scholarly journals ECTyper: in silico Escherichia coli serotype and species prediction from raw and assembled whole-genome sequence data

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Kyrylo Bessonov ◽  
Chad Laing ◽  
James Robertson ◽  
Irene Yong ◽  
Kim Ziebell ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
In Silico ◽  
Type Species ◽  
Outbreak Detection ◽  
Health Concern ◽  
Whole Genome ◽  
Content Type ◽  
Link Type ◽  
O Antigens

Escherichia coli is a priority foodborne pathogen of public health concern and phenotypic serotyping provides critical information for surveillance and outbreak detection activities. Public health and food safety laboratories are increasingly adopting whole-genome sequencing (WGS) for characterizing pathogens, but it is imperative to maintain serotype designations in order to minimize disruptions to existing public health workflows. Multiple in silico tools have been developed for predicting serotypes from WGS data, including SRST2, SerotypeFinder and EToKi EBEis, but these tools were not designed with the specific requirements of diagnostic laboratories, which include: speciation, input data flexibility (fasta/fastq), quality control information and easily interpretable results. To address these specific requirements, we developed ECTyper (https://github.com/phac-nml/ecoli_serotyping) for performing both speciation within Escherichia and Shigella , and in silico serotype prediction. We compared the serotype prediction performance of each tool on a newly sequenced panel of 185 isolates with confirmed phenotypic serotype information. We found that all tools were highly concordant, with 92–97 % for O-antigens and 98–100 % for H-antigens, and ECTyper having the highest rate of concordance. We extended the benchmarking to a large panel of 6954 publicly available E. coli genomes to assess the performance of the tools on a more diverse dataset. On the public data, there was a considerable drop in concordance, with 75–91 % for O-antigens and 62–90 % for H-antigens, and ECTyper and SerotypeFinder being the most concordant. This study highlights that in silico predictions show high concordance with phenotypic serotyping results, but there are notable differences in tool performance. ECTyper provides highly accurate and sensitive in silico serotype predictions, in addition to speciation, and is designed to be easily incorporated into bioinformatic workflows.

scholarly journals Evaluation of whole-genome sequencing-based subtyping methods for the surveillance of Shigella spp. and the confounding effect of mobile genetic elements in long-term outbreaks

2021 ◽  
Vol 7 (11) ◽  
Author(s):  
Isabelle Bernaquez ◽  
Christiane Gaudreau ◽  
Pierre A. Pilon ◽  
Sadjia Bekal
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Type Species ◽  
Core Genome ◽  
Outbreak Detection ◽  
Whole Genome ◽  
Content Type ◽  
Link Type ◽  
Interpretation Criteria

Many public health laboratories across the world have implemented whole-genome sequencing (WGS) for the surveillance and outbreak detection of foodborne pathogens. PulseNet-affiliated laboratories have determined that most single-strain foodborne outbreaks are contained within 0–10 multi-locus sequence typing (MLST)-based allele differences and/or core genome single-nucleotide variants (SNVs). In addition to being a food- and travel-associated outbreak pathogen, most Shigella spp. cases occur through continuous person-to-person transmission, predominantly involving men who have sex with men (MSM), leading to long-term and recurrent outbreaks. Continuous transmission patterns coupled to genetic evolution under antibiotic treatment pressure require an assessment of existing WGS-based subtyping methods and interpretation criteria for cluster inclusion/exclusion. An evaluation of 4 WGS-based subtyping methods [SNVPhyl, coreMLST, core genome MLST (cgMLST) and whole-genome MLST (wgMLST)] was performed on 9 foodborne-, travel- and MSM-related retrospective outbreaks from a collection of 91 Shigella flexneri and 232  Shigella sonnei isolates to determine the methods’ epidemiological concordance, discriminatory power, robustness and ability to generate stable interpretation criteria. The discriminatory powers were ranked as follows: coreMLST<SNVPhyl<cgMLST<wgMLST (range: 0.970–1.000). The genetic differences observed for non-MSM-related Shigella spp. outbreaks respect the standard 0–10 allele/SNV guideline; however, mobile genetic element (MGE)-encoded loci caused inflated genetic variation and discrepant phylogenies for prolonged MSM-related S. sonnei outbreaks via wgMLST. The S. sonnei correlation coefficients of wgMLST were also the lowest at 0.680, 0.703 and 0.712 for SNVPhyl, coreMLST and cgMLST, respectively. Plasmid maintenance, mobilization and conjugation-associated genes were found to be the main source of genetic distance inflation in addition to prophage-related genes. Duplicated alleles arising from the repeated nature of IS elements were also responsible for many false cg/wgMLST differences. The coreMLST approach was shown to be the most robust, followed by SNVPhyl and wgMLST for inter-laboratory comparability. Our results highlight the need for validating species-specific subtyping methods based on microbial genome plasticity and outbreak dynamics in addition to the importance of filtering confounding MGEs for cluster detection.

