Prevalence of day-care centre children (France) with faecal CTX-M-producing Escherichia coli comprising O25b:H4 and O16:H5 ST131 strains

Characterization of young infants with fecal carriage of multidrug-resistant Escherichia coli in Southern Taiwan

BACKGROUND

The accelerating prevalence of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistance (MDR) Escherichia coli(E. coli) become a public health challenge worldwide. This study aimed to discuss the prevalence of drug-resistant E. coli colonization and analyze its risk factors and clinical characteristics among young infants in Southern Taiwan.

METHODS

Stool samples were collected from young infants, aged less than three months, within three days of their hospitalization from September to December 2019 in a tertiary hospital. A questionnaire was designed for parents to complete. E. coli colonies were selected and analyzed for antimicrobial susceptibility. PCR-based multilocus sequence typing was to detect the presence of sequence type ST131 and blaCTX-M genes.

RESULTS

Among 100 enrolled infants, 36% had fecal carriage of E. coli isolates, of which twenty nine (80.5%) were MDR, thirteen (36.1%) were ESBL-producing isolates and five (13.8%) and ten (27.7%) were ST131 and strains carrying CTX-M-14 gene, respectively. Compared to non-ST131 and non-CTX-M-14 gene carrier, isolates of ST131 and CTX-M-14 gene carrier showed a significantly higher resistance rate to cefixime, ceftriaxone, and gentamycin, with p value all <0.05.

CONCLUSION

The prevalence of ESBL-producing and MDR E. coli fecal carriage were both high in young infants. The most common sequence type is ST131, of which all are strains carrying CTX-M-14. Further surveillance and investigation to control for the high prevalence of antimicrobial-resistant E. coli fecal carriage among infants in Taiwan are warranted.

Cross-border differences in the prevalence and risk factors for carriage of antimicrobial resistance in children attending daycare centers: a point prevalence study in the Netherlands and Belgium

BACKGROUND

Day care centres (DCCs) are ideal settings for drug-resistant bacteria to emerge. Prevalence numbers of faecal carriage of antimicrobial resistant bacteria in these settings are rare. We aimed to determine the prevalence of faecal antimicrobial resistant bacteria carriage in children attending DCCs and to assess and identify infection risk factors within DCCs in The Netherlands and Belgium.

METHODS

A point-prevalence study was conducted in 28 Dutch (499 children) and 18 Belgian (448 children) DCCs. Stool samples were taken from the children's diapers and a questionnaire was filled in by their parents. Hygiene related to stool and toilet use, hygiene related to food, environmental contamination, hand hygiene and hygiene guidelines were assessed conform a standardized questionnaire by the infection prevention and control expert visiting the DCC. Multilevel logistical regression analyses were used to define which characteristics predicted the presence of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Enterobacterales (CipR-E).

RESULTS

The ESBL-E prevalence was 16% (n = 71) in Belgium and 6% (n = 30) in the Netherlands. The CipR-E prevalence was 17% (n = 78) in Belgium and 8% (n = 38) in the Netherlands. Antimicrobial use (RR: 0.30; 95% CI: 0.33-0.48) and hospital admissions (RR: 0.37; 95% CI: 0.25-0.54) were lower in the Netherlands. Children travelling to Asia were at higher risk of being an ESBL-E carrier. Children using antimicrobials were at higher risk of being a CipR-E carrier. Cleaning the changing mat after each use was found as a protective factor for CipR-E carriage.

CONCLUSIONS

We established a significant difference in ESBL-E and CipR-E carriage and antimicrobial use and hospital admissions between the Netherlands and Belgium among children attending DCCs. The differences between both countries should be further studied to improve the policy on anti-microbial use and hospital admissions in children.

Resistome and virulome of high-risk pandemic clones of multidrug-resistant extra-intestinal pathogenic Escherichia coli (ExPEC) isolated from tertiary healthcare settings in Uganda

Multi-drug resistant (MDR) globally disseminated extraintestinal pathogenic high-risk Escherichia coli (ExPEC) clones are threatening the gains in bacterial disease management. In this study, we evaluated the genomic structure including the resistome and virulome of the E. coli isolates from extraintestinal infections using whole genome sequencing (WGS). The results highlight that isolates were highly resistant (≥ 90.0%) to commonly used antibiotics (Ampicillin, Trimethoprim-Sulfamethoxazole, Nalidixic acid, and Piperacillin) and were less (<14%) resistant to last resort antibiotics; Imipenem (10.94%) and Meropenem (10.20%). A greater proportion of the E. coli isolates belonged to phylogroup B2 (30.52%) and phylogroup A (27.37%). The sequence types ST131 of phylogroup B2 (21.05%) and ST648 of phylogroup F (9.3%) were the dominant pandemic high-risk clones identified in addition to the ST1193, ST410, ST69, ST38, ST405, and ST10. Many of the isolates were MDR and most (64.58%) carried the blaCTX-M-15 gene for extended-spectrum β-lactamases. There was a high correlation between phylogroups and the occurrence of both antimicrobial resistance and virulence genes. The cephalosporin-resistance gene blaEC-5 was only found in phylogroup B2 while blaEC-8 and blaEC-19, were only found within phylogroup D and phylogroup F respectively. Aminoglycoside gene (aadA1) was only associated with phylogroups D and C. The isolates were armed with a broad range of virulence genes including adhesins, toxins, secreted proteases, iron uptake genes, and others. The yfcv, chuA, and kpsE genes preferentially occurred among isolates of phylogroup B2. The study underlines the predominance of MDR internationally disseminated high-risk ExPEC clones with a broad range of virulence genes known to be highly transmissible in healthcare and community settings.

Epidemiology and molecular typing of multidrug-resistant bacteria in day care centres in Flanders, Belgium

The global prevalence and spread of multidrug-resistant organisms (MDROs) represent an emerging public health threat. Day care centre (DCC) attendance is a risk factor for MDRO carriage in children and their environment. This study aimed to map the epidemiology of carriage and potential transmission of these organisms within 18 Flemish DDCs (Belgium). An MDRO prevalence survey was organised between November 2018 and February 2019 among children attending the centres. Selective chromogenic culture media were used for the detection of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), and vancomycin-resistant Enterococci (VRE) in faecal swabs obtained from diapers or jars (n = 448). All isolated MDROs were subjected to resistance gene sequencing. A total of 71 of 448 samples (15.8%) yielded isolates of ESBL-E with a predominance of Escherichia coli (92.2% of ESBL-E) and ESBL resistance gene blaCTX-M-15 (50.7% of ESBL coding genes in E. coli). ESBL-E prevalence varied between DCCs, ranging from 0 to 50%. Transmission, based on the clonal relatedness of ESBL-E strains, was observed. CPE was identified in only one child carrying an E. coli with an OXA-244 gene. VRE was absent from all samples. The observed prevalence of ESBL-E in Flemish DCCs is high compared with previous studies, and our findings re-emphasise the need for rigorous hygiene measures within such centres to control the further spread of MDROs in the community.

Evaluation of presence of clone ST131 and biofilm formation in ESBL producing and non-producing Escherichia coli strains

OBJECTIVE

Escherichia coli ST131 is a pandemic clone associated with multidrug resistance, starting with beta-lactamase production and fluoroquinolone resistance in the first place, leading to significant systemic infections. Clones that develop due to the frequency of antimicrobial resistance and the rate of spread in our country are important issues that need to be investigated. This study aims to investigate the incidence of ST131which is a "high-risk pandemic clone E. coli" in ESBL-producing and non-ESBL-producing strains, as well as their biofilm-forming abilities and antibiotic resistance rates.

MATERIALS AND METHODS

A total of 86 E. coli isolates were used in the study. Bacterial identifications were performed by conventional and automated methods. The double disc synergy method was used to demonstrate the presence of ESBL. Molecular studies in all E. coli strains were performed by real-time PCR method.

FINDINGS

86 strains were studied, of which 83.72% were urine, 6.98% were wound, 4.65% were blood, and 2.33% were tracheal aspirate and sputum. 79.07% of these strains were ESBL-positive. 58.1% of the strains were female, whereas 41.9% were male patients, and the average age was 46.2. Out of 86 strains, 38.72% were ST131 positive, the H30 subclone was detected in 27.27% of them, and the H30-Rx subclone was detected in all of the H30 subclone positive strains. The presence of the ESBL resistance gene was detected at the rate of TEM 41.86%, SHV 37.21%, CTX-M 36.04%, and OXA 4.65%. Most commonly SHV gene (54.54%) was seen in ST131 clone-positive samples. Finally, while it was found that 48.83% of the strains formed biofilm by any method, biofilm formation was detected in 69.7% of the samples that were positive for the ST131 clone.

RESULT

Our study can reveal the dramatic prevalence of the ESBL-producing E. coli strains along with the high-risk ST131 clone, the dominance of the H30Rx subclone of this risky clone, as well as the importance of the influence of resistance mechanisms along with resistance and biofilm.

