Mark Pallen

Last updated

Mark Pallen
Born
Mark John Pallen

1960 (age 6364)
Carshalton, England
Alma mater Fitzwilliam College, Cambridge, London Hospital Medical College, Imperial College
Scientific career
Fields
Institutions
Doctoral advisor Gordon Dougan
Doctoral students Nick Loman
Website quadram.ac.uk/people/mark-pallen

Mark J. Pallen is a research leader at the Quadram Institute and Professor of Microbial Genomics at the University of East Anglia. In recent years, he has been at the forefront of efforts to apply next-generation sequencing to problems in microbiology and ancient DNA research.

Contents

Education

Pallen was educated at Wallington High School. [1] He completed an undergraduate degree in medical sciences at Fitzwilliam College, Cambridge and gained his medical qualification from the London Hospital Medical College. [2] [3] During the early 1990s, he gained an MD while working at St Bartholomew's Hospital Medical College. [4] In the mid-1990s, he worked for a PhD [5] under the supervision of Gordon Dougan at Imperial College. During this time, he captained the winning team from Imperial College in the TV quiz show University Challenge, [6] while also writing a series of articles for the British Medical Journal , introducing the medical profession to the Internet. [7]

Microbial genomics, metagenomics and bioinformatics

In 2011, Pallen led a crowdsourced analysis of the genome of the outbreak strain from the 2011 German E. coli O104:H4 outbreak, which had been genome-sequenced on the Ion Torrent platform by the BGI. [8] Around the same time, he also led a project in which an isolate from the 2011 German E. coli O104:H4 outbreak was genome-sequenced on three new benchtop sequencing platforms, benchmarking these new platforms. [9] He has also shown that whole-genome sequencing can be used to track the spread of resistant bacteria [10] and to study the emergence of antimicrobial resistance . [11]

Through analyses of fecal samples from the 2011 German E. coli O104:H4 outbreak and sputum samples from The Gambia, Pallen showed that metagenomics can be used as a culture-independent approach to the diagnosis of bacterial infection. [12] [13] He has pioneered the use of metagenomics to open up new avenues in ancient DNA research, recovering 200-year-old Mycobacterium tuberculosis genomes from human remains and a medieval Brucella genome sequence. [14] [15] With Vince Gaffney and Robin Allaby, he has applied shotgun metagenomics to sedimentary ancient DNA samples, showing the presence of wheat in the British Isles 2000 years earlier than expected. [16] Pallen has also used metagenomics to investigate the chicken gut microbiome, the gut microbiome of patients on the intensive care unit and the microbes that inhabit ticks. [17] [18] [19]

From 2014 to 2020, Pallen was Principal Investigator on the £8 million MRC-funded cloud-computing project the Cloud Infrastructure for Microbial Bioinformatics (CLIMB) and now serves as director of the successor project CLIMB-BIG-DATA. [20] [21] [22] [23] In 2020, the CLIMB project received the HPCWire Readers’ Best High Performance Computing Collaboration Award for supporting analysis and publication of coronavirus genome sequences during the COVID-19 pandemic. [24]

Microbial nomenclature

Pallen's studies on the chicken gut microbiome led him to propose over 800 new names for bacterial taxa found in this setting. [17] Pallen then developed a system for automating the creation of taxonomic names for bacteria, which resulted in the publication of over a million new names available for use by the microbiology research community to name new bacterial genera. [25] [26] Subsequently, in an opinion piece in the journal New Microbes and New Infections [27] and an invited talk for Bergey's International Society for Microbial Systematics, [28] Pallen outlined his ideas for making bacterial nomenclature more accessible. In 2022, Pallen published over 65,000 names for previously unnamed bacterial and archaeal taxa in the Genome Taxonomy Database, using Python scripts to create user-friendly arbitrary names that comply with the phonotactics and grammar of Latin. [29]

Pallen has also been active in viral nomenclature, starting with the creation of over 400 species epithets for the bacterial positive-sense single-stranded viruses in the family Leviviridae. [30] In March 2021, Pallen suggested in an Opinion article in New Scientist that an alternative should be found to the use of geographical names for variants of SARS-CoV-2, raiding the classical world for options. [31] In early 2021, Pallen participated in a WHO working group, priming adoption of a scheme for naming variants of SARS-CoV-2 after letters in the Greek alphabet. [32]

In recognition of Pallen's efforts in automating creation of names for microbes, in 2022 the name Palleniella was created for a new bacterial genus previously within the genus Prevotella. [33] [34] [35]

Public understanding of science

Pallen is the author of a popular science book, The Rough Guide to Evolution. [36] In the wake of the 2005 Kitzmiller v. Dover Area School District trial, he wrote a review with Nick Matzke, outlining the evidence that the bacterial flagellum is an evolved rather than designed entity. [37] He commissioned and peer-reviewed Baba Brinkman's Rap Guide to Evolution and was responsible for recruiting Alice Roberts to the role of Professor of Public Engagement in Science at the University of Birmingham. In June 2011, Pallen appeared in an episode of Melvin Bragg's In our Time radio programme. [38]

