 
Microbiology Today November 2004
November 2004 - Evolution in Action
Microbiologists confront evolution in action on a daily basis in their
work. Microbes resistant to antimicrobial agents have emerged through
mutation or by acquiring protective genes from other microbes. Gene
swapping or genetic reassortment allows viruses to stay one step ahead of
the immune system. Natural selection lets individuals within a microbial
community adapt and survive in a new environment/experiment. In this issue
of Microbiology Today we take a look at various aspects of microbial
evolution.
Microbial evolution in action
Richard Lenski (Michigan State University), tells us about his long-term
experiment with populations of E. coli. By propagating replicate cultures
for many generations in the lab, he has shown that natural selection can
lead to adaptation.
Bacterial populations adapt - genetically,
by natural selection - even in the lab!
Microbes are constantly adapting to their environment and Paul Rainey
(University of Auckland) asks 'are the bacteria that you started your
experiment with the same at the end?' His cautionary tale about the
adaptation of pseudomonads to their environment should make everyone think.
RNA viruses - evolution in action
Viruses also evolve at a frightening speed. Peter Simmonds (University of
Edinburgh) describes how the adaptation of RNA viruses to new
environments, new selection pressures and new hosts when opportunity
arises can make drug treatment of diseases such as HIV very difficult
indeed.
The evolution of antifungal
resistance in Candida species
Fungi are different from bacteria in that they have no plasmids or other
natural mechanisms for transferring genetic material between strains. This
makes the evolution of antifungal-resistance much slower in opportunistic
pathogens, such as Candida, as Frank Odds (University of Aberdeen)
explains.
Catabolic plasmids: fast-track bacterial evolution to combat pollution
Peter Williams (University of Wales, Bangor) informs us that the role of
plasmids in accelerating bacterial evolution can also be beneficial,
allowing the microbes to degrade new synthetic compounds, such as dyes or
solvents, thus helping to clean up pollution.
Serial endosymbiotic theory (SET) and
composite individuality
Lynn Margulis (University of Massachusetts-Amherst) gives her perspective
of the endosymbiotic associations between different micro-organisms that
allowed the transition from bacterial to eukaryotic genomes. The various
mergers over millennia between prokaryotic cells, and subsequently between
prokaryotes and early eukaryotes, gave rise to today's known living world
- including microbial, animal and plant cells. Many intermediary stages of
this process can still be seen in microbes today.
E-sy learning
For many, e-learning means putting lecture notes on the web. However, Sue
Assinder reports that there is much more to it than supplying online
resources to support conventional teaching, ranging from web-based support
of single modules through to fully online courses and global collaborative
research projects.
Comment - The role of expert judgement needs promoting
The public is constantly confused by the mixed messages they receive from
scientists about controversial issues. Tracey Brown, Director of Sense
About Science, argues that if the practice of peer review was promoted and
understood, then people would find it much easier to reach a balanced
judgement.
Schoolzone
Schoolzone looks at the evolution of microbes over the past 3,500 million
years, while Microbiology Today Editor, Gavin Thomas, describes some of
the available resources to support the teaching of evolution in schools.
Hot off the Press highlights some new developments in microbiological research published in the Society's journals -
Microbiology, Journal of General Virology, International Journal of Systematic and
Evolutionary Microbiology and Journal of Medical Microbiology. Topics covered include:
- Microbial 'aromatherapy'
- Virus evolution in action
- Abnormal prions in a human cancer cell line
- Killer amoeba
- A mucus-degrading bacterium found in the human gut
- A key event in the colonization of Bordetella
- Cultivation-independent study of vaginal microbial communities
Other items include:
Last updated 8 February 2005
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