sp. nov., a member of a novel genus of the family Enterobacteriaceae, isolated from the gut of the western honey bee Apis mellifera

A Gram-negative, motile, rod-shaped bacterial strain, CA-0114T, was isolated from the midgut of a western honey bee, Apis mellifera. The isolate exhibited ≤96.43 % 16S rRNA gene sequence identity (1540 bp) to members of the families Enterobacteriaceae and Erwiniaceae. Phylogenetic trees based on genome blast distance phylogeny and concatenated protein sequences encoded by conserved genes atpD, fusA, gyrB, infB, leuS, pyrG and rpoB separated the isolate from other genera forming a distinct lineage in the Enterobacteriaceae. In both trees, the closest relatives were Tenebrionicola larvae YMB-R21T and Tenebrionibacter intestinalis BIT-L3T, which were isolated previously from Tenebrio molitor L., a plastic-eating mealworm. Digital DNA-DNA hybridization, orthologous average nucleotide identity and average amino acid identity values between strain CA-0114T and the closest related members within the Enterobacteriaceae were ≤23.1, 75.45 and 76.04 %, respectively. The complete genome of strain CA-0114T was 4 451669 bp with a G+C content of 52.12 mol%. Notably, the apparent inability of strain CA-0114T to ferment d-glucose, inositol and l-rhamnose in the API 20E system is unique among closely related members of the Enterobacteriaceae. Based on the results obtained through genotypic and phenotypic analysis, we propose that strain CA-0114T represents a novel species and genus within the family Enterobacteriaceae, for which we propose the name Apirhabdus apintestini gen. nov., sp. nov. (type strain CA-0114T=ATCC TSD-396T=DSM 116385T).

Determining a urinary-specific antibiogram and risk factors of trimethoprim/sulfamethoxazole, ciprofloxacin and multidrug resistance among Enterobacterales in primary care

BACKGROUND

Risk factors for ciprofloxacin or MDR in primary care urine specimens are not well defined.

OBJECTIVES

We created a primary care-specific antibiogram for Escherichia coli isolates from cases with complicated and uncomplicated urinary tract infection (UTI) and evaluated risk factors for ciprofloxacin, trimethoprim/sulfamethoxazole and MDR among Enterobacterales.

METHODS

We conducted a cross-sectional study to determine resistance and risk factors by collecting urine cultures from all patients (≥18 years) presenting with provider-suspected UTI at two primary care, safety-net clinics in Houston, TX, USA between November 2018 and March 2020.

RESULTS

Among 1262 cultures, 308 cultures grew 339 uropathogens. Patients with Enterobacterales (n = 199) were mostly female (93.5%) with a mean age of 48.5 years. E. coli was the predominant uropathogen isolated (n = 187/339; 55%) and had elevated trimethoprim/sulfamethoxazole (43.6%) and ciprofloxacin (29.5%) resistance, low nitrofurantoin (1.8%) resistance, and no fosfomycin resistance. Among E. coli, 10.6% were ESBL positive and 24.9% had MDR. Birth outside the U.S.A., prior (2 year) trimethoprim/sulfamethoxazole resistance, and diabetes mellitus were associated with trimethoprim/sulfamethoxazole resistance. Prior (60 day) fluoroquinolone use, prior ciprofloxacin resistance and both diabetes mellitus and hypertension were strongly associated with ciprofloxacin resistance. Prior fluoroquinolone use and a history of resistance to any studied antibiotic were associated with MDR, while pregnancy was protective.

CONCLUSIONS

We found elevated resistance to UTI-relevant antimicrobials and novel factors associated with resistance; these data can be incorporated into clinical decision tools to improve organism and drug concordance.

Trends and predictors of antimicrobial resistance among patients with urinary tract infections at a tertiary hospital facility in Alexandria, Egypt: a retrospective record-based classification and regression tree analysis

BACKGROUND

The incidence of Antimicrobial Resistance (AMR) in uropathogens varies between countries and over time. We aim to study the patterns and potential predictors of AMR among patients with UTIs admitted to the Urology Department at Alexandria University Hospital.

METHODS

An observational retrospective record-based study was conducted on all patients admitted to the Urology department from October 2018 to October 2020. Data collected from patients' records included: demographic data, diagnosis on admission, history of chronic diseases, duration of hospital stay, insertion of a urinary catheter, duration of the catheter in days, history of the use of antibiotics in the previous three months, and history of urinary tract operations. If UTI was documented, we abstracted data about urine culture, use of antibiotics, results of urine cultures, type of organism isolated, and sensitivity to antibiotics. We conducted a multivariable logistic regression model. We performed Classification and Regression Tree Analysis (CART) for predicting risk factors associated with drug resistance among patients with UTI. Data were analyzed using SPSS statistical package, Version 28.0, and R software (2022).

RESULTS

This study encompassed 469 patients with UTIs. The most commonly isolated bacterium was Escherichia coli, followed by Klebsiella pneumoniae. Multidrug resistance (MDR) was found in 67.7% (149/220) of patients with hospital-acquired UTIs and in 49.4% (83/168) of patients with community-acquired UTIs. Risk factors independently associated with antimicrobial resistance according to logistic regression analysis were the use of antibiotics within three months (AOR = 5.2, 95% CI 2.19-12.31), hospital-acquired UTI (AOR = 5.7, 95% CI 3.06-10.76), diabetes mellitus (AOR = 3.8, 95% CI 1.24-11.84), age over 60 years (AOR = 2.9, 95% CI 1.27-6.72), and recurrent UTI (AOR = 2.6, 95% CI 1.08-6.20). Classification and regression tree (CART) analysis revealed that antibiotic use in the previous three months was the most significant predictor for developing drug resistance.

CONCLUSION

The study concluded a high level of antimicrobial resistance as well as significant MDR predictors among hospitalized patients with UTIs. It is vital to assess resistance patterns in our hospitals frequently to improve rational antibiotic treatment as well as to sustain antimicrobial stewardship programs and a rational strategy in the use of antibiotics. Empirical therapy for UTI treatment should be tailored to the potential pathogens' susceptibility to ensure optimal treatment. Strategic antibiotic use is essential to prevent further AMR increases. Further research should focus on suggesting new biological systems or designed drugs to combat the resistance of UTI pathogens.

Comparative Analysis of Microbial Species and Multidrug Resistance Patterns Associated with Lower Urinary Tract Infections in Preterm and Full-Term Births

The rise of multidrug-resistant organisms has significantly complicated the clinical management of urinary tract infections (UTIs), particularly in the context of pregnancy. This study aimed to identify and analyze the significant differences in microbial species and multidrug resistance patterns associated with UTIs in preterm versus full-term births, determine the bacterial species significantly associated with preterm birth, and describe the antibiotic resistance patterns affecting pregnant women with UTIs. This case-control study was conducted in western Romania and focused on pregnant women with UTIs admitted from 2019 to 2023. Data were retrospectively collected from 308 patients with positive cultures. Statistical analyses, including the Chi-square test, Fisher's exact test, and logistic regression models, were employed to compare the proportions of microbial species and resistance patterns between preterm (n = 126) and full-term (n = 182) birth groups and identify factors independently associated with preterm birth. The study found no significant differences in demographic or lifestyle factors between the groups. However, significant differences were observed in several infection and inflammation markers. The median white blood cell count was higher in the preterm group (12.3 vs. 9.1, p = 0.032), and the median C-reactive protein level was significantly higher in the preterm group (18 vs. 7, p < 0.001). The preterm group exhibited a higher incidence of multidrug-resistant organisms, notably ESBL-producing organisms (19.8% vs. 4.4%, p < 0.001) and carbapenem-resistant Enterobacteriaceae (4.8% with p = 0.003). Notably, the resistance to amoxicillin was significantly higher in the preterm group (20.6% vs. 6.6%, p < 0.001). Significant bacterial associations with preterm births included Group B Streptococcus (OR 2.5, p = 0.001) and Enterobacter spp. (OR 1.8, p = 0.022). The study confirmed significant differences in microbial species and multidrug resistance patterns between UTIs associated with preterm and full-term births. The higher prevalence of certain bacteria and increased resistance to commonly used antibiotics in the preterm group underscore the need for tailored antimicrobial therapies and robust microbial identification in managing UTIs during pregnancy.

Multidrug Resistance Urinary Tract Infection in Chronic Kidney Disease Patients: An Observational Study

OBJECTIVE

To determine the presence of multidrug-resistant (MDR) urinary tract infections (UTI) and the MDR pattern of the bacterial isolates causing MDR UTI in chronic kidney disease (CKD) patients.

METHODS

This cross-sectional study was conducted among 326 diagnosed CKD patients in the Department of Nephrology at Bangabandhu Sheikh Mujib Medical University (BSMMU). Purposive sampling technique was used, and data were collected from the respondents using a semi-structured questionnaire. From duly collected urine samples, identification of organisms and antibiotic susceptibility tests were done, maintaining proper procedure in the microbiology laboratory.

