MicrobiologyBytes

On the 11th October at the Society for Applied Microbiology hosted a lecture by Proffessor Willy Verstraete on Microbial Resource Management. Here’s the blurb:

In the 21st century, we are faced with a set of challenges: from climate change to the need for renewable energy sources, the threat of new pandemics and the general demise in environmental quality. The role of micro-organisms in each of these challenges is crucially important and to fully understand how microbes play a part, we must better explore our microbial resources as they currently exist – in culture collections or at evolved environmental sites. We need to develop key strategies to deal with microbial communities, instead of thinking in terms of haphazard assemblages of species. A pragmatic approach to this problem is proposed in this lecture, making use of current developments in molecular methods. Also, a list of potential environmental biotech solutions which are appropriate to the current market economy are presented. By upgrading the services of microbial communities through implementing Microbial Resource Management (MRM) and combining these communities with novel technology, we can indeed address these challenges.

And here’s the lecture:

Eben Bayer talks about MycoBond, a technology that uses a filamentous fungi to transform agricultural waste products into strong composite materials. MycoBond products include packaging and styrofoam substitute and in-development rigid insulation board for builders. These products require less energy to create than synthetics like foam, because they’re quite literally grown. Equally compelling, at the end of their useful life, they can be composted or used as garden mulch.

Mouse mammary tumor virus (MMTV), which was discovered as a milk‑transmitted, infectious cancer-inducing agent in the 1930s, has been used since that time as an animal model for the study of human breast cancer. Like other complex retroviruses, MMTV encodes a number of accessory proteins that both facilitate infection and affect host immune response. In vivo, the virus predominantly infects lymphocytes and mammary epithelial cells. High level infection of mammary epithelial cells ensures efficient passage of virus to the next generation. It also results in mammary tumor induction, since the MMTV provirus integrates into the mammary epithelial cell genome during viral replication and activates cellular oncogene expression. Thus, mammary tumor induction is a by-product of the infection cycle. A number of important oncogenes have been discovered by carrying out MMTV integration site analysis, some of which may play a role in human breast cancer.

Because MMTV has existed as an infectious virus in mice for millions of years, it has evolved to take advantage of its host’s biology, using host genes from transcription factors to immune regulatory molecules, to establish infection. Although it causes mammary tumors, this does not occur until relatively late in life and thus the virus has persisted, since infected mothers are able to transmit virus to offspring. The lack of acute MMTV-induced pathogenesis is most likely due to different host means of limiting virus infection, including factors that operate at the cellular level like intrinsic restriction factors and immune response genes. As additional host-antiviral genes are discovered, MMTV will continue to serve as an important model for testing the ability of these factors to function in vivo. In addition to serving as an important means for studying virus infection, MMTV has provided a number of critical models for understanding human breast cancer. Finally, the use of the MMTV LTR to direct oncogene expression to murine epithelial cells has resulted in the creation of numerous transgenic mouse strains that serve as critical models for understanding human breast cancer. It is likely that such transgenic mice will continue to be a critical tool as additional human breast cancer genes are identified through large-scale human genetic studies.

Mouse Mammary Tumor Virus Molecular Biology and Oncogenesis. (2010) Viruses 2010 2(9): 2000-2012 doi:10.3390/v2092000

Related:

• No HMTV in human breast cancer samples?
• Vaccines To Prevent Infections by Oncoviruses
• The search for infectious causes of human cancers

Educators, like researchers, face enormous pressure to keep up with the rapid pace of scientific discovery. But educators must also find compelling ways to communicate the latest scientific findings to their students. PLoS Biology recently launched a new education series. The Education Series combines open education – which freely shares teaching methods, initiatives, and materials – with open access publishing to present innovative approaches to teaching critical concepts, developments, and methods in biology. It will cover fundamental areas of biology, from evolution and ecology to cell biology and biochemistry, and take full advantage of Web-based open-access research and multimedia tools to create an interactive, dynamic resource to further understanding of fundamental questions in biology and of current methods to investigate them.

