Household contacts were key factor for children's colonization with resistant Escherichia coli in community setting

Amoxicillin duration and dose for community-acquired pneumonia in children: the CAP-IT factorial non-inferiority RCT

BACKGROUND

Data are limited regarding the optimal dose and duration of amoxicillin treatment for community-acquired pneumonia in children.

OBJECTIVES

To determine the efficacy, safety and impact on antimicrobial resistance of shorter (3-day) and longer (7-day) treatment with amoxicillin at both a lower and a higher dose at hospital discharge in children with uncomplicated community-acquired pneumonia.

DESIGN

A multicentre randomised double-blind 2 × 2 factorial non-inferiority trial in secondary care in the UK and Ireland.

SETTING

Paediatric emergency departments, paediatric assessment/observation units and inpatient wards.

PARTICIPANTS

Children aged > 6 months, weighing 6-24 kg, with a clinical diagnosis of community-acquired pneumonia, in whom treatment with amoxicillin as the sole antibiotic was planned on discharge.

INTERVENTIONS

Oral amoxicillin syrup at a dose of 35-50 mg/kg/day compared with a dose of 70-90 mg/kg/day, and 3 compared with 7 days' duration. Children were randomised simultaneously to each of the two factorial arms in a 1 : 1 ratio.

MAIN OUTCOME MEASURES

The primary outcome was clinically indicated systemic antibacterial treatment prescribed for respiratory tract infection (including community-acquired pneumonia), other than trial medication, up to 28 days after randomisation. Secondary outcomes included severity and duration of parent/guardian-reported community-acquired pneumonia symptoms, drug-related adverse events (including thrush, skin rashes and diarrhoea), antimicrobial resistance and adherence to trial medication.

RESULTS

A total of 824 children were recruited from 29 hospitals. Ten participants received no trial medication and were excluded. Participants [median age 2.5 (interquartile range 1.6-2.7) years; 52% male] were randomised to either 3 (n = 413) or 7 days (n = 401) of trial medication at either lower (n = 410) or higher (n = 404) doses. There were 51 (12.5%) and 49 (12.5%) primary end points in the 3- and 7-day arms, respectively (difference 0.1%, 90% confidence interval -3.8% to 3.9%) and 51 (12.6%) and 49 (12.4%) primary end points in the low- and high-dose arms, respectively (difference 0.2%, 90% confidence interval -3.7% to 4.0%), both demonstrating non-inferiority. Resolution of cough was faster in the 7-day arm than in the 3-day arm for cough (10 days vs. 12 days) (p = 0.040), with no difference in time to resolution of other symptoms. The type and frequency of adverse events and rate of colonisation by penicillin-non-susceptible pneumococci were comparable between arms.

LIMITATIONS

End-of-treatment swabs were not taken, and 28-day swabs were collected in only 53% of children. We focused on phenotypic penicillin resistance testing in pneumococci in the nasopharynx, which does not describe the global impact on the microflora. Although 21% of children did not attend the final 28-day visit, we obtained data from general practitioners for the primary end point on all but 3% of children.

CONCLUSIONS

Antibiotic retreatment, adverse events and nasopharyngeal colonisation by penicillin-non-susceptible pneumococci were similar with the higher and lower amoxicillin doses and the 3- and 7-day treatments. Time to resolution of cough and sleep disturbance was slightly longer in children taking 3 days' amoxicillin, but time to resolution of all other symptoms was similar in both arms.

FUTURE WORK

Antimicrobial resistance genotypic studies are ongoing, including whole-genome sequencing and shotgun metagenomics, to fully characterise the effect of amoxicillin dose and duration on antimicrobial resistance. The analysis of a randomised substudy comparing parental electronic and paper diary entry is also ongoing.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN76888927, EudraCT 2016-000809-36 and CTA 00316/0246/001-0006.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 60. See the NIHR Journals Library website for further project information.

Market Chickens as a Source of Antibiotic-Resistant Escherichia coli in a Peri-Urban Community in Lima, Peru

The widespread and poorly regulated use of antibiotics in animal production in low- and middle-income countries (LMICs) is increasingly associated with the emergence and dissemination of antibiotic resistance genes (ARGs) in retail animal products. Here, we compared Escherichia coli from chickens and humans with varying levels of exposure to chicken meat in a low-income community in the southern outskirts of Lima, Peru. We hypothesize that current practices in local poultry production result in highly resistant commensal bacteria in chickens that can potentially colonize the human gut. E. coli was isolated from cloacal swabs of non-organic (n = 41) and organic chickens (n = 20), as well as from stools of market chicken vendors (n = 23), non-vendors (n = 48), and babies (n = 60). 315 E. coli isolates from humans (n = 150) and chickens (n = 165) were identified, with chickens showing higher rates of multidrug-resistant and extended-spectrum beta-lactamase phenotypes. Non-organic chicken isolates were more resistant to most antibiotics tested than human isolates, while organic chicken isolates were susceptible to most antibiotics. Whole-genome sequencing of 118 isolates identified shared phylogroups between human and animal populations and 604 ARG hits across genomes. Resistance to florfenicol (an antibiotic commonly used as a growth promoter in poultry but not approved for human use) was higher in chicken vendors compared to other human groups. Isolates from non-organic chickens contained genes conferring resistance to clinically relevant antibiotics, including mcr-1 for colistin resistance, blaCTX-M ESBLs, and blaKPC-3 carbapenemase. Our findings suggest that E. coli strains from market chickens are a potential source of ARGs that can be transmitted to human commensals.