RESULTS

The study population was predominantly female (60.1%). The outpatient department provided the majority of the respondents (75.2%). A history of UTI within the last six months was present among 74.2% of the respondents, and 59.2% had a history of taking antibiotics. Bacterial isolates were predominantly gram-negative (79.4%). Escherichia coli was the most prevalent bacterial isolate, present in 55.5% of the study population. Among the respondents, 64.7% were found to have MDR UTI, and among them, 81.5% were gram-negative, and 18.5% were gram-positive isolates. Among all the antibiotics tested, Colistin Sulphate, Polymyxin B, Cefoxitin, Vancomycin, and Linezolid had the highest (100%) sensitivity, followed by Meropenem, with 94.9% sensitivity. Among the gram-negative isolates, Acinetobacter and Enterobacter were most resistant to aminoglycoside, at 70% and 91.7%, respectively. E. coli, Klebsiella, Proteus, and Pseudomonas were most resistant to quinolone at 76.8%, 76.9%, 83.3%, and 66.7%, respectively. Among the gram-positive isolates, Enterococci and Staphylococcus aureus were most resistant to aminoglycoside, 81.5% and 88.9%, respectively. Streptococcus was found to be most resistant to cephalosporin (75.0%). There was a statistically significant (p < 0.05) relationship between MDR UTI, history of UTI, and previous antibiotic intake, and diabetic CKD.

CONCLUSIONS

The prevalence of MDR UTI among CKD patients is considerably high. When treating UTI, choosing an appropriate antibiotic by urine culture and implementing a guideline on the rational use of antibiotics are essential to managing and preventing the development of MDR UTI.

Pediatric community acquired urinary tract infections due to extended-spectrum beta-lactamase versus non-extended-spectrum beta-lactamase producing bacteria

BACKGROUND

This study aimed to evaluate the demographics, clinical characteristics, risk factors, and antibiotic resistance of pediatric community-acquired urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing uropathogens.

METHODS

This retrospective study was conducted at a tertiary care hospital in Saudi Arabia, among children aged between 0 and 14 years, with a culture-proven diagnosis of community-acquired UTI between February 2019 and September 2021. Patients were divided into two groups based on whether or not their UTI was caused by ESBL-producing bacteria.

RESULTS

A total of 383 patients with community-acquired UTI were evaluated. Escherichia coli was detected in 72.6% of cultures. Extended-spectrum beta-lactamase-producing organisms were responsible for 35.7% of UTI episodes. Of these 69% and 31% were caused by E. coli and Klebsiella pneumoniae, respectively. There were no significant differences between the two groups with regard to clinical presentation or urine analysis. The resistance rates in the ESBL-producing group were 39.4% for amoxicillin/clavulanic acid, 65.7% for ciprofloxacin, 72.3% for co-trimoxazole, 32.8% for nitrofurantoin, 21.2% for gentamicin, and 0.7% for amikacin and carbapenems. In the non-ESBL-producing group, it was 22.4% for amoxicillin/clavulanic acid, 22.4% for ciprofloxacin, 38.2% for co-trimoxazole, 23.6% for nitrofurantoin, 6.1% for gentamicin, and zero for amikacin and carbapenems. The presence of renal abnormalities (p = 0.014) and male gender (p = 0.026) were determined to be independent risk factors for ESBL UTIs.

CONCLUSIONS

Recognizing risk factors and antibiotic resistance for ESBL-producing bacteria may aid in tailoring an antibiotic regimen for pediatric patients at high risk of ESBL-UTIs.

A review of recent advances in the treatment of adults with complicated urinary tract infection

INTRODUCTION

Complicated urinary tract infections (cUTIs) entail diverse clinical conditions that could be managed differently and not necessarily with premature empiric therapy. Since multidrug-resistant organisms (MDROs) are widely spreading worldwide, the possibility of encountering these resistant bacteria is inevitably part of the daily life of physicians who manage cUTIs.

AREAS COVERED

The advances in the management of cUTIs are explored, illustrating: 1) a proposed therapeutical approach to cUTIs within the antimicrobial stewardship context; 2) evidence regarding novel antibiotics targeting MDROs. Evidence research has been performed through MEDLINE/PubMed using appropriate keywords and terms regarding cUTIs published before June 2022.

EXPERT OPINION

Novel antimicrobial drugs are available in the clinicians' armamentarium. Selecting the optimal therapy for suitable patients may be challenging given the multifaceted group of cUTIs. Carbapenems use is widely increasing, the role of old β-lactam/β-lactamase inhibitors is constantly revised, and novel drugs lack real-life studies. Understanding the different ranges of the complexity of patients affected by cUTIs may help select the most suitable antibiotic for every single case. More multicentric observational studies targeting cUTIs are needed to elucidate the appropriate drug based on patient characteristics and presentations, providing stronger recommendations for cases encountered in everyday clinical practice.

High prevalence of fluoroquinolone-resistant UTI among US emergency department patients diagnosed with urinary tract infection, 2018-2020

BACKGROUND

Uropathogen resistance, fluoroquinolone-resistance (FQR), and extended spectrum beta-lactamase (ESBL), has been observed to be emerging worldwide with prevalences above recommended thresholds for routine empirical treatment. The primary aim of our study was to determine the prevalence of FQR from a geographically diverse sample of United States emergency departments (EDs).

METHODS

We conducted a multi-center, observational cohort study using a network of 15 geographically diverse US EDs. All patients ≥18 years of age with the primary or secondary diagnosis of urinary tract infection (UTI) in the ED identified using International Classification of Diseases (ICD-10) diagnosis code of cystitis, pyelonephritis, or UTI from 2018 to 2020 were included. We calculated descriptive statistics for uropathogens and susceptibilities. Logistic regression analysis was used to identify antimicrobial resistance risk factors associated with FQR Escherichia coli.

RESULTS

Among 3779 patients who met inclusion criteria, median age was 62.9 years (interquartile range [IQR]: 41-77.6) and 76.3% were female. The most common diagnoses were complicated (41.2%) and uncomplicated cystitis (40.3%). E. coli was the most common pathogen (63.2%), followed by Klebsiella pneumoniae (13.2%) and Enterococcus species (5.8%). Across all sites, overall E. coli FQ-resistance prevalence was 22.1%, ranging from 10.5 to 29.7% by site. The prevalence of ESBL-producing uropathogen was 7.4%, ranging from 3.6% to 11.6% by site. Previous IV or oral antimicrobial use in the past 90-days and history of a multi-drug resistant pathogen were associated with FQ-resistant E. coli (odds ratio [OR] 2.68, 95% confidence interval [CI]: 2.04-3.51, and OR 6.93, 95% CI: 4.95-9.70, respectively). Of the patients who had FQ-resistant E. coli or an ESBL-producing uropathogen isolated, 116 (37.1%) and 61 (36.7%) did not have any documented risk factors for resistance.

CONCLUSION

FQ-resistant E. coli is widely prevalent across US sites highlighting the need for ongoing monitoring of antimicrobial resistance and, at some locations, modification of empirical treatments.

Risk Factors for Community-Acquired Urinary Tract Infections Caused by Multidrug-Resistant Enterobacterales in Thailand

The dissemination of multidrug-resistant Enterobacterales (MDRE) in community settings is becoming a great concern. This study aimed to assess the incidence and risk factors associated with community-acquired urinary tract infections (CA-UTIs) caused by MDRE. A prospective case−control study was undertaken among patients with UTIs visiting an outpatient department in Phitsanulok Province, Thailand. Urine samples were collected and screened to include only patients with Enterobacterales infections. Risk factors were analyzed by multivariate logistic regression analysis. Of the 284 patients with CA-UTIs, 25.7% (n = 73) and 74.3% (n = 211) were positive for MDRE (case) and non-MDRE (control), respectively. Being a farmer was identified as an independent risk factor for MDRE-associated CA-UTIs (adjusted odds ratio = 3.101; 95% confidence interval = 1.272−7.564; p = 0.013). A total of 309 Enterobacterales isolates were recovered, and Escherichia coli was the most frequently detected (86.4%). The highest resistance rate was observed for ampicillin (67.0%), followed by ciprofloxacin (34.0%) and cotrimoxazole (32.7%), while resistance to third-generation cephalosporins (cefotaxime, ceftriaxone) and levofloxacin remained <20%. Resistance to ampicillin−gentamicin−cotrimoxazole was the most common pattern among MDRE isolates. Interestingly, we detected a colistin-resistant Enterobacter cloacae harboring mcr-9 (colistin MIC = 16 µg/mL). mcr-9 was transferable at high frequency (4.5 × 10−4) and resided on IncF plasmid. This study demonstrates that being a farmer is a risk factor for MDRE-associated CA-UTIs. Interestingly, this is the first report to identify mcr-9-positive E. cloacae from a Thai patient in the community.

Risk Factors for Antibiotic Resistant Urinary Pathogens in Patients Discharged From the Emergency Department

Purpose: Urinary tract infections (UTIs) are one of the most common indications for antimicrobial use in the emergency department (ED). Appropriate empiric selection is crucial to ensure optimal care while limiting broad-spectrum antibiotic use. The primary objective of this study was to evaluate the relationship between patient-specific risk factors and drug resistant urinary pathogens in patients discharged from the ED and followed by Emergency Medicine Pharmacists (EMPs). Methods: This was a single-center, retrospective chart review of adult (≥18 years old) patients with positive urine cultures discharged from the ED. The association between risk factors and pathogen resistance to ≥1 classes of antibiotics was evaluated using multivariate logistic regression. Risk factors included the following: hospitalization within the previous 30 days, intravenous antibiotic use within 90 days, diabetes, clinical atherosclerotic cardiovascular disease, psychiatric disorder, dementia, current antibiotic use for any indication, previous lifetime history of UTIs, indwelling or intermittent catheterization, hemodialysis, previous lifetime history of a urologic procedure, urinary tract abnormality, immunosuppressive disease or medications, current residence in a nursing or rehabilitation facility, and history of a multidrug resistant organism (MDRO). Results: A total of 1018 patients were included. There was an increase in the odds of antibiotic resistance in patients with cystitis and ≥2 risk factors (Odds Ratio [OR] = 1.70, 95% CI = 1.24-2.32). In those with pyelonephritis, there was a non-significant increase in the odds of resistance for those with ≥2 risk factors (OR = 1.83, 95% CI = 0.98-3.42). Patients with pyelonephritis discharged on inappropriate antibiotics were more likely to return to the ED within 30 days (P = .03). Conclusions: For patients with cystitis discharged from the ED, those with ≥2 patient-specific risk factors had significantly increased odds of antibiotic resistance. Patients with pyelonephritis, but not cystitis, who were discharged on inappropriate antibiotics were more likely to return to the ED within 30 days. In conjunction with an EMP culture follow-up program, the identification of risk factors for antimicrobial resistance can be used to design more patient-specific empiric antibiotic selections.

