C-Reactive Protein Testing to Guide Antibiotic Prescribing for COPD Exacerbations.

BACKGROUND: Point-of-care testing of C-reactive protein (CRP) may be a way to reduce unnecessary use of antibiotics without harming patients who have acute exacerbations of chronic obstructive pulmonary disease (COPD). METHODS: We performed a multicenter, open-label, randomized, controlled trial involving patients with a diagnosis of COPD in their primary care clinical record who consulted a clinician at 1 of 86 general medical practices in England and Wales for an acute exacerbation of COPD. The patients were assigned to receive usual care guided by CRP point-of-care testing (CRP-guided group) or usual care alone (usual-care group). The primary outcomes were patient-reported use of antibiotics for acute exacerbations of COPD within 4 weeks after randomization (to show superiority) and COPD-related health status at 2 weeks after randomization, as measured by the Clinical COPD Questionnaire, a 10-item scale with scores ranging from 0 (very good COPD health status) to 6 (extremely poor COPD health status) (to show noninferiority). RESULTS: A total of 653 patients underwent randomization. Fewer patients in the CRP-guided group reported antibiotic use than in the usual-care group (57.0% vs. 77.4%; adjusted odds ratio, 0.31; 95% confidence interval [CI], 0.20 to 0.47). The adjusted mean difference in the total score on the Clinical COPD Questionnaire at 2 weeks was -0.19 points (two-sided 90% CI, -0.33 to -0.05) in favor of the CRP-guided group. The antibiotic prescribing decisions made by clinicians at the initial consultation were ascertained for all but 1 patient, and antibiotic prescriptions issued over the first 4 weeks of follow-up were ascertained for 96.9% of the patients. A lower percentage of patients in the CRP-guided group than in the usual-care group received an antibiotic prescription at the initial consultation (47.7% vs. 69.7%, for a difference of 22.0 percentage points; adjusted odds ratio, 0.31; 95% CI, 0.21 to 0.45) and during the first 4 weeks of follow-up (59.1% vs. 79.7%, for a difference of 20.6 percentage points; adjusted odds ratio, 0.30; 95% CI, 0.20 to 0.46). Two patients in the usual-care group died within 4 weeks after randomization from causes considered by the investigators to be unrelated to trial participation. CONCLUSIONS: CRP-guided prescribing of antibiotics for exacerbations of COPD in primary care clinics resulted in a lower percentage of patients who reported antibiotic use and who received antibiotic prescriptions from clinicians, with no evidence of harm. (Funded by the National Institute for Health Research Health Technology Assessment Program; PACE Current Controlled Trials number, ISRCTN24346473.).

Evaluation of Antimicrobial Susceptibility Testing Methods for Burkholderia cenocepacia and Burkholderia multivorans Isolates from Cystic Fibrosis Patients.

The Burkholderia cepacia complex (BCC) is known for causing serious lung infections in people with cystic fibrosis (CF). These infections can require lung transplantation, eligibility for which may be guided by antimicrobial susceptibility testing (AST). While the Clinical and Laboratory Standards Institute recommends AST for BCC, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) does not, due to poor method performance and correlation with clinical outcomes. Furthermore, limited data exist on the performance of automated AST methods for BCC. To address these issues, reproducibility and accuracy were evaluated for disk diffusion (DD), broth microdilution (BMD), and MicroScan WalkAway using 50 B. cenocepacia and 50 B. multivorans isolates collected from people with CF. The following drugs were evaluated in triplicate: chloramphenicol (CAM), ceftazidime (CAZ), meropenem (MEM), trimethoprim-sulfamethoxazole (TMP-SMX), minocycline (MIN), levofloxacin (LVX), ciprofloxacin (CIP), and piperacillin-tazobactam (PIP-TAZ). BMD reproducibility was ≥ 95% for MEM and MIN only, and MicroScan WalkAway reproducibility was similar to BMD. DD reproducibility was < 90% for all drugs tested when a 3 mm cut-off was applied. When comparing the accuracy of DD to BMD, only MEM met all acceptance criteria. TMP-SMX and LVX had high minor errors, CAZ had unacceptable very major errors (VME), and MIN, PIP-TAZ, and CIP had both unacceptable minor errors and VMEs. For MicroScan WalkAway, no drugs met acceptance criteria. Analyses also showed that errors were not attributed to one species. In general, our data agree with EUCAST recommendations.