In 2018, Pallen published a book on the 1978 smallpox outbreak in the United Kingdom, The Last Days of Smallpox: Tragedy in Birmingham , [39] which includes a mixture of popular science and a historical narrative of the outbreak and subsequent court case. Pallen has served alongside Alice Roberts on the advisory board of the Milner Centre for Evolution at the University of Bath [40]

Related Research Articles

<i>Escherichia coli</i> Enteric, rod-shaped, gram-negative bacterium

Escherichia coli ( ESH-ə-RIK-ee-ə KOH-ly) is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes such as EPEC, and ETEC are pathogenic and can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. Most strains are part of the normal microbiota of the gut and are harmless or even beneficial to humans (although these strains tend to be less studied than the pathogenic ones). For example, some strains of E. coli benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by pathogenic bacteria. These mutually beneficial relationships between E. coli and humans are a type of mutualistic biological relationship — where both the humans and the E. coli are benefitting each other. E. coli is expelled into the environment within fecal matter. The bacterium grows massively in fresh fecal matter under aerobic conditions for three days, but its numbers decline slowly afterwards.

<span class="mw-page-title-main">Human microbiome</span> Microorganisms in or on human skin and biofluids

The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the skin, mammary glands, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary tract, and gastrointestinal tract. Types of human microbiota include bacteria, archaea, fungi, protists, and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition. In the context of genomics, the term human microbiome is sometimes used to refer to the collective genomes of resident microorganisms; however, the term human metagenome has the same meaning.

<span class="mw-page-title-main">Metagenomics</span> Study of genes found in the environment

Metagenomics is the study of genetic material recovered directly from environmental or clinical samples by a method called sequencing. The broad field may also be referred to as environmental genomics, ecogenomics, community genomics or microbiomics.

<span class="mw-page-title-main">16S ribosomal RNA</span> RNA component

16S ribosomal RNA is the RNA component of the 30S subunit of a prokaryotic ribosome. It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.

Jeffrey Ivan Gordon is a biologist and the Dr. Robert J. Glaser Distinguished University Professor and Director of the Center for Genome Sciences and Systems Biology at Washington University in St. Louis. He is internationally known for his research on gastrointestinal development and how gut microbial communities affect normal intestinal function, shape various aspects of human physiology including our nutritional status, and affect predisposition to diseases. He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences, the Institute of Medicine of the National Academies, and the American Philosophical Society.

<span class="mw-page-title-main">Human Microbiome Project</span> Former research initiative

The Human Microbiome Project (HMP) was a United States National Institutes of Health (NIH) research initiative to improve understanding of the microbiota involved in human health and disease. Launched in 2007, the first phase (HMP1) focused on identifying and characterizing human microbiota. The second phase, known as the Integrative Human Microbiome Project (iHMP) launched in 2014 with the aim of generating resources to characterize the microbiome and elucidating the roles of microbes in health and disease states. The program received $170 million in funding by the NIH Common Fund from 2007 to 2016.

<span class="mw-page-title-main">Microbiota</span> Community of microorganisms

Microbiota are the range of microorganisms that may be commensal, mutualistic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found to be crucial for immunologic, hormonal, and metabolic homeostasis of their host.

Pathogenomics is a field which uses high-throughput screening technology and bioinformatics to study encoded microbe resistance, as well as virulence factors (VFs), which enable a microorganism to infect a host and possibly cause disease. This includes studying genomes of pathogens which cannot be cultured outside of a host. In the past, researchers and medical professionals found it difficult to study and understand pathogenic traits of infectious organisms. With newer technology, pathogen genomes can be identified and sequenced in a much shorter time and at a lower cost, thus improving the ability to diagnose, treat, and even predict and prevent pathogenic infections and disease. It has also allowed researchers to better understand genome evolution events - gene loss, gain, duplication, rearrangement - and how those events impact pathogen resistance and ability to cause disease. This influx of information has created a need for bioinformatics tools and databases to analyze and make the vast amounts of data accessible to researchers, and it has raised ethical questions about the wisdom of reconstructing previously extinct and deadly pathogens in order to better understand virulence.

<span class="mw-page-title-main">Pan-genome</span> All genes of all strains in a clade

In the fields of molecular biology and genetics, a pan-genome is the entire set of genes from all strains within a clade. More generally, it is the union of all the genomes of a clade. The pan-genome can be broken down into a "core pangenome" that contains genes present in all individuals, a "shell pangenome" that contains genes present in two or more strains, and a "cloud pangenome" that contains genes only found in a single strain. Some authors also refer to the cloud genome as "accessory genome" containing 'dispensable' genes present in a subset of the strains and strain-specific genes. Note that the use of the term 'dispensable' has been questioned, at least in plant genomes, as accessory genes play "an important role in genome evolution and in the complex interplay between the genome and the environment". The field of study of pangenomes is called pangenomics.

