Salmonella phase variation

Patrick J. Fenneran pjfenneran at
Thu Nov 16 12:30:33 EST 2000

"Not Metew" <kjjhouhh at> wrote in message
news:8uf9on$r6t$1 at
> 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
> and even PhD level, might actually be just to gain the information!) But
> 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 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
> >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> wrote in message
> >news:8tsi6e$23r$1 at
> >> In article <eiFjiNQRAHA.283 at cpmsnbbsa07>, pjfenneran at says...
> >> >
> >> >I am starting my masters thesis on the salmonella pathengicity island.
> >am
> >> >thinking about growing them on  nitrocellulose with a probe and under
> >> >varying growth conditions finding the optimal factors for both phases.
> >> >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
> >> 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
> >> (40-60000) of publications on salmonellae.  Be sure you do your
> >> 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
> >>
> >> There is no point to taking 4 years (or 3 years) to get a masters
> >>
> >>
> >
> >

More information about the Microbio mailing list