The Genotypic and Phenotypic Characteristics Contributing to Flomoxef Sensitivity in Clinical Isolates of ESBL-Producing E. coli Strains from Urinary Tract Infections

We carried out a molecular biological analysis of extended-spectrum β-lactamase (ESBL)-producing E. coli strains and their sensitivity to flomoxef (FMOX). Sequence type (ST) analysis by multilocus sequence typing (MLST) and classification of ESBL genotypes by multiplex PCR were performed on ESBL-producing E. coli strains isolated from urine samples collected from patients treated at our institution between 2008 and 2018. These sequences were compared with results for antimicrobial drug susceptibility determined using a micro-liquid dilution method. We also analyzed cases treated with FMOX at our institution to examine its clinical efficacy. Of the 911 E. coli strains identified, 158 (17.3%) were ESBL-producing. Of these, 67.7% (107/158) were strain ST-131 in ST analysis. Nearly all (154/158; 97.5%) were CTX-M genotypes, with M-14 and M-27 predominating. The isolated strains were sensitive to FMOX in drug susceptibility tests. Among the patient samples, 33 cases received FMOX, and of these, 5 had ESBL-producing E. coli. Among these five cases, three received FMOX for surgical prophylaxis as urinary carriers of ESBL-producing E. coli, and postoperative infections were prevented in all three patients. The other two patients received FMOX treatment for urinary tract infections. FMOX treatment was successful for one, and the other was switched to carbapenem. Our results suggest that FMOX has efficacy for perioperative prophylactic administration in urologic surgery involving carriers of ESBL-producing bacteria and for therapeutic administration for urinary tract infections. Use of FMOX avoids over-reliance on carbapenems or β-lactamase inhibitors and thus is an effective antimicrobial countermeasure.

Portable Differential Detection of CTX-M ESBL Gene Variants, blaCTX-M-1 and blaCTX-M-15, from Escherichia coli Isolates and Animal Fecal Samples Using Loop-Primer Endonuclease Cleavage Loop-Mediated Isothermal Amplification

Cefotaximase-Munich (CTX-M) extended-spectrum beta-lactamase (ESBL) enzymes produced by Enterobacteriaceae confer resistance to clinically relevant third-generation cephalosporins. CTX-M group 1 variants, CTX-M-1 and CTX-M-15, are the leading ESBL-producing Enterobacteriaceae associated with animal and human infection, respectively, and are an increasing antimicrobial resistance (AMR) global health concern. The blaCTX-M-1 and blaCTX-M-15 genes encoding these variants have an approximate nucleotide sequence similarity of 98.7%, making effective differential diagnostic monitoring difficult. Loop-primer endonuclease cleavage loop-mediated isothermal amplification (LEC-LAMP) enables rapid real-time multiplex pathogen detection with single-base specificity and portable on-site testing. We have developed an internally controlled multiplex CTX-M-1/15 LEC-LAMP assay for the differential detection of blaCTX-M-1 and blaCTX-M-15. Assay analytical specificity was established using a panel of human, animal, and environmental Escherichia coli isolates positive for blaCTX-M-1 (n = 18), blaCTX-M-15 (n = 35), and other closely related blaCTX-Ms (n = 38) from Ireland, Germany, and Portugal, with analytical sensitivity determined using probit regression analysis. Animal fecal sample testing using the CTX-M-1/15 LEC-LAMP assay in combination with a rapid DNA extraction protocol was carried out on porcine fecal samples previously confirmed to be PCR-positive for E. coli blaCTX-M. Portable instrumentation was used to further analyze each fecal sample and demonstrate the on-site testing capabilities of the LEC-LAMP assay with the rapid DNA extraction protocol. The CTX-M-1/15 LEC-LAMP assay demonstrated complete analytical specificity for the differential detection of both variants with sensitive low-level detection of 8.5 and 9.8 copies per reaction for blaCTX-M-1 and blaCTX-M-15, respectively, and E. coli blaCTX-M-1 was identified in all blaCTX-M positive porcine fecal samples tested. IMPORTANCE CTX-M ESBL-producing E. coli is an increasing AMR public health issue with the transmission between animals and humans via zoonotic pathogens now a major area of interest. Accurate and timely identification of ESBL-expressing E. coli CTX-M variants is essential for disease monitoring, targeted antibiotic treatment and infection control. This study details the first report of portable diagnostics technology for the rapid differential detection of CTX-M AMR markers blaCTX-M-1 and blaCTX-M-15, facilitating improved identification and surveillance of these closely related variants. Further application of this portable internally controlled multiplex CTX-M-1/15 LEC-LAMP assay will provide new information on the transmission and prevalence of these CTX-M ESBL alleles. Furthermore, this transferable diagnostic technology can be applied to other new and emerging relevant AMR markers of interest providing more efficient and specific portable pathogen detection for improved epidemiological surveillance.

The genotypic and phenotypic characteristics contributing to high virulence and antibiotics resistance in Escherichia coli O25-B2-ST131 in comparison to non- O25-B2-ST131

BACKGROUND

Escherichia coli serogroup O25b-sequence type 131 (E. coli O25-B2-ST131) is considered as multidrug-resistant and hypervirulent organism. There is lack of data about involvement of this pathogen in the children's infection. In this study, the prevalence, and clonality, virulence capacity, and antibiotic resistance phenotype and genotype of E. coli O25-B2-ST131 compared with non-O25-B2-ST131 isolates were investigated in children with urinary tract infection in Tehran, Iran.

METHODS

The E. coli isolates from urine samples were identified using conventional microbiological methods. Characterization of E. coli O25-B2-ST131 clone, antibiotic susceptibility, biofilm formation, ESBLs phenotype and genotype, serum resistance, hemolysis, hydrophobicity, and formation of curli fimbriae were done using conventional microbiological and molecular methods. Clonality of the isolates was done by rep-PCR typing.

RESULTS

Among 120 E. coli isolates, the highest and lowest antibiotic resistance was detected against ampicillin (92, 76.6%) and imipenem 5, (4.1%), respectively. Sixty-eight (56.6%) isolates were ESBL-producing and 58 (48.3%) isolates were considered as multi-drug resistance (MDR). The prevalence of ESBL-producing and MDR isolates in O25-B2-ST131 strains was higher compared with the non-O25-B2-ST131 strains (p value < 0.05). O25-B2-ST131 strains showed significant correlation with serum resistance and biofilm formation. Amongst the resistance and virulence genes, the prevalence of iucD, kpsMTII, cnf1, vat, bla_CTX-M-15, and bla_SHV were significantly higher among O25-B2-ST131 isolates in comparison with non-O25-B2-ST131 isolates (p value < 0.05). Considering a ≥ 80% homology cut-off, fifteen different clusters of the isolates were shown with the same rep-PCR pattern.

CONCLUSIONS

Our results confirmed the involvement of MDR-ESBLs producing E. coli strain O25-B2-ST131 in the occurrence of UTIs among children. Source tracking and control measures seem to be necessary for containment of the spread of hypervirulent and resistance variants in children.

Prevalence of Plasmid-Mediated Quinolone Resistance (PMQRs) Determinants and Whole Genome Sequence Screening of PMQR-Producing E. coli Isolated from Men Undergoing a Transrectal Prostate Biopsy

Fluoroquinolones (FQs) are recommended as prophylaxis for men undergoing transrectal prostate biopsy (TRUS-Bx). Recent studies suggest a significant share of FQ-resistant rectal flora in post-TRUST-Bx infections. Methods: 435 Enterobacterales isolates from 621 patients attending 12 urological departments in Poland were screened by PCR for PMQR genes. PMQR-positive isolates were tested for quinolone susceptibility and investigated by whole genome sequencing (WGS) methods. Results: In total, 32 (7.35%) E. coli strains with ciprofloxacin MIC in the range 0.125–32 mg/L harbored at least one PMQR gene. qnrS and qnrB were the most frequent genes detected in 16 and 12 isolates, respectively. WGS was performed for 28 of 32 PMQR-producing strains. A variety of serotypes and sequence types (STs) of E. coli was noticed. All strains carried at least one virulence gene. AMR genes that encoded resistance against different classes of antibiotics were identified. Additionally, five of 13 ciprofloxacin-susceptible E. coli had alterations in codon 83 of the GyrA subunits. Conclusion: This study provides information on the common presence of PMQRs among E. coli, which may explain the cause for development of post-TRUS-Bx infections. High numbers of virulence and antimicrobial resistance genes detected show a potential for analysed strains to develop infections.

Antimicrobial-Resistant Escherichia coli Distribution and Whole-Genome Analysis of Sequence Type 131 Escherichia coli Isolates in Public Restrooms in Taiwan

The threat of antibiotic-resistant bacteria to public health may originate from public restrooms. To better understand the community burden of antimicrobial-resistant Escherichia coli and sequence type complex 131 E. coli (STc131) in the public restroom, we performed a surveillance in public restrooms in southern Taiwan. Swabs were sampled from randomly selected public restrooms in Tainan, Taiwan in 2019. Antimicrobial susceptibility, phylogenetic grouping, and multiplex PCR were performed for the major ST complex in the B2 phylogenetic group. If STc131 isolates were identified, the whole-genome sequencing was performed. A total of 613 collection sites found 132 sites (21.5%) positive for E. coli. The most common phylogenetic group was A (30.9%) followed by B2 (30.3%). Ceftriaxone-resistant E. coli and extended-spectrum β-lactamases–producing E. coli were found in 2.4 and 1.0% of total public restrooms, respectively. The isolates in rural areas had higher ceftriaxone non-susceptibility than those in the city centers (3.9 vs. 1.2%, P = 0.038). Nine STc131 isolates were found in public restrooms, and most (77.8%) belonged to the subtype fimH41, whereas 22.2% belonged to fimH30. With the inclusion of STc131 isolates from human and dog fecal colonization in Taiwan, whole-genome sequencing was performed in 35 isolates. A large cluster of fimH41 in SNP-tree and GrapeTree was found from different sources (human, dog, and environment) and geographical areas. In conclusion, our surveillance of antimicrobial-resistant E. coli showed a higher prevalence of E. coli detected in public restrooms in the rural areas compared to those in city centers. The whole-genome sequence implies that fimH41 STc131 strains are successfully circulated in the community in Taiwan.

Characterization of diarrheagenic Escherichia coli with special reference to antimicrobial resistance isolated from hospitalised diarrheal patients in Kolkata (2012-2019), India

AIMS

This study analyzes the prevalence and antimicrobial resistance (AMR) of major diarrheagenic Escherichia coli (DEC) pathotypes detected in hospitalized diarrheal patients in Kolkata, India, during 2012-2019.