Anaesthetic-analgesic ear drops to reduce antibiotic consumption in children with acute otitis media: the CEDAR RCT

BACKGROUND

Acute otitis media (AOM) is a common reason for primary care consultations and antibiotic prescribing in children. Options for improved pain control may influence antibiotic prescribing and consumption.

OBJECTIVE

The Children's Ear Pain Study (CEDAR) investigated whether or not providing anaesthetic-analgesic ear drops reduced antibiotic consumption in children with AOM. Secondary objectives included pain control and cost-effectiveness.

DESIGN

A multicentre, randomised, parallel-group (two-group initially, then three-group) trial.

SETTING

Primary care practices in England and Wales.

PARTICIPANTS

1- to 10-year-old children presenting within 1 week of suspected AOM onset with ear pain during the preceding 24 hours and not requiring immediate antibiotics. Participating children were logged into the study and allocated using a remote randomisation service.

INTERVENTIONS

Two-group trial - unblinded comparison of anaesthetic-analgesic ear drops versus usual care. Three-group trial - blinded comparison of anaesthetic-analgesic ear drops versus placebo ear drops and unblinded comparison with usual care.

MAIN OUTCOME MEASURES

The primary outcome measure was parent-reported antibiotic use by the child over 8 days following enrolment. Secondary measures included ear pain at day 2 and NHS and societal costs over 8 days.

RESULTS

Owing to a delay in provision of the placebo drops, the recruitment period was shortened and most participants were randomly allocated to the two-group study (n = 74) rather than the three-group study (n = 32). Comparing active drops with usual care in the combined two-group and three-group studies, 1 out of 39 (3%) children allocated to the active drops group and 11 out of 38 (29%) children allocated to the usual-care group consumed antibiotics in the 8 days following enrolment [unadjusted odds ratio 0.09, 95% confidence interval (CI) 0.02 to 0.55; p = 0.009; adjusted for delayed prescribing odds ratio 0.15, 95% CI 0.03 to 0.87; p = 0.035]. A total of 43% (3/7) of patients in the placebo drops group consumed antibiotics by day 8, compared with 0% (0/10) of the three-group study active drops groups (p = 0.051). The economic analysis of NHS costs (£12.66 for active drops and £11.36 for usual care) leads to an estimated cost of £5.19 per antibiotic prescription avoided, but with a high degree of uncertainty. A reduction in ear pain at day 2 in the placebo group (n = 7) compared with the active drops group (n = 10) (adjusted difference in means 0.67, 95% CI -1.44 to 2.79; p = 0.51) is consistent with chance. No adverse events were reported in children receiving active drops.

LIMITATIONS

Estimated treatment effects are imprecise because the sample size target was not met. It is not clear if delayed prescriptions of an antibiotic were written prior to randomisation. Few children received placebo drops, which hindered the investigation of ear pain.

CONCLUSIONS

This study suggests that reduced antibiotic use can be achieved in children with AOM by combining a no or delayed antibiotic prescribing strategy with anaesthetic-analgesic ear drops. Whether or not the active drops relieved ear pain was not established.

FUTURE WORK

The observed reduction in antibiotic consumption following the prescription of ear drops requires replication in a larger study. Future work should establish if the effect of ear drops is due to pain relief.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN09599764.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 34. See the NIHR Journals Library website for further project information. Alastair D Hay was funded by a NIHR Research Professorship (funding identifier NIHR-RP-02-12-012).

Fecal Contamination of Drinking Water Was Associated with Diarrheal Pathogen Carriage among Children Younger than 5 Years in Three Peruvian Rural Communities

Drinking water contamination is a frequent problem in developing countries and could be associated with bacterial pathogen carriage in feces. We evaluated the association between the risk of drinking water and bacterial carrier status in children younger than 5 years in a cross-sectional study conducted in 199 households from three Peruvian rural communities. Fecal samples from children were screened for pathogenic Aeromonas, Campylobacter, and Vibrio species, as well as for Enterobacteriaceae, including pathogenic Escherichia coli. The drinking water risk was determined using E. coli as an indicator of contamination. Nineteen (9.5%) children were colonized with pathogens and classified as carriers, all without diarrhea symptoms. Of 199 drinking water samples, 38 (19.1%) were classified as very high risk because of high fecal contamination (> 100 E. coli/100 mL). Shared-use water sources, daily washing of containers, and washing using only water were associated with higher prevalence of bacterial carriage, whereas there was no association between households reporting boiling and chlorination of water and carrier status. The prevalence of carriage in children exposed to very high-risk water was 2.82 (95% CI: 1.21-6.59) times the prevalence of those who consumed less contaminated water, adjusted by the water source and daily washing. Our results suggest that household drinking water plays an important role in the generation of carriers with diarrheal pathogens. Our findings also highlight the importance of interventions to ensure the safety of drinking water. Further studies are needed to validate the observed association and determine its significance with respect to diarrhea in the community.