Two Newly Isolated Enterobacter-Specific Bacteriophages: Biological Properties and Stability Studies

In an era of antibiotic therapy crisis caused by spreading antimicrobial resistance, and when recurrent urinary tract infections constitute a serious social and medical problem, the isolation and complex characterization of phages with a potential therapeutic application represents a promising solution. It is an inevitable, and even a necessary direction in the development of current phage research. In this paper, we present two newly isolated myoviruses that show lytic activity against multidrug-resistant clinical isolates of Enterobacter spp. (E. cloacae, E. hormaechei, and E. kobei), the genomes of which belong to a poorly represented phage group. Both phages were classified as part of the Tevenvirinae subfamily (Entb_43 was recognized as Karamvirus and Entb_45 as Kanagawavirus). Phage lytic spectra ranging from 40 to 60% were obtained. The most effective phage-to-bacteria ratios (MOI = 0.01 and MOI = 0.001) for both the phage amplification and their lytic activity against planktonic bacteria were also estimated. Complete adsorption to host cells were obtained after about 20 min for Entb_43 and 10 min for Entb_45. The phage lysates retained their initial titers even during six months of storage at both −70 °C and 4 °C, whereas storage at 37 °C caused a complete loss in their activity. We showed that phages retained their activity after incubation with solutions of silver and copper nanoparticles, which may indicate possible synergistic antibacterial activity. Moreover, a significant reduction in phage titers was observed after incubation with a disinfectant containing octenidinum dihydrochloridum and phenoxyethanol, as well as with 70% ethanol. The observed maintenance of phage activity during incubation in a urine sample, along with other described properties, may suggest a therapeutic potential of phages at the infection site after intravesical administration.

Magnetic Soft Millirobots 3D Printed by Circulating Vat Photopolymerization to Manipulate Droplets Containing Hazardous Agents for In Vitro Diagnostics

3D printing via vat photopolymerization (VP) is a highly promising approach for fabricating magnetic soft millirobots (MSMRs) with accurate miniature 3D structures; however, magnetic filler materials added to resin either strongly interfere with the photon energy source or sediment too fast, resulting in the nonuniformity of the filler distribution or failed prints, which limits the application of VP. To this end, a circulating vat photopolymerization (CVP) platform that can print MSMRs with high uniformity, high particle loading, and strong magnetic response is presented. After extensive characterization of materials and 3D printed parts, it is found that SrFe₁₂ O₁₉ is an ideal magnetic filler for CVP and can be printed with 30% particle loading and high uniformity. By using CVP, various tethered and untethered MSMRs are 3D printed monolithically and demonstrate the capability of reversible 3D-to-3D transformation and liquid droplet manipulation in 3D, an important task for in vitro diagnostics that are not shown with conventional MSMRs. A fully automated liquid droplet handling platform that manipulates droplets with MSMR is presented for detecting carbapenem antibiotic resistance in hazardous biosamples as a proof of concept, and the results agree with the benchmark.

Circumstances of the ambulatory prescription of quinolones in Urology and opportunities for intervention

INTRODUCTION AND OBJECTIVES

Antimicrobial stewardship programmes (AMSP) seldom focus on ambulatory prescribing. Our AMSP primarily supervises in-hospital prescribing, but as we aim to include the ambulatory setting, we sought opportunities for intervention on ambulatory quinolone prescription.

MATERIALS AND METHODS

We selected the prescriptions made by urologists during 2018 for analysis, and manually checked them for adequacy.

RESULTS

We analyzed 237 prescriptions. Of 136 therapeutic prescriptions, 18.4% had no reported diagnosis and 31.6% had no reported symptoms. Most patients (60.3%) did not have any urinalysis or urine culture; among those who had, 27.7% had a urinalysis not suggestive of urinary tract infection and 67.4% had a positive culture, 83.9% of which had a suitable oral alternative to quinolones. Antimicrobial therapy was not indicated in 13.9% of cases; when it was, quinolones were considered inadequate in 67.8% of cases. Incorrect duration was found in 51.1% of cases. Forty-six prescriptions were made for prophylaxis; all of these were considered inadequate.

CONCLUSION

We found a high prevalence of inadequate ambulatory quinolone prescriptions in Urology. Many followed incomplete recordings, lack of laboratory use, or inattention to alternatives. Treatment duration and quinolone choice were frequently inadequate. Quinolone prescribing for prophylaxis was always considered inadequate. These prescribing errors could serve as a starting point for future interventions.

Pediatric Febrile Urinary Tract Infection Caused by ESBL Producing Enterobacteriaceae Species

BACKGROUND

Over the past decade, drug resistance pattern has worsened for many of the uropathogens due to overuse of antibiotics for empiric treatment. The burden of extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae associated urinary tract infections (UTI) has become increasingly more common, limiting treatment options among children presenting with febrile UTI. We investigated the burden and correlates of ESBL producing Enterobacteriaceae associated UTI among children and antibacterial resistance pattern.

METHODS

284 midstream urine specimens were collected using standard aseptic techniques from 284 children who were diagnosed with suspected UTI. Urine culture and bacteria isolation were performed following standard bacteriological techniques. The Kirby-Bauer disk diffusion technique and the double-disc synergy test were used to investigate antibiotic susceptibility and presence of ESBL production.

RESULTS

UTI was confirmed using a positive urine culture for a relevant pathogen in 96/284 (33.8%) of the cases. Enterobacteriaceae accounted for 75% (72/96) of etiologies of UTI in children. The most frequent Enterobacteriaceae spp. were E. coli, 44.4% (32/72) and K. pneumonia, 27.8% (20/72). The overall multidrug resistance rate was 86.1% (62/72). ESBL-producers accounted for 41.7% (30/72) of the isolated Enterobacteriaceae. ESBL producing K. pneumonia and E. coli isolates accounted for 70% (14/20) and 37.5% (12/32), respectively. History of UTI in the past 1 year (adjusted odds ratio (AoR) = 0.08, 95%CI (0.01 - 0.57)) and medium family wealth index (AoR = 0.03, 95%CI (0.00 - 0.27)) protected from infection with ESBL-producing Enterobacteriaceae. Conclusion. ESBL production was more common in K. pneumonia and appeared to be a major factor contributing drug resistance UTI in children. The findings call for the need to incorporate ESBL testing in the routine clinical practice. The resistance level to commonly prescribed first-line antibiotics observed within Enterobacteriaceae was alarming calling for strengthened antimicrobial stewardship.

Fosfomycin susceptibility of uropathogens at Charlotte Maxeke Johannesburg Academic Hospital

Background

Multidrug-resistant uropathogens are becoming widespread both in community and hospital setting. Safe yet effective treatments are a priority. Fosfomycin is an antibacterial that displays good activity against most bacteria causing urinary tract infections (UTIs), including multidrug-resistant bacteria. The aim of this study was to evaluate fosfomycin susceptibility for uropathogens isolated from a microbiology laboratory at a tertiary academic hospital. In addition, this was compared to the susceptibility of other oral antimicrobials.

Methods

We conducted a retrospective analysis of laboratory reports for uropathogens isolated at Charlotte Maxeke Johannesburg Academic Hospital from September 2015 to August 2017. Antimicrobial susceptibility testing of the isolates was performed using the Kirby–Bauer disk diffusion method or the Vitek^® 2 system according to the Clinical and Laboratory Standards Institute.

Results

Overall susceptibility of fosfomycin for the 4700 Enterobacteriaceae isolates was 95.7%; 95% confidence interval (CI) 95.1–96.2. The overall susceptibility for fosfomycin against the gram-positives was 98.6%. There were 37.9% multidrug-resistant Enterobacteriaceae (MDRE) isolated during the study period. Fosfomycin displayed activity against 94.4% of extended-spectrum β-lactamase (ESBL) producers and 90.7% for carbapenem-resistant Enterobacteriaceae (CRE). None of the methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus isolates tested was fosfomycin resistant. The overall in vitro susceptibility was significantly higher for fosfomycin (p = 0.0001) compared to amoxicillin/clavulanic acid, cephalexin, cefuroxime, ciprofloxacin, trimethoprim/sulfamethoxazole and nitrofurantoin.

Conclusion

This study confirmed the high susceptibility of fosfomycin against UTI pathogens isolated at our institution. In an era of increasing antimicrobial resistance, fosfomycin represents a potential option for the treatment of UTIs at Charlotte Maxeke Johannesburg Academic Hospital.

Prevalence of multidrug-resistant bacteria in Ethiopia: a systematic review and meta-analysis

OBJECTIVES

Multidrug-resistant (MDR) bacteria are a significant public-health threat worldwide, especially in low- and middle-income countries. Comprehensive data are important to understand the magnitude of multidrug resistance (MDR), however these are not available in Ethiopia.

