Using whole-genome sequencing to assess the diversity of Paenibacillus larvae within an outbreak and a beekeeping operation

The spore-forming bacterium Paenibacillus larvae is the causative agent of American foulbrood (AFB), a devastating disease of honeybees (Apis mellifera). In the present study, we used whole-genome sequencing (WGS) to investigate an extensive outbreak of AFB in northwestern Slovenia in 2019. A total of 59 P . larvae isolates underwent WGS, of which 40 originated from a single beekeeping operation, to assess the diversity of P. larvae within the beekeeping operation, apiary and colony. By applying a case-specific single-linkage threshold of 34 allele differences (AD), whole-genome multilocus sequence typing (wgMLST) identified two outbreak clusters represented by ERIC II-ST11 clones. All isolates from a single beekeeping operation fell within cluster 1 and the median pairwise AD between them was 10 (range=1–22). The median pairwise AD for apiaries of the same beekeeping operation ranged from 8 to 11 (min.=1, max.=22). For colonies of the same apiary and honey samples from these colonies, the median pairwise AD ranged from 8 to 14 (min.=1, max.=20). The maximum within-cluster distance was 33 pairwise AD for cluster 1 and 44 for cluster 2 isolates. The minimum distance between the outbreak-related and non-related isolates was 37 AD, confirming the importance of associated epidemiological data for delineating outbreak clusters. The observed transmission events could be explained by the activities of honeybees and beekeepers. The present study provides insight into the genetic diversity of P. larvae at different levels and thus provides information for future AFB surveillance.

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Harmonization of whole-genome sequencing for outbreak surveillance of Enterobacteriaceae and Enterococci

Microbial Genomics ◽

10.1099/mgen.0.000567 ◽

2021 ◽

Vol 7 (7) ◽

Author(s):

Casper Jamin ◽

Sien De Koster ◽

Stefanie van Koeveringe ◽

Dieter De Coninck ◽

Klaas Mensaert ◽

...

Keyword(s):

Whole Genome Sequencing ◽

Genome Sequencing ◽

Type Species ◽

De Novo ◽

Whole Genome ◽

Data Generation ◽

Sequencing Data ◽

Content Type ◽

Link Type ◽

Antimicrobial Resistance Genes

Whole-genome sequencing (WGS) is becoming the de facto standard for bacterial typing and outbreak surveillance of resistant bacterial pathogens. However, interoperability for WGS of bacterial outbreaks is poorly understood. We hypothesized that harmonization of WGS for outbreak surveillance is achievable through the use of identical protocols for both data generation and data analysis. A set of 30 bacterial isolates, comprising of various species belonging to the Enterobacteriaceae family and Enterococcus genera, were selected and sequenced using the same protocol on the Illumina MiSeq platform in each individual centre. All generated sequencing data were analysed by one centre using BioNumerics (6.7.3) for (i) genotyping origin of replications and antimicrobial resistance genes, (ii) core-genome multi-locus sequence typing (cgMLST) for Escherichia coli and Klebsiella pneumoniae and whole-genome multi-locus sequencing typing (wgMLST) for all species. Additionally, a split k-mer analysis was performed to determine the number of SNPs between samples. A precision of 99.0% and an accuracy of 99.2% was achieved for genotyping. Based on cgMLST, a discrepant allele was called only in 2/27 and 3/15 comparisons between two genomes, for E. coli and K. pneumoniae, respectively. Based on wgMLST, the number of discrepant alleles ranged from 0 to 7 (average 1.6). For SNPs, this ranged from 0 to 11 SNPs (average 3.4). Furthermore, we demonstrate that using different de novo assemblers to analyse the same dataset introduces up to 150 SNPs, which surpasses most thresholds for bacterial outbreaks. This shows the importance of harmonization of data-processing surveillance of bacterial outbreaks. In summary, multi-centre WGS for bacterial surveillance is achievable, but only if protocols are harmonized.

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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

Microbial Genomics ◽

10.1099/mgen.0.000672 ◽

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.

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

Microbial Genomics ◽

10.1099/mgen.0.000391 ◽

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.

