Regional spread of an atypical ESBL-producing Escherichia coli ST131H89 clone among different human and environmental reservoirs in Western Switzerland.

We describe the inter-regional spread of a novel ESBL-producing Escherichia coli subclone (ST131H89) in long-term care facility residents, general population, and environmental water sources in Western Switzerland between 2017 and 2020. The study highlights the importance of molecular surveillance for tracking emerging antibiotic-resistant pathogens in healthcare and community settings.

Gut microbiome dynamics in index patients colonized with extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales after hospital discharge and their household contacts.

IMPORTANCE: Colonization with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) often precedes infections and is therefore considered as a great threat for public health. Here, we studied the gut microbiome dynamics in eight index patients colonized with ESBL-PE after hospital discharge and the impact of exposure to this index patient on the gut microbiome dynamics of their household contacts. We showed that the microbiome composition from index patients is different from their household contacts upon hospital discharge and that, in some of the index patients, their microbiome composition over time shifted toward the composition of their household contacts. In contrast, household contacts showed a stable microbiome composition over time irrespective of low-level extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) gut colonization, suggesting that, in healthy microbiomes, colonization resistance is able to prevent ESBL-PE expansion.

Populations of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella pneumoniae are different in human-polluted environment and food items: a multicentre European study.

OBJECTIVES: To assess the extent to which food items are a source of extended-spectrum ß-lactamase (ESBL) -producing Escherichia coli (ESBL-Ec) and ESBL-producing Klebsiella pneumoniae (ESBL-Kp) for humans in five European cities. METHODS: We sampled 122 human polluted (hp)-environments (sewers and polluted rivers, as a proxy of human contamination) and 714 food items in Besançon (France), Geneva (Switzerland), Sevilla (Spain), Tübingen (Germany) and Utrecht (The Netherlands). A total of 254 ESBL-Ec and 39 ESBL-Kp isolates were cultured. All genomes were fully sequenced to compare their sequence types (ST) and core genomes, along with the distribution of blaESBL genes and their genetic supports (i.e. chromosome or plasmid). RESULTS: Sequence data revealed that ESBL-Ec and ESBL-Kp isolates from hp-environments were genetically different from those contaminating food items. ESBL-Ec ST131 was widespread in the hp-environment (21.5% of the isolates) but absent from the food items tested. ESBL-Ec ST10 was in similar proportions in hp-environments and food items (15 and 10 isolates, respectively) but mostly carried reservoir-specific blaESBL. blaCTX-M-1 and blaSHV-12 predominated in food-related E. coli isolates (32% and 34% of the isolates, respectively), whereas blaCTX-M-15 and blaCTX-M-27 predominated in isolates from hp-environments (52% and 15% of the isolates, respectively). CONCLUSIONS: We found a very limited connection between ESBL-Ec and ESBL-Kp populations retrieved in food items and from hp-environments and blaESBL. This suggests that human-to-human contamination, rather than the food chain, is possibly the most frequent route of ESBL-Ec and ESBL-Kp transmission in high-income countries.

Extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing Escherichia coli isolates causing bacteremia in the Netherlands (2014 - 2016) differ in clonal distribution, antimicrobial resistance gene and virulence gene content.

BACKGROUND: Knowledge on the molecular epidemiology of Escherichia coli causing E. coli bacteremia (ECB) in the Netherlands is mostly based on extended-spectrum beta-lactamase-producing E. coli (ESBL-Ec). We determined differences in clonality and resistance and virulence gene (VG) content between non-ESBL-producing E. coli (non-ESBL-Ec) and ESBL-Ec isolates from ECB episodes with different epidemiological characteristics. METHODS: A random selection of non-ESBL-Ec isolates as well as all available ESBL-Ec blood isolates was obtained from two Dutch hospitals between 2014 and 2016. Whole genome sequencing was performed to infer sequence types (STs), serotypes, acquired antibiotic resistance genes and VG scores, based on presence of 49 predefined putative pathogenic VG. RESULTS: ST73 was most prevalent among the 212 non-ESBL-Ec (N = 26, 12.3%) and ST131 among the 69 ESBL-Ec (N = 30, 43.5%). Prevalence of ST131 among non-ESBL-Ec was 10.4% (N = 22, P value < .001 compared to ESBL-Ec). O25:H4 was the most common serotype in both non-ESBL-Ec and ESBL-Ec. Median acquired resistance gene counts were 1 (IQR 1-6) and 7 (IQR 4-9) for non-ESBL-Ec and ESBL-Ec, respectively (P value < .001). Among non-ESBL-Ec, acquired resistance gene count was highest among blood isolates from a primary gastro-intestinal focus (median 4, IQR 1-8). Median VG scores were 13 (IQR 9-20) and 12 (IQR 8-14) for non-ESBL-Ec and ESBL-Ec, respectively (P value = .002). VG scores among non-ESBL-Ec from a primary urinary focus (median 15, IQR 11-21) were higher compared to non-ESBL-Ec from a primary gastro-intestinal (median 10, IQR 5-13) or hepatic-biliary focus (median 11, IQR 5-18) (P values = .007 and .04, respectively). VG content varied between different E. coli STs. CONCLUSIONS: Non-ESBL-Ec and ESBL-Ec blood isolates from two Dutch hospitals differed in clonal distribution, resistance gene and VG content. Also, resistance gene and VG content differed between non-ESBL-Ec from different primary foci of ECB.

mlplasmids: a user-friendly tool to predict plasmid- and chromosome-derived sequences for single species.

Assembly of bacterial short-read whole-genome sequencing data frequently results in hundreds of contigs for which the origin, plasmid or chromosome, is unclear. Complete genomes resolved by long-read sequencing can be used to generate and label short-read contigs. These were used to train several popular machine learning methods to classify the origin of contigs from Enterococcus faecium, Klebsiella pneumoniae and Escherichia coli using pentamer frequencies. We selected support-vector machine (SVM) models as the best classifier for all three bacterial species (F1-score E. faecium=0.92, F1-score K. pneumoniae=0.90, F1-score E. coli=0.76), which outperformed other existing plasmid prediction tools using a benchmarking set of isolates. We demonstrated the scalability of our models by accurately predicting the plasmidome of a large collection of 1644 E. faecium isolates and illustrate its applicability by predicting the location of antibiotic-resistance genes in all three species. The SVM classifiers are publicly available as an R package and graphical-user interface called 'mlplasmids'. We anticipate that this tool may significantly facilitate research on the dissemination of plasmids encoding antibiotic resistance and/or contributing to host adaptation.