A prospective surveillance study to determine the prevalence of 16S rRNA methyltransferase-producing Gram-negative bacteria in the UK.

OBJECTIVES: To determine the prevalence of 16S rRNA methyltransferase- (16S RMTase-) producing Gram-negative bacteria in patients in the UK and to identify potential risk factors for their acquisition. METHODS: A 6 month prospective surveillance study was conducted from 1 May to 31 October 2016, wherein 14 hospital laboratories submitted Acinetobacter baumannii, Enterobacterales and Pseudomonas aeruginosa isolates that displayed high-level amikacin resistance according to their testing methods, e.g. no zone of inhibition with amikacin discs. Isolates were linked to patient travel history, medical care abroad, and previous antibiotic exposure using a surveillance questionnaire. In the reference laboratory, isolates confirmed to grow on Mueller-Hinton agar supplemented with 256 mg/L amikacin were screened by PCR for 16S RMTase genes armA, rmtA-rmtH and npmA, and carbapenemase genes (blaKPC, blaNDM, blaOXA-48-like and blaVIM). STs and total antibiotic resistance gene complement were determined via WGS. Prevalence was determined using denominators for each bacterial species provided by participating hospital laboratories. RESULTS: Eighty-four isolates (44.7%), among 188 submitted isolates, exhibited high-level amikacin resistance (MIC >256 mg/L), and 79 (94.0%) of these harboured 16S RMTase genes. armA (54.4%, 43/79) was the most common, followed by rmtB (17.7%, 14/79), rmtF (13.9%, 11/79), rmtC (12.7%, 10/79) and armA + rmtF (1.3%, 1/79). The overall period prevalence of 16S RMTase-producing Gram-negative bacteria was 0.1% (79/71 063). Potential risk factors identified through multivariate statistical analysis included being male and polymyxin use. CONCLUSIONS: The UK prevalence of 16S RMTase-producing Gram-negative bacteria is low, but continued surveillance is needed to monitor their spread and inform intervention strategies.

False amoxicillin/clavulanic acid susceptibility in Bacteroides fragilis using gradient strip tests.

BACKGROUND: Repeatedly, too low MIC results were obtained in Bacteroides fragilis quality assessment strains, using gradient strip tests with a ratio of amoxicillin:clavulanic acid of 2:1. We aimed to find the most accurate available gradient strip tests for susceptibility testing of amoxicillin/clavulanic acid in B. fragilis in comparison with agar dilution with EUCAST methodology and breakpoints. METHODS: Twenty-seven clinical B. fragilis isolates were investigated using gold standard EUCAST amoxicillin/clavulanic acid agar dilution (fixed clavulanic acid concentration at 2 mg/L, with increasing amoxicillin concentrations) as well as three commercial gradient strip tests: XL (ratio), AUG (ratio) or AMC (fixed concentration). RESULTS: Using agar dilution (fixed concentration), 19 isolates were susceptible, 1 isolate was susceptible increased exposure (I) and 7 isolates were resistant. Categorical agreement of the gradient strip tests with agar dilution (fixed concentration) was 70% for XL (ratio), 71% for AUG (ratio) and 89% for AMC (fixed concentration). Very major error rates in comparison with agar dilution (fixed concentration) were 100%, 0%, and 0%, respectively. CONCLUSIONS: EUCAST breakpoint usage in amoxicillin/clavulanic acid susceptibility tests for B. fragilis should be accompanied by EUCAST methodology. When using alternative methods such as gradient strip tests, a higher degree of alignment with EUCAST methodology, such as using fixed clavulanic acid concentrations, improves precision.