METHODS AND RESULTS

A total of 8,891 stool samples were collected from the Infectious Diseases Hospital, Kolkata and screened for the presence of enteric pathogens. Multiplex-PCR identified the presence of DEC in 7.8% of the samples, in which ETEC was most common (47.7%) followed by EAEC (38.4%) and EPEC (13.9%). About 54% cases were due to sole DEC infections. Majority of the mixed DEC infections was caused by the Vibrio spp. (19.1%) followed by Rotavirus (14.1%) and Campylobacter spp. (8.4%). ETEC and EAEC were associated significantly with diarrhea in children <5 years of age, whereas EPEC and also ETEC were prevalent in patients aged between 5 and 14 years. AMR profile showed high prevalence of multidrug resistance (MDR) among DEC (56.9%) in which 9% were resistant to antibiotics of six different antimicrobial classes. Screening of the AMR conferring genes of DEC showed the presence of bla_CTX-M3 (30.2%) in highest number followed by bla_TEM (27.5%), tetB (18%), sul2 (12.6%), strA (11.8%), aadA1 (9.8%), bla_OXA-1 (9%), dfrA1 (1.6%) and bla_SHV (1.2%).

CONCLUSIONS

These findings highlighted the high prevalence of MDR in major DEC pathotypes that could be considered as the leading etiologic bacterial agent responsible for diarrhea and suggests a significant public health threat.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study can help to improve the understanding of the epidemiology of DEC infections in patients with diarrhea. Monitoring of AMR surveillance needs special attention because the DEC isolates were highly resistant to commonly used antimicrobials in the treatment of diarrhea.

High Fecal Carriage of Multidrug Resistant Bacteria in the Community among Children in Northwestern Tanzania

Colonization of multidrug resistant (MDR) bacteria is associated with subsequent invasive infections in children with comorbidities. This study aimed to determine the resistance profile and factors associated with MDR pathogen colonization among HIV−and HIV+ children below five years of age in Mwanza, Tanzania. A total of 399 (HIV− 255 and HIV+ 144) children were enrolled and investigated for the presence of MDR bacteria. The median [IQR] age of children was 19 (10–36) months. Out of 27 Staphylococcus aureus colonizing the nasal cavity, 16 (59.5%) were methicillin resistant while 132/278 (47.2%) of Enterobacteriaceae from rectal swabs were resistant to third generation cephalosporins, with 69.7% (92/132) exhibiting extended spectrum beta lactamase (ESBL) phenotypes. The proportion of resistance to gentamicin, amoxicillin/clavulanic acid and meropenem were significantly higher among HIV+ than HIV− children. A history of antibiotic use in the last month OR 2.62 [1.1, 6.9] (p = 0.04) and history of a relative admitted from the same household in the past three months OR 3.73 [1.1, 13.2] (p = 0.03) independently predicted ESBL rectal colonization. HIV+ children had significantly more fecal carriage of isolates resistant to uncommonly used antibiotics. There is a need to strengthen antimicrobial stewardship and Infection Prevention and Control (IPC) programs to prevent the emergence and spread of MDR pathogens in children.

Insights and genetic features of extended-spectrum beta-lactamase producing Escherichia coli isolates from two hospitals in Ghana

Recently, the emergence and rapid dissemination of extended-spectrum beta-lactamase (ESBL)-producing bacteria, particularly of the family Enterobacteriaceae, has posed serious healthcare challenges. Here, we determined the antimicrobial susceptibility and genetic characteristics of 164 Escherichia coli strains isolated from infected patients in two hospitals in Ghana. In total, 102 cefotaxime-resistant isolates (62.2%) were identified as ESBL-producers. Multilocus sequence typing of the ESBL-producers identified 20 different sequence types (STs) with ST131 (n = 25, 24.5%) as the dominant group. Other detected STs included ST410 (n = 21, 20.6%) and ST617 (n = 19, 18.6%). All identified ESBL-producers harbored bla_CTX-M-14, bla_CTX-M-15, or bla_CTX-M-27, with bla_CTX-M-15 (n = 96, 94.1%) being the most predominant ESBL allele. Further analysis showed that the immediate genetic environment around bla_CTX-M-15 is conserved within bla_CTX-M-15 containing strains. Five of the 25 ST131 isolates were clustered with clade A, one with sub-clade C1, and 19 with the dominant sub-clade C2. The results show that fluoroquinolone-resistant, bla_CTX-M-14- and bla_{CTX- M-15}-producing ESBL E. coli ST131 strains belonging to clade A and sub-clades C1 and C2 are disseminating in Ghanaian hospitals. To the best of our knowledge, this is the first report of the ST131 phylogeny in Ghana.

Genomic comparisons of Escherichia coli ST131 from Australia

Escherichia coli ST131 is a globally dispersed extraintestinal pathogenic E. coli lineage contributing significantly to hospital and community acquired urinary tract and bloodstream infections. Here we describe a detailed phylogenetic analysis of the whole genome sequences of 284 Australian ST131 E. coli isolates from diverse sources, including clinical, food and companion animals, wildlife and the environment. Our phylogeny and the results of single nucleotide polymorphism (SNP) analysis show the typical ST131 clade distribution with clades A, B and C clearly displayed, but no niche associations were observed. Indeed, interspecies relatedness was a feature of this study. Thirty-five isolates (29 of human and six of wild bird origin) from clade A (32 fimH41, 2 fimH89, 1 fimH141) were observed to differ by an average of 76 SNPs. Forty-five isolates from clade C1 from four sources formed a cluster with an average of 46 SNPs. Within this cluster, human sourced isolates differed by approximately 37 SNPs from isolates sourced from canines, approximately 50 SNPs from isolates from wild birds, and approximately 52 SNPs from isolates from wastewater. Many ST131 carried resistance genes to multiple antibiotic classes and while 41 (14 %) contained the complete class one integron-integrase intI1, 128 (45 %) isolates harboured a truncated intI1 (462-1014 bp), highlighting the ongoing evolution of this element. The module intI1-dfrA17-aadA5-qacEΔ1-sul1-ORF-chrA-padR-IS1600-mphR-mrx-mphA, conferring resistance to trimethoprim, aminoglycosides, quaternary ammonium compounds, sulphonamides, chromate and macrolides, was the most common structure. Most (73 %) Australian ST131 isolates carry at least one extended spectrum β-lactamase gene, typically bla_CTX-M-15 and bla_CTX-M-27. Notably, dual parC-1aAB and gyrA-1AB fluoroquinolone resistant mutations, a unique feature of clade C ST131 isolates, were identified in some clade A isolates. The results of this study indicate that the the ST131 population in Australia carries diverse antimicrobial resistance genes and plasmid replicons and indicate cross-species movement of ST131 strains across diverse reservoirs.

Molecular Epidemiology of Multidrug-Resistant Uropathogenic Escherichia coli O25b Strains Associated with Complicated Urinary Tract Infection in Children

Background: Uropathogenic Escherichia coli (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases. Aim: The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity. Methods: Resistance profiles were identified using the Kirby–Bauer method, including the phenotypic production of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST). Results: UPEC strains (n = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the fimH (95.23%), csgA (91.26%), papGII (80.95%), chuA (95.23%), iutD (88.09%), satA (84.92%), and intl1 (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D. Conclusion: UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics.

Carriage of Multidrug-Resistant Bacteria in Healthy People: Recognition of Several Risk Groups

The increase in multidrug-resistant (MDR) bacteria in hospitalized people and the hospital environment has been thoroughly documented. In contrast, little is known about their presence in the community. However, increasing evidence is showing a high level of carriage in people without infectious signs. Colonized people can later develop infections due to MDR bacteria and may be able to transmit them to susceptible people (the number of which is increasing worldwide), for example, people with comorbidities such as diabetes, cancer, or inflammatory diseases and those in extreme age groups. Risk factors for the acquisition of MDR bacteria are as follows: (1) residence or travel in countries with high levels of MDR bacteria; (2) occupational risks such as health workers or people with close contact with animals (farmers, veterinarians) who frequently use antibiotics; and (3) comorbidities. Eradication is rather difficult and, thus far, has not shown clear-cut results. Preventive measures will be important in the future with a reinforcement of hygienic measures not only in the hospital, but also in the community.

Investigation of High-Risk ST131 Clone in Extended Spectrum β-Lactamase–Producing Escherichia coli Isolates in Children

Objective Antimicrobial resistance poses a serious threat to children's health. In recent years, high-risk Escherichia coli ST131 has become an important target for global surveillance studies. The E.coli ST131 clone is associated with extended spectrum β-lactamase (ESBL) production, as well as multidrug resistance and treatment failure. Studies on this clone in the pediatric age group are limited. We aim to investigate the rate of high-risk E. coli ST131 clone in ESBL-positive E. coli isolates obtained from pediatric patients.

Methods A total of 292 ESBL-positive E. coli isolates from clinical samples of pediatric patients was included in the study. MALDI-TOF MS system was used for bacterial identification. Susceptibility tests were performed using BD Phoenix automated system. ST131 detection was done by MALDI-TOF-MS. Fisher's exact test was used to compare the groups (significance <0.05).

Results A total of 292 isolates was analyzed. The high-risk ST131 clone was detected in 117 (40%) of the 292 ESBL-positive isolates. ST131 rates were found to be significantly higher in children under the age of 5 years compared with children over the age of 5 years (49.3 vs. 31.1%, p = 0.0019). Ciprofloxacin resistance was higher in ST131 isolates (45.6 vs. 31.7%; p < 0.05).

