MicrobiologyBytes

The University of the Year scholarship package scheme – a series of Open Research Scholarships available to students from the EU and UK – will create a range of opportunities for funded PhD study. These scholarships are available across a full range of disciplines at the University of Leicester; science, arts, social sciences, law, medicine and the biological sciences. Those joining the scheme will benefit from a package worth over £17,000 each year including a stipend, fee waiver and research training support grant.

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When I’m not here blogging about the latest developments in microbiology, my day job involves teaching microbiology (and a few other things) at the University of Leicester. I blog about my education work over at Science of the Invisible, and I’m honoured that Science of the Invisible has been nominated in the Best Teacher Edublog category of the 2008 Edublog Awards. Voting closes on December 21st, and if you’d like to vote for me (or even one of the other nominees ;-) this is the link.

While you’re there, why not vote in some of the other categories too.

My colleague at the University of Leicester, Dr Martha Clokie, has recently co-edited a two-volume book on how to work with bacteriophages. Ranging from the evolution of pathogenicity to oceanic carbon cycling, the many and varied roles that bacteriophages play in microbial ecology and evolution have inspired increased interest within the scientific community. The book pulls together the vast body of knowledge and expertise from top international bacteriophage researchers to provide both classical and state-of-the-art molecular techniques, including laboratory protocols and a notes section which details tips on troubleshooting and avoiding known pitfalls. Volume 1 “Isolation, Characterization, and Interactions” examines a number of topics, including the isolation of phages, morphological and molecular characterization, and interaction with bacteria. Volume 2 “Molecular and Applied Aspects” examines bacteriophage genomics, metagenomics, transcriptomics, and proteomics, along with applied bacteriophage biology.

Bacteriophages: Methods and Protocols, Volume 1: Isolation, Characterization, and Interactions
Editors: Martha R.J Clokie, Andrew M. Kropinski
Methods in Molecular Biology , Vol. 501
ISBN: 978-1-58829-682-5 (Hardcover)

Bacteriophages: Methods and Protocols, Volume 2: Molecular and Applied Aspects
ISBN: 978-1-60327-564-4 (Hardcover)

The University of Leicester has been named University of the Year 2008 in the Times Higher Education Awards.

Where better to study for a degree or a PhD?

Joseph Morley of the University of Leicester has been awarded the Society for General Microbiology Undergraduate Microbiology Prize 2008 – an award for best performance in second year microbiology modules. This prize aims to encourage excellence in the study of microbiology by undergraduate students, and to promote scholarship in and awareness of microbiology in universities.

The Society for General Microbiology (SGM) is the largest microbiological society in Europe. It has over 5000 members of whom 75% are resident in the UK with the rest in more than 60 countries worldwide. Joseph, who is currently working on his final year research project on marine cyanophages, was awarded a cheque for £150, a certificate and one year’s free undergraduate membership of the SGM. Joseph says he is delighted to be awarded this prestigious national prize.

Iron is a nutrient that bacteria need for many essential processes in the cell. As part of the response to infection by bacteria, animals restrict the amount of iron available. In mammals lactoferrin (in mucosal secretions) and transferrin (in serum) tightly bind free iron to restrict its availability. Unfortunately, successful disease-causing bacteria have found ways to grab iron back from the host. The bacterial mechanisms involved in acquiring iron in the host usually consist of a specific pore on the outer surface of the bacterial cell and an associated transport system that makes the iron available inside the cell.

The most important food-associated bacterium that infects humans is Campylobacter and as such is responsible for much misery and economic loss in the UK. Campylobacter normally lives in the intestine of many animals, notably chickens, where they do not always cause disease. However, when humans eat food contaminated with campylobacters, an highly unpleasant cramping diarrhoea can follow. Food producers strive to minimise the risks of food poisoning for consumers, but if Campylobacter could be eliminated from the intestines of farm animals, particularly chickens, it would have a significant impact on human health by preventing many thousands of cases of food borne disease each year.

If control is to be achieved it is important that we better understand how Campylobacter colonises the intestine. Several components of campylobacters that are essential for growth in the intestine are involved in acquiring iron within the host. In our preliminary work, we have identified a system in campylobacters that can grab iron directly from lactoferrin and transferrin to support bacterial growth. This work has identified candidates for the specific pore on the outer surface of the bacterial cell and the associated transport system that moves the iron to the inside of the cell. Work by my colleague Julian Ketley, Department of Genetics, University of Leicester, aims to verify the identify of the components of the system and determine the methods by which iron is removed from lactoferrin/transferrin to allow bacterial growth. With a better understanding of the iron acquisition system we will be able to determine if it would be an suitable target for intervention on the farm in order to block growth in the animal gut and reduce food contamination.