Drug repurposing: phosphate prodrugs of anticancer and antiviral FDA-approved nucleosides as novel antimicrobials.

OBJECTIVES: Following a drug repurposing approach, we aimed to investigate and compare the antibacterial and antibiofilm activities of different classes of phosphate prodrugs (HepDirect, cycloSal, SATE and mix SATE) of antiviral and anticancer FDA-approved nucleoside drugs [zidovudine (AZT), floxouridine (FUDR) and gemcitabine (GEM)] against a variety of pathogenic Gram-positive and -negative bacteria. METHODS: Ten prodrugs were synthesized and screened for antibacterial activity against seven Gram-negative and two Gram-positive isolates fully susceptible to traditional antibiotics, alongside six Gram-negative and five Gram-positive isolates with resistance mechanisms. Their ability to prevent and eradicate biofilms of different bacterial pathogens in relation to planktonic growth inhibition was also evaluated, together with their effect on proliferation, viability and apoptosis of different eukaryotic cells. RESULTS: The prodrugs showed decreased antibacterial activity compared with the parent nucleosides. cycloSal-GEM-monophosphate (MP) prodrugs 20a and 20b were the most active agents against Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and retained their activity against antibiotic-resistant isolates. cycloSal-FUDR-MP 21a partially retained good activity against the Gram-positive bacteria E. faecalis, Enterococcus faecium and S. aureus. Most of the prodrugs tested displayed very potent preventive antibiofilm specific activity, but not curative. In terms of cytotoxicity, AZT prodrugs did not affect apoptosis or cell viability at the highest concentration tested, and only weak effects on apoptosis and/or cell viability were observed for GEM and FUDR prodrugs. CONCLUSIONS: Among the different prodrug approaches, the cycloSal prodrugs appeared the most effective. In particular, cycloSal (17a) and mix SATE (26) AZT prodrugs combine the lowest cytotoxicity with high and broad antibacterial and antibiofilm activity against Gram-negative bacteria.

Effect of Probiotic Use on Antibiotic Administration Among Care Home Residents: A Randomized Clinical Trial.

Importance: Probiotics are frequently used by residents in care homes (residential homes or nursing homes that provide residents with 24-hour support for personal care or nursing care), although the evidence on whether probiotics prevent infections and reduce antibiotic use in these settings is limited. Objective: To determine whether a daily oral probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 compared with placebo reduces antibiotic administration in care home residents. Design, Setting, and Participants: Placebo-controlled randomized clinical trial of 310 care home residents, aged 65 years and older, recruited from 23 care homes in the United Kingdom between December 2016 and May 2018, with last follow-up on October 31, 2018. Interventions: Study participants were randomized to receive a daily capsule containing a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 (total cell count per capsule, 1.3 × 1010 to 1.6 × 1010) (n = 155), or daily matched placebo (n = 155), for up to 1 year. Main Outcomes and Measures: The primary outcome was cumulative antibiotic administration days for all-cause infections measured from randomization for up to 1 year. Results: Among 310 randomized care home residents (mean age, 85.3 years; 66.8% women), 195 (62.9%) remained alive and completed the trial. Participant diary data (daily data including study product use, antibiotic administration, and signs of infection) were available for 98.7% randomized to the probiotic group and 97.4% randomized to placebo. Care home residents randomized to the probiotic group had a mean of 12.9 cumulative systemic antibiotic administration days (95% CI, 0 to 18.05), and residents randomized to placebo had a mean of 12.0 days (95% CI, 0 to 16.95) (absolute difference, 0.9 days [95% CI, -3.25 to 5.05]; adjusted incidence rate ratio, 1.13 [95% CI, 0.79 to 1.63]; P = .50). A total of 120 care home residents experienced 283 adverse events (150 adverse events in the probiotic group and 133 in the placebo group). Hospitalizations accounted for 94 of the events in probiotic group and 78 events in the placebo group, and deaths accounted for 33 of the events in the probiotic group and 32 of the events in the placebo group. Conclusions and Relevance: Among care home residents in the United Kingdom, a daily dose of a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 did not significantly reduce antibiotic administration for all-cause infections. These findings do not support the use of probiotics in this setting. Trial Registration: ISRCTN Identifier:16392920.