Conclusion The rate of the ST131 clone was found to be high in the pediatric population. The significantly high rate of resistance to ciprofloxacin, which is not commonly used in the pediatric population, in ST131 isolates reveals the importance of the spread of high-risk clones for the development of resistance.

Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates from Jurong Lake, Singapore with Whole-Genome-Sequencing

Background: The fast-spreading of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli (ESBL-producing E. coli) and ESBL genes has become a big challenge to public health. The risk of spreading ESBL genes and pathogens in the environment and community has raised public health concern. The characterizing and whole-genome sequencing studies of ESBL-producing bacteria from reservoir water in Singapore is still limited. Materials and methods: The reservoir water sample was taken from two randomly selected sampling points of the Chinese Garden (Jurong river reservoir), which is a popular reservoir park in Singapore. The bacteria of the water sample were collected with 0.45 µm filter membranes and enriched before processing with ESBL-producing E. coli screening. The collected ESBL positive isolates were further characterized by both phenotypic tests including disc diffusion and microdilution Minimum Inhibitory Concentration (MIC) test, and also genotypic test as whole-genome sequencing analysis. Besides, to investigate the transferability of the resistance gene, a conjugation test was performed with the J53 E. coli strain as the gene receptor. Result: Nine ESBL-producing E. coli isolates were collected and confirmed as ESBL-producing with both phenotypic and genotypic tests. A potential pathogen as ST131 clade A isolate was identified, and all isolates were determined to harbor a bla_CTX-M gene. Among them, strain J1E4 was resistant to polymyxin E and confirmed to harboring a conjugatable mcr-1 gene. Further genetic environment analysis has reflected a conversed gene cluster formed by insert sequence (IS), bla_CTX-M-15, and WbuC family cupin-fold metalloprotein, which may potentially jump from the plasmids to the chromosome. Conclusion: The first time we reported the whole genome sequencing (WGS) data of ESBL-producing E. coli including potential pathogen (ST131) present in reservoir water in Singapore. The ESBL-producing E. coli from reservoir water also carrying conjugatable colistin resistance genes which may become a risk to human health.

Genomic Analysis of CTX-M-Group-1-Producing Extraintestinal Pathogenic E. coli (ExPEc) from Patients with Urinary Tract Infections (UTI) from Colombia

Background: The dissemination of the uropathogenic O25b-ST131 Escherichia coli clone constitutes a threat to public health. We aimed to determine the circulation of E. coli strains belonging to O25b:H4-B2-ST131 and the H30-Rx epidemic subclone causing hospital and community-acquired urinary tract infections (UTI) in Colombia. Methods: Twenty-six nonduplicate, CTX-M group-1-producing isolates causing UTI in the hospital and community were selected for this study. Results: Twenty-two E. coli isolates harboring CTX-M-15, one CTX-M-3, and three CTX-M-55 were identified. Multilocus Sequence Typing (MLST) showed a variety of sequence types (STs), among which, ST131, ST405, and ST648 were reported as epidemic clones. All the E. coli ST131 sequences carried CTX-M-15, from which 80% belonged to the O25b:H4-B2 and H30-Rx pandemic subclones and were associated with virulence factors iss, iha, and sat. E. coli isolates (23/26) were resistant to ciprofloxacin and associated with amino acid substitutions in quinolone resistance-determining regions (QRDR). We detected two carbapenem-resistant E. coli isolates, one coproducing CTX-M-15, KPC-2, and NDM-1 while the other presented mutations in ompC. Additionally, one isolate harbored the gene mcr-1. Conclusions: Our study revealed the circulation of the E. coli ST131, O25b:H4-B2-H30-Rx subclone, harboring CTX-M-15, QRDR mutations, and other resistant genes. The association of the H30-Rx subclone with sepsis and rapid dissemination warrants attention from the public health and infections control.

Prevalence and molecular epidemiology of ESBLs, plasmid-determined AmpC-type β-lactamases and carbapenemases among diarrhoeagenic Escherichia coli isolates from children in Gwangju, Korea: 2007-16

OBJECTIVES

Young children could act as important carriers of cefotaxime-resistant Enterobacteriaceae. However, most studies on these bacteria have focused on hospitalized adults. Therefore, we determined the prevalence and characteristics of ESBL-, plasmid-determined AmpC-type β-lactamase (PABL)- and carbapenemase-producing diarrhoeagenic Escherichia coli isolates mainly from infants and children in the south-west region of Korea over a 10 year period.

METHODS

Non-duplicate E. coli clinical isolates were recovered from diarrhoeagenic patient specimens at 12 hospitals in Gwangju, Korea, between January 2007 and December 2016. Antimicrobial susceptibilities and molecular features of ESBL- and carbapenemase-producing isolates were determined.

RESULTS

A total of 1047 pathogenic E. coli isolates were collected and 58 cefotaxime-resistant E. coli isolates (5.5%) were identified. The prevalence and types of β-lactamase genes increased steadily from 5.7% in 2007 to 11.6% in 2016 with some fluctuations. CTX-M-14 (53.4%) was the predominant CTX-M genotype. PFGE revealed high genetic heterogeneities among diarrhoeagenic E. coli isolates, suggesting horizontal transfer of antibiotic resistance genes, which was also proved by conjugation assay.

CONCLUSIONS

Progressive increases in carriage rates and the number of β-lactamase types, and the possibility of community outbreaks of these food-borne bacteria in young children, may pose tangible public health threats.

Distribution of Pathogenicity Island Markers and H-Antigen Types of Escherichia coli O25b/ST131 Isolates from Patients with Urinary Tract Infection in Iran

Escherichia coli serogroup O25b-sequence type 131 (E. coli O25b/ST131) is known as a multidrug-resistant organism with high virulence potential and has received attention internationally. We aim to investigate the prevalence of O25b/ST131 and the distribution of bla_CTX-M-15, pathogenicity island (PAI) markers, phylogenetic groups, and H-antigen typing in the E. coli O25b/ST131 isolated from patients with urinary tract infection (UTI) in Tehran, the capital of Iran. Seventy (26.9%) E. coli isolates were identified as O25b/ST131. There was also a significant difference in the prevalence of virulence genes, including papA, sfa, sat, cnf1, iutA, kpMII, traT, and usp, in the O25b/ST131 isolates rather than non-O25b/ST131 ones (p ≤ 0.05). Furthermore, 78% of the O25b/ST131 isolates carried four to seven PAIs, while 71% of non-O25b/ST131 isolates carried two to four PAI markers (p ≤ 0.05). Our study showed that in addition to H4, other H-antigens may play a role in the O25b/ST131 virulence potential. Besides, a significant association was found between the history of previous UTIs and infection among the O25b/ST131 clone isolates. Pulsed-field gel electrophoresis revealed circulating of O25b:H4-ST131/PST43 clone in both hospital and community. Approximately one in every three uropathogenic E. coli isolates was the O25b/ST131 clone, representing a significant public health threat. Practical investigation on O25b/ST131 can be helpful in better understanding of ST131 evolution and controlling UTI in hospitals.

High Prevalence of ST131 Subclades C2-H30Rx and C1-M27 Among Extended-Spectrum β-Lactamase-Producing Escherichia coli Causing Human Extraintestinal Infections in Patients From Two Hospitals of Spain and France During 2015

The present study was carried out to evaluate the prevalence of sequence type 131 (ST131) among 188 extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) collected in 2015 in Lucus Augusti University hospital (Lugo, Spain) and AP-HP Beaujon hospital (Clichy, France) with regard to other STs and to characterize, the types of ESBL produced, serotypes, virulence factor (VF)-encoding genes and the ST131 clades and subclades. ST131 was detected in 33 (39.1%) and 46 (47.9%) of the isolates in Lucus Augusti and Beaujon, respectively. The 109 remaining isolates displayed 57 other STs, the following STs being displayed by at least three isolates: ST10 (8 isolates), ST23 (3), ST38 (4), ST58 (3), ST88 (5), ST95 (4), ST167 (3), ST354 (5), ST361 (3), ST410 (6), ST648 (4), ST744 (3), and ST1615 (6). ST354, ST410, and ST1615 were significantly (P < 0.05) more frequent in Lucus Augusti (5.4%, 6.5%, and 6.5%) than in Beaujon (0% for the three STs). The new globally emerging clone ST1193 among extraintestinal clinical ESBL-EC was identified in one isolate from France and one from Spain. CTX-M-15 was the commonest ESBL detected in the two hospitals (44.6% in Lucus Augusti and 50.0% in Beaujon). CTX-M-14 was significantly (P = 0.0003) more frequent in Lucus Augusti (31.5%) than in Beaujon (10.4%), whereas CTX-M-1 (20.8 vs. 7.6%; P = 0.008) and CTX-M-27 (15.6 vs. 6.5%; P = 0.0389) were more frequent in Beaujon than in Lucus Augusti. The ST131 isolates showed a higher virulence score (mean 13.367) compared with the non-ST131 isolates (mean 7.661) (P < 0.001). Among the 79 ST131 isolates, most of them (52; 65.8%) belonged to subclade C2 (also known as subclone H30Rx) followed by those belonging to subclade C1 (cluster C1-M27: 16 isolates, 20.3%; cluster non-C1-M27: 6 isolates, 7.6%) and clade A (4 isolates; 5.1%). The C2 subclade isolates showed a higher VF-encoding gene score (mean 14.250) compared with the C1-M27 cluster isolates (mean 10.875) (P < 0.001). In conclusion, this study highlights the epidemiological differences between the ESBL-EC isolated from two hospitals of France and Spain obtain in 2015 and reports, for the first time, the presence of clone ST1193 in Spain.

