N10 wrote:
> "Jane Gonzales" <jrpatto at emory.edu> wrote in message
> news:BC51243F.27E6%jrpatto at emory.edu...>>>Good Morning!
>>>>I'm attempting to provide the research for chemists devising a new method
>>for detecting pathogenic bacteria in food, and have what I thought would
>> be
>>>a simple question. However, after several days of intensive research, I
>> have
>>>not been able to put my finger on it, most likely due to my lack of
>> working
>>>knowledge in microbiology!
>>>>Would anyone be so kind as to inform me where I can find a list or
>> database
>>>(or ANYTHING!!) of the metabolites/products/gases/stuff exuded/given
>>off/produced by bacteria,specifically those involved in food poisoning and
>>food spoilage? I've located a database of metabolic pathways, but do not
>>have the background to determine which of the end-products would actually
>> be
>>>excreted by the cell into the environment.
>>>>I am grateful for any help that is offered!
>>>>---
>>> Hi Jane
>> I really dont think you are going to be very lucky on this one unless you
> can a find list of
> exotic compounds ,characteristic and specific to the types of organisms you
> have mention.
>> Im fairly familar with the metabolic products of most group II food borne
> pathogens and nothing really stikes me as target
> which might be usufull as an organism specific identifier in a food matirx.
>> Frankly I would be predict that detection or quatation by metabolite
> production would be a very
> unreliable technique for many reasons.
>> Firstly consider the example of Salmonella which may be present but capable
> of infection in levels as
> low as 10 cells per KG of food mateial !!!! You are not going ot detect
> many metabolites from that level of contamination
> and then ad the various factors of metabolic stress due to food processing
> and things become more even difficult for you.
>> Pcr based systems would and do however detect such low low levels of
> contamination with accuracy and rapidity.
>> Also unless you go for exotics my guess is that most food matrices will
> contain a mozaic of microbial metabolites in
> almost random patterns depending on the type of processing and various
> factors relating to ingredients.
>> Also may metabolites are common to several genera and few are group
> specific enough in isolation to
> unqiuely identify a particular organism or even genus of organism.
>> Genreal metabolite detection and their effect on conductivity and
> capacitance was the basis of Impdeance technique.
>> These were higly non specific and required elegant cultural situations to
> produce
> presumtive isolation of specific target organism..in other words cumbersome
> and at best an interesting system for no specific pesudo quatation.
>>> If you turn your attenion to toxin detection as an idndicator of specific
> pathogenic contamination then you pressuppose
> toxin is produce in all instanses of contamination which it is not.
>> I really dont want to pour water on your vison but the best tools we have
> for rapid and accurate detection of food borne pathogens
> todate focus around PCR and ELISA assay. Ememrging techquies invovle probes
> tragetign cel wal structures and intra cellualr structures but
> not metabolites.
>> Perhapes you could expand a little more on the proposed technique just in
> case I havent fully understood the direction thi sresearch wil take.
>> Best N10
>
This is a database of genes that are sorted into biochemical pathways
that might be of some use... you'll have to browse around for a while
though, I think, to find anything that you might find useful, since it's
not really designed for this kind of thing. Anyhow, it has a lot of
pathways listed, so maybe it's of some help.
http://www.genome.jp/kegg/kegg2.html