METHODS

Five electronic databases and grey literature of Addis Ababa University Repository were searched for data regarding the prevalence of MDR bacteria in Ethiopia. OpenMetaAnalyst R1.3 was used for analysis using a random-effects model to determine the effect size. Heterogeneity among articles was checked using the inconsistency index (I²). Funnel plot was used to check for publication bias. The quality of each article was checked using the Newcastle-Ottawa checklist adapted for cross-sectional studies.

RESULTS

Through database searching, 2094 articles were identified, of which 37 fulfilled the study inclusion criteria. This review comprises 6856 bacteria, of which 4949 isolates were MDR. The overall pooled prevalence of MDR was 70.5% (95% CI 64.9-76.1%), with considerable heterogeneity (I² = 97.48%, P < 0.001). Funnel plot revealed no publication bias. Sidama (81.7%) had the highest MDR and Tigray (51.1%) the lowest. The greatest source of MDR was from multiple sites of infection (MSI) (76.8%); the least was from bloodstream infections (62.9%). MDR was higher in studies conducted on hospital-acquired infections (72.1%) compared with both hospital- and community-acquired infections (69.8%).

CONCLUSION

Our study indicates a high prevalence of MDR in Ethiopia. Sidama region, MSI and hospital-acquired infections showed the highest MDR in subgroup analysis. Regional hospitals should implement infection prevention and proper use of antibiotics in the community.

A 3D-printed magnetic digital microfluidic diagnostic platform for rapid colorimetric sensing of carbapenemase-producing Enterobacteriaceae

Carbapenemase-producing Enterobacteriaceae (CPE) are a group of drug-resistant Gram-negative pathogens that are classified as a critical threat by the World Health Organization (WHO). Conventional methods of detecting antibiotic-resistant pathogens do not assess the resistance mechanism and are often time-consuming and laborious. We have developed a magnetic digital microfluidic (MDM) platform, known as MDM Carba, for the identification of CPE by measuring their ability to hydrolyze carbapenem antibiotics. MDM Carba offers the ability to rapidly test CPE and reduce the amount of reagents used compared with conventional phenotypic testing. On the MDM Carba platform, tests are performed in droplets that function as reaction chambers, and fluidic operations are accomplished by manipulating these droplets with magnetic force. The simple droplet-based magnetic fluidic operation allows easy system automation and simplified hands-on operation. Because of the unique "power-free" operation of MDM technology, the MDM Carba platform can also be operated manually, showing great potential for point-of-care testing in resource-limited settings. We tested 27 bacterial isolates on the MDM Carba platform, and the results showed sensitivity and specificity that were comparable to those of the widely used Carba NP test. MDM Carba may shorten the overall turnaround time for CPE identification, thereby enabling more timely clinical decisions for better clinical outcomes. MDM Carba is a technological platform that can be further developed to improve diagnostics for other types of antibiotic resistance with minor modifications.

Multidrug-Resistant and Carbapenemase-Producing Enterobacteriaceae in Addis Ababa, Ethiopia

Background

The emergence and spread of multi-drug resistant (MDR) bacteria have become a public health problem in recent years. For the last many years, carbapenem antibiotics have been used successfully to treat infections caused by MDR Enterobacteriaceae. However, recently, Enterobacteriaceae producing carbapenemases have emerged, which confer broad resistance to most β-lactam antibiotics including carbapenems. Therefore, this study is aimed at determining the magnitude of MDR and carbapenemase-producing Enterobacteriaceae (CPE) isolated from various clinical specimens in Addis Ababa, Ethiopia.

Methods

A cross-sectional study was conducted from January to April 2018. A total of 312 Enterobacteriaceae isolates were identified from various clinical specimens. The Phoenix automated system (BD Phoenix100) was used for bacterial identification and antimicrobial susceptibility testing. Potential carbapenemase producers were confirmed by the modified carbapenem inactivation test, and KPC, MBL, and OXA-48 were phenotypically characterized by the disk diffusion method. The data obtained were entered and analyzed using SPSS version 20 software. Descriptive statistics, chi square, bivariate and multivariable logistic regression analyses were performed. P value ≤ 0.05 with corresponding 95% confidence interval was considered for statistical significance.

Results

A total of 312 Enterobacteriaceae were recovered. Of these isolates, 68.6% were MDR and 2.6% were CPE with different classes including OXA-48 1.6% (5/312), MBL 0.6% (2/312), and KPC and OXA-48 0.3% (1/312). The predominant bacterial isolates were E. coli 72.4% (226/312) followed by K. pneumoniae 13.8% (43/312). The antibiotic resistance rates of CPE isolates were significantly higher than other MDRE including ampicillin (100% versus 77.6%), cefoxitin (75% versus 20.6%), and piperacillin/tazobactam (50% versus 13.1%).

Conclusion

In this study, a relatively higher prevalence of MDR was observed, and the highest resistance was recorded against ampicillin, amoxicillin with clavulanic acid, and sulfamethoxazole-trimethoprim. Detection of CPE is important for implementing appropriate antimicrobial therapy and in controlling the spread of the infection. Furthermore, continuous screening and investigations, including genotypic characterization of CPE, are required for the prevention and control of the spread of antimicrobial-resistant pathogens.

Potential Probiotics Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895 Co-Aggregate with Clinical Isolates of Proteus mirabilis and Prevent Biofilm Formation

A urinary tract infection (UTI) is a multi-factorial disease including cystitis, pyelonephritis, and pyelitis. After Escherichia coli, Proteus mirabilis is the most common UTI-associated opportunistic pathogen. Antibiotic resistance of bacteria and infection recurrence can be connected to biofilm formation by P. mirabilis. In this study, human and sheep isolates of P. mirabilis were investigated for antibiotic sensitivity using an antibiotic disk test. Co-aggregation of the tested potential probiotic bacilli, Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933, with the isolated pathogen was also evaluated. Then, the anti-biofilm activity of naturally derived metabolites, such as subtilin and subtilosin, in the bacilli-free supernatants was assessed against biofilms of P. mirabilis isolates. The isolated pathogens were sensitive to 30 μg of amikacin and 5 μg of ciprofloxacin but resistant to other tested antibiotics. After 24 h, auto-aggregation of B. amyloliquefaciens B-1895 was at 89.5% and higher than auto-aggregation of B. subtilis KATMIRA1933 (59.5%). B. amyloliquefaciens B-1895 strongly co-aggregated with P. mirabilis isolates from human UTIs. Cell-free supernatants of B. amyloliquefaciens B-1895 and B. subtilis KATMIRA1933 showed higher antimicrobial activity against biofilms of P. mirabilis isolated from humans as compared with biofilms of sheep isolates. According to our knowledge, this is the first report evaluating the anti-biofilm activity of probiotic spore-forming bacilli against clinical and animal UTI isolates of P. mirabilis. Further studies are recommended to investigate the anti-biofilm activity and the mode of action for the antimicrobial substances produced by these bacilli, subtilosin and subtilin.

Antimicrobial Resistance Patterns and Dynamics of Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli in Cusco, Peru

Urinary tract infections (UTIs) are a common human infection. Antibiotic resistance in extended-spectrum β-lactamase (ESBL)-producing uropathogenic E. coli (UPEC) is a major therapeutic challenge due to limited treatment alternatives. The aim was to characterize the antimicrobial resistance (AMR) and dynamics of ESBL-producing UPEC isolates from UTI cases seen at a local hospital in Cusco, Peru. Ninety-nine isolates from respective patients were characterized against 18 different antibiotics. Latent class analysis (LCA) was used to evaluate the dynamics across the study time according to resistance patterns. The median age of patients was 51 years old, and nearly half were women. ESBL-producing UPEC isolates were slightly more frequent in outpatient services than emergency rooms, and there were higher resistance rates in males compared to females. Half of the ESBL producers were resistant to aminoglycosides and nitrofurantoin. Cefoxitin and fosfomycin resistance was 29.3% and 14.1%, respectively. Resistance to carbapenems was not observed. All isolates were multidrug-resistant bacteria, and 16.2% (16/99) were also classified as extensively drug-resistant bacteria. The resistance patterns varied across the study time and differed regarding sex and healthcare service. The study revealed high levels of AMR to commonly used antimicrobials and a dynamic circulation of ESBL-producing UPEC isolates with varying resistance patterns.

Detection of mobile colistin-resistance gene variants (mcr-1 and mcr-2) in urinary tract pathogens in Bangladesh: the last resort of infectious disease management colistin efficacy is under threat

Background: Currently, colistin-resistant pathogens emerged has become a global health concern. This study assessed the distribution of mcr-1 to mcr-5 variants with the phenotypic colistin-resistance in bacterial isolates from urinary tract infection (UTI) patients in Bangladesh.Methods: A cross-sectional study was conducted between April 2017 and March 2018 to enroll uncomplicated UTI patients, and 142 urine samples were analyzed. Uropathogens were identified using the API-20E biochemical panel and 16s rRNA gene sequencing. Polymerase chain reactions detected the mcr gene variants in the UTI isolates. The phenotypic colistin-susceptibility was determined by the Kirby-Bauer disc-diffusion method and the minimal inhibitory concentration (MIC) measurement.Results: The combined carriage of mcr-1 and mcr-2 genes in 11.4% (14/123) of urinary tract pathogens. The mcr-positive pathogens include five Escherichia coli, three Klebsiella pneumoniae, three Pseudomonas putida, two Enterobacter cloacae, and one Enterobacter hormaechei. The mcr-positive variant showed significantly higher phenotypic colistin resistance with MIC between >16 µg/mL and >128 µg/mL (p< 0.001). Over 85% of colistin-resistant isolates showed MDR phenomena.Conclusions: The emergence of the clinical MDR pathogens with resistance to a highly selective drug may lead to a lack of treatment options for the infectious diseases and spread of infection to the unaffected cohorts.

