Improved characterisation of MRSA transmission using within-host bacterial sequence diversity
- University of Oxford, United Kingdom
- University of St Andrews, United Kingdom
- Sunpasitthiprasong Hospital, Thailand
- Mahidol University, Thailand
- University of Cambridge, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, United Kingdom
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) transmission in the hospital setting has been a frequent subject of investigation using bacterial genomes, but previous approaches have not yet fully utilised the extra deductive power provided when multiple pathogen samples are acquired from each host. Here, we use a large dataset of MRSA sequences from multiply-sampled patients to reconstruct colonisation of individuals in a high-transmission setting in a hospital in Thailand. We reconstructed transmission trees for MRSA. We also investigated transmission between anatomical sites on the same individual, finding that this either occurs repeatedly or involves a wide transmission bottleneck. We examined the between-subject bottleneck, finding a wide range in the amount of diversity transmitted. Finally, we compared our approach to the simpler method of identifying transmission pairs using single nucleotide polymorphism (SNP) counts. This suggested that the optimum threshold for identifying a pair is 39 SNPs, if sensitivities and specificities are equally weighted.
Data availability
Illumina read data is available in the European Nucleotide Archive as part of study accession number PRJEB4140. Genome assemblies will be made available prior to publication. We are unable to provide patient data for reasons of confidentiality.
-
Staphylococcus aureus ST239 diversity in ThailandEuropean Nucleotide Archive, PRJEB4140.
-
Evolution of MRSA During Hospital Transmission and Intercontinental SpreadEuropean Nucleotide Archive, PRJEB2489.
-
Staphylococcus aureus ST239 diversityEuropean Nucleotide Archive, PRJEB2076.
Article and author information
Author details
Direk Limmathurotsakul
Funding
Wellcome (098051)
- Matthew TG Holden
- Sharon J Peacock
Chief Scientist Office (SIRN10)
- Matthew TG Holden
Wellcome (106698/Z/14/Z)
- Vanaporn Wuthiekanun
Medical Research Council (G1000803)
- Sharon J Peacock
European Research Council (PBDR-339251)
- Matthew D Hall
- Christophe Fraser
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Ethical approval was obtained from the Ethical and Scientific Review subcommittee of the Royal Thai Government Ministry of Public Health (85/2550), and the Oxford Tropical Research Ethics Committee (024 07). All patients admitted to the two ICUs were eligible for inclusion and were enrolled after written informed consent, and consent to publish, was obtained.
Copyright
© 2019, Hall et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,312
- views
-
- 328
- downloads
-
- 40
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Improved characterisation of MRSA transmission using within-host bacterial sequence diversity
eLife 8:e46402.
https://doi.org/10.7554/eLife.46402
Further reading
-
- Epidemiology and Global Health
Artificially sweetened beverages containing noncaloric monosaccharides were suggested as healthier alternatives to sugar-sweetened beverages. Nevertheless, the potential detrimental effects of these noncaloric monosaccharides on blood vessel function remain inadequately understood. We have established a zebrafish model that exhibits significant excessive angiogenesis induced by high glucose, resembling the hyperangiogenic characteristics observed in proliferative diabetic retinopathy (PDR). Utilizing this model, we observed that glucose and noncaloric monosaccharides could induce excessive formation of blood vessels, especially intersegmental vessels (ISVs). The excessively branched vessels were observed to be formed by ectopic activation of quiescent endothelial cells (ECs) into tip cells. Single-cell transcriptomic sequencing analysis of the ECs in the embryos exposed to high glucose revealed an augmented ratio of capillary ECs, proliferating ECs, and a series of upregulated proangiogenic genes. Further analysis and experiments validated that reduced foxo1a mediated the excessive angiogenesis induced by monosaccharides via upregulating the expression of marcksl1a. This study has provided new evidence showing the negative effects of noncaloric monosaccharides on the vascular system and the underlying mechanisms.
-
- Epidemiology and Global Health
- Microbiology and Infectious Disease
Influenza viruses continually evolve new antigenic variants, through mutations in epitopes of their major surface proteins, hemagglutinin (HA) and neuraminidase (NA). Antigenic drift potentiates the reinfection of previously infected individuals, but the contribution of this process to variability in annual epidemics is not well understood. Here, we link influenza A(H3N2) virus evolution to regional epidemic dynamics in the United States during 1997—2019. We integrate phenotypic measures of HA antigenic drift and sequence-based measures of HA and NA fitness to infer antigenic and genetic distances between viruses circulating in successive seasons. We estimate the magnitude, severity, timing, transmission rate, age-specific patterns, and subtype dominance of each regional outbreak and find that genetic distance based on broad sets of epitope sites is the strongest evolutionary predictor of A(H3N2) virus epidemiology. Increased HA and NA epitope distance between seasons correlates with larger, more intense epidemics, higher transmission, greater A(H3N2) subtype dominance, and a greater proportion of cases in adults relative to children, consistent with increased population susceptibility. Based on random forest models, A(H1N1) incidence impacts A(H3N2) epidemics to a greater extent than viral evolution, suggesting that subtype interference is a major driver of influenza A virus infection ynamics, presumably via heterosubtypic cross-immunity.