Multi-Antibiotic Resistance and Factors Affecting Carriage of Extended Spectrum β-Lactamase-Producing Enterobacteriaceae in Pediatric Population of Enugu Metropolis, Nigeria

Extended-spectrum β-lactamase (ESBL)-producing organisms have become a serious challenge in healthcare delivery globally. The prevalence of ESBL carriage in healthy and sick children in Enugu, Nigeria, was bacteriologically investigated in this study. Four hundred and twenty-two biological samples (mid-stream urine and feces) were bacteriologically analyzed. The isolates were screened for ESBL production using Clinical and Laboratory Standards Institute (CLSI) breakpoints. The suspected ESBL producers were confirmed using double disc synergy test method. Out of the 162 isolates screened, 32 (19.8%) were confirmed as ESBL positive, with a prevalence of 25.32% among sick children in Enugu State University Teaching Hospital (ESUTH), Parklane, Enugu and 13.89% in apparently healthy children in a community setting. Klebsiella spp. and Escherichia coli had the highest prevalence of 34.6% and 28.6%, respectively; Citrobacter spp. and Enterobacter spp. were 18.2% and 16.7%, respectively. The ESBL positive isolates were resistant to sulfamethoxazole/trimethoprim (100%), tetracycline (100%), kanamycin (96.9%), nitrofurantoin (84.4%), ciprofloxacin (68.6%), and chloramphenicol (62.5%) but susceptible to meropenem (100%), colistin (56.3%), and gentamicin (50%). Klebsiella spp. had the highest ESBL occurrence among sick children while E. coli had the highest ESBL occurrence among healthy children in Enugu. All ESBL-positive isolates were multiply resistant to conventional antibiotics. The emergence and spread of β-lactamase-producing Enterobacteriaceae in hospital and community environments highlight the possibility for an infection outbreak if not checked.

Epidemiology and Antimicrobial Resistance Characteristics of the Sequence Type 131-H30 Subclone Among Extraintestinal Escherichia coli Collected From US Children

Background

Escherichia coli sequence type (ST) 131-H30 is a globally important pathogen implicated in rising rates of multidrug resistance among E. coli causing extraintestinal infections. Previous studies have focused on adults, leaving the epidemiology of H30 among children undefined.

Methods

We used clinical data and isolates from a case-control study of extended-spectrum cephalosporin-resistant E. coli conducted at 4 US children's hospitals to estimate the burden and identify host correlates of infection with H30. H30 isolates were identified using 2-locus genotyping; host correlates were examined using log-binomial regression models stratified by extended-spectrum cephalosporin resistance status.

Results

A total of 339 extended-spectrum cephalosporin-resistant and 1008 extended-spectrum cephalosporin-susceptible E. coli isolates were available for analyses. The estimated period prevalence of H30 was 5.3% among all extraintestinal E. coli isolates (95% confidence interval [CI], 4.6%-7.1%); H30 made up 43.3% (81/187) of extended-spectrum β-lactamase (ESBL)-producing isolates in this study. Host correlates of infection with H30 differed by extended-spectrum cephalosporin resistance status: Among resistant isolates, age ≤5 years was positively associated with H30 infection (relative risk [RR], 1.83 [95% CI, 1.19-2.83]); among susceptible isolates, age ≤5 years was negatively associated with H30 (RR, 0.48 [95% CI, .27-.87]), while presence of an underlying medical condition was positively associated (RR, 4.49 [95% CI, 2.43-8.31]).

Conclusions

ST131-H30 is less common among extraintestinal E. coli collected from children compared to reported estimates among adults, possibly reflecting infrequent fluoroquinolone use in pediatrics; however, it is similarly dominant among ESBL-producing isolates. The H30 subclone appears to disproportionately affect young children relative to other extended-spectrum cephalosporin-resistant E. coli.

Prevalence and molecular characteristics of sequence type 131 clone among clinical uropathogenic Escherichia coli isolates in Riyadh, Saudi Arabia

Background

The antimicrobial resistance of extraintestinal pathogenic Escherichia coli (ExPEC) has progressively been reported worldwide. This resistance has been ascribed to global dissemination of a single E. coli clone, namely E. coli sequence type 131 (E. coli ST131). The main goal of this study is to determine the prevalence and molecular traits of ST131 and its subclones among E. coli clinical urine isolates in Riyadh, Saudi Arabia.

Methods

Sixty E. coli urine isolates, of different extended spectrum β-lactamase (ESBL) carriage, were involved in this study. Molecular characterization was carried out to determine the ST131 status, phylogenetic groups and virulence carriage of these isolates. ST131 isolates were further tested to evaluate the prevalence of different phylogenetic groups, subclones and virulence carriage.

Results

Group B2 was the most common phylogroup from which E. coli isolates derived. Overall, 37 of 60 (61.7%) isolates belonged to ST131 clones. Of these, 19 (31.7%) isolates were from the H30 subclone, including 10 (16.7%) H30 non-Rx and 9 (15%) H30Rx. The remaining 18 (30%) ST131 isolates belonged to other non H30 subclones. H30 subclone was significantly higher in the virulence carriage in comparison to non H30 ST131 subclones.

Conclusion

This study reported the prevalence and traits of clinical E. coli ST131 main subclones in Saudi Arabia. It also demonstrated the high prevalence of E. coli ST131 locally, and found different virulence genotypes and antimicrobial resistance phenotypes among ST131 subclones. In the future, preforming whole genome sequence-based studies on ST131 and its subclones is crucial to elucidate factors that drive the success of these organisms.

Intestinal Colonization Traits of Pandemic Multidrug-Resistant Escherichia coli ST131

Background

Epidemiological studies point to the gut as a key reservoir of multidrug resistant Escherichia coli multilocus sequence type 131 (ST131), a globally dominant pathogenic clone causing urinary tract and bloodstream infections. Here we report a detailed investigation of its intestinal lifestyle.

Methods

Clinical ST131 isolates and type 1 fimbriae null mutants were assessed for colonization of human intestinal epithelia and in mouse intestinal colonization models. Mouse gut tissue underwent histologic analysis for pathology and ST131 localization. Key findings were corroborated in mucus-producing human cell lines and intestinal biopsy specimens.

Results

ST131 strains adhered to and invaded human intestinal epithelial cells more than probiotic and commensal strains. The reference ST131 strain EC958 established persistent intestinal colonization in mice, and expression of type 1 fimbriae mediated higher colonization levels. Bacterial loads were highest in the distal parts of the mouse intestine and did not cause any obvious pathology. Further analysis revealed that EC958 could bind to both mucus and underlying human intestinal epithelia.

Conclusions

ST131 strains can efficiently colonize the mammalian gut and persist long term. Type 1 fimbriae enhance ST131 intestinal colonization, suggesting that mannosides, currently developed as therapeutics for bladder infections and Crohn’s disease, could also be used to limit intestinal ST131 reservoirs.

Escherichia coli O25b-ST131 and O16-ST131 causing urinary tract infection in women in Changsha, China: molecular epidemiology and clinical characteristics

Objective

This study aimed to investigate the prevalence of Escherichia coli ST131 and molecularly characterize the O25b-ST131 and O16-ST131 subgroups among urinary tract infection (UTI) E. coli isolates from women in central China. We also assessed the clinical characteristics and outcomes of infections caused by E. coli ST131.

Methods

Between January 2014 and December 2015, a total of 216 consecutive, non-repetitive E. coli isolates were recovered from UTI urine samples from women in Changsha, China. All isolates were analyzed for phylogenetic groups, antimicrobial resistance and virulence genotypes. ST131 clonal groups were identified using PCR and characterized using O serotyping, CTX-M genotypes, fimH, gyrA, and parC alleles, fluoroquinolone resistance genes and pulsed-field gel electrophoresis (PFGE). Clinical data were obtained from medical records.

Results

Overall, 41 (19.0%) of 216 E. coli isolates were identified to contain ST131 strains, among which 27 were O25b-ST131 strains and 14 were O16-ST131 strains. The clinical characteristics and outcomes of the ST131 group did not differ significantly from those of the non-ST131 group, except for the presence of urinary stones (43.9% vs 27.4%, P=0.039). Ciprofloxacin resistance was found to be significantly higher in O25b-ST131 isolates than O16-ST131 isolates (96.3% vs 14.3%, P<0.001). The majority of O25b-ST131 isolates belonged to fimH30 (92.6%), followed by fimH41 (3.7%) and fimH27 (3.7%). O25b-H30 and O25b-H41 isolates were resistant to ciprofloxacin, and possessed gyrA1AB/parC1aAB combination. All of the O16-S131 isolates were found to belong to fimH41, and of which, two of the ciprofloxacin-resistant strains harbored gyrA1AB/parC3A combination. Three PFGE clusters, consisting of 38 (92.7%) isolates, with more than 70% similarity were identified.

Conclusion

The O25b and O16 sub-lineages have emerged as an important group of E. coli ST131 in UTI isolates from women in China. UTI patients with a history of urinary stones may need to be particularly vigilant against ST131 infection.