Multidrug-Resistant Micro-Organisms Associated with Urinary Tract Infections in Orthopedic Patients: A Retrospective Laboratory-Based Study

Background: The risk of healthcare-associated infections (HAIs) in surgical wards remains closely related to the type of surgery and procedures performed on patients. Those factors also condition the risk of various forms of clinical infections, especially urinary tract infections (UTIs). UTIs are most frequently (70–80% of cases) caused by the use of bladder catheter in the perioperative period. The aim of this study was to perform an epidemiological and microbiological analysis of UTIs in orthopedic patients, with an emphasis on multidrug-resistant (MDR) micro-organisms. Methods: The study was conducted in a 38-bed Department of Orthopedic-Traumatic Surgery in Sosnowiec, Poland. 5239 patients, operated on in 2013–2015, were included in the study. The urinary catheter use rate was 30.7%. Laboratory-based study used the UTI definition of the HAI-Net program. A micro-organism was declared MDR if it was resistant to at least one antibiotic from three or more groups of antibacterial drugs, and extensively drug-resistant (XDR) if it was sensitive to antibiotics from no more than two groups of drugs. Results: The UTI incidence was 3.2% (168 cases), the CA-UTI incidence density was 9.6/1000 catheter days. The highest risk of UTI was found in patients aged 75 or older. Monomicrobial cultures were detected in 163 specimens (78% of all microbiologically confirmed UTIs). Gram-negative flora prevailed among the micro-organisms, the predominantly isolated Enterobacteriaceae being Escherichiacoli and Klebsiellapneumoniae. In 16 patients (7.7% of microbiologically confirmed UTIs), yeast infection was confirmed. Isolated micro-organisms were fully sensitive to carbapenems. Gram-negative bacilli showed the lowest sensitivity to extended substrate spectrum penicillins and fluoroquinolones (37–64%), as well as to trimethoprim-sulfamethoxazole (50%). The MDR prevalence was 24.4%. Conclusions: The presented data indicates that UTIs are a significant problem in the studied population, so is antimicrobial resistance, especially to quinolones, and extended-spectrum cephalosporins, which are often used as first-line therapy. To tackle the problem of high UTI incidence and MDR prevalence, reducing the UTI risk factors should be prioritized.

Uropathogens antibiotic susceptibility as an indicator for the empirical therapy used for urinary tract infections: a retrospective observational study

Background and Objectives

Urinary tract infection (UTI) is a common infection affects people of different ages. It is important to explore the antibiotics susceptibility of the bacterial agents to improve the empirical antibacterial prescription because of emerging of multi-drug resistant (MDR) bacteria.

Materials and Methods

This is a retrospective observational study including 322 patients with UTI at the largest hospital at the center of Al-Basrah Governorate in the far south of Iraq from August 2018 to November 2019. Bacterial isolates from urine samples with significant bacteria were investigated by automated VITEK® 2 compact system to determine the causative bacteria and their antibiotics susceptibility.

Results

Escherichia coli and Klebsiella pneumoniae were the first and second most frequent Gram-negative isolates, whereas Staphylococcus haemolyticus and Enterococcus faecalis were the first and second most frequent Gram-positive isolates. Fosfomycin, tigecycline, colistin, meropenem, imipenem, amikacin and nitrofurantoin had high susceptibility rates against Gram-negative isolates. Nitrofurantoin, tigecycline, daptomycin, teicoplanin, vancomycin and linezolid had a high effect against Gram-positive isolates.

Conclusion

The leading causative isolates especially the most predominant Gram-negative isolates E. coli and K. pneumoniae show high resistance rates against important antibiotics including penicillin/β-lactamase inhibitors piperacillin/tazobactam, ceftazidime cefepime, ciprofloxacin, levofloxacin and trimethoprim/sulfamethoxazole which call for reconsidering them for treatment of UTI.

Critically Ill Health Care-Associated Urinary Tract Infection: Broad vs. Narrow Antibiotics in the Emergency Department Have Similar Outcomes

BACKGROUND

Urinary tract infection (UTI) is the second most common infection requiring intensive care unit (ICU) admission in emergency department (ED) patients. Optimal empiric management for health care-associated (HCA) UTI is unclear, particularly in the critically ill.

OBJECTIVE

To compare clinical failure of broad vs. narrow antibiotic selection in the ED for patients presenting with HCA UTI admitted to the ICU.

METHODS

Observational cohort of patients started on empiric antibiotic for UTI with at least one HCA risk factor (recurrent UTI, chronic urinary catheter or dialysis, urologic procedures, previous antibiotic exposure, hospitalization, or group facility residence). Broad antibiotics covered Pseudomonas spp. and extended-spectrum beta-lactamase. Clinical failure was a composite of multiorgan dysfunction (MODS) by day 2 and in-hospital mortality. Secondary outcomes were length of stay (LOS), readmission, recurrent infection, development of multidrug-resistant organisms, and Clostridium difficile infection. Associations were reported with odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

There were 272 patients included; 196 (72.1%) received broad and 76 (27.9%) received narrow therapy. There was no association between antibiotic selection and clinical failure (OR 1.05, 95% CI 0.5-2.25, p = 0.89) or between antibiotic selection and number of HCA risk factors (OR 0.98, 95% CI 0.73-1.31, p = 0.87). There was an association between clinical failure and MODS on ICU admission (OR 9.14, 95% CI 4.70-17.78, p < 0.001). Hospital LOS and readmission did not differ between antibiotic groups.

CONCLUSION

Initial empiric broad or narrow antibiotic coverage in HCA UTI patients who presented to the ED and required ICU admission had similar clinical outcomes.

Gram-negative Organisms from Patients with Community-Acquired Urinary Tract Infections and Associated Risk Factors for Antimicrobial Resistance: A Single-Center Retrospective Observational Study in Japan

A specific antibiogram is necessary for the empiric antibiotic treatment of community-acquired urinary tract infections (UTI) because of the global spread of antimicrobial resistance. This study aimed to develop an antibiogram specific for community-acquired UTI and assess the risk factors associated with community-acquired UTI caused by antimicrobial-resistant organisms. This cross-sectional observational retrospective study included patients with community-acquired UTI caused by Gram-negative rods (GNR) who were admitted to the emergency department at a tertiary care hospital in Ibaraki, Japan, in 2017–2018. A total of 172 patients were enrolled (including 38 nursing home residents). Of the 181 GNR strains considered as causative agents, 135 (75%) were Escherichia coli, and 40 (22%) exhibited third-generation cephalosporin resistance. Extended-spectrum β-lactamase (ESBL)-producing E. coli accounted for 25/40 (63%) of resistant GNR. Overall susceptibility rate of Enterobacterales was 92%, 81%, 100%, 75%, and 89% for cefmetazole, ceftriaxone, meropenem, levofloxacin, and trimethoprim–sulfamethoxazole, respectively. Residence in a nursing home (odds ratio (OR), 2.83; 95% confidence interval (CI), 1.18–6.79) and recent antibiotic use (OR, 4.52; 95% CI, 1.02–19.97) were independent risk factors for UTI with resistant GNR. ESBL-producing E. coli was revealed to have a strong impact on antimicrobial resistance pattern. Therefore, an antibiotic strategy based on a disease-specific antibiogram is required.

Occurrence of Multidrug-resistant Uropathogens Implicated in Asymptomatic Bacteriuria in Adults with Sickle Cell Disease in Ile-Ife, Southwest Nigeria

OBJECTIVES

We sought to determine the prevalence of asymptomatic bacteriuria (ASB) in patients with sickle cell disease (SCD), the susceptibility profile of its agents and their extended-spectrum β-lactamase (ESBL) production.

METHODS

Fifty-nine patients with SCD and 116 healthy controls were investigated. Urine samples were collected and cultured by standard techniques. We used the disc diffusion technique to determine antibiotic susceptibility. ESBL was detected by the combination disc method and detection of bla SHV, bla TEM, and bla CTX-M genes by multiplex-polymerase chain reaction.

RESULTS

The prevalence of ASB was higher among patients with SCD (8.6%) than controls (0.9%) (p = 0.016), predominantly among females. Coagulase-negative staphylococci (n = 2; 33.3%) predominated among the isolates. Other uropathogens included Stenotrophomonas maltophilia, Acinetobacter baumannii, and Enterobacter cloacae. All isolates were sensitive to meropenem but were resistant to ceftazidime, ampicillin, and tetracycline. bla SHV, bla TEM, and bla CTX-M-15 were detected in Enterobacter cloacae.

CONCLUSIONS

The prevalence of ASB is high in patients with SCD predominantly among females. Rare multidrug-resistant uropathogens were implicated. We posit a need for resistance surveillance programs and antibiotic stewardship to prevent treatment failure and reduce drug resistance.