Escherichia coli O104:H4 is an enteroaggregative Escherichia coli strain of the bacterium Escherichia coli, and the cause of the 2011 Escherichia coli O104:H4 outbreak. The "O" in the serological classification identifies the cell wall lipopolysaccharide antigen, and the "H" identifies the flagella antigen.

Biological dark matter is an informal term for unclassified or poorly understood genetic material. This genetic material may refer to genetic material produced by unclassified microorganisms. By extension, biological dark matter may also refer to the un-isolated microorganism whose existence can only be inferred from the genetic material that they produce. Some of the genetic material may not fall under the three existing domains of life: Bacteria, Archaea and Eukaryota; thus, it has been suggested that a possible fourth domain of life may yet be discovered, although other explanations are also probable. Alternatively, the genetic material may refer to non-coding DNA and non-coding RNA produced by known organisms.

In metagenomics, binning is the process of grouping reads or contigs and assigning them to individual genome. Binning methods can be based on either compositional features or alignment (similarity), or both.

<span class="mw-page-title-main">Karen E. Nelson</span> Jamaican-born American microbiologist

Karen Nelson is a Jamaican-born American microbiologist who was formerly president of the J. Craig Venter Institute (JCVI). On July 6, 2021 she joined Thermo Fisher Scientific as Chief Scientific Officer.

<span class="mw-page-title-main">Microbiome</span> Microbial community assemblage and activity

A microbiome is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps et al. as "a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity". In 2020, an international panel of experts published the outcome of their discussions on the definition of the microbiome. They proposed a definition of the microbiome based on a revival of the "compact, clear, and comprehensive description of the term" as originally provided by Whipps et al., but supplemented with two explanatory paragraphs. The first explanatory paragraph pronounces the dynamic character of the microbiome, and the second explanatory paragraph clearly separates the term microbiota from the term microbiome.

Metatranscriptomics is the set of techniques used to study gene expression of microbes within natural environments, i.e., the metatranscriptome.

PICRUSt is a bioinformatics software package. The name is an abbreviation for Phylogenetic Investigation of Communities by Reconstruction of Unobserved States.

<span class="mw-page-title-main">Virome</span>

Virome refers to the assemblage of viruses that is often investigated and described by metagenomic sequencing of viral nucleic acids that are found associated with a particular ecosystem, organism or holobiont. The word is frequently used to describe environmental viral shotgun metagenomes. Viruses, including bacteriophages, are found in all environments, and studies of the virome have provided insights into nutrient cycling, development of immunity, and a major source of genes through lysogenic conversion. Also, the human virome has been characterized in nine organs of 31 Finnish individuals using qPCR and NGS methodologies.

<span class="mw-page-title-main">Pharmacomicrobiomics</span>

Pharmacomicrobiomics, proposed by Prof. Marco Candela for the ERC-2009-StG project call, and publicly coined for the first time in 2010 by Rizkallah et al., is defined as the effect of microbiome variations on drug disposition, action, and toxicity. Pharmacomicrobiomics is concerned with the interaction between xenobiotics, or foreign compounds, and the gut microbiome. It is estimated that over 100 trillion prokaryotes representing more than 1000 species reside in the gut. Within the gut, microbes help modulate developmental, immunological and nutrition host functions. The aggregate genome of microbes extends the metabolic capabilities of humans, allowing them to capture nutrients from diverse sources. Namely, through the secretion of enzymes that assist in the metabolism of chemicals foreign to the body, modification of liver and intestinal enzymes, and modulation of the expression of human metabolic genes, microbes can significantly impact the ingestion of xenobiotics.

Nikos Kyrpides is a Greek-American bioscientist who has worked on the origins of life, information processing, bioinformatics, microbiology, metagenomics and microbiome data science. He is a senior staff scientist at the Berkeley National Laboratory, head of the Prokaryote Super Program and leads the Microbiome Data Science program at the US Department of Energy Joint Genome Institute.

The Genome Taxonomy Database (GTDB) is an online database that maintains information on a proposed nomenclature of prokaryotes, following a phylogenomic approach based on a set of conserved single-copy proteins. In addition to resolving paraphyletic groups, this method also reassigns taxonomic ranks algorithmically, updating names in both cases. Information for archaea was added in 2020, along with a species classification based on average nucleotide identity. Each update incorporates new genomes as well as automated and manual curation of the taxonomy.

References

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  2. "Good reads from Fitz". www.fitz.cam.ac.uk. 17 April 2020.
  3. Society, Microbiology. "Fleming Showcase speaker profile: Professor Mark Pallen". microbiologysociety.org.
  4. Pallen, Mark John (1993). Detection and characterisation of diphtheria toxin genes and insertion sequences by PCR and other molecular techniques. MD thesis, St Bartholomew's Hospital Medical College, 1993 (Ph.D).
  5. Pallen, Mark John (1998). An investigation into the links between stationary phase and virulence in Salmonella enterica entercial serovar typhimurium. PhD thesis, Imperial College London, 1998 (Ph.D).
  6. "University Challenge winners – May 1996".
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