scholarly journals Genomic surveillance of Escherichia coli and Klebsiella spp. in hospital sink drains and patients

2020 ◽  
Vol 6 (7) ◽  
Author(s):  
Bede Constantinides ◽  
Kevin K. Chau ◽  
T. Phuong Quan ◽  
Gillian Rodger ◽  
Monique I. Andersson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Type Species ◽  
Whole Genome ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Antimicrobial Resistance Genes

Escherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonized with diverse populations of E. coli , Klebsiella pneumoniae and Klebsiella oxytoca , including both antimicrobial-resistant and susceptible strains. Using whole-genome sequencing of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies, which may vary as a result of different inputs and selection pressures. Whole-genome sequencing of 46 contemporaneous patient isolates identified one (2 %; 95 % CI 0.05–11 %) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10 % of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including bla CTX-M, bla SHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention. This article contains data hosted by Microreact.

scholarly journals Cluster-specific gene markers enhance Shigella and enteroinvasive Escherichia coli in silico serotyping

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Xiaomei Zhang ◽  
Michael Payne ◽  
Thanh Nguyen ◽  
Sandeep Kaur ◽  
Ruiting Lan
Keyword(s):  
Escherichia Coli ◽  
In Silico ◽  
Type Species ◽  
Specific Gene ◽  
Read Mapping ◽  
Gene Markers ◽  
Genetic Characteristics ◽  
Content Type ◽  
Link Type ◽  
Invasion Mechanisms

Shigella and enteroinvasive Escherichia coli (EIEC) cause human bacillary dysentery with similar invasion mechanisms and share similar physiological, biochemical and genetic characteristics. Differentiation of Shigella from EIEC is important for clinical diagnostic and epidemiological investigations. However, phylogenetically, Shigella and EIEC strains are composed of multiple clusters and are different forms of E. coli , making it difficult to find genetic markers to discriminate between Shigella and EIEC. In this study, we identified 10 Shigella clusters, seven EIEC clusters and 53 sporadic types of EIEC by examining over 17000 publicly available Shigella and EIEC genomes. We compared Shigella and EIEC accessory genomes to identify cluster-specific gene markers for the 17 clusters and 53 sporadic types. The cluster-specific gene markers showed 99.64% accuracy and more than 97.02% specificity. In addition, we developed a freely available in silico serotyping pipeline named Shigella EIEC Cluster Enhanced Serotype Finder (ShigEiFinder) by incorporating the cluster-specific gene markers and established Shigella and EIEC serotype-specific O antigen genes and modification genes into typing. ShigEiFinder can process either paired-end Illumina sequencing reads or assembled genomes and almost perfectly differentiated Shigella from EIEC with 99.70 and 99.74% cluster assignment accuracy for the assembled genomes and read mapping respectively. ShigEiFinder was able to serotype over 59 Shigella serotypes and 22 EIEC serotypes and provided a high specificity of 99.40% for assembled genomes and 99.38% for read mapping for serotyping. The cluster-specific gene markers and our new serotyping tool, ShigEiFinder (installable package: https://github.com/LanLab/ShigEiFinder, online tool: https://mgtdb.unsw.edu.au/ShigEiFinder/), will be useful for epidemiological and diagnostic investigations.

scholarly journals Whole genome sequencing reveals great diversity of Vibrio spp in prawns at retail

2021 ◽  
Vol 7 (9) ◽  
Author(s):  
Nicol Janecko ◽  
Samuel J. Bloomfield ◽  
Raphaëlle Palau ◽  
Alison E. Mather
Keyword(s):  
Public Health ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Resistance Genes ◽  
Type Species ◽  
Whole Genome ◽  
Content Type ◽  
Link Type ◽  
Critical Control Points ◽  
Antimicrobial Resistance Genes