Antimicrobial potential of the food-grade additive carvacrol against uropathogenic E. coli based on membrane depolarization, reactive oxygen species generation, and molecular docking analysis

The antibiotic resistance of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has increased drastically in recent years. In our study, we determined the principle mechanisms of action for the food-grade additive carvacrol against ESBL E. coli isolated from the blood of patients with a urinary tract infection. Carvacrol, which has a minimum inhibitory concentration of 150 μg/ml and a minimum bactericidal concentration of 300 μg/ml, reduced E. coli cell counts in a time-dependent manner. After treatment with carvacrol, the E. coli killing time was found to be 120 min. Fluorescent staining confirmed an increase in bacterial cell death, greater membrane depolarization, and an elevated oxidative burst in carvacrol-treated E. coli. Carvacrol also induced the release of cellular DNA, proteins, and potassium ions from bacterial cells and reduced both the number of E. coli in invasion assays against macrophages and the levels of the inflammatory proteins TNF-α and COX-2. In addition, carvacrol was found to inhibit β-lactamase enzyme activity (in vitro), which was supported by in silico results. Moreover, carvacrol inhibited motility, and protected against bacterial invasion. Overall, the findings suggest that carvacrol has significant antimicrobial potential against ESBL E. coli.

Empirical treatment of urinary tract infections: how rational are our guidelines?

Objectives

This study considers susceptibility test results obtained over a 6 month period for Enterobacteriaceae that caused urinary tract infections (UTIs) in the Cork region of Ireland and uses these results to examine the suitability of Irish empirical treatment guidelines.

Patients and methods

UTI-causing Enterobacteriaceae isolates were analysed using EUCAST guidelines to determine resistance to a set of commonly prescribed antimicrobial agents, i.e. ampicillin, amoxicillin/clavulanate, cefalexin, ciprofloxacin, nitrofurantoin and trimethoprim. Patients were categorized by age and patient type, based on origin (hospital inpatients, patients in long-term care facilities and all other non-hospitalized patients). In total, 8999 test results were analysed using the IBM Cognos Analytics Series 7 interrogation tool and Microsoft Office Excel.

Results

A variety of resistance patterns were observed. Only one antimicrobial agent, nitrofurantoin, demonstrated a resistance rate of less than 20% for all patient categories considered.

Conclusions

Previous studies determined that a resistance rate of >20% renders an antimicrobial agent unsuitable for use as an empirical treatment option. This study demonstrated that this resistance rate is exceeded in many cases, potentially rendering some antimicrobial agents unsuitable for use as empirical treatment. We suggest that the focus on susceptibility when producing surveillance data to create empirical treatment guidelines may inadvertently camouflage resistance rates. The findings of this study highlight the need for laboratory-guided treatment of UTIs and ideally a pre-emptive sample should be obtained for laboratory investigation prior to commencement of antimicrobial therapy.

Characterisation and risk factor profiling of Pseudomonas aeruginosa urinary tract infections: pinpointing those likely to be caused by multidrug-resistant strains

This study aimed to characterise UTIs caused by Pseudomonas aeruginosa in hospitalised adults and to identify risk factors for infections caused by multidrug-resistant (MDR) strains. A retrospective case-case-control study was conducted in two Italian teaching hospitals. Totally, 242 monomicrobial P. aeruginosa UTIs were analysed; 65 (26.9%) were caused by MDR strains. Clinical treatment failure at 72 h in 215 patients receiving empirical therapy was more frequent in MDR versus non-MDR cases [35/59 (59.3%) vs. 55/156 (35.3%); P = 0.001], particularly when a β-lactam/β-lactamase inhibitor or fluoroquinolone was initially prescribed. By Day 7 (when all regimens were consistent with antimicrobial susceptibility results), treatment failure rates were similar [MDR 15/65 (23.1%) vs. non-MDR 25/177 (14.1%); P = 0.09]. In-hospital mortality rates remained low in both groups [6/65 (9.2%) vs. 22/177 (12.4%); P = 0.49], but median hospital stay for MDR cases was longer (48 vs. 22 days; P ≤ 0.001). Models for predicting MDR and non-MDR P. aeruginosa UTIs displayed good discriminatory power. Presence of ≥3 risk factors for MDR P. aeruginosa UTI was associated with an OR for this outcome of 7.44 (95% CI 3.24-17.57; P < 0.001; specificity 91%, accuracy 75%). The model for predicting non-MDR P. aeruginosa UTI displayed similar accuracy (74%) with a risk factor burden threshold of ≥2 (OR = 7.02, 95% CI 4.61-10.70; P < 0.001). Risk factor assessment can identify UTIs in hospitalised patients likely to be caused by MDR P. aeruginosa, thereby facilitating targeted infection control and timelier effective treatment.

Diagnosis and Empirical Treatment of Urinary Tract Infections in Urologic Outpatients

<b><i>Introduction:</i></b> Due to a continuing increase of bacterial resistance in common uropathogens, we wanted to revisit our standards for the diagnosis and treatment of lower urinary tract infections, in the setting of urological outpatient care in a conurbation in Germany. <b><i>Patients and Methods:</i></b> All subjects presenting with significant bacteriuria at our urology clinics in Mülheim, Germany, in 2011 were included. Comorbidity, bacterial species, urinary tract symptoms, and empirically prescribed antibiotics were taken from the patients’ records. <b><i>Results:</i></b> In 2011, a total of 1,324 patients were included (793 female, 531 male). Of the 771 patients with symptomatic bacteriuria, 647 received antibiotic treatment, as well as 116 of 409 patients with asymptomatic bacteriuria. <i>Escherichia coli</i> was identified in 60% of the included patients. In 427 <i>E. coli</i> infections, bacterial resistance was found in 14% of 316 cases treated with quinolone, in 21% of 53 cases treated with co-trimoxazole, and in only 3% of 58 cases treated with nitrofurantoin. <b><i>Conclusions:</i></b> We found a high use of fluoroquinolones for empirical first-line antibiotics in the treatment of lower urinary tract infections. In our regional setting, antibiotic stewardship needs to be promoted, along national and international guidelines, to avoid unnecessary prescription of fluoroquinolones for empirical treatment.

Antibiotic prescribing for acute uncomplicated cystitis in Lebanese community pharmacies using a simulated patient

BACKGROUND

Urinary tract infections are considered as one of the most frequent bacterial infections in the community and hospital settings. In this era of increasing antimicrobial resistance, antimicrobial stewardship has become highly important in the struggle to preserve the effectiveness of available drugs. One the main causes of antibiotic resistance is the inappropriate prescribing of antibiotics; which evidence show that community pharmacists contribute to.

OBJECTIVE

This study aims to evaluate antibiotic prescribing rate and responses of the contact persons in community pharmacies and to assess the conformity of the prescribed antibiotics with international guidelines. It also aims to evaluate the responses with sociodemographic characteristics.

METHODS

A cross-sectional, nationwide study conducted between February and May 2017 using a simulated patient case of acute uncomplicated cystitis. Two hundred fifty pharmacies were included. Descriptive data was reported for the medications prescribed, conformity, questions asked and counseling. Bivariate analysis using the Pearson chi-squared, Fisher's exact and Student's t-tests were used to identify possible factors affecting the prescribing rates and responses in community pharmacies.

RESULTS

The prescribing rate of antibiotics was 83.6% (n=209) with ciprofloxacin being the most prescribed (50.2%, n=105). The global conformity to international guidelines was 3.8% (n=8) with the highest conformity rate for the antibiotic choice (91.4%, n=191). Counseling about what to do in case symptoms persist was 12.8% (n=32) and that of non-pharmacological management was 53.6% (n=134). Male participants (88.1%) had a higher prescribing rate than female participants (77.6%) (p<0.05). The number of questions asked was higher in pharmacists and in female participants (p<0.05). Other results showed non-significant differences in diagnosis, antibiotic prescribing, conformity rates, referral rates and counseling points between the pharmacists and assistants.

CONCLUSIONS

The high antibiotic prescribing rate in Lebanese community pharmacies is alarming and calls for action. This should be tackled by legislative bodies, which should enforce laws that restrict such practices.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and urinary tract infections in pregnant/postpartum women: A systematic review and meta-analysis

BACKGROUND

Urinary tract infections (UTI) and asymptomatic bacteriuria (AB) during pregnancy can result in considerable maternal and foetal adverse outcomes. Production of extended-spectrum beta-lactamase (ESBL) is a major antibiotic resistance mechanism by Enterobacteriaceae.

OBJECTIVES

To determine the global prevalence of ESBL-producing (ESBL-P) Enterobacteriaceae in symptomatic UTI/AB among pregnant/postpartum females.

DATA SOURCES

A systematic review of the PubMed, Embase, Scopus, WOS (Web of Science), ProQuest and the grey literature was conducted.

STUDY SELECTION AND DATA EXTRACTION

Studies that reported the frequency of ESBL-P Enterobacteriaceae in pregnant/postpartum women with UTI and/or AB were eligible. First, the titles and abstracts of the retrieved articles were reviewed. Then, the full texts of the remained articles were reviewed.

SYNTHESIS

In order to estimate the pooled prevalence and the 95% confidence interval (95% CI), meta-analysis was performed using the random-effects model.

RESULTS

Twenty-three studies (six from Africa, two from North America, one from South America, 12 from Asia and two European studies) that reported data on 20 033 Enterobacteriaceae strains were included. The pooled prevalence of ESBL-P Enterobacteriaceae was 25% (95% CI 18%, 32%); I2  = 98.8%. The estimated prevalence (95% CI) rates were 45% (22, 67%) in Africa, 33% (22, 44%) in India, 15% (6, 24%) in other Asian countries, 5% (2, 8%) in Europe, 4% (1, 11%) in South America and 3% (1, 5%) in North America (P < .001). This estimate was 21% (95% CI 11, 31%) in patients with symptomatic UTI and it was 28% (95% CI 15, 41%) in patients with AB (P = .40).