Efficacy, safety and impact on antimicrobial resistance of duration and dose of amoxicillin treatment for young children with Community-Acquired Pneumonia: a protocol for a randomIsed controlled Trial (CAP-IT)

INTRODUCTION

Community-acquired pneumonia (CAP) is a common indication for antibiotic treatment in young children. Data are limited regarding the ideal dose and duration of amoxicillin, leading to practice variation which may impact on treatment failure and antimicrobial resistance (AMR). Community-Acquired Pneumonia: a randomIsed controlled Trial (CAP-IT) aims to determine the optimal amoxicillin treatment strategies for CAP in young children in relation to efficacy and AMR.

METHODS AND ANALYSIS

The CAP-IT trial is a multicentre, randomised, double-blind, placebo-controlled 2×2 factorial non-inferiority trial of amoxicillin dose and duration. Children are enrolled in paediatric emergency and inpatient environments, and randomised to receive amoxicillin 70-90 or 35-50 mg/kg/day for 3 or 7 days following hospital discharge. The primary outcome is systemic antibacterial treatment for respiratory tract infection (including CAP) other than trial medication up to 4 weeks after randomisation. Secondary outcomes include adverse events, severity and duration of parent-reported CAP symptoms, adherence and antibiotic resistance. The primary analysis will be by intention to treat. Assuming a 15% primary outcome event rate, 8% non-inferiority margin assessed against an upper one-sided 95% CI, 90% power and 15% loss to follow-up, 800 children will be enrolled to demonstrate non-inferiority for the primary outcome for each of duration and dose.

ETHICS AND DISSEMINATION

The CAP-IT trial and relevant materials were approved by the National Research Ethics Service (reference: 16/LO/0831; 30 June 2016). The CAP-IT trial results will be published in peer-reviewed journals, and in a report published by the National Institute for Health Research Health Technology Assessment programme. Oral and poster presentations will be given to national and international conferences, and participating families will be notified of the results if they so wish. Key messages will be constructed in partnership with families, and social media will be used in their dissemination.

TRIAL REGISTRATION NUMBER

ISRCTN76888927, EudraCT2016-000809-36.

Excess body weight and age associated with the carriage of fluoroquinolone and third-generation cephalosporin resistance genes in commensal Escherichia coli from a cohort of urban Vietnamese children

PURPOSE

Antimicrobial-resistant bacterial infections in low- and middle-income countries (LMICs) are a well-established global health issue. We aimed to assess the prevalence of and epidemiological factors associated with the carriage of ciprofloxacin- and ceftriaxone-resistant Escherichia coli and associated resistance genes in a cohort of 498 healthy children residing in urban Vietnam.

METHODOLOGY

We cultured rectal swabs onto MacConkey agar supplemented with resistant concentrations of ciprofloxacin and ceftriaxone. Additionally, we screened meta-E. coli populations by conventional PCR to detect plasmid-mediated quinolone resistance (PMQR)- and extended-spectrum β-lactamase (ESBL)-encoding genes. We measured the associations between phenotypic/genotypic resistance and demographic characteristics using logistic regression.Results/Key findings. Ciprofloxacin- and ceftriaxone-resistant E. coli were cultured from the faecal samples of 67.7 % (337/498) and 80.3 % (400/498) of children, respectively. The prevalence of any associated resistance marker in the individual samples was 86.7 % (432/498) for PMQR genes and 90.6 % (451/498) for β-lactamase genes. Overweight children were significantly more likely to carry qnr genes than children with lower weight-for-height z-scores [odds ratios (OR): 1.24; 95 % confidence interval (CI): 10.5-1.48 for each unit increase in weight for height; P=0.01]. Additionally, younger children were significantly more likely to carry ESBL CTX-M genes than older children (OR: 0.97, 95 % CI: 0.94-0.99 for each additional year, P=0.01).

CONCLUSION

The carriage of genotypic and phenotypic antimicrobial resistance is highly prevalent among E. coli in healthy children in the community in Vietnam. Future investigations on the carriage of antimicrobial resistant organisms in LMICs should focus on the progression of carriage from birth and structure of the microbiome in obesity.

Fecal carriage of multidrug-resistant Escherichia coli by community children in southern Taiwan

BACKGROUND

The emergence of multidrug-resistant (MDR) Escherichia coli (E. coli), particularly E. coli sequence type ST131, is becoming a global concern. Commensal bacteria, an important reservoir of antibiotic resistance genes, facilitate the spread of such genes to pathogenic bacterial strains. The objective of the study is to investigate the fecal carriage of MDR E. coli and ST131 E. coli in community children in Southern Taiwan.

METHODS

In this prospective study, stool samples from children aged 0-18 years were obtained within 3 days of hospitalization from October 2013 to September 2014. Children with a history of underlying diseases, antibiotic treatment, or hospitalization in the 3 months before specimen collection were excluded. E. coli colonies were selected and tested for antimicrobial susceptibility, and O25b-ST131, multilocus sequence typing, and blaCTX-M gene groups were detected.