Utilization of lactoferrin-bound and transferrin-bound iron by Campylobacter jejuni. J Bacteriol. 2008 190:1900-11
Campylobacter jejuni NCTC 11168 was capable of growth to levels comparable with FeSO4 in defined iron-limited medium (minimal essential medium alpha [MEMalpha]) containing ferrilactoferrin, ferritransferrin, or ferri-ovotransferrin. Iron was internalized in a contact-dependent manner, with 94% of cell-associated radioactivity from either 55Fe-loaded transferrin or lactoferrin associated with the soluble cell fraction. Partitioning the iron source away from bacteria significantly decreased cellular growth. Excess cold transferrin or lactoferrin in cultures containing 55Fe-loaded transferrin or lactoferrin resulted in reduced levels of 55Fe uptake. Growth of C. jejuni in the presence of ferri- and an excess of apoprotein reduced overall levels of growth. Following incubation of cells in the presence of ferrilactoferrin, lactoferrin became associated with the cell surface; binding levels were higher after growth under iron limitation. A strain carrying a mutation in the cj0178 gene from the iron uptake system Cj0173c-Cj0178 demonstrated significantly reduced growth promotion in the presence of ferrilactoferrin in MEMalpha compared to wild type but was not affected in the presence of heme. Moreover, this mutant acquired less 55Fe than wild type when incubated with 55Fe-loaded protein and bound less lactoferrin. Complementation restored the wild-type phenotype when cells were grown with ferrilactoferrin. A mutant in the ABC transporter system permease gene (cj0174c) showed a small but significant growth reduction. The cj0176c-cj0177 intergenic region contains two separate Fur-regulated iron-repressible promoters. This is the first demonstration that C. jejuni is capable of acquiring iron from members of the transferrin protein family, and our data indicate a role for Cj0178 in this process.

Related:

• Campylobacter jejuni
• How Campylobacter jejuni survives within cells
• Protein promotes antibiotic resistance in Campylobacter

A University of Leicester researcher has discovered how a protein in the blood linked to defence against meningitis plays a more vital role than previously understood in the body’s immune defence system. The published research has helped to advance medical understanding of how the body defends against disease and heals itself. The study also reveals that the same protein, properdin – discovered half a century ago – can also harm internal organs under certain circumstances. Lack of the protein in the human body has previously been linked to susceptibility to meningitis. But the new findings by Cordula Stover of the Department of Infection, Immunity and Inflammation at the University of Leicester assign hitherto unappreciated importance to this protein of the immune defence. Dr Stover, a Lecturer in Immunology, said:

I have a broad interest in immune mechanisms of health and disease, though recently, I have focused on a particular component of the first line immune defence, a protein called properdin. Properdin deficiency in families, though rare, predisposes people to develop meningococcal meningitis, usually with poor outcome of the infection. I hypothesised that the importance of properdin extends beyond this particular infectious disease, and that indeed it is an important player in health generally, and that its importance becomes apparent in conditions involving both acute and chronic states of inflammation.

Now Dr Stover’s paper published in the Journal of Immunology demonstrates that properdin plays a significant role in the survival of conditions relating to surgical perforation of the gut and activation of the immune system by wall components of bacteria. In conditions relating to multi-organ dysfunction, a complication which can occur in response to severe sepsis, properdin however aggravates organ damage.

So far, the system properdin is a part of – the so-called complement system – is classified as a first line, innate, acutely effective immune activation mechanism. This work shows that the activity of properdin extends beyond the acute phase and, importantly, that properdin is stepping onto the stage as an important player in different inflammatory conditions. As the worldwide burden of chronic inflammatory disease increases, it is of practical relevance to understand the contribution of this immune protein.

Properdin Deficiency in Murine Models of Nonseptic Shock
The Journal of Immunology 2008 180: 6962-6969

According to The Guardian:

Leicester students certainly appear to be happy bunnies: it came joint top for teaching quality and overall satisfaction in the National Student Survey two years in a row and the drop-out rate is notably low. The appeal might lie in the friendly and compact campus – a 10-minute walk from one end to the other, providing you don’t get sidetracked by any of the on-campus facilities. Victoria Park next door is a convenient and popular place to relax when the weather is good. As well as that, Leicester puts up a consistently strong academic performance across all its subject areas. It’s understandably proud of its most famous research achievement: the development of DNA genetic fingerprinting. Add on Leicester, a lively, multicultural city with great facilities and transport links, and it’s no wonder everyone is so pleased to be there.

The latest version of the Good University Guide puts the University of Leicester in 12th place, up from 20th last year.
More importantly ;-) Biological Sciences came 10th out of 87 in the subject rankings, our highest ever position in the Guide.