7.13 News from the cutting edge of microbiological research
By Matt Ford | Published:
September 11, 2008 - 11:15AM CT
This week the Society for General Microbiology
(SGM) is holding their fall meeting at Trinity College in Dublin, Ireland, and
we at Nobel Intent are keen to bring our readers the cutting edge of
research in the field. The material presented here is from conference lectures
and posters, which precede peer-reviewed publications. While the individual
studies have not yet undergone peer-review, this work was deemed important
enough to be presented to the microbiology community at large.
One of the major risks of staying in a
hospital is the possibility of acquiring an infection. Most infections can be
cured with a simple course of antibiotics, but recent outbreaks
of methicillin-resistant Staphylococcus aureus (MRSA) are cause for
alarm since traditional remedies don't work. Professor Gerald Pier from Harvard
Medical School reported on work that alters the complex sugar PNAG and
uses it as an MRSA vaccine. Through chemical manipulation, researchers have
found a way to successfully elicit an immune response to the ccompound in
animals. In addition to acting as a potential vaccine, the group has created
antibodies that can be administered to patients at risk of an infection, and
hope to begin using it on humans in the next 12 to 18 months.
Staying on the topic of
infections in hospitals, the best way to avoid them is clearly to not let harmful
bacteria spread. Research presented in another seminar at the conference looked
at a material, already used in buildings, that may be able to stop bacteria
dead: paint. Researchers found that titanium dioxide, the compound that makes
white paint white, has antibacterial properties on the nanoscale when excited
by UV light. Through some tweaking, they found that they could kill E. Coli
bacteria using this paint and normal florescent lights. However, other typical
paint additives lessened the effectiveness.
While the best way to stay
healthy is to not get infected in the first place, a third group of researchers
looked at way of using light to cure infections. Dr. Ghada Omar from
University College in London reports on his group's work using a green dye and
near-infrared light to kill MRSA bacteria. The dye, indocyanine green, is
harmless to humans but, when excited with near-IR light, it emits a toxic
chemical that kills bacteria in the presence of oxygen. Dr. Omar reports that
"even with low oxygen levels, a very wide range of bacteria were killed,
including over 70% of Streptococcus pyogenes and Staphylococcus
aureus."
Moving from infections that
can come from hospitals to infections that can come from restaurants and food,
sessions at the conference discussed research into methods to reduce and
prevent food-borne illnesses. Dr Jeong-Weon Huh found that, if a brass plate is
placed at the bottom of fish tanks, then the risk of food poisoning from eating
the tank's content can be greatly reduced. Work has shown that copper ions from
the brass can kill off Vibrio, a bacterium related to cholera that lives on the
fish. Dr. Huh's work found that the brass plate killed off over 99.99 percent
of Vibrio bacterium after 40 hours in the tank. This work explains why raw fish
and shellfish served in traditional Korean bowls called bangzza is safer:
bangzza kitchenware is 78 percent copper.
Researchers from Manchester
Metropolitan University discussed findings that suggest that food-borne illness
can be reduced by changing food preparation surfaces from stainless steel to
titanium. While the work mentioned above showed that TiO2 can kill
bacteria, the reduction in bacteria here comes from the fact that titanium is
hard to scratch, dent, or damage. The researchers found that different types of
bacteria readily hide in different sized and shaped scratches in steel
surfaces, even after cleaning—Listeria was found to remain in scratches
less than half a micron across. The presenters believe that a harder titanium
coating will reduce the space for bacteria to hide.
Finally, at least as far as
our coverage of the conference goes, is work that found that Listeria
can exist on surfaces for longer periods of time if they get a little help from
their friends. Researchers from the University of Nottingham found that if Pseudomonas
fluorescens—another food spoilage bacteria—is present on surfaces, then Listeria
monocytogenes will have a much easier time attaching to the surface. The same
work also examined the effect of various meats on surfaces, and found that
bacteria can more readily stick on surfaces where duck was prepared compared to
other types of meat, such as beef, pork, lamb, chicken. For the duck lovers
among us, be extra careful dealing with your cooking surfaces; no matter how
tasty that duck carpaccio might be, food poisoning will surely ruin it.