RESULTS

Among 157 E. coli isolates, the rates of nonsusceptibility to ampicillin, amoxycillin + clavulanate, trimethoprim-sulfamethoxazole, and cefazolin were 70, 65.6, 47.1, and 32.5%, respectively. Twenty-nine (18.5%) isolates were nonsusceptible to ciprofloxacin. MDR E. coli accounted for 58 (37%) of all isolates. Thirteen (8.3%) isolates produced extended-spectrum β-lactamase (ESBL). Furthermore, 26 (16.6%) and 13 (8.3%) isolates were O25b and ST131 positive, respectively. Five (38.5%) of the 13 ESBL-producing E. coli belonged to blaCTX-M group 9, among which were CTXM-14 and 4 (80%) were O25b-ST131 positive. Compared with the non-ESBL and ciprofloxacin-susceptible groups, the ESBL and ciprofloxacin-nonsusceptible groups showed significantly higher rates of O25b-ST131 positivity.

CONCLUSIONS

The prevalence of the fecal carriage of nonsusceptible E. coli in children was high; among these E. coli, 37% were MDR, 18.5% were nonsusceptible to ciprofloxacin, and 8.3% produced ESBL. O25b-ST131 was the most common ESBL-producing E. coli clonal group present in the feces of children, and the ESBL and ciprofloxacin-nonsusceptible groups showed significantly higher rates of O25b-ST131 positivity.

Effect of outpatient antibiotics for urinary tract infections on antimicrobial resistance among commensal Enterobacteriaceae: a multinational prospective cohort study

OBJECTIVES

We quantified the impact of antibiotics prescribed in primary care for urinary tract infections (UTIs) on intestinal colonization by ciprofloxacin-resistant (CIP-RE) and extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), while accounting for household clustering.

METHODS

Prospective cohort study from January 2011 to August 2013 at primary care sites in Belgium, Poland and Switzerland. We recruited outpatients requiring antibiotics for suspected UTIs or asymptomatic bacteriuria (exposed patients), outpatients not requiring antibiotics (non-exposed patients), and one to three household contacts for each patient. Faecal samples were tested for CIP-RE, ESBL-PE, nitrofurantoin-resistant Enterobacteriaceae (NIT-RE) and any Enterobacteriaceae at baseline (S1), end of antibiotics (S2) and 28 days after S2 (S3).

RESULTS

We included 300 households (205 exposed, 95 non-exposed) with 716 participants. Most exposed patients received nitrofurans (86; 42%) or fluoroquinolones (76; 37%). CIP-RE were identified in 16% (328/2033) of samples from 202 (28%) participants. Fluoroquinolone treatment caused transient suppression of Enterobacteriaceae (S2) and subsequent two-fold increase in CIP-RE prevalence at S3 (adjusted prevalence ratio (aPR) 2.0, 95% CI 1.2-3.4), with corresponding number-needed-to-harm of 12. Nitrofurans had no impact on CIP-RE (aPR 1.0, 95% CI 0.5-1.8) or NIT-RE. ESBL-PE were identified in 5% (107/2058) of samples from 71 (10%) participants, with colonization not associated with antibiotic exposure. Household exposure to CIP-RE or ESBL-PE was associated with increased individual risk of colonization: aPR 1.8 (95% CI 1.3-2.5) and 3.4 (95% CI 1.3-9.0), respectively.

CONCLUSIONS

These findings support avoidance of fluoroquinolones for first-line UTI therapy in primary care, and suggest potential for interventions that interrupt household circulation of resistant Enterobacteriaceae.

Risk Factors For and Outcomes of Multidrug-Resistant Escherichia coli Infections in Children

Introduction

The recent increase in multidrug-resistant (MDR) Escherichia coli infections is not well described in children. We determined the risk factors and outcomes of extraintestinal E. coli infections in children in our region.

Methods

We conducted a retrospective cohort study of children ≤18 years in Olmsted County, MN, USA, between January 1, 2012 and December 31, 2012. MDR isolates were defined as resistant to ≥3 antibiotic classes.

Results

A total of 368 children each contributed 1 isolate. Isolates were predominantly community-associated (82%) and from urine (90%), and outpatients (86%); 46 (13%) isolates were MDR. In multivariable analysis, genitourinary (GU) tract anomaly (OR 2.42, 95% CI 1.03–5.68), invasive devices (OR 3.48, 95% CI 1.37–8.83) and antibiotic use at presentation (OR 2.62, 95% CI 1.06–6.47) were associated with MDR E. coli. Children with MDR infections were more likely to have a complex infection (35% vs. 17%, P = 0.026), less likely to receive effective empiric antibiotics (47% vs. 74%, P < 0.001), had longer time to receipt of effective antibiotics (median 19.2 vs. 0.6 h, P < 0.001), and longer hospitalization (median 10 vs. 4 days, P = 0.029) than children with non-MDR infections.

Conclusion

Pediatric MDR E. coli infection was associated with GU tract anomaly, invasive devices, antibiotic use, delays in effective therapy and longer hospitalization.

