Salmonella phase variation

Derek Law dlaw at idgplc.com
Fri Nov 17 03:48:52 EST 2000


Salmonella also produce an array of proteins that are involved in invasion
of eukaryotic cells. These proteins are carried on pathogenicity islands and
their expression and translocation into eukaryotic cells is carried out by a
type III secretion system. This I believe is similar to that used for
flagella expression. There will be several type II secretion systems active
at the same time which are all very similar it may be difficult to find
which is involved in flagella assembly.

There is an article in the November issue of Journal of bacteriology Vol22.
describing swarming motility by Salmonella. No specific signals which
induced swarming could be identified, those tested included amino acids, ph,
oxygen, iron starvation, viscosity and autoinducers.

Derek Law

Company Microbiologist

IDG (UK)


Patrick J. Fenneran <pjfenneran at msn.com> wrote in message
news:O4XTLL$TAHA.327 at cpmsnbbsa09...
>
> "Not Metew" <kjjhouhh at tu.edu> wrote in message
> news:8uf9on$r6t$1 at news.tamu.edu...
> > What are type III secretions and how are they related to phase
variation,
> > or why do you think they are related to phase variation??
>
> This is one of my aims to my general background review.  S. Typhimurium
has
> a unique aspect of phase variation of a specific  promoter sequence that
> yields a specific flagallar protein.  So far I have found that when normal
> the promoter starts the translational process of H2 which then transcribes
a
> protein rH1, which blocks transcription of H1.  This causes a immune
> response in the host.  For survivablility, about 1 in 1000 the promoter is
> reversed and H1 is transcribed giving salmonella another tool to surivive
> and infect due to the fact that the host response is to the normal antigen
> expression and not to the H1 expression.  I am trying to figure out if
this
> response is the type III secretion response that the literature talks
about.
> >
> > What benefit is accrued to our understanding of salmonellae by learning
> > this information?
> >
>
> Any basic information on growth aspects can be utilized in research, to
> determine optimal efficiency is just one step in many that I hope to
> endeauvor in my research aims.
>
> > I ask the first because I don't know the answer.
> >
> > I ask the second because it is something you should be able to answer,
> > at least partially before selecting a project.  (A good answer for the
MS
> level
> > and even PhD level, might actually be just to gain the information!) But
> do
> > you have something more in mind?
>
> Yes hopefully I can use this information to incorporate this basic
research
> into the space program.  I am fortunate enough to be in a school that has
a
> close working relationship to Kennedy Space Center and the shuttle
program.
> I am currently working on a grant that will put this research in space and
> see if the response is the same a 0 g vice 9.8 g
> > In article <#Ud1PioSAHA.330 at cpmsnbbsa09>, pjfenneran at msn.com says...
> > >
> > >I was thinking about growing several strains on various media types, ph
> > >levels, and temperature.  Then with a probe find out which produced the
> > >highest concentration of the type III secretion.  Again, I am just
> starting
> > >my lit review and in fact have found volumes of journals that have
> > >concentrated on this organism.  I am just looking for some guidance.
> > >
> > >Patrick
> > >"N. Okia" <loisfeh at tu.edu> wrote in message
> > >news:8tsi6e$23r$1 at news.tamu.edu...
> > >> In article <eiFjiNQRAHA.283 at cpmsnbbsa07>, pjfenneran at msn.com says...
> > >> >
> > >> >I am starting my masters thesis on the salmonella pathengicity
island.
> I
> > >am
> > >> >thinking about growing them on  nitrocellulose with a probe and
under
> > >> >varying growth conditions finding the optimal factors for both
phases.
> I
> > >> >would like to see if anyone has any guidance on this venture
> > >> >
> > >> >
> > >> I'm not sure what you mean by finding the optimal factors for both
> phases.
> > >> Clinical labs have long had a way to get the organisms to exhibit
> > >> each phase, so what are you getting at?
> > >>
> > >> Let's here some more about this, but keep in mind that there are
> thousands
> > >> (40-60000) of publications on salmonellae.  Be sure you do your
> literature
> > >> homework before deciding on a thesis and be sure that what you decide
> > >> you want to do CAN BE DONE in the laboratory where you are learning
and
> > >> that it can be DONE IN A REASONABLE AMOUNT OF TIME.
> > >>
> > >> There is no point to taking 4 years (or 3 years) to get a masters
> degree.
> > >>
> > >>
> > >
> > >
> >
>
>







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