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Neisseria gonorrhoeae clustering to reveal major European whole-genome-sequencing-based genogroups in association with antimicrobial resistance

Microbial Genomics ◽

10.1099/mgen.0.000481 ◽

2020 ◽

Author(s):

Miguel Pinto ◽

Vítor Borges ◽

Joana Isidro ◽

João Carlos Rodrigues ◽

Luís Vieira ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Neisseria Gonorrhoeae ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Type Species ◽

Transmitted Disease ◽

Epidemiological Surveillance ◽

Whole Genome ◽

Content Type ◽

Link Type

Neisseria gonorrhoeae , the bacterium responsible for the sexually transmitted disease gonorrhoea, has shown an extraordinary ability to develop antimicrobial resistance (AMR) to multiple classes of antimicrobials. With no available vaccine, managing N. gonorrhoeae infections demands effective preventive measures, antibiotic treatment and epidemiological surveillance. The latter two are progressively being supported by the generation of whole-genome sequencing (WGS) data on behalf of national and international surveillance programmes. In this context, this study aims to perform N. gonorrhoeae clustering into genogroups based on WGS data, for enhanced prospective laboratory surveillance. Particularly, it aims to identify the major circulating WGS-genogroups in Europe and to establish a relationship between these and AMR. Ultimately, it enriches public databases by contributing with WGS data from Portuguese isolates spanning 15 years of surveillance. A total of 3791 carefully inspected N. gonorrhoeae genomes from isolates collected across Europe were analysed using a gene-by-gene approach (i.e. using cgMLST). Analysis of cluster composition and stability allowed the classification of isolates into a two-step hierarchical genogroup level determined by two allelic distance thresholds revealing cluster stability. Genogroup clustering in general agreed with available N. gonorrhoeae typing methods [i.e. MLST (multilocus sequence typing), NG-MAST ( N. gonorrhoeae multi-antigen sequence typing) and PubMLST core-genome groups], highlighting the predominant genogroups circulating in Europe, and revealed that the vast majority of the genogroups present a dominant AMR profile. Additionally, a non-static gene-by-gene approach combined with a more discriminatory threshold for potential epidemiological linkage enabled us to match data with previous reports on outbreaks or transmission chains. In conclusion, this genogroup assignment allows a comprehensive analysis of N. gonorrhoeae genetic diversity and the identification of the WGS-based genogroups circulating in Europe, while facilitating the assessment (and continuous monitoring) of their frequency, geographical dispersion and potential association with specific AMR signatures. This strategy may benefit public-health actions through the prioritization of genogroups to be controlled, the identification of emerging resistance carriage, and the potential facilitation of data sharing and communication.

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

Microbial Genomics ◽

10.1099/mgen.0.000647 ◽

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.

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A stop–gain mutation in sigma factor SigH (MAB_3543c) may be associated with tigecycline resistance in Mycobacteroides abscessus

Journal of Medical Microbiology ◽

10.1099/jmm.0.001378 ◽

2021 ◽

Vol 70 (7) ◽

Author(s):

Col Lin Lee ◽

Hien Fuh Ng ◽

Yun Fong Ngeow ◽

Zin Thaw

Keyword(s):

Stress Response ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Sigma Factor ◽

Type Species ◽

Treatment Modalities ◽

Gene Overexpression ◽

Whole Genome ◽

Content Type ◽

Link Type

Introduction. Tigecycline is currently acknowledged to be one of the most effective antibiotics against infections caused by Mycobacteroides abscessus . Gap statement. The genetic determinants of tigecycline resistance in M. abscessus are not well understood. Aim. In this study, we characterized a tigecycline-resistant M. abscessus mutant, designated CL7, to identify the potential resistance mechanism. Methodology. CL7 was characterized using antimicrobial susceptibility testing, whole-genome sequencing, PCR and RT-qPCR. For biological verification, gene overexpression assays were carried out. Results. Whole-genome sequencing and the subsequent gene overexpression assays showed that CL7 harboured a stop–gain mutation in MAB_3543 c, which may be responsible for the tigecycline resistance phenotype. This gene encodes an orthologue of SigH, which is involved in the positive regulation of physiological stress response and is negatively regulated by the RshA anti-sigma factor in Mycobacterium tuberculosis . We hypothesized that the MAB_3543 c mutation may disrupt the interaction between SigH and RshA (MAB_3542 c). RT-qPCR analyses revealed the upregulation of MAB_3543 c and other key stress response genes, which has previously been shown to be a hallmark of SigH–RshA bond disruption and tigecycline resistance. Conclusion. The MAB_3543c mutation may represent a novel determinant of tigecycline resistance in M. abscessus . The findings of this study will hopefully contribute to our knowledge of potential tigecycline resistance mechanisms in M. abscessus , which may lead to better diagnostics and treatment modalities in the future.