Multicenter Clinical Evaluation of Etest Meropenem-Vaborbactam (bioMérieux) for Susceptibility Testing of Enterobacterales (Enterobacteriaceae) and Pseudomonas aeruginosa.

Meropenem-vaborbactam (MEV) is a novel carbapenem-beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration (FDA) for treatment of complicated urinary tract infections, including pyelonephritis, in adults. In this study, we evaluated the performance of Etest MEV (bioMérieux, Marcy l'Etoile, France) compared to that of broth microdilution for 629 Enterobacterales and 163 Pseudomonas aeruginosa isolates. According to CLSI/FDA breakpoints, 13 Enterobacterales isolates (12 clinical and 1 challenge) were resistant to MEV. Overall, Etest MEV demonstrated 92.4% essential agreement (EA), 99.2% category agreement (CA), 0% very major errors (VME), 0% major errors (ME), and 0.8% minor errors (mE) with clinical and challenge isolates of Enterobacterales Individual species demonstrated EA rates of ≥80%, with the exception of Proteus mirabilis, for which clinical and challenge isolates demonstrated 34.3% EA, 97.1% CA, 0% ME, and 2.9% mE, precluding the use of Etest MEV with this species. Excluding P. mirabilis, MEV Etest MEV demonstrated 95.8% EA, 99.3% CA, 0% VME, 0% ME, and 0.7% mE with Enterobacterales isolates. When evaluated using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, Etest MEV performance with clinical (16 MEV resistant) and challenge (12 MEV resistant) isolates of Enterobacterales (excluding P. mirabilis) and P. aeruginosa demonstrated an unacceptably high VME rate of 7.1% despite 95.2% EA, 99.2% CA, and 0.5% ME compared to the reference method. In conclusion, we report that Etest MEV is accurate and reproducible for MEV susceptibility testing for P. aeruginosa and Enterobacterales, with the exception of P. mirabilis, using CLSI/FDA breakpoints. Etest MEV should not be used with P. mirabilis due to unacceptable analytical performance.

Rapid detection of IMP, NDM, VIM, KPC and OXA-48-like carbapenemases from Enterobacteriales and Gram-negative non-fermenter bacteria by real-time PCR and melt-curve analysis.

Carbapenemase-producing microorganisms are increasingly isolated and often associated with treatment failures and outbreaks. The need for reliable and timely detection and/or confirmation of carbapenemase production is paramount; therefore, a real-time PCR assay targeting IMP, NDM, VIM, KPC and OXA-48-like carbapenemases was designed and validated. All available allele variants of the above carbapenemases were downloaded from the Beta-Lactamase DataBase ( http://bldb.eu/ ), aligned with Clustal Omega and primers designed using Primer-BLAST. Real-time PCR monoplexes were optimized for the QuantStudio 6-Flex (Applied Biosystems) using the PowerUp SYBR Green Master Mix (Life Technologies) and validated using a panel of 204 characterised strains carrying a wide range of beta-lactamases, sometimes in combination. Melt-curve analysis was used to confirm positive results. The in silico approach allowed primers to be designed in conserved regions of the KPC and NDM alignments, while three primer sets for IMP and two for VIM were necessary to ensure amplification of the different variants. One primer set was designed for OXA-48-like; however, it is unlikely to detect all variants. Expected results were obtained for all 204 tested strains, with 100% sensitivity and specificity. Melt-curve analysis showed consistent Tm results for KPC, NDM, and OXA-48-like; differences were instead noted for IMP and VIM as likely consequence of higher variability in the PCR target regions. Inhibition was not observed. The assay is rapid, easy to perform and implement. It enables unequivocal detection of IMP, NDM, VIM, KPC and OXA-48-like carbapenemases even when more than one type is present simultaneously.

