If you consider destruction of the biofilm as a possible route you might
also want to consider cytometric assessment methods. I worked on dental
biofilms and there scraping and sonication worked well on 24 hour
plaque(see
http://www.cyto.purdue.edu/flowcyt/research/micrflow/gerhard/gerhard.htm
)
but with older plaque the dextran matrix did not shift any more. Plating
does not work to obtain absolute counts as you can not identify the guys
that grow on your aerobe and your anaerobe plates and the ones that grow
on both, let alone thet a lot of those guys only grow when next to their
best friend.
If you want to quantify the biomass of a biofilm any bulk measurement
will fail as it can not cope with the heterogeneity of the cells.
However you could consider measuring total DNA by fluorimetry and
postulating an average DNA content.
Good luck
Gerhard
In article <3.0.6.32.19990701075209.007afd80 at leela.swt.edu>,
Bob McLean <rm12 at swt.edu> wrote:
> Hi Mary,
> First let me welcome you to the biofilm field. Although activity on
this
> discussion group is low right now, the field as a whole is really
> progressing well.
> I am a little unclear about your definition of polymers. Do you refer
to
> plastics, polypeptides, polysaccharides? In any case, there are a
number
> of antifouling agents on the market right now. Often they are marketed
> under the generic names as biocide, slimicide, etc. You might try
> searching for medical references using medline
> (http://igm-01.nlm.nih.gov/index.html). As well I would recommend
using
> other indexing services such as chemical abstracts, biological
abstracts,
> etc. Try keywords such as biofilm, control, antifouling, as well as
> specific names of the chemicals that you are interested in.
> In response to your question about measuring biofilms, chemical and
> spectrophotometric analyses are certainly easy. In my experience, they
are
> about an order of magnitude less sensitive than conventional
sonication
> (with a bath sonicator) and dilution plating. Other approaches include
> growing biofilms with radiolabelled bacteria and enumerating with a
> scintillation counter, doing acridine orange direct counts. There is a
new
> volume of Methods in Enzymology (vol 310, edited by Ron Doyle) devoted
> entirely to biofilms, which is due to be published in the next few
months.
> This volume will have a pretty comprehensive and up to date list of
> techniques for biofilm work.
> Best wishes and good luck,
> Bob McLean
> At 11:04 PM 6/29/99 -0400, you wrote:
> >I am researching topics for my graduate project and my advisor would
> >like to do some work with biofilms.
> >My current work involves the use of polymers as drug treatments and
we
> >are just getting into the anti-infective field. It would be nice if I
> >could mesh the two together (or so I thought).
> >When I did a literature search nothing comes up with polymers and
> >biofilms. However through web surfing I have found a number of
> >commercial companies out there that manufacture polymers and use them
> >for treatment of industrial waste water, paper mills, cooling towers
> >etc. An example of this is Buckman Laboratories, who market a
> >polyionene compound for biofilm eradication. Have any of these
> >companies published their data? Maybe I am searching in the wrong
> >place, is PubMed an unreasonable place to look for this information?
My
> >thought had been to look at commercially available polymers of
differing
> >molecular weight and different charge densities and see what effect
they
> >would have on established biofilms. There is no sense in my
reinventing
> >the wheel if the information is out there. Can any of you out there
> >offer some helpful suggestions? Just to clarify, I am not talking
about
> >the polymers as surface components but as soluble antimicrobials.
> >Another question (if I may take up some more of your time) was about
> >quantifying biofilms after treatment. I had come across a method that
> >uses crystal violet to stain the biofilm, extracting it with DMSO,
and
> >measuring the absorbance in a spec. It appealed to me because of its
> >simplicity and ease of use. Any objections or cautions about this
> >approach?
> >Thank you in advance for your replies.
> >Mary Pitruzzello
> >pitruzzello at mediaone.net> >
> >
> >
> >-------------------------------------------------------------------
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> >the address biofilms at net.bio.net is included in the "To:" field.
> >
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> >on how to (un)subscribe and post to the Biofilms newsgroup.
> >
> >
> >
>________________________________________________________________________
___
> R.J.C. (Bob) McLean, Ph.D.
> Dept. Biology
> Southwest Texas State University
> 601 University Drive
> San Marcos, Tx 78666
> USA
> (512)245-3365 phone
> (512)245-8713 FAX
> Email: RM12 at swt.edu>http://www.bio.swt.edu/biofac/mclean/mclean.html>> -------------------------------------------------------------------
> To reply to the group as well as to the originator, make sure that
> the address biofilms at net.bio.net is included in the "To:" field.
>> See the BIOFILMS homepage at http://www.im.dtu.dk/biofilms for info
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>>
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