Articles will feature initiatives that incorporate current life sciences research and allow students to use authentic research tools to investigate real-world problems and generate solid data – crucial elements for nurturing students’ interest in science. Toward this end, approaches that use genomics databases and bioinformatics tools, with their easy online access and mathematical expression of biological concepts, are particularly effective in the classroom. Alternately, taking students out in the field to test questions about relationships between species abundance and the presence of contaminants can provide a memorable lesson in environmental science. By mining the promise of open education and harnessing the collective imagination and talent of PLoS Biology readers and contributors, the Education Series will create a virtual biology education library that will be available through PLoS Biology Collections.

In the first article, Louise Charkoudian, Jay Fitzgerald, Andrea Champlin and Chaitan Khosla show that Streptomyces-derived natural products provide an untapped source of pigments, showing others how to explore the potential of biopigments in the classroom as well as in art and industry. The authors share their experiences in harnessing these biopigments to create paint and paintings and provide educators with the tools to replicate their experiments in the classroom.

In Living Color: Bacterial Pigments as an Untapped Resource in the Classroom and Beyond. PLoS Biol 8(10): e1000510. doi:10.1371/journal.pbio.1000510
Recent advances in the study of natural products made by bacteria have laid the foundation for engineering these molecules and for developing cost-effective ways to manufacture them. In our lab, we study a number of natural products that are synthesized by harmless soil bacteria of the Streptomyces genus. Whereas our primary interest in these molecules is due to their antibiotic properties, many of these natural products have distinct colors. (The reasons for why Streptomyces make antibiotics or pigments remain mysterious.) This article is intended to make the case to the scientific and educational communities that Streptomyces-derived natural products are an untapped source of useful biopigments. By sharing some of our own experiences in harnessing these pigments to create paint and paintings, we also hope to inspire others to explore the potential of Streptomyces-derived pigments in art, industry, and perhaps most importantly, the classroom.

Related:

• Microbial Art
• Color me bad – microbial pigments as virulence factors

Nematode worms burrowing through the soil encounter thousands of species of bacteria, but how do they find safe food choices from this vast buffet? A major part of the nematode’s ability to distinguish between food sources relies on a sophisticated chemosensory system that enables it to sense and respond to a wide range of volatile and water-soluble chemicals. During the past decade, the roundworm Caenorhabditis elegans has become a popular model for the study of host/pathogen relationships, leading to a wealth of information about microbial virulence factors and host defense pathways. Although the complicated interactions between C. elegans and the many pathogens that it encounters in the soil have become clearer in recent years, there is still much to learn. What are the cues that worms use to detect food sources? How do worms choose which bacterial species to eat and which to leave alone? Once a pathogen is encountered, what are the microbial killing mechanisms and the nematode’s survival mechanisms? This paper provides a rare view of one C. elegans/pathogen relationship. It describes the signals Bacillus nematocida uses to attract C. elegans, the virulence factors it uses to kill worms from within, and the specific host proteins targeted.

A Trojan horse mechanism of bacterial pathogenesis against nematodes. (2010) PNAS USA 107 (38) 16631–16636
Understanding the mechanisms of host–pathogen interaction can provide crucial information for successfully manipulating their rela- tionships. Because of its genetic background and practical advantages over vertebrate model systems, the nematode Caenorhabditis elegans model has become an attractive host for studying microbial pathogenesis. Here we report a “Trojan horse” mechanism of bacterial pathogenesis against nematodes. We show that the bacterium Bacillus nematocida B16 lures nematodes by emitting potent volatile organic compounds that are much more attractive to worms than those from ordinary dietary bacteria. Seventeen B. nematocida-attractant volatile organic compounds are identified, and seven are individually confirmed to lure nematodes. Once the bacteria enter the intestine of nematodes, they secrete two proteases with broad substrate ranges but preferentially target essential intestinal proteins, leading to nematode death. This Trojan horse pattern of bacterium–nematode interaction enriches our understanding of microbial pathogenesis.