Longitudinal Comparison of Antibiotic Resistance in Diarrheagenic and Non-pathogenic Escherichia coli from Young Tanzanian Children

Enteroaggregative, enteropathogenic, and enterotoxigenic Escherichia coli contribute significantly to the burden of diarrheal infections particularly in developing countries. Antibiotic resistance is increasingly common among bacterial pathogens including pathogenic E. coli. We assessed the relationship between pathogenic E. coli carriage and resistance to six antibiotics in E. coli isolated from young children in rural Tanzania. We surveyed temporal stability in antibiotic resistance in 2492 E. coli isolated from fecal samples obtained from young children in rural Tanzania collected over a 6 months period. Approximately half of the 377 children sampled were exposed to an azithromycin mass treatment program for trachoma control and half resided in control villages. Children were sampled at baseline, 1-, 3-, and 6 months following azithromycin treatment. We compared resistance to six antibiotics in pathogenic and non-pathogenic strains at the population level, within fecal specimens, and within individuals over time using chi-square tests, paired odds ratios, and logistic regression, respectively. Resistance to ampicillin and trimethoprim/sulfamethoxazole was highly prevalent (>65%). Resistance to 5 of 6 antibiotics tested and multi-drug resistance occurred more frequently in pathogenic isolates (p ≤ 0.001) within fecal specimens and overall. Azithromycin mass treatment exposure was significantly associated with increased odds of carriage of isolates resistant to erythromycin (OR 3.64, p < 0.001) and trimethoprim/sulfamethoxazole (OR 1.60, p < 0.05). Pathogenic isolates were approximately twice as likely to be resistant to erythromycin, ampicillin, or trimethoprim/sulfamethoxazole compared to non-pathogenic isolates from the same fecal specimen. The potential linkage between resistance and virulence in E. coli suggests hygiene and sanitation interventions aimed at reducing disease burden could play a role in controlling transmission of antibiotic resistance.

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.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1697-6) contains supplementary material, which is available to authorized users.

Prevalence of antimicrobial resistance in enteric Escherichia coli from domestic pets and assessment of associated risk markers using a generalized linear mixed model

Antimicrobial resistance (AMR) is a growing global public health problem, which is caused by the use of antimicrobials in both human and animal medical practice. The objectives of the present cross-sectional study were as follows: (1) to determine the prevalence of resistance in Escherichia coli isolated from the feces of pets from the Porto region of Portugal against 19 antimicrobial agents and (2) to assess the individual, clinical and environmental characteristics associated with each pet as risk markers for the AMR of the E. coli isolates. From September 2009 to May 2012, rectal swabs were collected from pets selected using a systematic random procedure from the ordinary population of animals attending the Veterinary Hospital of Porto University. A total of 78 dogs and 22 cats were sampled with the objective of isolating E. coli. The animals' owners, who allowed the collection of fecal samples from their pets, answered a questionnaire to collect information about the markers that could influence the AMR of the enteric E. coli. Chromocult tryptone bile X-glucuronide agar was used for E. coli isolation, and the disk diffusion method was used to determine the antimicrobial susceptibility. The data were analyzed using a multilevel, univariable and multivariable generalized linear mixed model (GLMM). Several (49.7%) of the 396 isolates obtained in this study were multidrug-resistant. The E. coli isolates exhibited resistance to the antimicrobial agent's ampicillin (51.3%), cephalothin (46.7%), tetracycline (45.2%) and streptomycin (43.4%). Previous quinolone treatment was the main risk marker for the presence of AMR for 12 (ampicillin, cephalothin, ceftazidime, cefotaxime, nalidixic acid, ciprofloxacin, gentamicin, tetracycline, streptomycin, chloramphenicol, trimethoprim-sulfamethoxazole and aztreonam) of the 15 antimicrobials assessed. Coprophagic habits were also positively associated with an increased risk of AMR for six drugs, ampicillin, amoxicillin-clavulanic acid, cephamycin, ciprofloxacin, streptomycin, and trimethoprim-sulfamethoxazole. In summary, pets with a record of one or more previous quinolone treatments and exhibiting coprophagic habits were at an increased risk of harboring multidrug-resistant E. coli strains in their feces compared to pets without these characteristics. AMR is a serious global problem, and assessing the risk markers for the presence of drug-resistant bacteria in pets, a very close source of resistance determinants to humans, is essential for the implementation of safe handling procedures for companion animals and for the prudent selection of antimicrobial compounds in veterinary practice.