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Genome sequencing identifies Listeria fleischmannii subsp. coloradonensis subsp. nov., isolated from a ranch

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.048587-0 ◽

2013 ◽

Vol 63 (Pt_9) ◽

pp. 3257-3268 ◽

Cited By ~ 30

Author(s):

Henk C. den Bakker ◽

Clyde S. Manuel ◽

Esther D. Fortes ◽

Martin Wiedmann ◽

Kendra K. Nightingale

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Type Strain ◽

Type Species ◽

Rrna Gene ◽

Whole Genome ◽

Content Type ◽

Link Type

Twenty Listeria -like isolates were obtained from environmental samples collected on a cattle ranch in northern Colorado; all of these isolates were found to share an identical partial sigB sequence, suggesting close relatedness. The isolates were similar to members of the genus Listeria in that they were Gram-stain-positive, short rods, oxidase-negative and catalase-positive; the isolates were similar to Listeria fleischmannii because they were non-motile at 25 °C. 16S rRNA gene sequencing for representative isolates and whole genome sequencing for one isolate was performed. The genome of the type strain of Listeria fleischmannii (strain LU2006-1T) was also sequenced. The draft genomes were very similar in size and the average MUMmer nucleotide identity across 91 % of the genomes was 95.16 %. Genome sequence data were used to design primers for a six-gene multi-locus sequence analysis (MLSA) scheme. Phylogenies based on (i) the near-complete 16S rRNA gene, (ii) 31 core genes and (iii) six housekeeping genes illustrated the close relationship of these Listeria -like isolates to Listeria fleischmannii LU2006-1T. Sufficient genetic divergence of the Listeria -like isolates from the type strain of Listeria fleischmannii and differing phenotypic characteristics warrant these isolates to be classified as members of a distinct infraspecific taxon, for which the name Listeria fleischmannii subsp. coloradonensis subsp. nov. is proposed. The type strain is TTU M1-001T ( = BAA-2414T = DSM 25391T). The isolates of Listeria fleischmannii subsp. coloradonensis subsp. nov. differ from the nominate subspecies by the inability to utilize melezitose, turanose and sucrose, and the ability to utilize inositol. The results also demonstrate the utility of whole genome sequencing to facilitate identification of novel taxa within a well-described genus. The genomes of both subspecies of Listeria fleischmannii contained putative enhancin genes; the Listeria fleischmannii subsp. coloradonensis subsp. nov. genome also encoded a putative mosquitocidal toxin. The presence of these genes suggests possible adaptation to an insect host, and further studies are needed to probe niche adaptation of Listeria fleischmannii .

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Re-identification of strains deposited as Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas putida in GenBank based on whole genome sequences

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.004468 ◽

2020 ◽

Vol 70 (11) ◽

pp. 5958-5963

Author(s):

Yuh Morimoto ◽

Mari Tohya ◽

Zulipiya Aibibula ◽

Tadashi Baba ◽

Hiroyuki Daida ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Genome Sequencing ◽