Sequence Types, Clonotypes, Serotypes, and Virotypes of Extended-Spectrum β-Lactamase-Producing Escherichia coli Causing Bacteraemia in a Spanish Hospital Over a 12-Year Period (2000 to 2011)

The aim of the present study was to examine the prevalence and determine the molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) causing bacteraemia in a Spanish Hospital over a 12-year period (2000 to 2011). As far as we know, this is the first study which has investigated and compared the serotypes, phylogroups, clonotypes, virotypes, and PFGE profiles of ST131 and non-ST131 clones of bacteraemia ESBL-EC isolates. Of the 2,427 E. coli bloodstream isolates, 96 (4.0%) were positive for ESBL production: 40 for CTX-M-15, 36 for CTX-M-14, eight for CTX-M-1, four for CTX-M-9, CTX-M-32, and SHV-12. The number of ESBL-EC increased from 1.0% during 2000 to 2005 to 5.5% during 2006-2011 (P < 0.001). The 96 ESBL-EC isolates belonged to 36 different STs. The commonest was ST131 (41 isolates), followed by ST58, ST354, ST393 and ST405 (four isolates each). Most CTX-M-15 isolates (87.5%, 35/40) were ST131, whereas the 36 CTX-M-14 isolates belonged to 23 different STs and only 3 (8.3%) of them were ST131. The 35 ST131 CTX-M-15-producing isolates belonged to the H30Rx subclone and 29 of them showed the virotype A. A drastic change in ST131 virotypes happened in 2011 due to the emergence of the virotypes E (sat, papGII, cnf1, hlyA, and kpsMII-K5) and F (sat, papGII, and kpsMII-K5) which displaced virotype A (afa/draBC, afa operon FM955459, sat, and kpsMII-K2). Although the 96 ESBL-EC isolates showed 21 O serogroups and 17 H flagellar antigens, 39 belonged to serotype O25b:H4 (ST131 isolates). The second most prevalent serotype (O15:H1) was found to be associated with another important high-risk clone (ST393). In conclusion, the ST131 was the most frequent sequence type, being the H30Rx subclone responsible for the significant increase of ESBL-EC isolates since 2006. Here, we report two new virotypes (E and F) of the H30Rx subclone emerged in 2011. Future molecular studies are needed to understand the dynamics of expansion of this successful high-risk subclone in order to prevent its spread and establish the importance of the two new virotypes.

Independent Host Factors and Bacterial Genetic Determinants of the Emergence and Dominance of Escherichia coli Sequence Type 131 CTX-M-27 in a Community Pediatric Cohort Study

The recent emergence and diffusion in the community of Escherichia coli isolates belonging to the multidrug-resistant and CTX-M-27-producing sequence type 131 (ST131) C1-M27 cluster makes this cluster potentially as epidemic as the worldwide E. coli ST131 subclade C2 composed of multidrug-resistant isolates producing CTX-M-15. Thirty-five extended-spectrum beta-lactamase (ESBL)-producing ST131 isolates were identified in a cohort of 1,885 French children over a 5-year period. They were sequenced to characterize the ST131 E. coli isolates producing CTX-M-27 recently emerging in France. ST131 isolates producing CTX-M-27 (n = 17), and particularly those belonging to the C1-M27 cluster (n = 14), carried many resistance-encoding genes and predominantly an F1:A2:B20 plasmid type. In multivariate analysis, having been hospitalized since birth (odds ratio [OR], 10.9; 95% confidence interval [CI], 2.4 to 48.8; P = 0.002) and being cared for in a day care center (OR, 9.4; 95% CI, 1.5 to 59.0; P = 0.017) were independent risk factors for ST131 CTX-M-27 fecal carriage compared with ESBL-producing non-ST131 isolates. No independent risk factor was found when comparing CTX-M-15 (n = 11)- and CTX-M-1/14 (n = 7)-producing ST131 isolates with ESBL-producing non-ST131 isolates or with non-ESBL-producing isolates. Several factors may contribute to the increase in fecal carriage of CTX-M-27-producing E. coli isolates, namely, resistance to multiple antibiotics, capacity of the CTX-M-27 enzyme to hydrolyze both cefotaxime and ceftazidime, carriage of a peculiar F-type plasmid, and/or capacity to colonize children who have been hospitalized since birth or who attend day care centers.

[Bloodstream infections with Escherichia coli O16-ST131 and O25b-ST131: molecular epidemiology, phylogenetic analysis and antimicrobial resistance]

OBJECTIVE

To investigate the phylogenetics and prevalence of bloodstream infections with Escherichia coli ST131, the antimicrobial resistance profiles of the pathogens, and the clinical features.

METHODS

Non-duplicate Escherichia coli isolates were collected from 144 patients with bloodstream infections in our hospital between January and December, 2016.The phylogenetic groups of the isolates were analyzed using multiplex PCR, and O serotyping of ST131 strains was performed by allele-specific PCR.The clinical characteristics of the 144 patients were analyzed to define the differences in the clinical features between patients with ST131 infection and those with non-ST131 infection.Antibiotic susceptibility of the isolates was determined using the Vitek 2 compact system.

RESULTS

The phylogenetic group analysis showed a domination by group B2 (41.0%[59/144]), followed by group F, group B1 and group E, which accounted for 16.7%(24/144), 13.9%(20/144), and 13.2% (19/144), respectively.Nine strains (6.3%) of Escherichia coli were identified to be ST131 strains, among which 8 were O25b-B2-ST131 strains and 1 was O16-B2-ST131 strain.Of the 9 cases of ST131 infection, 7(77.8%) were found to occur in a nosocomial setting.The demographic characteristics and clinical features of the ST131-infected patients were similar to those of non-ST131-infected patients.ST131 strains were sensitive to piperacillin/tazobactam, imipenem, ertapenem, and amikacin, but showed high resistance rates to cefazolin, ceftriaxone, ciprofloxacin, levofloxacin, gentamicin, and trimethoprim/ sulfamethoxazole (all over 50%).The positivity rate of ESBLs in the ST131 strains was 77.8%, and the multidrug resistance rate reached 88.9%, which was higher than that of non-ST131 isolates, but the difference was not statistically significant.

CONCLUSIONS

The most common phylogenetic groups of Escherichia coli isolates from patients with bloodstream infections are group B2 and F, and the positivity rate of ST131 is low.We for the first time detected O16-ST131 in patients with blood-borne infections in China.The clinical features of ST131-infected patients are similar to those of non-ST131-infected patients.The positivity rate of ESBLs and the multidrug resistance rate are high in ST131 strains, which may raise concerns in the future.

Adherent/invasive Escherichia coli (AIEC) isolates from asymptomatic people: new E. coli ST131 O25:H4/H30-Rx virotypes

BACKGROUND

The widespread Escherichia coli clone ST131 implicated in multidrug-resistant infections has been recently reported, the majority belonging to O25:H4 serotype and classified into five main virotypes in accordance with the virulence genes carried.

METHODS

Pathogenicity Islands I and II (PAI-I and PAI-II) were determined using conventional PCR protocols from a set of four E. coli CTXR ST131 O25:H4/H30-Rx strains collected from healthy donors' stool. The virulence genes patterns were also analyzed and compared them with the virotypes reported previously; then adherence, invasion, macrophage survival and biofilm formation assays were evaluated and AIEC pathotype genetic determinants were investigated.

FINDINGS

Non-reported virulence patterns were found in our isolates, two of them carried satA, papA, papGII genes and the two-remaining isolates carried cnfI, iroN, satA, papA, papGII genes, and none of them belonged to classical ST131 virotypes, suggesting an endemic distribution of virulence genes and two new virotypes. The presence of PAI-I and PAI-II of Uropathogenic E. coli was determined in three of the four strains, furthermore adherence and invasion assays demonstrated higher degrees of attachment/invasion compared with the control strains. We also amplified intI1, insA and insB genes in all four samples.

INTERPRETATION

The results indicate that these strains own non-reported virotypes suggesting endemic distribution of virulence genes, our four strains also belong to an AIEC pathotype, being this the first report of AIEC in México and the association of AIEC with healthy donors.

Intestinal Carriage of Third-Generation Cephalosporin-Resistant and Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Healthy US Children

BACKGROUND

The epidemiology of antibiotic-resistant Enterobacteriaceae intestinal carriage in healthy US children has not been well characterized.

METHODS

Children between 14 days and 14 years of age were enrolled during well-child visits in Oakland, California, Kansas City, Kansas, and Nashville, Tennessee, between December 2013 and March 2015. Data on recent antibiotic use by the child and travel and hospitalization history of all members of each child's household were obtained with a risk-factor survey. Stool specimens collected from the subjects were screened for extended-spectrum β-lactamase-producing (ESBL-P) bacteria using CHROMagar ESBL medium. Putative ESBL-P Escherichia coli and Klebsiella colonies underwent phenotypic confirmation by double-disk synergy testing; confirmed third-generation cephalosporin-resistant (3GCR) isolates underwent additional antibiotic-susceptibility testing.

RESULTS

In 519 subjects, the overall 3GCR Enterobacteriaceae carriage rate was 4.4% (n = 23) and ranged from 3.4% to 5.1% among the study sites. The ESBL-P Enterobacteriaceae carriage rate was 3.5% (n = 18). The rates of 3GCR Enterobacteriaceae carriage was highest in 1 to <2 year olds at 6.5%, and was 5.2% in <5 year-olds vs 1.7% in ≥5-year-olds (P = .11). 3GCR and ESBL-P Enterobacteriaceae carriage was associated with international travel within the previous year; 11.1% of ESBL-P Enterobacteriaceae carriers reported this history compared with 1.6% of noncarriers (P = .004). No other queried factor was found to increase risk. Of the 24 analyzed 3GCR isolates, 58% were multidrug resistant.

CONCLUSIONS

The 3GCR Enterobacteriaceae carriage rate exceeds 5% in healthy US children <5 years of age. International travel within the previous year increased the risk of 3GCR and ESBL-P Enterobacteriaceae carriage. In contrast, we found no differences in the rates of hospitalization or recent antibiotic exposure between carriers and noncarriers. Young children, who have the highest prevalence of colonization, might be a sentinel population to study to gain a better understanding of community sources of antibiotic-resistant Enterobacteriaceae.

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.