Consumption of prawns as a protein source has been on the rise worldwide with seafood identified as the predominant attributable source of human vibriosis. However, surveillance of non-cholera Vibrio is limited both in public health and in food. Using a population- and market share-weighted study design, 211 prawn samples were collected and cultured for Vibrio spp. Contamination was detected in 46 % of samples, and multiple diverse Vibrio isolates were obtained from 34 % of positive samples. Whole genome sequencing (WGS) and phylogenetic analysis illustrated a comprehensive view of Vibrio species diversity in prawns available at retail, with no known pathogenicity markers identified in Vibrio parahaemolyticus and V. cholerae . Antimicrobial resistance genes were found in 77 % of isolates, and 12 % carried genes conferring resistance to three or more drug classes. Resistance genes were found predominantly in V. parahaemolyticus , though multiple resistance genes were also identified in V. cholerae and V. vulnificus . This study highlights the large diversity in Vibrio derived from prawns at retail, even within a single sample. Although there was little evidence in this study that prawns are a major source of vibriosis in the UK, surveillance of non-cholera Vibrio is very limited. This study illustrates the value of expanding WGS surveillance efforts of non-cholera Vibrios in the food chain to identify critical control points for food safety through the production system and to determine the full extent of the public health impact.

scholarly journals Isolation of the human-associated bla CTX-M-15-harbouring Klebsiella pneumoniae ST307 from a tortoise in the UK

2020 ◽  
Vol 2 (12) ◽  
Author(s):  
Geoffrey Foster ◽  
Manal AbuOun ◽  
Romain Pizzi ◽  
Bryn Tennant ◽  
Margaret McCall ◽  
...  
Keyword(s):  
Public Health ◽  
Klebsiella Pneumoniae ◽  
Type Species ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Public Health Concern ◽  
Emerging Pathogen ◽  
Content Type ◽  
Link Type ◽  
The Uk

The ST307 multidrug-resistant CTX-M-15-producing Klebsiella pneumoniae is an emerging pathogen, which has become disseminated worldwide in humans but is rarely reported from other reservoirs. We report the first isolation of K. pneumoniae from an animal in Europe and also from a reptile, a captive tortoise, whose death it probably caused. Detection of this clone from an animal adds to evidence of niche expansion in non-human environments, where it may amplify, recycle and become of greater public health concern.

scholarly journals Easy phylotyping of Escherichia coli via the EzClermont web app and command-line tool

2020 ◽  
Vol 2 (9) ◽  
Author(s):  
Nicholas R. Waters ◽  
Florence Abram ◽  
Fiona Brennan ◽  
Ashleigh Holmes ◽  
Leighton Pritchard
Keyword(s):  
Escherichia Coli ◽  
Type Species ◽  
Whole Genome ◽  
Command Line ◽  
Content Type ◽  
Link Type ◽  
Command Line Tool ◽  
Pcr Method ◽  
Web App ◽  
Genome Assemblies

The Clermont PCR method for phylotyping Escherichia coli remains a useful classification scheme even though genome sequencing is now routine, and higher-resolution sequence typing schemes are now available. Relating present-day whole-genome E. coli classifications to legacy phylotyping is essential for harmonizing the historical literature and understanding of this important organism. Therefore, we present EzClermont – a novel in silico Clermont PCR phylotyping tool to enable ready application of this phylotyping scheme to whole-genome assemblies. We evaluate this tool against phylogenomic classifications, and an alternative software implementation of Clermont typing. EzClermont is available as a web app at www.ezclermont.org, and as a command-line tool at https://nickp60.github.io/EzClermont/.

scholarly journals The epidemiology of AmpC-producing Escherichia coli isolated from dairy cattle faeces on pasture-fed farms

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Sara A. Burgess ◽  
Adrian L. Cookson ◽  
Lisa Brousse ◽  
Enrico Ortolani ◽  
Jackie Benschop ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sequence Analysis ◽  
Type Species ◽  
Dairy Farms ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Genome Sequence Analysis ◽  
Content Type ◽  
E Coli ◽  
Link Type

Introduction. Antibiotic use, particularly amoxicillin-clavulanic acid in dairy farming, has been associated with an increased incidence of AmpC-hyperproducing Escherichia coli . Gap statement. There is limited information on the incidence of AmpC-hyperproducing E. coli from seasonal pasture-fed dairy farms. Aim. We undertook a New Zealand wide cross-sectional study to determine the prevalence of AmpC-producing E. coli carried by dairy cattle. Methodology. Paddock faeces were sampled from twenty-six dairy farms and were processed for the selective growth of both extended-spectrum beta-lactamase (ESBL)- and AmpC-producing E. coli . Whole genome sequence analysis was carried out on 35 AmpC-producing E. coli . Results. No ESBL- or plasmid mediated AmpC-producing E. coli were detected, but seven farms were positive for chromosomal mediated AmpC-hyperproducing E. coli . These seven farms were associated with a higher usage of injectable amoxicillin antibiotics. Whole genome sequence analysis of the AmpC-producing E. coli demonstrated that the same strain (<3 SNPs difference) of E. coli ST5729 was shared between cows on a single farm. Similarly, the same strain (≤15 SNPs difference) of E. coli ST8977 was shared across two farms (separated by approximately 425 km). Conclusion. These results infer that both cow-to-cow and farm-to-farm transmission of AmpC-producing E. coli has occurred.