Dna Hybridization ◽

Type Species ◽

Whole Genome ◽

Average Nucleotide Identity ◽

Genome Sequences ◽

Content Type ◽

Link Type

The taxonomic classification of Pseudomonas species has been revised and updated several times. This study utilized average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) cutoff values of 95 and 70 %, respectively, to re-identify the species of strains deposited in GenBank as P. aeruginosa , P. fluorescens and P. putida . Of the 264 deposited P. aeruginosa strains, 259 were correctly identified as P. aeruginosa , but the remaining five were not. All 28 deposited P. fluorescens strains had been incorrectly identified as P. fluorescens . Four of these strains were re-identified, including two as P. kilonensis and one each as P. aeruginosa and P. brassicacearum , but the remaining 24 could not be re-identified. Similarly, all 35 deposited P. putida strains had been incorrectly identified as P. putida . Nineteen of these strains were re-identified, including 12 as P. alloputida , four as P. asiatica and one each as P. juntendi , P. monteilii and P. mosselii . These results strongly suggest that Pseudomonas bacteria should be identified using ANI and dDDH analyses based on whole genome sequencing when Pseudomonas species are initially deposited in GenBank/DDBJ/EMBL databases.

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Whole-Genome Sequencing Data for Serotyping Escherichia coli—It's Time for a Change!

Journal of Clinical Microbiology ◽

10.1128/jcm.01448-15 ◽

2015 ◽

Vol 53 (8) ◽

pp. 2402-2403 ◽

Cited By ~ 9

Author(s):

Claire Jenkins

Keyword(s):

Escherichia Coli ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Whole Genome Sequencing Data ◽

Whole Genome ◽

Sequencing Data ◽

Content Type ◽

Link Type ◽

Article Type ◽

User Friendly

The accessibility of whole-genome sequencing (WGS) presents the opportunity for national reference laboratories to provide a state-of-the-art public health surveillance service. The replacement of traditional serology-based typing ofEscherichia coliby WGS is supported by user-friendly, freely available data analysis Web tools. Anarticle in this issueof theJournal of Clinical Microbiology(K. G. Joensen, A. M. M. Tetzschner, A. Iguchi, F. M. Aarestrup, and F. Scheutz, J Clin Microbiol, 53:2410–2426, 2015,http://dx.doi.org/10.1128/JCM.00008-15) describes SerotypeFinder, an essential guide to serotypingE. coliin the 21st century.

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Phylogeny of Salmonella enterica subspecies arizonae by whole-genome sequencing reveals high incidence of polyphyly and low phase 1 H antigen variability

Microbial Genomics ◽

10.1099/mgen.0.000522 ◽

2021 ◽

Vol 7 (2) ◽

Author(s):

Nikki W. Shariat ◽

Ruth E. Timme ◽

Abigail T. Walters

Keyword(s):

Whole Genome Sequencing ◽

Genome Sequencing ◽

Salmonella Enterica ◽

Phylogenetic Analyses ◽

Phase 1 ◽

Whole Genome Sequencing Data ◽

Whole Genome ◽

Type Vi Secretion System ◽

Content Type ◽

Link Type

Salmonella enterica subspecies arizonae is frequently associated with animal reservoirs, particularly reptiles, and can cause illness in some mammals, including humans. Using whole-genome sequencing data, core genome phylogenetic analyses were performed using 112 S . enterica subsp. arizonae isolates, representing 46 of 102 described serovars. Nearly one-third of these are polyphyletic, including two serovars that appear in four and five distinct evolutionary lineages. Subspecies arizonae has a monophasic H antigen. Among the 46 serovars investigated, only 8 phase 1 H antigens were identified, demonstrating high conservation for this antigen. Prophages and plasmids were found throughout this subspecies, including five novel prophages. Polyphyly was also reflected in prophage content, although some clade-specific enrichment for some phages was observed. IncFII(S) was the most frequent plasmid replicon identified and was found in a quarter of S. enterica subsp. arizonae genomes. Salmonella pathogenicity islands (SPIs) 1 and 2 are present across all Salmonella , including this subspecies, although effectors sipA, sptP and arvA in SPI-1 and sseG and ssaI in SPI-2 appear to be lost in this lineage. SPI-20, encoding a type VI secretion system, is exclusive to this subspecies and is well maintained in all genomes sampled. A number of fimbral operons were identified, including the sas operon that appears to be a synapomorphy for this subspecies, while others exhibited more clade-specific patterns. This work reveals evolutionary patterns in S. enterica subsp. arizonae that make this subspecies a unique lineage within this very diverse species.

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