Global epidemiology of CTX-M β-lactamases: temporal and geographical shifts in genotype

Globally, rates of ESBL-producing Enterobacteriaceae are rising. We undertook a literature review, and present the temporal trends in blaCTX-M epidemiology, showing that blaCTX-M-15 and blaCTX-M-14 have displaced other genotypes in many parts of the world. Explanations for these changes can be attributed to: (i) horizontal gene transfer (HGT) of plasmids; (ii) successful Escherichia coli clones; (iii) ESBLs in food animals; (iv) the natural environment; and (v) human migration and access to basic sanitation. We also provide explanations for the changing epidemiology of blaCTX-M-2 and blaCTX-M-27. Modifiable anthropogenic factors, such as poor access to basic sanitary facilities, encourage the spread of blaCTX-M and other antimicrobial resistance (AMR) genes, such as blaNDM, blaKPC and mcr-1. We provide further justification for novel preventative and interventional strategies to reduce transmission of these AMR genes.

Current Trends in Antimicrobial Resistance of Escherichia coli

Escherichia coli is the most common Gram-negative bacterial pathogen, presenting both a clinical and an epidemiological challenge. In the last decade, several successful multidrug-resistant high-risk strains, such as strain E. coli ST131 have evolved, mainly due to the growing selective pressure of antimicrobial use. These strains present enhanced fitness and pathogenicity, effective transmission and colonization abilities, global distribution due to efficient dissemination, and resistance to various antimicrobial resistances. Here, we describe the emerging trends and epidemiology of resistant E. coli, including carbapenemase-producing E. coli, E. coli ST131 and colistin resistant E. coli.

Route of infection alters virulence of neonatal septicemia Escherichia coli clinical isolates

Escherichia coli is the leading cause of Gram-negative neonatal septicemia in the United States. Invasion and passage across the neonatal gut after ingestion of maternal E. coli strains produce bacteremia. In this study, we compared the virulence properties of the neonatal E. coli bacteremia clinical isolate SCB34 with the archetypal neonatal E. coli meningitis strain RS218. Whole-genome sequencing data was used to compare the protein coding sequences among these clinical isolates and 33 other representative E. coli strains. Oral inoculation of newborn animals with either strain produced septicemia, whereas intraperitoneal injection caused septicemia only in pups infected with RS218 but not in those injected with SCB34. In addition to being virulent only through the oral route, SCB34 demonstrated significantly greater invasion and transcytosis of polarized intestinal epithelial cells in vitro as compared to RS218. Protein coding sequences comparisons highlighted the presence of known virulence factors that are shared among several of these isolates, and revealed the existence of proteins exclusively encoded in SCB34, many of which remain uncharacterized. Our study demonstrates that oral acquisition is crucial for the virulence properties of the neonatal bacteremia clinical isolate SCB34. This characteristic, along with its enhanced ability to invade and transcytose intestinal epithelium are likely determined by the specific virulence factors that predominate in this strain.

The ST131 Escherichia coli H22 subclone from human intestinal microbiota: Comparison of genomic and phenotypic traits with those of the globally successful H30 subclone

Background

In 2006, we found healthy subjects carrying ST131 Escherichia coli in their intestinal microbiota consisting of two populations: a subdominant population of fluoroquinolone-resistant E. coli belonging to subclone H30 (H30-R or subclade C1), the current worldwide dominant ST131 subclone, and a dominant E. coli population composed of antibiotic-susceptible E. coli belonging to subclone H22 (clade B), the precursor of subclone H30. We sequenced the whole genome of fecal H22 strain S250, compared it to the genomes of ExPEC ST131 H30-Rx strain JJ1886 and commensal ST131 H41 strain SE15, sought the H22-H30 genomic differences in our fecal strains and assessed their phenotypic consequences.

Results

We detected 173 genes found in the Virulence Factor Database, of which 148 were shared by the three ST131 genomes, whereas some were genome-specific, notably those allowing determination of virotype (D for S250 and C for JJ1886). We found three sequences of the FimH site involved in adhesion: two in S250 and SE15 close and identical, respectively, to that previously reported to confer strong intestinal adhesion, and one in JJ1886, corresponding to that commonly present in uropathogenic E. coli. Among the genes involved in sugar metabolism, one encoding a gluconate kinase lacked in S250 and JJ1886. Although this gene was also absent in both our fecal H22 and H30-R strains, H22 strains showed a higher capacity to grow in minimal medium with gluconate. Among the genes involved in gluconate metabolism, only the ghrB gene differed between S250/H22 and JJ1886/H30-R strains, resulting in different gluconate reductases. Of the genes involved in biofilm formation, two were absent in the three genomes and one, fimB, in the JJ1886 genome. Our fecal H30-R strains lacking intact fimB displayed delayed biofilm formation relative to our fecal H22 strains. The H22 strains differed by subclade B type and plasmid content, whereas the H30-R strains were identical.

Conclusions

Phenotypic analysis of our fecal strains based on observed genomic differences between S250 and JJ1886 strains suggests the presence of traits related to bacterial commensalism in our H22 strains and traits commonly found in uropathogenic E. coli in our H30-R strains.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-017-0984-8) contains supplementary material, which is available to authorized users.

Detection of Escherichia coli ST131 clonal complex (ST705) and Klebsiella pneumoniae ST15 among faecal carriage of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae

PURPOSE

The objective of the present study was to evaluate the prevalence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in non-selected hospitalized and non-hospitalized patients from the same geographic area of Madrid.

METHODOLOGY

A total of 501 fecal samples were screened. Diluted samples in saline were cultured in MacConkey agar plates with ceftazidime, cefotaxime, imipenem and meropenem disks. Colonies growing within the inhibition zone of either disk were selected. Characterization of ESBLs and CPEs were performed by PCR and sequencing. The Wider system was used for the bacterial identification. In addition, clonal analysis was carried out for species predominant among the fecal carriage.

KEY FINDINGS

Among the 501 patients enrolled, 43 (8.6 %) carried ESBL-E and 8 (1.6 %) patients exhibited CPE. The main intestinal colonizer among ESBL-E was CTX-M-producing Escherichia coli isolates in both settings (community and hospital). ST131 clonal complex was the most common among faecal ESBL-producing E. coli. All gut carriers of CPE were hospitalized patients, Klebsiella pneumoniae being the most prevalent species. Two OXA-48-producing K. pneumoniae isolates belonging to ST15 were detected.

CONCLUSION

Present study reveals that faecal carriage of ESBL is common among inpatients and outpatients, whereas carbapenemase producers are only present in the hospital setting. Therefore, active surveillance will be useful for reducing transmission of antimicrobial-resistant bacteria and preventing infection.

Healthcare costs doubled when children had urinary tract infections caused by extended-spectrum β-lactamase-producing bacteria

AIM

The impact of the emergence of antimicrobial resistant organisms has rarely been studied in children, including the healthcare costs of urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria. We evaluated the effect of ESBL on UTI healthcare costs and risk factors for paediatric UTIs.

METHODS

This retrospective case-control study covered 2005-2014 and focused on children below 16 years of age treated in a University hospital: 22 children with UTIs caused by ESBL-producing bacteria and 56 ESBL-negative UTI controls.

RESULTS

The median healthcare costs were 3929 Euros for the 22 ESBL patients and 1705 Euros for the 56 controls (p = 0.015). The mean and standard deviation length of hospital stay was 7.4 (5.9) days for the ESBL group and 3.6 (2.3) days for the controls (p = 0.007), and the figures for antibiotic treatment were 12.3 (5.5) days versus 5.8 (3.0) days (p < 0.001), respectively. The odd ratios for ESBL were underlying disease (6.63, p = 0.013), previous hospitalisation (6.07, p = 0.009) and antibiotic prophylaxis (5.20, p = 0.035).

CONCLUSION

Healthcare costs more than doubled when children had ESBL-related UTIs, mainly due to their increased length of stay. Effective oral antibiotics are urgently needed to treat paediatric infections caused by ESBL-producing bacteria.

High Prevalence of Faecal Carriage of ESBL-Producing Enterobacteriaceae among Children in Dar es Salaam, Tanzania

Background

Faecal carriage of ESBL-producing bacteria is a potential risk for transmission and infection. Little is known about faecal carriage of antibiotic resistance in Tanzania. This study aimed to investigate the prevalence of faecal carriage of ESBL-producing Enterobacteriaceae and to identify risk factors for carriage among young children in Tanzania.

Methodology/Principal Findings

From August 2010 to July 2011, children below 2 years of age were recruited in Dar es Salaam, including healthy community children (n = 250) and children hospitalized due to diarrhoea (n = 250) or other diseases (n = 103). ChromID ESBL agar and ChromID CARBA SMART agar were used for screening. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL genotypes were identified by Real-Time PCR and sequencing.

The overall prevalence of ESBL carriage was 34.3% (207/ 603). The prevalence of ESBL carriage was significantly higher among hospitalized children (50.4%), compared to community children (11.6%; P < 0.001; OR = 7.75; 95% CI: 4.99–12.03). We found high prevalence of Multidrug-resistance (94%) among Escherichia coli and Klebsiella pneumoniae isolates. No resistance to carbapenems was detected. For the majority of isolates (94.7%) we detected a bla_CTX-M-15-like gene. In addition, the plasmid mediated AmpC beta-lactamase CMY-2 was detected for the first time in Tanzania. ESBL prevalence was significantly higher among HIV positive (89.7%) than HIV negative (16.9%) children (P = 0.001; OR = 9.99; 95% CI: 2.52–39.57). Use of antibiotics during the past 14 days and age below 1 year was also associated with ESBL carriage.

Conclusions/Significance

We report a high rate of faecal carriage of ESBL-producing Enterobacteriaceae among children below 2 years of age in Tanzania, particularly those with HIV-infection. Resistance to a majority of the available antimicrobials commonly used for children in Tanzania leaves few treatment options for infections when caused by these bacteria.