CONCLUSIONS

The prevalence of ESBL-P Enterobacteriaceae among pregnant women with UTI/AB was significant and geographic region was a major source for heterogeneity. The findings could be taken into account by healthcare providers and programmers in the management and antibiotic selection of UTI/AB during pregnancy, especially in high prevalence areas.

Phenotypic and Genotypic Characterization of Escherichia coli Causing Urinary Tract Infections in Kidney-Transplanted Patients

Urinary tract infection (UTI), frequently caused by uropathogenic Escherichia coli (UPEC), is the most common infection after kidney transplantation (KTx). Untreated, it can lead to urosepsis and impairment of the graft function. We questioned whether the UPEC isolated from KTx patients differed from the UPEC of non-KTx patients. Therefore, we determined the genome sequences of 182 UPEC isolates from KTx and control patients in a large German university clinic and pheno- and genotypically compared these two isolated groups. Resistance to the β-lactams, trimethoprim or trimethoprim/sulfamethoxazole was significantly higher among UPEC from KTx than from control patients, whereas both the isolated groups were highly susceptible to fosfomycin. Accordingly, the gene content conferring resistance to β-lactams or trimethoprim, but also to aminoglycosides, was significantly higher in KTx than in control UPEC isolates. E. coli isolates from KTx patients more frequently presented with uncommon UPEC phylogroups expressing higher numbers of plasmid replicons, but interestingly, less UPEC virulence-associated genes than the control group. We conclude that there is no defining subset of virulence traits for UPEC from KTx patients. The clinical history and immunocompromised status of KTx patients enables E. coli strains with low uropathogenic potential, but with increased antibiotic resistance to cause UTIs.

Direct medical costs of urinary tract infections by Gram-negative bacilli resistant to beta-lactams in a tertiary care hospital in Medellín, Colombia

Introduction: Urinary tract infections are very frequent in the hospital environment and given the emergence of antimicrobial resistance, they have made care processes more complex and have placed additional pressure on available healthcare resources. Objective: To describe and compare excess direct medical costs of urinary tract infections due to Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa resistant to beta-lactams. Materials and methods: A cohort study was conducted in a third level hospital in Medellín, Colombia, from October, 2014, to September, 2015. It included patients with urinary tract infections caused by beta-lactam-susceptible bacteria, third and fourth generation cephalosporin-resistant, as well as carbapenem-resistant. Costs were analyzed from the perspective of the health system. Clinical-epidemiological information was obtained from medical records and the costs were calculated using standard tariff manuals. Excess costs were estimated with multivariate analyses. Results: We included 141 patients: 55 (39%) were sensitive to beta-lactams, 54 (38.3%) were resistant to cephalosporins and 32 (22.7%) to carbapenems. The excess total adjusted costs of patients with urinary tract infections due to cephalosporin- and carbapenem-resistant bacteria were US$ 193 (95% confidence interval (CI): US$ -347-734) and US$ 633 (95% CI: US$ -50-1316), respectively, compared to the group of patients with beta-lactam sensitive urinary tract infections. The differences were mainly found in the use of broad-spectrum antibiotics such as meropenem, colistin, and fosfomycin. Conclusion: Our results show a substantial increase in the direct medical costs of patients with urinary tract infections caused by beta-lactam-resistant Gram-negative bacilli (cephalosporins and carbapenems). This situation is of particular concern in endemic countries such as Colombia, where the high frequencies of urinary tract infections and the resistance to beta-lactam antibiotics can generate a greater economic impact on the health sector.

Performance of an Easy and Simple New Scoring Model in Predicting Multidrug-Resistant Enterobacteriaceae in Community-Acquired Urinary Tract Infections

Background

Multidrug resistance (MDR) is a growing global problem in bacterial community-acquired urinary tract infections (CUTIs). We aimed to propose an easy-to-use clinical prediction model to identify patients with MDR in CUTI.

Methods

We conducted a retrospective study including 770 patients with documented CUTI diagnosed during 2010–2017. Logistic regression–based prediction scores were calculated based on variables independently associated with MDR. Sensitivities and specificities at various cutoff points were determined, and the area under the receiver operating characteristic curve (AUROC) was computed.

Results

We found MDR Enterobacteriaceae in 372 cases (45.1%). Multivariate analysis showed that age ≥70 years (adjusted odds ratio [aOR], 2.5; 95% confidence interval [CI], 1.8–3.5), diabetes mellitus (aOR, 1.65; 95% CI, 1.19–2.3), history of urinary tract surgery in the last 12 months (aOR, 4.5; 95% CI, 1.22–17), and previous antimicrobial therapy in the last 3 months (aOR, 4.6; 95% CI, 3–7) were independent risk factors of MDR in CUTI. The results of Hosmer-Lemshow chi-square testing were indicative of good calibration of the model (χ² = 3.4; P = .49). At a cutoff of ≥2, the score had an AUROC of 0.71, a sensitivity of 70.5%, a specificity of 60%, a positive predictive value of 60%, a negative predictive value of 70%, and an overall diagnostic accuracy of 65%. When the cutoff was raised to 6, the sensitivity dropped (43%), and the specificity increased appreciably (85%).

Conclusions

We developed a novel scoring system that can reliably identify patients likely to be harboring MDR in CUTI.

Susceptibility patterns of uropathogens identified in hospitalized children

BACKGROUND

Urinary tract infection (UTI) is the most common serious bacterial infection in childhood. The aim of the present study was therefore to identify the organisms responsible for community-acquired febrile UTI in children, to investigate their susceptibility to commonly used antibiotics, and to identify possible risk factors for antibiotic resistance.

METHODS

A total of 284 children (male, 38%; female, 62%), who were hospitalized due to a community-acquired UTI over a 5 year period in a general district hospital of southern Greece, were enrolled in the study.

RESULTS

Escherichia coli was the leading uropathogen followed by Klebsiella spp. (9.15%) and Proteus spp. (5.28%). E. coli isolates were most commonly resistant to ampicillin (41.8%), followed by piperacillin (40.3%), amoxicillin-clavulanic acid (28.6%) and trimethoprim-sulfamethoxazole (17.8%), while 27 strains (12.6%) were multi-drug resistant (MDR). Of the E. coli strains, 4.21% were producing extended-spectrum beta-lactamases. Parenteral second- and third-generation cephalosporins, the most commonly used antibiotic agents (81.3%) in the present cohort, remained highly active against E. coli and other urinary isolates, given that >95% of E. coli strains were susceptible to cefuroxime and cefotaxime. Vesicoureteral reflux was a significant risk factor for MDR (P = 0.04).

CONCLUSION

Contrary to current local practice, amoxicillin/clavulanic acid may not be the best option for the empirical treatment of community-acquired UTI in southern Greece.

Incidence of single-drug resistant, multidrug-resistant and extensively drug-resistant Escherichia coli urinary tract infections: An Australian laboratory-based retrospective study

OBJECTIVES

The aim of this study was to evaluate the incidence of single-drug resistant, multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) Escherichia coli urinary tract infections (UTIs) in a sample of Australian Capital Territory (ACT) residents.

METHODS

Laboratory-based retrospective data from all ACT residents whose urine samples were processed from January 2009 to December 2013 at ACT Pathology were utilised. Multivariate logistic regression models were constructed to determine the associations of age, sex, urine sample source and socioeconomic status with risk of resistant infections.

RESULTS

A total of 146 915 urine samples from 57 837 ACT residents were identified over 5 years. The mean±standard deviation age of residents at first sample submitted was 48±26years, and 64.4% were female. The 5-year incidence of single-drug resistant E. coli UTI was high for ampicillin, trimethoprim and cefazolin (6.8%, 3.5% and 1.9%, respectively). No PDR E. coli UTI was detected. Five-year incidences of MDR and XDR E. coli UTIs were 1.9% and 0.2%, respectively, which is low in comparison with international rates. Female sex and age ≥38 years were significantly associated with single-drug and multidrug resistance. The risk of single-drug resistance was significantly higher in samples from after-hours general practice (GP) clinics compared with hospitals, office-hours GP clinics, and community and specialist health services (adjusted odds ratio=2.6, 95% confidence interval 2.2-3.1).

CONCLUSIONS

These findings have significant implications for antimicrobial prescribing given the identified risk factors for the detection of resistance, especially in patients attending after-hours GP clinics.

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

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

Validation of a Clinical Decision Rule to Identify Risk Factors Associated With Multidrug-Resistant Urinary Pathogens in the Emergency Department

BACKGROUND

Antimicrobial resistance remains a significant obstacle for clinicians when treating patients presenting to the emergency department (ED) with urinary tract infections.

OBJECTIVE

The goal of the proposed study was to validate a previously developed clinical decision rule identifying risk factors for multidrug-resistant (MDR) urinary pathogens.

METHODS

We conducted a validation study of a previously published clinical decision rule to identify patients with MDR urinary pathogens using a cohort from an urban academic center ED with annual census over 80 000. Using our previously identified clinical risk factors, we determined the sensitivity, specificity, positive likelihood ratio (+LR), and negative LR (-LR) to estimate measures of precision of our clinical decision rule in the validation cohort.