A new clone sweeps clean: the enigmatic emergence of Escherichia coli sequence type 131

Escherichia coli sequence type 131 (ST131) is an extensively antimicrobial-resistant E. coli clonal group that has spread explosively throughout the world. Recent molecular epidemiologic and whole-genome phylogenetic studies have elucidated the fine clonal structure of ST131, which comprises multiple ST131 subclones with distinctive resistance profiles, including the (nested) H30, H30-R, and H30-Rx subclones. The most prevalent ST131 subclone, H30, arose from a single common fluoroquinolone (FQ)-susceptible ancestor containing allele 30 of fimH (type 1 fimbrial adhesin gene). An early H30 subclone member acquired FQ resistance and launched the rapid expansion of the resulting FQ-resistant subclone, H30-R. Subsequently, a member of H30-R acquired the CTX-M-15 extended-spectrum beta-lactamase and launched the rapid expansion of the CTX-M-15-containing subclone within H30-R, H30-Rx. Clonal expansion clearly is now the dominant mechanism for the rising prevalence of both FQ resistance and CTX-M-15 production in ST131 and in E. coli generally. Reasons for the successful dissemination and expansion of the key ST131 subclones remain undefined but may include increased transmissibility, greater ability to colonize and/or persist in the intestine or urinary tract, enhanced virulence, and more-extensive antimicrobial resistance compared to other E. coli. Here we discuss the epidemiology and molecular phylogeny of ST131 and its key subclones, possible mechanisms for their ecological success, implications of their widespread dissemination, and future research needs.

A multinational study of colonization with extended spectrum β-lactamase-producing Enterobacteriaceae in healthcare personnel and family members of carrier patients hospitalized in rehabilitation centres

The study aims were: (i) to define the prevalence of and risk factors for colonization by extended spectrum β-lactamase (ESBL) -producing Enterobacteriaceae (EPE) among healthcare workers (HCWs) and family members (FMs) of EPE-colonized patients in rehabilitation units and (ii) to compare EPE isolates from these three groups. The study included 286 FMs of 194 EPE-carrying patients identified in five rehabilitation units located in Israel, Italy, France and Spain. The EPE were detected in rectal swabs from 26 (9%) of 286 FMs screened. In multivariate analyses, older age of FM, greater mean number of hours spent with the patient, being a daughter or a female spouse of a patient, and chronic lung disease of the patient were significantly associated with carriage in the FM. Escherichia coli was the most common organism (76%), followed by Klebsiella pneumoniae (19%). Isolates were typed by pulsed field gel electrophoresis and multilocus sequence typing, and ESBLs were identified by PCR sequencing. A comparison of paired species isolates from FMs and their respective patient showed that 17 of 23 strains were indistinguishable. EPE were detected in 35 (3.5%, E. coli = 34) of the 1001 HCWs screened. Feeding patients was associated with EPE carriage by HCWs. Only 7 of 23 E. coli subclones cultured from HCWs were also represented among 376 patient-derived ESBL-producing E. coli isolates from the same rehabilitation units. In Spain, a higher proportion of HCWs and FMs were ESBL carriers than elsewhere (p <0.05). In conclusion, the molecular and epidemiological data suggest that FMs are at higher risk of EPE acquisition from their relative patients than HCWs.

Socioeconomic characteristics of residential areas and risk of death: is variation in spatial units for analysis a source of heterogeneity in observed associations?

OBJECTIVES

Evidence on the association between the adverse socioeconomic characteristics of residential area and mortality is mixed. We examined whether the choice of spatial unit is critical in detecting this association.

DESIGN

Register-linkage study.

SETTING

Data were from the Finnish Public Sector study's register cohort.

PARTICIPANTS

The place of residence of 146 600 cohort participants was linked to map grids and administrative areas, and they were followed up for mortality from 2000 to 2011. Residential area socioeconomic deprivation and household crowding were aggregated into five alternative areas based on map grids (250×250 m, 1×1 km and 10×10 km squares), and administrative borders (zip-code area and town).

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause mortality.

RESULTS

For the 250×250 m area, mortality risk increased with increasing socioeconomic deprivation (HR for top vs bottom quintile 1.36, 95% CI 1.21 to 1.52). This association was either weaker or missing when broader spatial units were used. For household crowding, excess mortality was observed across all spatial units, the HRs ranging from 1.14 (95% CI 1.03 to 1.25) for zip code, and 1.21 (95% CI 1.11 to 1.31) for 250×250 m areas to 1.28 (95% CI 1.10 to 1.50) for 10×10 km areas.

CONCLUSIONS

Variation in spatial units for analysis is a source of heterogeneity in observed associations between residential area characteristics and risk of death.

National multidrug-resistant bacteria (MDRB) surveillance in France through the RAISIN network: a 9 year experience

BACKGROUND

In the mid-1990s, the prevalence rate of multidrug-resistant bacteria (MDRB) in French hospitals was high and control of MDRB spread then became a major priority in the national infection control programme (ICP).

METHODS

To evaluate the impact of the ICP, a national coordination of MDRB surveillance was set up in 2002. Data were collected 3 months a year in healthcare facilities (HCFs) on a voluntary basis. All clinical specimens of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBLE) were prospectively included. Incidences per 1000 patient days (PDs) were calculated and trends in incidence from 2003 to 2010 were assessed.