Comparison of risk factors for, and prevalence of, antibiotic resistance in contaminating and pathogenic urinary Escherichia coli in children in primary care: prospective cohort study.

Background: All-cause antibiotic prescribing affects bowel flora antimicrobial susceptibility, and may increase risk of urinary autoinoculation with antibiotic-resistant microbes. However, little is known about relative prevalence of, or risk factors for, antimicrobial resistance among potentially pathogenic microbes thought to be contaminating and infecting urine. Methods: Secondary analysis of 824 children under 5 years of age consulting in primary care for an acute illness and their Escherichia coli isolates cultured at ≥103 cfu/mL from the Diagnosis of Urinary Tract infection in Young children (DUTY) study. Multivariable logistic regression investigating risk factors for resistance to amoxicillin, co-amoxiclav, cefalexin, ciprofloxacin, trimethoprim, nitrofurantoin and cefpodoxime in microbes meeting the laboratory criteria for urinary tract infection: 'pathogens' (>105 cfu/mL, n = 79) and 'contaminants' (103 to 105 cfu/mL, n = 745). Results: Forty-three percent of E. coli were resistant to at least one tested antibiotic, with resistance highest to amoxicillin (49.37% pathogenic versus 37.32% contaminant, P = 0.04), trimethoprim (27.85% versus 16.52%, P = 0.01) and co-amoxiclav (16.46% versus 21.48%, P = 0.30). Multidrug resistance (to ≥3 antibiotic groups) was present in 17.07% of pathogens and 30.13% of contaminants (P = 0.04). No isolates were resistant to nitrofurantoin. Recent (0-3 months) exposure to antibiotics was associated with resistance in both pathogens (aOR: 1.10, 95% CI: 1.01-4.39) and contaminants (1.69, 1.09-2.67). Conclusions: Prevalence of resistance (including multidrug) was high, but there was no consistent relationship between isolate pathogen/contamination status and resistance. Recent all-cause antibiotic prescribing increased the probability of antimicrobial resistance in both pathogenic and contaminating urinary E. coli in children in primary care.

Design, Synthesis and Microbiological Evaluation of Novel Compounds as Potential Staphylococcus aureus Phenylalanine tRNA Synthetase Inhibitors.

AS THE RESISTANCE of Staphylococcus aureus to antibiotics represents a major threat to global health, anti-infectives with novel mechanisms must be developed. Novel compounds were generated as potential phenylalanine tRNA synthetase (PheRS) inhibitors based on the published homology model of S. aureus PheRS to aid the design process using Molecular Operating Environment (MOE) software. PheRS was selected as it is structurally unique enzyme among the aminoacyl-tRNA synthetases (aaRS), it is considerably different from human cytosolic and human mitochondrial aaRS and it is essential and conserved across bacterial species. The designed compounds were synthesized according to different clear schemes. The compounds were confirmed by 1H NMR, 13C NMR, HRMS and/or microanalysis, and they were microbiologically evaluated.

Towards better antimicrobial susceptibility testing: impact of the Journal of Antimicrobial Chemotherapy.

Susceptibility testing of bacteria is one of the most important tests performed in a clinical microbiology laboratory. Improvements in laboratory techniques, especially the move towards standardized susceptibility testing, has provided better consistency and accuracy of testing. When used in conjunction with the most recently developed interpretative criteria, the result is better prediction of the outcome of antimicrobial therapy for infected patients. Throughout the last four decades this Journal has published numerous articles evidencing improvements and new techniques, a valuable source of information for microbiology laboratories.