scholarly journals Whole-genome sequence analysis of environmental Escherichia coli from the faeces of straw-necked ibis (Threskiornis spinicollis) nesting on inland wetlands

2020 ◽  
Vol 6 (6) ◽  
Author(s):  
Ethan R. Wyrsch ◽  
Piklu Roy Chowdhury ◽  
Louise Wallis ◽  
Max L. Cummins ◽  
Tiziana Zingali ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Type Species ◽  
Whole Genome ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Inland Wetlands ◽  
Novel Variants ◽  
Sequence Types

Wildlife, and birds in particular, play an increasingly recognized role in the evolution and transmission of Escherichia coli that pose a threat to humans. To characterize these lineages and their potential threat from an evolutionary perspective, we isolated and performed whole-genome sequencing on 11 sequence types (STs) of E. coli recovered from the desiccated faeces of straw-necked ibis (Threskiornis spinicollis) nesting on inland wetlands located in geographically different regions of New South Wales, Australia. Carriage of virulence-associated genes was limited, and no antimicrobial resistance genes were detected, but novel variants of an insertion element that plays an important role in capturing and mobilizing antibiotic resistance genes, IS26, were identified and characterized. The isolates belonged to phylogroups B1 and D, including types known to cause disease in humans and animals. Specifically, we found E. coli ST58, ST69, ST162, ST212, ST446, ST906, ST2520, ST6096 and ST6241, and a novel phylogroup D strain, ST10208. Notably, the ST58 strain hosted significant virulence gene carriage. The sequences of two plasmids hosting putative virulence-associated factors with incompatibility groups I1 and Y, an extrachromosomal integrative/conjugative element, and a variant of a large Escherichia phage of the family Myoviridae, were additionally characterized. We identified multiple epidemiologically relevant gene signatures that link the ibis isolates to sequences from international sources, plus novel variants of IS26 across different sequence types and in different contexts.

PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Type Species ◽  
Pentose Phosphate ◽  
Bacterial Cells ◽  
Surface Adhesion ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

scholarly journals Amedibacterium intestinale gen. nov., sp. nov., isolated from human faeces, and reclassification of Eubacterium dolichum Moore et al. 1976 (Approved Lists 1980) as Amedibacillus dolichus gen. nov., comb. nov

2020 ◽  
Vol 70 (6) ◽  
pp. 3656-3664 ◽  
Author(s):  
Nao Ikeyama ◽  
Atsushi Toyoda ◽  
Sho Morohoshi ◽  
Tadao Kunihiro ◽  
Takumi Murakami ◽  
...  
Keyword(s):  
In Silico ◽  
Type Species ◽  
Novel Species ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Content Type ◽  
Monophyletic Cluster ◽  
Link Type ◽  
Gene Sequence Analysis ◽  
Faecal Samples

Four strains (9CBEGH2T, 9BBH35, 6BBH38 and 6EGH11) of Gram-stain-positive, obligately anaerobic, rod-shaped bacteria were isolated from faecal samples from healthy Japanese humans. The results of 16S rRNA gene sequence analysis indicated that the four strains represented members of the family Erysipelotrichaceae and formed a monophyletic cluster with ‘ Absiella argi ’ strain N6H1-5 (99.4% sequence similarity) and Eubacterium sp. Marseille-P5640 (99.3 %). Eubacterium dolichum JCM 10413T (94.2 %) and Eubacterium tortuosum ATCC 25548T (93.7 %) were located near this monophyletic cluster. The isolates, 9CBEGH2T, ‘ A. argi ’ JCM 30884 and Eubacterium sp. Marseille-P5640 shared 98.7–99.1% average nucleotide identity (ANI) with each other. Moreover, the in silico DNA–DNA hybridization (DDH) values among three strains were 88.4–90.6%, indicating that these strains represent the same species. Strain 9CBEGH2T showed 21.5–24.1 % in silico DDH values with other related taxa. In addition, the ANI values between strain 9CBEGH2T and other related taxa ranged from 71.2 % to 73.5 %, indicating that this strain should be considered as representing a novel species on the basis of whole-genome relatedness. Therefore, we formally propose a novel name for ‘ A. argi ’ strains identified because the name ‘ A. argi ’ has been effectively, but not validly, published since 2017. On the basis of the collected data, strain 9CBEGH2T represents a novel species of a novel genus, for which the name Amedibacterium intestinale gen. nov., sp. nov. is proposed. The type strain of A. intestinale is 9CBEGH2T (=JCM 33778T=DSM 110575T).

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