Whole-Genome Sequencing Identifies In Vivo Acquisition of a blaCTX-M-27-Carrying IncFII Transmissible Plasmid as the Cause of Ceftriaxone Treatment Failure for an Invasive Salmonella enterica Serovar Typhimurium Infection

We report a case of ceftriaxone treatment failure for bacteremia caused by Salmonella enterica subsp. enterica serovar Typhimurium, due to the in vivo acquisition of a bla_CTX-M-27-encoding IncFII group transmissible plasmid. The original β-lactamase-susceptible isolate ST882S was replaced by the resistant isolate ST931R during ceftriaxone treatment. After relapse, treatment was changed to ciprofloxacin, and the patient recovered. Isolate ST931R could transfer resistance to Escherichia coli at 37°C. We used whole-genome sequencing of ST882S and ST931R, the E. coli transconjugant, and isolated plasmid DNA to unequivocally show that ST882S and ST931R had identical chromosomes, both having 206 identical single-nucleotide polymorphisms (SNPs) versus S Typhimurium 14028s. We assembled a complete circular genome for ST931R, to which ST882S reads mapped with no SNPs. ST882S and ST931R were isogenic except for the presence of three additional plasmids in ST931R. ST931R and the E. coli transconjugant were ceftriaxone resistant due to the presence of a 60.5-kb IS26-flanked, bla_CTX-M-27-encoding IncFII plasmid. Compared to 14082s, ST931R has almost identical Gifsy-1, Gifsy-2, and ST64B prophages, lacks Gifsy-3, and instead carries a unique Fels-2 prophage related to that found in LT2. ST882S and ST931R both had a 94-kb virulence plasmid showing >99% identity with pSLT14028s and a cryptic 3,904-bp replicon; ST931R also has cryptic 93-kb IncI1 and 62-kb IncI2 group plasmids. To the best of our knowledge, in vivo acquisition of extended-spectrum β-lactamase resistance by S Typhimurium and bla_CTX-M-27 genes in U.S. isolates of Salmonella have not previously been reported.

Trends of extended-spectrum β-lactamase-producing Escherichia coli sequence type 131 and its H30 subclone in a French hospital over a 15-year period

Sequence type 131 (ST131) is a predominant lineage among extraintestinal pathogenic Escherichia coli. It plays a major role in the worldwide dissemination of E. coli producing extended-spectrum β-lactamases (ESBLs). Here we describe the long-term epidemiology of this clonal group in a French university hospital, where the incidence of ESBL-producing E. coli has increased from 0.018 case per 1000 patient-days in the year 2000 to 0.50 case per 1000 patient-days in 2014. The first of the 141 ST131 isolates was recovered in 2006, and the ST131 clonal group accounted for 18.1% of total ESBL-producing E. coli over the whole period (2000-2014). Subclonal typing showed that 75.9% (107/141) of ST131 isolates were H30, of which 81.3% (87/107) were H30-Rx. The large majority (137/141) of ESBLs produced were of the CTX-M group, with 94 CTX-M-15, 19 CTX-M-1, 10 CTX-M-27, 8 CTX-M-14 and four other CTX-M types (n = 6). Pulsed-field gel electrophoresis (PFGE) analysis showed high diversity, which increased during the course of the study. The 141 ST131 isolates clustered in 53 pulsotypes (PTs), with 2 dominant PTs (PT14 and PT13) with 36 and 17 isolates, respectively. These findings showed that ST131 was a predominant clone among ESBL-producing E. coli in our hospital, even though it only accounted for <20%. Moreover, ST131 should be regarded not as a unified entity but as a cluster of distinct clonal subsets even if the increase in resistance within ST131 has a strong clonal basis, being attributable mainly to the spread of C1/H30-R and C2/H30-Rx clades.

Paediatric antibiotic prescriptions in primary care in the Alpes-Maritimes area of southeastern France between 2008 and 2013

France has remained among the top five European countries for ambulatory antibiotic consumption since such monitoring began in 1998. Young children are major antibiotic consumers, in spite of the viral origin of most infections in this population. Recommendations were updated in 2011 to limit prescriptions. In order to assess their impact, diagnoses and prescriptions were compared in a population of children attending daycare centres in southeastern France in 2008 and 2012. Trends in the reimbursement of paediatric antibiotic prescriptions by the national health insurance (NHI) for the whole area were also studied. Distribution of diagnoses accounting for antibiotic treatment and type of antibiotic prescribed over the previous 3 months to children below 4 years of age attending daycare centres in the Alpes-Maritimes area in southeastern France were compared between 2008 and 2012 prior to and following the availability of these new recommendations. Trends in reimbursed ambulatory antibiotic prescriptions by general practitioners and paediatricians in the area were studied for this age group from 2008 to 2012 and in 2013. The majority of recorded diagnoses concerned upper respiratory tract infections (URTI). Inappropriate antibiotic prescription persisted for colds and bronchitis in similar proportions during both surveys. Improvement in the choice of antibiotic with fewer prescriptions for third-generation cephalosporins was observed both in daycare centres and according to NHI data; however, this was mainly recorded among paediatricians. The management of paediatric URTI still needs improvement, pointing to the need to investigate and adequately address the reasons for inappropriate antibiotic prescription.

ESBL/AmpC-producing Enterobacteriaceae in households with children of preschool age: prevalence, risk factors and co-carriage

OBJECTIVES

ESBL/AmpC-producing Enterobacteriaceae are an emerging public health concern. As households with preschool children may substantially contribute to the community burden of antimicrobial resistance, we determined the prevalence, risk factors and co-carriage of ESBL/AmpC-producing bacteria in preschool children and their parents.

METHODS

From April 2013 to January 2015, each month 2000 preschool children were randomly selected from Dutch population registries. The parents were invited to complete an epidemiological questionnaire and to obtain and send a faecal sample from the selected child and from one parent. Samples were tested for ESBL/AmpC-producing bacteria. Logistic regression was used to identify risk factors for ESBL/AmpC carriage in children and parents, and findings were internally validated by bootstrapping.

RESULTS

In total, 1016 families were included and ESBL/AmpC prevalence was 4.0% (95% CI 3.2%-5.0%); 3.5% (95% CI 2.5%-4.8%) in children and 4.5% (95% CI 3.4%-6.0%) in parents. Attending a daycare centre (DCC) was the only significant risk factor for children (OR 2.1, 95% CI 1.0-4.3). For parents, the only significant risk factor was having one or more children attending DCCs (OR 2.2, 95% CI 1.2-4.8). For parents of ESBL/AmpC-positive children the OR for ESBL/AmpC carriage was 19.7 (95% CI 9.2-42.4). Co-carriage of specific ESBL/AmpC genotypes in child and parent occurred more often than expected by chance (14.6% versus 1.1%, P < 0.001).

CONCLUSIONS

In this study, intestinal carriage with ESBL/AmpCs was detected in ∼4% of households with preschool children. DCC attendance was a risk factor in both children and parents and co-carriage of specific genotypes frequently occurred in child-parent pairs. These findings suggest household transmission or/and family-specific exposure to common sources of ESBL/AmpC-producing bacteria.

Urinary tract infection in infants caused by extended-spectrum beta-lactamase-producing Escherichia coli: comparison between urban and rural hospitals

BACKGROUND

Community-acquired urinary tract infection (UTI) caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is an emerging problem. Compared with urban infants, rural infants may encounter different distributions of community-acquired resistant strains and various barriers to efficient management.

METHODS

A retrospective survey and comparison was conducted for infants with UTI caused by ESBL-producing E. coli admitted to an urban hospital (n = 111) and a rural hospital (n = 48) in southern Taiwan from 2009 to 2012.

RESULTS

Compared with 2009 and 2010, the total number of cases at both hospitals significantly increased in 2011 and 2012 (p < 0.001). Compared with the rural patients, the urban patients were significantly younger, and they had fewer days of fever before and after admission, fewer presentations of poor activity and poor appetite, and a lower serum creatinine level. Most of the patients had no prior history of illness, and we could not identify any significant different risk factors for acquiring ESBL-producing E. coli, such as past antimicrobial use, hospitalization, UTI, and underlying renal diseases, between the urban and rural populations.

CONCLUSIONS

The increase in community-acquired UTI in infants caused by ESBL-producing E. coli was similar between the urban and rural populations. Our preliminary data suggest that the rural-urban disparities were probably related to easy access to health care by the urban population. ESBL complicates disease management, and the increase in the prevalence of ESBL producers is a major health concern and requires further healthy carrier and environmental surveillance.

Beta-lactamases in Enterobacteriaceae infections in children

Multi-drug resistance in Gram negative bacteria, particularly in Enterobacteriaceae, is a major clinical and public health challenge. The main mechanism of resistance in Enterobacteriaceae is linked to the production of beta-lactamase hydrolysing enzymes such as extended spectrum beta-lactamases (ESBL), AmpC beta-lactamases and carbapenemases (Carbapenemase Producing Enterobacteriaceae (CPE)). ESBL and CPE resistance genes are located on plasmids, which can be transmitted between Enterobacteriaceae, facilitating their spread in hospitals and communities. These plasmids usually harbour multiple additional co-resistance genes, including to trimethoprim-sulfamethoxazole, aminoglycosides, and fluoroquinolones, making these infections challenging to treat. Asymptomatic carriage in healthy children as well as community acquired infections are increasingly reported, particularly with ESBL. Therapeutic options are limited and previously little used antimicrobials such as fosfomycin and colistin have been re-introduced in clinical practice. Paediatric experience with these agents is limited hence there is a need to further examine their clinical efficacy, dosage and toxicity in children. Antimicrobial stewardship along with strict infection prevention and control practices need to be adopted widely in order to preserve currently available antimicrobials. The future development of novel agents effective against beta-lactamases producers and their applicability in children is urgently needed to address the challenge of multi-resistant Gram negative infections.