Oral and Topical Antibiotics for Clinically Infected Eczema in Children: A Pragmatic Randomized Controlled Trial in Ambulatory Care.

PURPOSE: Eczema may flare because of bacterial infection, but evidence supporting antibiotic treatment is of low quality. We aimed to determine the effect of oral and topical antibiotics in addition to topical emollient and corticosteroids in children with clinically infected eczema. METHODS: We employed a 3-arm, blinded, randomized controlled trial in UK ambulatory care. Children with clinical, non-severely infected eczema were randomized to receive oral and topical placebos (control), oral antibiotic (flucloxacillin) and topical placebo, or topical antibiotic (fusidic acid) and oral placebo, for 1 week. We compared Patient Oriented Eczema Measure (POEM) scores at 2 weeks using analysis of covariance (ANCOVA). RESULTS: We randomized 113 children (40 to control, 36 to oral antibiotic, and 37 to topical antibiotic). Mean (SD) baseline Patient Oriented Eczema Measure scores were 13.4 (5.1) for the control group, 14.6 (5.3) for the oral antibiotic group, and 16.9 (5.5) for the topical antibiotic group. At baseline, 104 children (93%) had 1 or more of the following findings: weeping, crusting, pustules, or painful skin. Mean (SD) POEM scores at 2 weeks were 6.2 (6.0) for control, 8.3 (7.3) for the oral antibiotic group, and 9.3 (6.2) for the topical antibiotic group. Controlling for baseline POEM score, neither oral nor topical antibiotics produced a significant difference in mean (95% CI) POEM scores (1.5 [-1.4 to 4.4] and 1.5 [-1.6 to 4.5] respectively). There were no significant differences in adverse effects and no serious adverse events. CONCLUSIONS: We found rapid resolution in response to topical steroid and emollient treatment and ruled out a clinically meaningful benefit from the addition of either oral or topical antibiotics. Children seen in ambulatory care with mild clinically infected eczema do not need treatment with antibiotics.

Clinicians' interpretations of point of care urine culture versus laboratory culture results: analysis from the four-country POETIC trial of diagnosis of uncomplicated urinary tract infection in primary care.

Background: Urine culture at the point of care minimises delay between obtaining the sample and agar inoculation in a microbiology laboratory, and quantification and sensitivity results can be available more rapidly in primary care. Objective: To identify the degree to which clinicians' interpretations of a point-of-care-test (POCT) urine culture (Flexicult™ SSI-Urinary Kit) agrees with laboratory culture in women presenting to primary care with symptoms of uncomplicated urinary tract infections (UTI). Methods: Primary care clinicians used the Flexicult™-POCT, recorded their findings and took a photograph of the result, which was interpreted by microbiology laboratory technicians. Urine samples were additionally processed in routine care laboratories. Cross tabulations were used to identify important differences in organism identification, quantification and antibiotic susceptibility between these three sources of data. The influence of various laboratory definitions for UTI on culture were assessed. Results: Primary care clinicians identified 202/289 urine samples (69.9%) as positive for UTI using the Flexicult™-POCT, whereas laboratory culture identified 94-190 (32.5-65.7%) as positive, depending on definition thresholds. 82.9% of samples identified positive for E. coli on laboratory culture were also considered positive for E. coli using the Flexicult™ -POCT, and susceptibilities were reasonably concordant. There were major discrepancies between laboratory staff interpretation of Flexicult™ photographs, clinicians' interpretation of the Flexicult™ test, and laboratory culture results. Conclusion: Flexicult™-POCT overestimated the positivity rate of urine samples for UTI when laboratory culture was used as the reference standard. However, it is unclear whether point-of-care or laboratory based urine culture provides the most valid diagnostic information.

Antimicrobial susceptibility testing breakpoints and methods from BSAC to EUCAST.