RESULTS

Participation in the surveillance increased from 478 HCFs in 2002 to 933 in 2010. In 2010, MRSA incidence was 0.40/1000 PDs: 1.14 in intensive care units (ICUs), 0.48 in acute care facilities (ACFs) and 0.27 in rehabilitation and long-term care facilities (RLTCFs). ESBLE incidence was 0.39/1000 PDs: 1.63 in ICUs, 0.46 in ACFs and 0.23 in RLTCFs. MRSA incidence significantly decreased from 0.72/1000 PDs in 2003 to 0.41/1000 PDs in 2010 (P<10(-3)); in contrast, ESBLE incidence significantly increased from 0.17/1000 PDs to 0.48/1000 PDs (P<10(-3)). The most prevalent ESBLE were Enterobacter aerogenes (34%) and Escherichia coli (25%) in 2003 and E. coli (60%) and Klebsiella pneumoniae (18%) in 2010.

CONCLUSION

These results demonstrate the positive impact of the national ICP on MRSA rates. In contrast, ESBLE incidence, especially ESBL-producing E. coli, is increasing dramatically and represents a serious threat for hospitals and for the community that deserves specific control actions.

High prevalence of antibiotic resistance in commensal Escherichia coli among children in rural Vietnam

BACKGROUND

Commensal bacteria represent an important reservoir of antibiotic resistance genes. Few community-based studies of antibiotic resistance in commensal bacteria have been conducted in Southeast Asia. We investigated the prevalence of resistance in commensal Escherichia coli in preschool children in rural Vietnam, and factors associated with carriage of resistant bacteria.

METHODS

We tested isolates of E. coli from faecal samples of 818 children aged 6-60 months living in FilaBavi, a demographic surveillance site near Hanoi. Daily antibiotic use data was collected for participating children for three weeks prior to sampling and analysed with socioeconomic and demographic characteristics extracted from FilaBavi's re-census survey 2007. Descriptive statistics were generated, and a logistic regression model was used to identify contributions of the examined factors.

RESULTS

High prevalences of resistance were found to tetracycline (74%), co-trimoxazole (68%), ampicillin (65%), chloramphenicol (40%), and nalidixic acid (27%). Two isolates were resistant to ciprofloxacin. Sixty percent of isolates were resistant to three or more antibiotics. Recent sulphonamide use was associated with co-trimoxazole resistance [OR 3.2, 95% CI 1.8-5.7], and beta-lactam use with ampicillin resistance [OR 1.8, 95% CI 1.3-2.4]. Isolates from children aged 6-23 months were more likely to be resistant to ampicillin [OR 1.8, 95% CI 1.3-2.4] and co-trimoxazole [OR 1.5, 95% CI 1.1-2.0]. Associations were identified between geographical areas and tetracycline and ampicillin resistance.

CONCLUSIONS

We present high prevalence of carriage of commensal E. coli resistant to commonly used antibiotics. The identified associations with recent antibiotic use, age, and geographical location might contribute to our understanding of carriage of antibiotic resistant commensal bacteria.

The role of drinking water in the transmission of antimicrobial-resistantE. coli

To determine whether drinking water contaminated with antimicrobial-resistantE. coliis associated with the carriage of resistantE. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005–2006 were asked to participate in a cross-sectional study. Household members aged ⩾12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain ofE. coliand 28% carried a multidrug-resistant strain. The risk of carriage of resistantE. coliwas 1·26 times higher for users of water contaminated with resistantE. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance inE. coli.

Antimicrobial resistance in fecal Escherichia coli isolates from healthy urban children of two age groups in relation to their antibiotic therapy

The study was performed in the Czech Republic during 2007 to 2009. Of Escherichia coli isolates from 275 children aged 6 weeks, 36% (n = 177) were resistant to 1 to 7 antibiotics. Of isolates from 253 children aged 6 to 17 years, 24% (n = 205) were resistant to 1 to 5 antibiotics. There was no significant difference in the prevalences of antibiotic-resistant E. coli isolates between these groups of children, even though the consumptions of antibiotics were quite different.

Impact of outpatient antibiotic use on carriage of ampicillin-resistant Escherichia coli

Studies about the relationship between antibiotic consumption and carriage of antibiotic-resistant Escherichia coli in individual patients have yielded conflicting results. The goal of this study was to identify individual- and household-level factors associated with carriage of ampicillin (AMP)-resistant E. coli during consumption of a course of oral antibiotics. We enrolled outpatients and their families in a prospective household study of AMP-resistant or AMP-susceptible E. coli carriage. Two kinds of index patients were identified. Group 1 consisted of outpatients who were being initiated on a new antibiotic course at the time of a clinic visit, and group 2 consisted of outpatients not starting antibiotics. Each participant was asked to submit three stool swab samples (at baseline, week 1, and week 4) and to complete a questionnaire. Antimicrobial susceptibility testing was performed on each phenotypically distinct E. coli colony. The study included 149 group 1 households (total, 570 participants) and 38 group 2 households (total, 131 participants). AMP-resistant E. coli was recovered from 29% of stool samples. Observed associations with antibiotic exposure varied by drug class. Penicillins, which were the most frequently prescribed drug class, were associated with a modest increase in AMP-resistant E. coli carriage and a modest decrease in AMP-susceptible E. coli carriage. Neither change by itself was statistically significant. Macrolides were associated with reduced carriage of both AMP-resistant E. coli and AMP-susceptible E. coli (P < 0.05). Both AMP-resistant and AMP-susceptible E. coli demonstrated household clustering (P < 0.001). In summary, the overall effect of antibiotics on individual risk of carriage of AMP-resistant E. coli was small. However, even a modest alteration of the competitive balance between AMP-resistant and AMP-susceptible E. coli may promote population spread of resistant E. coli. Examining changes in both resistant and susceptible organisms in antibiotic-treated individuals and their close contacts improves understanding of antibiotic selection pressure.