RESULTS

Factors associated with MDR urinary pathogen included sex, recent hospitalization, nursing home residency, and catheter placement. Using our previously defined threshold of greater than 1 risk factor, the adjusted model in the validation cohort identified that only nursing home residency was associated with positive MDR pathogen (adjusted odds ratio = 4.13; 95% CI = 1.95-8.77). The clinical decision rule in the validation cohort yielded a sensitivity of 56.4%, specificity of 66.3%, +LR of 1.7, and -LR of 0.7. Conclusion and Relevance: Our clinical decision rule to identify patients at risk for MDR urinary pathogens was unable to be validated in the setting of different antimicrobial resistance patterns. Future studies should evaluate an improved clinical decision rule identifying risk factors associated with MDR pathogens that performs well in varying patient populations.

Antimicrobial Resistance of Uropathogenic Escherichia coli from Elderly Patients at a General Hospital, Argentina

Background:

Urinary Tract Infection (UTI) is a common cause of morbidity and mortality in older adults.

Objective:

To investigate antimicrobial resistance of uropathogenicEscherichia colifrom elderly patients in a General Hospital, Argentina.

Method:

During the period July 2011-July 2015, patients over 70 years old with urinary tract infections, without urinary catheters and with no antimicrobial therapy the previous week before sampling, were included. Phenotypic characterization was carried out.In vitroqualitative and quantitative antimicrobial resistances were investigated. Antimicrobials assayed: ampicillin, amoxicillin-clavulanate, cefazolin, cefuroxime, cefoxitin, cefotaxime, ceftazidime, cefepime, imipenem, ertapenem, gentamicin, nalidixic acid, ciprofloxacin, trimethoprim-sulfamethoxazole (TMS) and nitrofurantoin. Patients’ medical records were produced, and risk factors were analyzed by multivariate analysis.

Results:

768 bacterial isolates were identified asE. coli. Resistances to ampicillin (80.5%), nalidixic acid (61.7%), ciprofloxacin (42.8%), TMS (37.6%), amoxicillin-clavulanate (28.6%), cefazolin (21.6%), cefuroxime (20.7%), gentamicin (13.8%), cefotaxime (9.7%), ceftazidime (9.7%), cefepime (8.4%), cefoxitin (3.1%) and nitrofurantoin (2.3%) were observed. Resistance to carbapenems was not expressed. Production of extended spectrum β-lactamases was detected (7.6%) in community acquired (96%) and healthcare associated (4%) isolates. The independent risk factors for urinary infections produced by multi-resistantE. coliwere: diabetes mellitus, recurrent infections, hospitalization during the last year and exposure to β-lactams in the last 3 months.

Conclusion:

A high prevalence of resistance to β-lactams and to other antimicrobials was observed. Detection of antimicrobial multi-resistant isolates highlights the need of antimicrobial resistance surveillance in elderly patients with urinary tract infections.

An evaluation of E. coli in urinary tract infection in emergency department at KAMC in Riyadh, Saudi Arabia: retrospective study

Background

Urinary tract infection (UTIS) is a common infectious disease in which level of antimicrobial resistance are alarming worldwide. Therefore, this study aims to describe the prevalence and the resistance pattern of the main bacteria responsible for UTIS Escherichia coli (E. coli).

Methods

Retrospective chart review for patients admitted to emergency department and diagnosed with UTIS at KAMC, in Riyadh, Saudi Arabia between January to March 2008 was performed. Antimicrobial susceptibility to ampicillin, augmentin (amoxicillin/clavulanate), cefazolin, co-trimoxazole (sulfamethoxazole/trimethoprim), ciprofloxacin, and nitrofurantoin, and cefpodoxime was determined for 101 E. coli urinary isolates.

Results

Escherichia coli was the most prevalent pathogen contributing to UTIS representing 93.55, 60.24, and 45.83% of all pathogen isolated from urine culture of pediatric, adult, and elderly, respectively. High rates of resistance to ampicillin (82.76, 58, and 63.64%) and co-trimoxazole (51.72, 42, and 59.09%), among E. coli isolated from pediatric, adult and elderly respectively. Nitrofurantoin was the most active agent, followed by ciprofloxacin, augmentin and cefazolin. 22.77% of E. coli isolates exhibited multiple drug resistance (MDR). Among 66 and 49 isolates resistant to ampicillin and co-trimoxazole, respectively, 34.84 and 42.85% were MDR. In contrast, all isolates resistant to augmentin and nitrofurantoin were MRD, while 72.7 and 82.4% of isolates resistant to ciprofloxacin and cefazolin were MDR.

Conclusions

High resistance was observed to ampicillin and co-trimoxazole which commonly used as empirical treatments for UTIS, limiting their clinical use. This necessitates continuous surveillance for resistance pattern of uropathogens against antibiotics.

Risk factors for aquiring multidrug-resistant organisms in urinary tract infections: A systematic literature review

Background

This is the first review to analyze literature identifying risk factors for a multidrug-resistant urinary tract infection (MDR UTI). Risk factors for other infections involving multidrug-resistant organisms have been evaluated in other reviews, but they do not assess urinary tract infections. The purpose of this study is to collect currently published data to determine the most commonly and consistently identified risk factors for UTIs.

Material and methods

For this study, 3 independent researchers searched PubMed, Embase, and Cochrane database from 1966 to February 2016 for articles identifying risk factors for MDR UTI.

Results

A total of 25 studies including 31,284 patients with positive cultures provide evidence for 12 possible risk factors for MDR UTI . The most commonly identified risk factor was previous antibiotic usage as evidenced in 16 of the 20 studies that evaluated this possible risk factor. The time range utilized to define previous antibiotic usage ranged from 2 days to 365 days. Other risk factors with the strongest supporting data were urinary catheterization, previous hospitalization, and nursing home residence.

Conclusion

We identified 12 different possible risk factors for a MDR UTI, however several risk factors have minimal or conflicting evidence. The definitions of the risk factors varied widely among the studies, and should be standardized for future studies.

Fluoroquinolone-Resistant and Extended-Spectrum β-Lactamase-Producing Escherichia coli Infections in Patients with Pyelonephritis, United States(1)

For 2013-2014, we prospectively identified US adults with flank pain, temperature >38.0°C, and a diagnosis of acute pyelonephritis, confirmed by culture. Cultures from 453 (86.9%) of 521 patients grew Escherichia coli. Among E. coli isolates from 272 patients with uncomplicated pyelonephritis and 181 with complicated pyelonephritis, prevalence of fluoroquinolone resistance across study sites was 6.3% (range by site 0.0%-23.1%) and 19.9% (0.0%-50.0%), respectively; prevalence of extended-spectrum β-lactamase (ESBL) production was 2.6% (0.0%-8.3%) and 12.2% (0.0%-17.2%), respectively. Ten (34.5%) of 29 patients with ESBL infection reported no exposure to antimicrobial drugs, healthcare, or travel. Of the 29 patients with ESBL infection and 53 with fluoroquinolone-resistant infection, 22 (75.9%) and 24 (45.3%), respectively, were initially treated with in vitro inactive antimicrobial drugs. Prevalence of fluoroquinolone resistance exceeds treatment guideline thresholds for alternative antimicrobial drug strategies, and community-acquired ESBL-producing E. coli infection has emerged in some US communities.

Antimicrobial Potential of Carvacrol against Uropathogenic Escherichia coli via Membrane Disruption, Depolarization, and Reactive Oxygen Species Generation

Bacterial resistance to antibiotics poses a serious threat to cure diseases associated with microbial infection. Among the resistant bacteria, extended-spectrum β-lactamase (ESBL)-producing bacteria are the most concerned one as they encode the enzyme β-lactamase that confers resistance to most β-lactam antibiotics. The present study was carried out to determine the antimicrobial potential and the principle mechanism of action of carvacrol against ESBL Escherichia coli isolated from ascitic fluid of a patient having a urinary tract infection. Carvacrol exhibited a minimum inhibitory concentration (MIC) of 450 μg/ml at which it reduced E. coli cell counts significantly in a time-dependent manner. Carvacrol completely diminished the growth of E. coli after 2 h of incubation at its MIC. Fluorescent imaging displayed the elevated reactive oxygen species level and bacterial membrane depolarization leading to E. coli cell death in presence of carvacrol at its MIC. Furthermore, carvacrol displayed a severe detrimental effect on bacterial membrane disruption and cellular material release. In addition, a significant effect of carvacrol at sub-inhibitory concentration was observed on motility of E. coli cells and invasion of human colon HCT-116 cells in an ex vivo model. Based on the results, we conclude a potential antimicrobial role of carvacrol against ESBL E. coli.

Clinical Management of an Increasing Threat: Outpatient Urinary Tract Infections Due to Multidrug-Resistant Uropathogens

Urinary tract infections (UTIs) are among the most commonly treated bacterial infections. Over the past decade, antimicrobial resistance has become an increasingly common factor in the management of outpatient UTIs. As treatment options for multidrug-resistant (MDR) uropathogens are limited, clinicians need to be aware of specific clinical and epidemiological risk factors for these infections. Based on available literature, the activity of fosfomycin and nitrofurantoin remain high for most cases of MDR Escherichia coli UTIs. Trimethoprim-sulfamethoxazole retains clinical efficacy, but resistance rates are increasing internationally. Beta-lactam agents have the highest rates of resistance and lowest rates of clinical success. Fluoroquinolones have high resistance rates among MDR uropathogens and are being strongly discouraged as first-line agents for UTIs. In addition to accounting for local resistance rates, consideration of patient risk factors for resistance and pharmacological principles will help guide optimal empiric treatment of outpatient UTIs.