The BSAC Standing Committee on Antimicrobial Susceptibility Testing is one of several European national breakpoint committees that agreed in 2002 to harmonize clinical MIC breakpoints. The process of harmonization has since been completed for commonly used agents, and breakpoints for new agents have been set by EUCAST in accordance with a procedure defined by the EMA. EUCAST breakpoints have now been adopted by a large majority of laboratories in Europe. BSAC implemented the EUCAST breakpoints in its own disc diffusion susceptibility testing method as harmonized breakpoints were agreed to over the years. Since the development of the EUCAST disc diffusion method, several countries with their own disc diffusion methods have switched to the EUCAST method, and BSAC will replace support of its own disc diffusion method with support for the EUCAST method from January 2016. The EUCAST breakpoints are also available in automated systems. The harmonized breakpoints and methods will help to avoid different reports of susceptibility for the same isolate in different countries and enable more reliable comparison of resistance rates in surveillance studies in different countries.

Improving the Diagnosis and Treatment of Urinary Tract Infection in Young Children in Primary Care: Results from the DUTY Prospective Diagnostic Cohort Study.

PURPOSE: Up to 50% of urinary tract infections (UTIs) in young children are missed in primary care. Urine culture is essential for diagnosis, but urine collection is often difficult. Our aim was to derive and internally validate a 2-step clinical rule using (1) symptoms and signs to select children for urine collection; and (2) symptoms, signs, and dipstick testing to guide antibiotic treatment. METHODS: We recruited acutely unwell children aged under 5 years from 233 primary care sites across England and Wales. Index tests were parent-reported symptoms, clinician-reported signs, urine dipstick results, and clinician opinion of UTI likelihood (clinical diagnosis before dipstick and culture). The reference standard was microbiologically confirmed UTI cultured from a clean-catch urine sample. We calculated sensitivity, specificity, and area under the receiver operator characteristic (AUROC) curve of coefficient-based (graded severity) and points-based (dichotomized) symptom/sign logistic regression models, and we then internally validated the AUROC using bootstrapping. RESULTS: Three thousand thirty-six children provided urine samples, and culture results were available for 2,740 (90%). Of these results, 60 (2.2%) were positive: the clinical diagnosis was 46.6% sensitive, with an AUROC of 0.77. Previous UTI, increasing pain/crying on passing urine, increasingly smelly urine, absence of severe cough, increasing clinician impression of severe illness, abdominal tenderness on examination, and normal findings on ear examination were associated with UTI. The validated coefficient- and points-based model AUROCs were 0.87 and 0.86, respectively, increasing to 0.90 and 0.90, respectively, by adding dipstick nitrites, leukocytes, and blood. CONCLUSIONS: A clinical rule based on symptoms and signs is superior to clinician diagnosis and performs well for identifying young children for noninvasive urine sampling. Dipstick results add further diagnostic value for empiric antibiotic treatment.

Faecal carriage of antibiotic resistant Escherichia coli in asymptomatic children and associations with primary care antibiotic prescribing: a systematic review and meta-analysis.

BACKGROUND: The faecal reservoir provides optimal conditions for the transmission of resistance genes within and between bacterial species. As key transmitters of infection within communities, children are likely important contributors to endemic community resistance. We sought to determine the prevalence of antibiotic-resistant faecal Escherichia coli from asymptomatic children aged between 0 and 17 years worldwide, and investigate the impact of routinely prescribed primary care antibiotics to that resistance. METHODS: A systematic search of Medline, Embase, Cochrane and Web of Knowledge databases from 1940 to 2015. Pooled resistance prevalence for common primary care antibiotics, stratified by study country OECD status. Random-effects meta-analysis to explore the association between antibiotic exposure and resistance. RESULTS: Thirty-four studies were included. In OECD countries, the pooled resistance prevalence to tetracycline was 37.7 % (95 % CI: 25.9-49.7 %); ampicillin 37.6 % (24.9-54.3 %); and trimethoprim 28.6 % (2.2-71.0 %). Resistance in non-OECD countries was uniformly higher: tetracycline 80.0 % (59.7-95.3 %); ampicillin 67.2 % (45.8-84.9 %); and trimethoprim 81.3 % (40.4-100 %). We found evidence of an association between primary care prescribed antibiotics and resistance lasting for up to 3 months post-prescribing (pooled OR: 1.65, 1.36-2.0). CONCLUSIONS: Resistance to many primary care prescribed antibiotics is common among faecal E. coli carried by asymptomatic children, with higher resistance rates in non-OECD countries. Despite tetracycline being contra-indicated in children, tetracycline resistance rates were high suggesting children could be important recipients and transmitters of resistant bacteria, or that use of other antibiotics is leading to tetracycline resistance via inter-bacteria resistance transmission.

