Today February 2001
Ever under increasing threat from infectious disease, the world's
population of both humans and animals needs clinical microbiologists.
These important scientists strive to diagnose, treat and study microbial
infections. The SGM has recently founded a new Clinical Microbiology
subject interest group for its members and this issue of Microbiology
Today looks at some of the problems currently facing practitioners and
Stephen Gillespie, of the Royal Free & University College Medical
School, London, is convener of the new Group . He looks back at the
discoveries in medicine at the end of the 19th century that paved the way
to transforming the health of millions over the past hundred years and
contemplates the Golden Age of clinical microbiology that might be to
come. Technological revolutions brought about by genomics, proteomics and
structural biology hold great promise for answering critical scientific
questions in infection.
One of the questions that has long puzzled microbiologists is what
makes one organism pathogenic whilst another lives harmlessly in the body
and indeed may be beneficial. Tony Hart and Craig Winstanley of Liverpool
University describe how 'pathogenicity islands' in the DNA of harmful
micro-organisms encode for secretion systems which wreak havoc on the
cells of their unwilling hosts. Greater understanding of how microbial and
mammalian cells interact may lead to exciting new ways of preventing and
treating infectious diseases.
You don't want to come out hospital more ill than when you went in, but
the risks of acquiring an infection whilst in the wards are not
insignificant. Getting a nosocomial infection is bad enough, but if the
pathogen is multi-resistant to antibiotics as well, making treatment
difficult, what can be done? Peter Hawkey of Leeds University describes
the rising incidence of microbes like MRSA and speculates how
microbiologists will cope with the major challenges caused by
hospital-acquired infections in the future.
One aspect of the problem of antimicrobial resistance is the need to
detect and identify resistant organisms very quickly. Conventional methods
take days, whereas modern molecular techniques such as PCR and DNA chip
applications can be done within hours, as Ad Fluit (Utrecht) and
Franz-Joseph Schmitz (Dusseldorf) describe.
New technology is also being used to identify previously unknown
pathogens which cannot be cultured in the laboratory by traditional
methods. Work on genomes is beginning to reveal core genes involved in
pathogenicity or virulence. Maybe one day micro-arrays will allow clinical
samples to be screened quickly for all members of a virus family, or
possibly all pathogens. The potential applications of genomics,
bioinformatics and other molecular methods are both infinite and exciting,
as Robin Weiss and Paul Kellam of the Wohl Virion Centre, London describe.
Fungal infections often occur in healthy people; most women get an
attack of thrush (Candida) at some time in their lives and athlete's foot
is suffered by sporty types everywhere. Such infections are usually easily
treated, but in people whose immune system is compromised, perhaps by
chemotherapy or because they have AIDS, fungal diseases can result in
severe illness or even death. Marc Mendelson, formerly of Addenbrooke's
Hospital, Cambridge, describes the different types of mycoses, how they
are acquired and what can be done to treat them.
There has been no malaria in England since the 1950s, but factors as
diverse as foreign travel and climate changes put us a risk of contracting
this disease. Other protozoan parasites can be unwelcome holiday souvenirs
as well, causing a range of unpleasant and sometimes long lasting
symptoms. Diarrhoea is a common feature of these illnesses, but some
home-grown organisms can also be a cause. Cryptosporidium and
Giardia from domestic water supplies have been implicated in recent
outbreaks, costing millions and resulting in a change in the legal
requirements for testing water. Tim McHugh of the Royal Free and
University College Medical School describes all of these parasites and a
range of others that occur in the UK.
Who was the first microbiologist? Science historians will not agree on
this point, but Milton Wainwright (University of Sheffield) is sure that
it was not Louis Pasteur. He explores a range of microbiological
discoveries made in the period between Leeuvenhoek's observations of
animalcules in the late 17th century and Pasteur's fermentation studies
which began in 1857.
Although virus diseases such as polio have been controlled by
vaccination and one, smallpox, has been eradicated, viruses remain a
potent threat to human and animal health. The SGM is holding a conference
to discuss the broad-ranging issues involved and Geoff Smith, convener of
the Virus Group, previews the lecture topics.
Hot off the Press
[Acrobat PDF] highlights
developments in microbiological research that have been published in the
journals - Microbiology, Journal of General Virology and
Journal of Systematic and Evolutionary Microbiology. Topics covered
[Acrobat PDF], which features
- Chlamydial controversy - modern DNA-based methods have led to
proposals to revise the classification of these obligately parasitic
bacteria; but will this help clinicians?
- Microbial alternative to plastics - biodegradable polymers made
by bacteria hold promise as a future packaging material
- Natural transformation - how bacteria take up DNA from their
surroundings and incorporate it into their chromosomes
- A 'jumbo' virus problem - a newly discovered killer virus in
- Collagen look-alike involved in streptococcal infection -
Streptococcus pyogenes produces a protein similar to collagen
- Turning up the heat for BSE - how hot does it have to be to
degrade prion protein effectively?
- The fungal village - Mike Milner describes his fun weekend
promoting the understanding of fungi to villagers in Northumberland
- ScienceWorld - from medicine to media - Chris Smith describes
his science hour on local radio
Other items include:
Last updated 29 May 2003