Related:

• Nematode provides new animal model for emerging pathogen

Here at MicrobiologyBytes I like to report each and every time someone claims to have found “the” cause of Colony Collapse Disorder (CCD) of bees. This isn’t the first such report, and it won’t be the last:

Iridovirus and Microsporidian Linked to Honey Bee Colony Decline. (2010) PLoS ONE 5(10): e13181. doi:10.1371/journal.pone.0013181
Background: In 2010 Colony Collapse Disorder (CCD), again devastated honey bee colonies in the USA, indicating that the problem is neither diminishing nor has it been resolved. Many CCD investigations, using sensitive genome-based methods, have found small RNA bee viruses and the microsporidia, Nosema apis and N. ceranae in healthy and collapsing colonies alike with no single pathogen firmly linked to honey bee losses.
Methodology/Principal Findings: We used Mass spectrometry-based proteomics (MSP) to identify and quantify thousands of proteins from healthy and collapsing bee colonies. MSP revealed two unreported RNA viruses in North American honey bees, Varroa destructor-1 virus and Kakugo virus, and identified an invertebrate iridescent virus (IIV) (Iridoviridae) associated with CCD colonies. Prevalence of IIV significantly discriminated among strong, failing, and collapsed colonies. In addition, bees in failing colonies contained not only IIV, but also Nosema. Co-occurrence of these microbes consistently marked CCD in bees from commercial apiaries sampled across the U.S. in 2006–2007, bees sequentially sampled as the disorder progressed in an observation hive colony in 2008, and bees from a recurrence of CCD in Florida in 2009. The pathogen pairing was not observed in samples from colonies with no history of CCD, namely bees from Australia and a large, non-migratory beekeeping business in Montana. Laboratory cage trials with a strain of IIV type 6 and Nosema ceranae confirmed that co-infection with these two pathogens was more lethal to bees than either pathogen alone.
Conclusions/Significance: These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe, and Asia. We next need to characterize the IIV and Nosema that we detected and develop management practices to reduce honey bee losses.

Related:

• Colony Collapse Disorder
• The great bee swindle – colony collapse disorder
• Bee-Killing Parasite Genome Sequenced
• Picorna-like viruses associated with colony collapse disorder of bees

The Nobel Prizes have been in the news this week. I didn’t win one. Once upon a time the Nobel Prize website was a creaky old thing, but it’s been smartened up recently, and one of the best new features is the education section which has a range of interactive learning games of varying degrees of difficulty. The Medicine Prize Related games are particularly good – give them a try.

Related:

• Nobel Prizes for Virologists
• MicrobiologyBytes: Games

Last month Martin Fenner wrote about creating a reading list for his blog, Goobledygook. This was such a good idea that I decided to copy it, so now you can get a list of all the papers referred to on MicrobiologyBytes. (It doesn’t go all the way back to the beginning of time, but I will keep it up to date from now on.) Of course, you might already have your own system for filing away the references from this site, but if not, I’m making them available to you in a handy and easy to access format (if you’re not familiar with CiteULike (or Mendeley) it’s worth checking them out):

CiteULike (RSS feed)

So how might you use this? Well that’s really up to you. Whether you’re a teacher preparing a lecture or a student writing an essay, you may vaguely remember you read something about it here, you can search through this site or search through one of the reference lists, which will provide you with the full reference in a format you can insert directly in your writing.

I’m sure there will be lots of other ways this will be useful to you. Please let everyone know what they are by leaving a comment below.

In this week’s PLoS Medicine, Gabriel Leung from the Government of the Hong Kong SAR and Angus Nicoll from the European Centre for Disease Prevention and Control offer their reflections on the international response to the 2009 H1N1 influenza pandemic, including what went well and what changes need to be made on the part of global and national authorities in anticipation of future flu pandemics.

Summary points:

• Many of the initial responses to the 2009 H1N1 pandemic went well but there are many lessons to learn for future pandemic planning.
• Clear communication of public health messages is crucial, and should not confuse what could happen (and should be prepared for) with what is most likely to happen.
• Decisions regarding pandemic response during the exigencies of a public health emergency must be judged according to the best evidence available at the time.
• Revising pandemic plans – to be more flexible and more detailed – should wait for WHO leadership if national plans are not to diverge. Surveillance beyond influenza should be stepped up, and contingencies drawn up for the emergence or re-emergence of other novel and known pathogens.
• Data collection and sharing are paramount, and include epidemiological and immunological data. Clinical management of severe influenza disease should not be limited to the current antiviral regimen, and include the development of other therapeutics (e.g., novel antivirals and immunotherapy).
• Greater and more timely access to antivirals and influenza vaccines worldwide remains an ongoing challenge.

Reflections on Pandemic (H1N1) 2009 and the International Response. (2010) PLoS Med 7(10): e1000346. doi:10.1371/journal.pmed.1000346

Related:

• The Biology of Influenza
• 10 things you should know about H1N1 (swineflu)