Risk factors for antibiotic-resistant Escherichia coli carriage in young children in Peru: community-based cross-sectional prevalence study

Few studies have examined the influence of individual-, household-, and community-scale risk factors on carriage of resistant commensal bacteria. We determined children's medical, agricultural, and environmental exposures by household, pharmacy, and health facility surveys and Escherichia coli cultures of children, mothers' hands, household animals, and market chickens in Peru. Among 522 children with a positive stool culture, by log-binomial regression, using "any antibiotic" and 1-14 (versus 0) sulfa doses in the past 3 months increased children's risk, respectively, for ampicillin- and sulfamethoxazole-resistant E. coli carriage (P = 0.01-0.02). Each household member taking "any antibiotic" increased children's risk for sulfamethoxazole- and multidrug-resistant E. coli carriage (P < 0.0001). Residence in a zone where a larger proportion of households served home-raised chicken (as contrasted with intensively antibiotic-raised market chicken) protected against carrying E. coli resistant to all drugs (P = 0.0004-0.04). Environmental contamination with drug-resistant bacteria appeared to significantly contribute to children's carriage of antibiotic-resistant E. coli.

Genetic elements associated with antimicrobial resistance in enteropathogenic Escherichia coli (EPEC) from Brazil

Background

We recently observed an association of resistance with a certain enteropathogenic Escherichia coli (EPEC) serotypes and identified a conjugative plasmid, similar to plasmid pED208, that was conserved among archival O111:H2/NM and O119:H2 strains of diverse geographical origin. In this study, we sought to determine the prevalence and distribution of this plasmid among a collection of EPEC isolates from Brazil, as well as to study the susceptibilities of these isolates to antimicrobial agents.

Results

Resistance was more commonly seen in typical EPEC than atypical strains. The most prevalent resistances were to ampicillin, tetracycline, streptomycin and the sulfonamides. Markers for the EPEC conjugative multiresistance plasmid, were detected in 21 (30%) of typical but only 4 (5%) of atypical strains (p = 0.001, Chi-squared test). This plasmid, previously reported from only O111 and O119 strains was found in O55 and O127 strains and was associated with the presence of class 1 integrons.

Conclusion

Our data suggest a limited but expanding host range for the EPEC resistance plasmid.

Risk factors for antibiotic-resistant E. coli in children in a rural area

We surveyed antimicrobial susceptibility in faecal Escherichia coli in primary schoolchildren in rural Tamil Nadu, India. Resistance profiles of E. coli samples from local water sources were also obtained. We investigated sociodemographic characteristics as risk factors for resistance and local paediatric prescription patterns. In 119 stool samples, carriage of resistance to 1 antibiotic was 63% and multiple drug resistance was 32%. Resistance outcomes were associated with school of attendance, having a sibling attend the same school, younger age, and less crowded households. Eight of nine water samples were resistant to > or =1 antibiotic. Recent history of medication use was not associated with resistance carriage. Resistance patterns may have been influenced by local paediatric prescription patterns and veterinary antibiotic use. Frequent, low-cost surveillance of commensal resistance can guide development of locally appropriate treatment guidelines. School-based hygiene programmes should be considered as means of limiting the spread of antibiotic resistance.

An ecological analysis of sociodemographic factors associated with the incidence of salmonellosis, shigellosis, and E. coli O157:H7 infections in US counties

Identifying county-level sociodemographic and economic factors associated with the incidence of enteric disease may provide new insights concerning the dynamics of community transmission of these diseases as well as opportunities for prevention. We used data from the National Notifiable Diseases Surveillance System, the U.S. Census Bureau, and the Health Resources and Services Administration to conduct an ecological analysis of 26 sociodemographic and economic factors associated with the incidence of salmonellosis, shigellosis, and E. coli O157:H7 infections in US counties for the period 1993 to 2002. Our study indicates that race, ethnicity, place of residence, age, educational attainment, and poverty may affect the risk of acquiring one of these enteric bacterial diseases. The lack of specificity of information regarding salmonellae and shigellae serotypes may have led to less specific associations between community-level determinants and reported incidence of those diseases. Future ecological analyses should use serotype-specific data on incidence, which may be available from laboratory-based surveillance systems.

High rate of intestinal colonization with extended-spectrum-beta-lactamase-producing organisms in household contacts of infected community patients

Fecal carriage of extended-spectrum-beta-lactamase (ESBL)-producing organisms was detected in 70% of index cases of patients (n = 40) with community-acquired infections due to ESBL producers and reached 16.7% in household contacts (n = 54). A total of 66% of ESBL-producing organisms from index cases were indistinguishable from isolates from household contacts by pulsed-field gel electrophoresis. Patients with community infections and members of their households represent a reservoir for ESBL producers, increasing dispersal of resistance in healthy people.