Empiric antibiotic treatment for urinary tract infection in preschool children: susceptibilities of urine sample isolates.

BACKGROUND: Antibiotic treatment recommendations based on susceptibility data from routinely submitted urine samples may be biased because of variation in sampling, laboratory procedures and inclusion of repeat samples, leading to uncertainty about empirical treatment. OBJECTIVE: To describe and compare susceptibilities of Escherichia coli cultured from routinely submitted samples, with E. coli causing urinary tract infection (UTI) from a cohort of systematically sampled, acutely unwell children. METHODS: Susceptibilities of 1458 E. coli isolates submitted during the course of routine primary care for children <5 years (routine care samples), compared to susceptibilities of 79 E. coli isolates causing UTI from 5107 children <5 years presenting to primary care with an acute illness [systematic sampling: the Diagnosis of Urinary Tract infection in Young children (DUTY) cohort]. RESULTS: The percentage of E. coli sensitive to antibiotics cultured from routinely submitted samples were as follows: amoxicillin 45.1% (95% confidence interval: 42.5-47.7%); co-amoxiclav using the lower systemic break point (BP) 86.6% (84.7-88.3%); cephalexin 95.1% (93.9-96.1%); trimethoprim 74.0% (71.7-76.2%) and nitrofurantoin 98.2% (97.4-98.8%). The percentage of E. coli sensitive to antibiotics cultured from systematically sampled DUTY urines considered to be positive for UTI were as follows: amoxicillin 50.6% (39.8-61.4%); co-amoxiclav using the systemic BP 83.5% (73.9-90.1%); co-amoxiclav using the urinary BP 94.9% (87.7-98.4%); cephalexin 98.7% (93.2-99.8%); trimethoprim 70.9% (60.1-80.0%); nitrofurantoin 100% (95.3-100.0%) and ciprofloxacin 96.2% (89.4-98.7%). CONCLUSION: Escherichia coli susceptibilities from routine and systematically obtained samples were similar. Most UTIs in preschool children remain susceptible to nitrofurantoin, co-amoxiclav and cephalexin.

A demonstration of the susceptibility of clinical isolates obtained from cystic fibrosis patients to manuka honey.

Pseudomonas and Burkholderia pose a significant health threat to people with chronic respiratory conditions; the resistance inherent in these bacteria indicates that new antimicrobial strategies are required. Susceptibility of 56 strains of P. aeruginosa and 55 strains of Burkholderia to manuka honey, tobramycin and colistin using microbroth dilution and E strip was determined. MICs of antibiotics with honey were determined to search for synergistic combinations against two representative strains of each genus. All strains exhibited susceptibility to honey ≤10 % (w/v); mean susceptibility of Burkholderia (4.6 % w/v) was lower than P. aeruginosa (7.3 % w/v). Synergistic or additive combinations were found with all four strains tested. Combinations of manuka honey with antibiotics can be used to lower the MIC need to successfully inhibit both P. aeruginosa and B. cepacia. The use of honey as a combination agent may be possible for the management of P. aeruginosa and B. cepacia.